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This study describes Apseudopsis formosus sp. nov., a new apseudomorph tanaidacean species from the Ria Formosa lagoon (southern Portugal). Species description was based on 223 individuals (22 juveniles, 60 males and 141 females), comprising diverse developmental stages (juveniles II, males I and II, preparatory, copulatory and intermediate females). The total length of the studied population ranged from 2.2 to 3.0 mm in juveniles, 2.5 to 4.8 mm in males and 2.9 to 4.9 mm in females. Overall, Apseudopsis formosus sp. nov. differs from congeneric tanaidaceans from the Atlantic Ocean and Mediterranean Sea by the presence of combined different morphological characters such as short pointed rostrum, posterolateral pointed corners on pereonites 2-6, hyposphenium only on pereonite 6, antennular outer flagellum 7- to 10-segmented, inner flagellum 3-segmented and five spines on propodus of pereopod 1, and sexual dimorphism evidenced by a pronounced mid-dorsal triangular wing-shaped protuberance on male merus cheliped, unique in Apseudopsis genus. At each studied developmental stage, some individuals presented abnormalities in spination, having only four spines in one of the propodus of pereopod 1. Additionally, five first records of Apseudopsis from the Algarve coast (A. adami, A. bacescui, A. elisae, A. mediterraneus and A. uncidigitatus) are reported for Portuguese waters. A biogeographic overview of the genus Apseudopsis is presented through the compilation and mapping of all worldwide reported occurrences. Passive dispersion can explain the most recent species distribution, yet not disregarding that the study area is taxonomically understudied. This study contributes to improve the current knowledge on tanaidacean taxonomy and updates the geographical distribution range of the Apseudopsis-complex. Portuguese Fisheries Operational Programme (Mar2020) [MAR-02-01-02-FEAMP-0061] European Maritime and Fisheries Fund (EMFF 2014-2020) Fundacao para a Ciencia e a Tecnologia (FCT)Portuguese Foundation for Science and Technology [SFRH/BPD/94985/2013] Centro de Estudos do Ambiente e do Mar (CESAM) [UID/AMB/50017] FCT/MEC FEDER, within the PT2020 Partnership Agreement FEDER, within Compete 2020European Union (EU)

This study describes the reproductive cycle of the common limpet (Patella vulgata) and rough limpet (Patella ulyssiponensis) from the Algarve coast (southern Portugal). Individuals of both species were sampled monthly during two consecutive years, and subjected to gonad histology and calculation of the mean gonadal index (GI). Both species had balanced sex ratios (P. vulgata = 1M: 0.98F; P. ulyssiponensis = 1M: 1.03F), similar size-frequency distribution between sexes, and equivalent mean shell lengths (SL) and total weights (TW) between males and females. In these protandrous hermaphrodites, the estimated size at sex change was slightly smaller in P. vulgata (SL50 approximate to 29 mm) than in P. ulyssiponensis (SL50 approximate to 36 mm). The reproductive cycles of both species were characterised by a main spawning season in early spring to early summer, sometimes including subsidiary spawning events. A comparison of the main spawning season throughout the species distributional ranges revealed that populations of P. vulgata and P. ulyssiponensis from southern Portugal have later spawning periods than other populations from the northeastern Atlantic Ocean. The present information is relevant for conservation purposes and for the proposal of management measures for the harvesting activity targeting P. vulgata and P. ulyssiponensis in southern Portugal. Agência financiadora Fisheries Operational Programme (MAR 2020) European Maritime and Fisheries Fund (EMFF 2014-2020) Corporation Bank of India info:eu-repo/semantics/publishedVersion

The present study reports a detailed description of the catches of cuttlefish (Sepia officinalis) in the trap fishery performed seasonally off the Algarve coast (southern Portugal). A total of 86 fishing surveys were performed during the fishing season (May-September) from 2009 to 2014, on sandy bottoms at bathymetrics ranging from 8 to 10 m depth. During the whole study period, fishing operations involved 6311 cuttlefish traps with a gear catch rate of 37% (frequency of traps with cuttlefish) and a mean of 0.9 S. officinalis caught per trap. A total of 5883 S. officinalis (1424.0 kg) were caught, being only recorded 282 dead individuals (mortality rate of 4.6%). The mean fishing yield (standardised CPUE's in number and weight) was 46.6 individuals and 11.3 kg 50 traps(-1). Overall, males (n = 3188) outnumbered females (n = 2695), producing a significant male-biased (1 M: 0.85 F) sex ratio. On average, females were significantly larger and heavier (124.4 +/- 22.9 mm ML; 253.1 +/- 148.8 g TW) than males (121.9 +/- 24.0 mm ML; 230.7 +/- 143.1 g TW). Accordingly, the length-frequency distributions displayed significant gender differences, with 89.6% of females and 85.8% of males accomplishing the MCRS (100 mm ML). This markedly seasonal, highly sustainable and low impacting small-scale fishery constitutes a locally important socio-economic activity during spring and summer. Undamaged catches and highly fresh individuals further contribute to the considerable price reached by S. officinalis caught using this artisanal fishing gear. Agência financiadora European Union (EU) Fisheries Operational Programme (MAR 2020) European Maritime and Fisheries Fund (EMFF 2014-2020) info:eu-repo/semantics/publishedVersion

This study reports the reproductive cycle, condition index, size at first maturity, growth and the morphometric relationships of the common cockle Cerastoderma edule in Ria de Aveiro (NW Portugal), fundamental knowledge in fisheries management planning and ecosystem conservation. The reproductive cycle was monitored for a period of two years, from January 2013 to December 2014. Spawning extended from June to October, with a peak in the summer months (July to September). The condition index showed a seasonal pattern which appear related to food availability and gametogenic cycle. Sexual maturity was attained at a shell length of 18.6 mm during the first year of life, which stands below the minimum landing size currently in force (25 mm). The von Bertalanffy growth equation was based on size-at-age data obtained from the microscopic analysis of growth rings in sectioned shells: Lt = 40.7[1-e −0.74(t-0.30)]. The morphometric relationships between shell dimensions (length, height and width) were studied in order to understand the effects of ontogenetic changes in cockles` shell morphology, an information that is useful to improve the selectivity of the fishing gears and the size-sorting devices. Some management strategies for the Ria de Aveiro cockle fishery were proposed.

This is the first attempt to apply an expert-based ecological vulnerability assessment of the effects of climate change on the main marine resources of Portugal. The vulnerability, exposure, sensitivity, adaptive capacity, and expected directional effects of 74 species of fish and invertebrates of commercial interest is estimated based on criteria related to their life-history and level of conservation or exploitation. This analysis is performed separately for three regions of Portugal and two scenarios of climate change (RCP 4.5 and RCP 8.5). To do that, the fourth assessment report IPCC framework for vulnerability assessments was coupled to the outputs of a physical-biogeochemical model allowing to weight the exposure of the species by the expected variability of the environmental variables in the future. The highest vulnerabilities were found for some migratory and elasmobranch species, although overall vulnerability scores were low probably due to the high adaptive capacity of species from temperate ecosystems. Among regions, the highest average vulnerability was estimated for the species in the Central region while higher vulnerabilities were identified under climate change scenario RCP 8.5 in the three regions, due to higher expected climatic variability. This work establishes the basis for the assessment of the vulnerability of the human activities relying on marine resources in the context of climate change. FCT: UIDB/04326/2020/ UIDP/50017/2020+UIDB/50017/2020; MAR2020-FEAMP through project CLIMA-PESCA: MAR-01.03.02-FEAMP-0052/ n2/SAICT/2017-SAICT/ SAICT-45-2017-02/ ALG-01-0145-FEDER-028518/ PTDC/ASP-PES/28518/2017 info:eu-repo/semantics/publishedVersion

Biological invasions are among the most challenging ecological and conservation riddles of our times. Fortunately, citizen science projects became a valuable tool to detect non-indigenous species (NIS), document their spread, prevent dispersion, and eradicate localized populations. We evaluated the most undisputed definitions of citizen science and proposed that a combination of two of them is a better reflection of what citizen science has become. Thus, citizen science is any environmental and/or biological data collection and analysis, including data quality control, undertaken by members of the general public, as individuals or as organized groups of citizens, with the guidance and/or assistance of scientists toward solving environmental and/or community questions. With this review, we also assessed how citizen science has been advancing biological invasions research and its focus, by analyzing 126 peer-reviewed articles that used citizen science methods or data concerning NIS. Most of the articles studied terrestrial species (68%) and terrestrial plants were the most studied group (22.7%). Surprisingly, most first detection reports were of non-indigenous marine fish probably due to the constraints in accessing aquatic ecosystems which delays the detection of new NIS. Citizen science projects running over broad geographical areas are very cost-effective for the early detection of NIS, regardless of the studied environment. We also discuss the applicability and need to adapt the methods and approaches toward the studied ecosystem and species, but also the profile of the participating citizens, their motivations, level of engagement, or social status. We recommend authors to better acknowledge the work done by contributing citizens, and the putative limitations of data generated by citizen science projects. The outreach planning of citizen science projects is also evaluated, including the use of dedicated web platforms vs. pre-existent and disseminated web platforms, while discussing how such outreach actions can be maximized. Lastly, we present a framework that contextualizes the contributions of citizen science, scientific research, and regional and national stakeholders toward the integrated management of biological invasions. FCT: SFRH/BD/140556/2018/ UIDB/04326/2020 info:eu-repo/semantics/publishedVersion

Understanding the diversity and community composition of marine communities in coastal areas is of utmost importance to understand how overlapping anthropogenic pressures impact the marine environment. The demersal and epibenthic communities of the Portuguese northern continental shelf were surveyed using a bottom trawl to understand their taxonomic composition, abundance, spatial distribution, and their relationship with environmental variables such as sediment, organic matter, depth and latitude. Bottom sediments were homogenous, being mainly composed by sand particles. The diversity of the study area was low, but high abundance of important commercial species, as Trisopterus luscus, Trachurus trachurus, Palaemon serratus and Merluccius merluccius, in the juvenile stage of life, points out the importance of the area as nursery grounds. Four assemblages were identified, with a visible geographical pattern. Results obtained supply background information that may contribute to the development of future management and monitoring plans for this important and sensible coastal area. Project PRESPO 2008-1/038; PD/BD/135065/2017 info:eu-repo/semantics/publishedVersion

Coastal bivalve populations are characterized by large temporal fluctuations, driven by recruitment success dependent on environmental conditions. The present study evaluated the relationship of rainfall, chlorophyll-α, sea surface temperature (SST) and wind, with the biomass of four commercial bivalve species (Spisula solida, Donax trunculus, Chamelea gallina and Ensis siliqua) that occur both along the Barlavento (western region), and the Sotavento (eastern region), along the South coast of Portugal, between 1999 and 2011. Multiple regression models were used to test two hypotheses: a) the association between environmental conditions three months prior to the spawning period and the biomass in the following year (response variable) and b) the association between environmental conditions during the spawning season plus one month and the biomass in the following year. Wind was not included in the model to test a). The environmental variables considered were not important for E. siliqua. In the period prior to spawning, temperature was significant for S. solida (both study areas), rain for D. trunculus and C. gallina (western area) and chlorophyll-α for C. gallina (western area). All the correlations were positive. During the spawning period, rain was significant for all three species but with different trends. The correlation with rain in months early in the spawning season was positive for S. solida (both areas) and D. trunculus (western area). The correlation with the rain in months towards the end of the spawning period was negative for D. trunculus, and C. gallina (western area). Chlorophyll-α in months at later stages of spawning was significant and positive for D. trunculus (both areas) and C. gallina (western area). The wind, expressed as an index developed to indicate the overall occurrence of winds blowing parallel to the coast (assumes to favour the retention of larvae in appropriate environments), was negatively correlated with biomass for mid to late spawning season for S. solida (eastern area) and D. trunculus (western area). For C. gallina there was a positive correlation with wind early in the spawning season. The SST was not an important variable during the spawning period with the exception of D. trunculus where the temperature at mid spawning season was significant with a negative correlation in the western coast and positive in the eastern coast. This study highlighted the annual spatial distribution of four commercially important bivalves and how environmental factors are likely to play an important role on both biomass and location of the fishing beds. Monitoring of the environmental variables could provide information to predict biomasses of bivalve species, an important tool for its management, as well as predict trends and plan strategies in response to global environmental changes. info:eu-repo/semantics/publishedVersion

Populations of marine bivalves are subject to large interannual fluctuations as a result of their sensitivity to unfavourable environmental conditions. These populations have a strong dependence on recruitment, which constitutes a risk to stock conservation and the sustainability of the commercially exploited species. Bivalve sanctuaries comprising no‐take areas can promote the restocking of large coastal areas as a result of the high fecundity and the potentially long‐distance larval dispersal of bivalves. The present study explores a novel spatio‐temporal approach to investigate suitable locations for bivalve sanctuaries, aimed at protecting and enhancing stocks along the Algarve coast in southern Portugal. In the context of small‐scale fisheries, bivalve dredging constitutes an important socio‐economic activity. Three bivalve species are targeted: the striped venus (Chamelea gallina), the donax clam (Donax trunculus), and the surf clam (Spisula solida). Data gathered from 36 bivalve fishing surveys conducted over three decades (1986–2015) were analysed using geostatistical methods, accounting for temporal and spatial autocorrelation to produce continuous prediction maps of species distribution for each survey. The approach taken permitted the use of all scattered historical data collected by different methods. The predictions were then used to summarize and illustrate the spatial distribution of species across time, in terms of average biomass, variability, and maximum potential biomass, and to delimit the areas as a function of the species persistence (recurrent, occasional, or rare). The temporal patterns through space were further investigated using empirical orthogonal function (EOF) analysis. The areas accounting for 80% of the species biomass were also estimated. Results of this set of analyses led to the proposal of locations for establishing bivalve sanctuaries, aimed at enhancing the stocks of commercial bivalve species in the long term. Such an innovative spatio‐temporal approach and management strategy is replicable in other fishing resources and geographic areas.

This study examined temporal distributions of macrobenthic communities in relation to bottom depth and specifically addressed whether variation in sedimentary dynamics affects species composition and functional structure. Sampling was carried in 2014 (February, May and September) off Tavira Island (southern Portugal). In each sampling period, three replicates of sediment samples were collected at 7, 12, 17 and 22 m deep for both macrobenthic and sediment characterisation. Distributional patterns of macrofauna communities were a function of the interaction between depth and temporal variability, influenced by a gradient in hydrodynamics and species recruitment. The duration of sediment remobilisation and the organic matter content in sediments were the main features of the shoreface sedimentary dynamics responsible for differences in macrobenthic species composition and feeding habits. At low depths (7 m), under intense hydrodynamic conditions and longer period of sediment remobilisation, sediments were characterised by slightly gravelly sand with low contents of organic matter and calcium carbonate. Macrobenthic communities inhabiting shallow depths displayed low abundance and species richness, being dominated by grazers and suspension feeders. In contrast, at the highest studied depth (22 m), subject to low sediment remobilisation, sediments were composed by gravelly sand with high contents of organic matter and calcium carbonate. This depth (22 m) was characterised by high abundances and species richness, reflecting a more stable macrobenthic community composed mainly by surface deposit feeders. According to the benthic communities, the seaward limit of significant wave effects on the seabed is around 7 m in low-energy periods and over 17 m in high hydrodynamic energy periods.

The present study reports the weight-length (W-L) relationships and assesses the relative growth of the common cuttlefish (Sepia officinalis) from the Algarve coast (southern Portugal). Overall, were sampled and analysed 5883 individuals with broad ranges in both mantle length and total weight, with females being significantly larger and heavier than males. In males, females and sexes combined, the W-L relationships were highly significant and the morphometric parameters were highly correlated. Regarding relative growth, males, females and sexes combined displayed negative allometries, reflecting a slower growth rate in total weight than in mantle length during the species ontogeny, being the hypoallometric growth less intense in females than in males. An extensive compilation of analogous data reported throughout the distributional range of S. officinalis (Atlantic Ocean and Mediterranean Sea) further confirmed that negative allometries (weaker in females than in males) between specimen size and total weight are a typical feature in this species. The main factors responsible for this hypoallometric growth are analysed and their implications are discussed in terms of the species functional morphology and behavioural ecology.

In the current work we propose a new method to sample surface sediment during bivalve fishing surveys. Fishing institutes all around the word carry out regular surveys with the aim of monitoring the stocks of commercial species. These surveys comprise often more than one hundred of sampling stations and cover large geographical areas. Although superficial sediment grain sizes are among the main drivers of benthic communities and provide crucial information for studies on coastal dynamics, overall there is a strong lack of this type of data, possibly, because traditional surface sediment sampling methods use grabs, that require considerable time and effort to be carried out on regular basis or on large areas. In face of these aspects, we developed an easy and un-expensive method to sample superficial sediments, during bivalve fisheries monitoring surveys, without increasing survey time or human resources. The method was successfully evaluated and validated during a typical bivalve survey carried out on the Northwest coast of Portugal, confirming that it had any interference with the survey objectives. Furthermore, the method was validated by collecting samples using a traditional Van Veen grabs (traditional method), which showed a similar grain size composition to the ones collected by the new method, on the same localities. We recommend that the procedure is implemented on regular bivalve fishing surveys, together with an image analysis system to analyse the collected samples. The new method will provide substantial quantity of data on surface sediment in coastal areas, using a non-expensive and efficient manner, with a high potential application in different fields of research.

This paper develops a decision support tool that can help fishery authorities to forecast bivalve landings for the dredge fleet accounting for several contextual conditions. These include weather conditions, phytotoxins episodes, stock-biomass indicators per species and tourism levels. Vessel characteristics and fishing effort are also taken into account for the estimation of landings. The relationship between these factors and monthly quantities landed per vessel is explored using multiple linear regression models and data mining techniques (random forests, support vector machines and neural networks). The models are specified for different regions in the Portugal mainland (Northwest, Southwest and South) using six years of data 2010-2015). Results showed that the impact of the contextual factors varies between regions and also depends on the vessels target species. The data mining techniques, namely the random forests, proved to be a robust decision support tool in this context, outperforming the predictive performance of the most popular technique used in this context, i.e. linear regression. Foundation for Science and Technology (FCT, Portugal) [SFRH/BPD/99570/2014] ERDF European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE Programme [POCI-01-0145-FEDER-006961] National Funds through the FCT Fundacao para a Ciencia e a Tecnologia (Portuguese Foundation for Science and Technology) [UID/EEA/50014/2013] project MONTEREAL MAR Program European fund for Fisheries and Maritime Affairs (EFFM) Portuguese Government info:eu-repo/semantics/publishedVersion

The main objectives of this study were (i) to provide an updated age-length key for D. trunculus from Atlantic waters, and (ii) to evaluate population dynamics, the timing of recruitment and production parameters of the wedge clam Donax trunculus in two moderately exposed sandy beaches (the protected area of Donana National Park and the tourist destination of Isla Canela) along the littoral of Huelva (SW Spain). First an in-depth analysis of the shell and updated estimation of growth parameters of the intertidal D. trunculus population were performed between January 2014 and July 2015 using two different methods i) thin-layer cross section (TL) (ii) length-frequency distributions (LFD). Von Bertalanffy growth functions provided an asymptotic length of 46 mm (LFD) and 46.7 mm (TL) and growth constants of 0.48 (LFD) and 0.47 yr(-1) (TL) in Donana beach. In addition, several deformities as well as signs of shell repair were observed. Population dynamics analyses through length frequency distribution clarified the timing of recruitment (February-March and July). The mean annual biomass ((B) over bar) of intertidal populations of D. trunculus ranged between 3.03 (Donana) and 3.31 g ash-free dry mass (AFDW) m(-2) yr(-1) (Isla Canela). Individual production showed the highest value at 27 mm length (0.117 g AFDW m(-2) yr(-1)) and annual production (P) ranged between 3.40 (Donana) and 4.91 g (Isla Canela), resulting in renewal rate (P/(B) over bar) values between 1.03 and 1.61, respectively. The present results, together with information on environmental parameters, revealed clear differences in population dynamics and production between beaches related to the presence or absence of a protection figure. European Fisheries Fund info:eu-repo/semantics/publishedVersion

The present study reports the first record of the Monrovia doctorfish, Acanthurus monroviae (Steindachner, 1876) in the Algarve coast (southern Portugal). A female (257 mm TL) was caught 21 April 2016 off the beach of Olhos d’Agua by a small-scale fishing boat operating bottom-set gill nets at approximately 15 m depth. Morphometric and meristic parameters of the specimen are reported and compared with previous records of A. monroviae. This is the second occurrence of this tropical fish species in Portuguese waters and the second northernmost capture ever reported for the northeastern Atlantic. The present record is an additional example of tropicalisation of the ichthyofauna in temperate waters by a thermophilic tropical species. Indeed, although not established in the study area, A. monroviae found a suitable seawater temperature regime in southern Portugal and further expanded its distributional range along the Iberian coasts. For biogeographic purposes, all reported occurrences of this species in the northeastern Atlantic and Mediterranean (including very recent records and sightings) are compiled and mapped.

A multimetric approach was used to detect structural, compositional, and functional shifts in the underlying macrobenthic communities of an offshore mussel (Mytilus galloprovincialis) farm in a Portuguese Aquaculture Production Area. Sampling stations distributed inside and outside this area were used to evaluate sediment descriptors and macrobenthic samples collected before (April and September 2010) and after (June and September 2014) the initiation of mussel farming. Sediment fine fraction, organic matter content, and trace element concentrations were found to increase with depth, independently from the mussel farm. Moreover, the structure and composition of the macrobenthic communities were likewise structured by depth. Turnover was the dominant temporal and spatial pattern of beta diversity for all communities. Furthermore, the functional diversity of these communities was unaffected by the mussel farm. These results suggested that an offshore profile allowed hydrodynamic conditions to weaken the impact of mussel farming and highlighted the importance of conducting an integrative multimetric analysis when studying aquaculture impacts on benthic communities. FEDER Program through the project IAPAA "Avaliacao do impacto da area de producao aquicola da Armona no ecossistema costeiro e comunidades locais" (PROMAR project) [31-03-01-FEP-0014]

The present study reports six new and consecutive records of the Atlantic blue crab (Callinectes sapidus Rathbun, 1896) in the southern coast of Portugal. Specimens were caught during less than two months (22nd November 2018 - 18th January 2019) as bycatch of trammel nets operated by small-scale fishing boats in scattered locations along the Algarve coast and in the Ria Formosa lagoon. Four adult males (221-236 mm carapace width) and two adult females (191-207 mm carapace width) were caught at relatively shallow depths (1-6 m), on muddy and sandy bottoms in the Ria Formosa lagoon and in the Algarve coast. Morphometric parameters of the specimens are compiled and the respective occurrences are mapped for biogeographic purposes. These first three occurrences in the Algarve coast and the second, third and fourth records in the Ria Formosa lagoon, further supported by additional anecdotal evidences and recent sales at the wholesale market, reveal a rapid westward expansion and confirm the establishment of C. sapidus along the southern coast of Portugal. Possible sources of introduction and causes for the distributional expansion are evaluated. The potential impacts of this invasive species on local ecosystems and fishing/harvesting resources are discussed. Fisheries Operational Programme (MAR 2020) European Maritime and Fisheries Fund (EMFF 2014-2020) info:eu-repo/semantics/publishedVersion

The Atlantic blue crab Callinectes sapidus Rathbun, 1896 is native in the western Atlantic, however it is a non-indigenous species across Europe since 1900, among other world regions. In this paper, we report the first occurrences of this species in the Ria Formosa lagoon and in the Guadiana estuary (SW-Iberian Peninsula, Europe) which occurred in 2016 and July 2017, respectively. We hypothesize that the introduction of this species into these ecosystems might be due to the expansion of the Guadalquivir estuary population through natural processes (larval advection, active movement), or due to unintended introduction events after being transported aboard fishing boats, or, less likely, through ballast water. Changes in Guadiana's river flow after the construction of the Alqueva dam might also explain the presence of another non-indigenous species in the Guadiana estuary. The hypotheses presented, regarding the introduction of the Atlantic blue crab into these ecosystems and of its co-occurrence with other decapod species, are framed in a broader context to serve as a future research framework. The use of the Atlantic blue crab as a new fishing resource is also proposed, namely if it is to be used exclusively by local communities and if no deleterious impacts upon other fisheries and the ecosystem occur from this new fishery. Agência financiadora / Número do projeto Delta Stewardship Council Delta Science Program 1167 Foundation for Science and Technology (FCT, Portugal) UID/Multi/04326/2013 European Regional Development Fund (COMPETE program-Operational Competitiveness Programme) FCT IF/00661/2014/CP1234 SFRH/BD/104209/2014 SFRH/BPD/108949/2015 Berkeley Research Impact Initiative (BRII) - UC Berkeley Library 16-01-04-FMP-0005 info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/publishedVersion

The present study assessed the metal genotoxicity potential at chromosome-level in the bivalve Ruditapes philippinarum collected along different areas of the Tagus estuary. Higher levels of aneuploidy on gill cells were detected at the most sediment contaminated area both in May (31.7%) and October (36.0%) when compared to a less contaminated area over the same periods (203% and 29.0% respectively). Interestingly, metal bioaccumulation in gills was higher in the specimens collected at the least contaminated area with the exception of Pb. Indeed, the multivariate analysis revealed a stronger relation between aneuploidy and sediment contamination than between aneuploidy and the bioaccumulation of the metals. The temporal and spatial inconsistency found for the bioaccumulation of metals in It philippinarum and the positive correlation between sediment contamination and aneuploidy at the most contaminated area suggest that these chromosome-level effects might be due to chronic metal contamination occurring in the Tagus estuary, rather than a direct result of the temporal variation of bioavailable contaminants. The vertical transmission phenomenon of bivalve aneuploidy levels may then be perpetuating those levels on clams from the most contaminated area. The present results shed light about the effect of metal toxicity at the chromosome-level in species inhabiting chronic contaminated areas and highlight the use of aneuploidy as an effective tool to identify persistent contamination in worldwide transitional waters. (C) 2016 Elsevier B.V. All rights reserved. Fundacao para a Ciencia e Tecnologia (FCT) project "ECOAPPROACH" [PTDC/AAC-AMB/121037/2010] FCT [SFRH/BPD/69563/2010] "Estrutura de Missao para a Extensao da Plataforma Continental" (EMEPC)

This study reports the morphometric relationships and relative growth of 20 uncommon bivalve species collected along the Algarve coast (southern Portugal). Morphometric relationships were established between three linear variables (shell length, height and width) and one ponderal variable (total weight) and the relative growth between variables (isometryvsallometry) was analysed in order to assess their variation throughout ontogeny. In addition, morphometric indices (elongation, compactness, convexity and density) based on ratios of those linear and ponderal variables were calculated in order to further characterize morphologically the bivalve species. A total of 2512 individuals belonging to nine bivalve families were analysed, comprising specimens with broad ranges in both shell length (11.8–109.0 mm SL) and total weight (0.2–354.6 g TW). All morphometric relationships were highly significant (P< 0.001) and displayed invariably high correlation coefficients (r= 0.727–0.998). Among a total of 60 morphometric relationships, 27 isometries, 25 positive allometries and 8 negative allometries were registered. The morphometric indices displayed a remarkable variation among taxa, reflecting the high morphological diversity of these miscellaneous bivalve species. Discriminant analysis provided a spatial visualization of the species morphometric variables that further evidenced their main shape features, the distinctness between some species and families (e.g. Pharidae and Cardiidae) and the morphological resemblance among some species belonging to other families (e.g. Veneridae and Tellinidae). Overall, this information is useful and has practical application in diverse research fields, including studies on systematics and taxonomy, physiology, biology, ecology, fisheries assessment and management.

The reproductive cycle of Acanthocardia tuberculata (Linnaeus, 1758) was studied in M’diq Bay. The gonadal development was determined by means of standard histological techniques, mean oocyte diameters and a condition index. Rough cockle is a gonochoric species with synchronous gonadal development and spawning in males and females. The sex ratio obtained was not significantly different to 1:1. Gametogenesis began in late winter (November) coinciding with the temperature drop. In June, with increasing sea water temperature, most of the population was spent and resting oocytes appeared dispersed in the gonad. Resting stage occurred from August to October, during which time sex could not be determined in 100% of the population. A. tuberculata showed a clear seasonality in its gametogenic cycle, with one spawning peak per year in June. Quantitative measurements of 6318 oocyte diameters indicated the patterns of development observed in the qualitative staging. The results obtained revealed the direct influence of temperature on the reproductive cycle. First sexual maturity occurred at 42.77 mm shell length. The information gathered in this study allowed preliminary management measures to be suggested for the fishery of this species, including a closed season during the main spawning season (May-June) and the establishment of a minimum landing size (at least 50 mm shell length) for A. tuberculata from the Moroccan Mediterranean coast.

This study reports a detailed description of the bycatch, discards and survival rates in the cuttlefish (Sepia officinalis) trap fishery off the Algarve coast (southern Portugal). A total of 86 fishing surveys involving 6,311 cuttlefish traps were performed between May and September from 2009 to 2014. Bycatch species were caught in 1,037 traps (bycatch catchability rate of 16.4%), comprising 1576 individuals with an overall weight of 268.3 kg. During the study period, bycatch CPUEs were 12.5 ind./50 traps and 2.1 kg/50 traps, with bycatch rates of 21.1% by number and 15.9% by weight. Thirty-four species (89.5% of bycatch taxa) were discarded at sea, corresponding to discard rates of 19.5% by number and 11.1% by weight. The short-snouted seahorse, Hippocampus hippocampus (L.), was the third most abundant bycatch species (11.6% No.; 0.4% kg) and the second most discarded (12.6% No.; 0.6% kg), being invariably discarded live and undamaged owing its conservation status. This markedly seasonal small-scale trap fishery constitutes a locally important socio-economic activity during spring and summer, characterised by low bycatch and discard rates, complemented by high survival rates of discards. Agência financiadora Interreg IVB-Atlantic Arc Programme European Union (EU) Fisheries Operational Programme MAR 2020 European Maritime and Fisheries Fund EMFF 2014-2020 info:eu-repo/semantics/publishedVersion

Macrobenthic responses to dredging activities were evaluated in a mesotidal coastal lagoon (Ria Formosa South Portugal). Four areas (2 dredged and 2 non-dredged) were analysed along different dredging situations (pre-dredging, during dredge 1, during dredge 2 and post-dredging). Beyond the evaluation of sediment descriptors and classical ecological indicators (number of species and abundance), the beta diversity component (partitioned into turnover and nestedness) was used to detect dredging effects on macrobenthic communities, together with a multivariate analysis (both quantitative and qualitative) including the ecological status assessment. Results confirmed the limitations of alpha diversity indicators in detecting dredging effects in naturally stressed systems, given the absence of clear patterns regarding number of species, abundance and equitability among areas and dredging situations. Moreover, post-dredging presented a higher number of species compared to pre-dredging, suggesting a positive disequilibrium induced by these activities. In contrast, partitioned beta diversity analysis revealed higher nestedness values at dredged areas, while turnover clearly prevailed at non-dredged ones. Such results suggest an effective impact of dredging on these communities, namely through the decrease of rarer species after sediment removal. This qualitative analysis, based on presence absence data (Sorensen dissimilarity), was complemented by multivariate analysis (SIMPER and PERMANOVA) based on quantitative data (Bray-Curtis dissimilarity), highlighting the importance of adopting both approaches to detect dredging impacts on benthic communities. Lower effectiveness was found for M-AMBI index when evaluating benthic Ecological Status, since the apparent absence of organic matter and sediment composition shifts induced by dredging, together with the noticeable high diversity even during dredging situations, strongly limited the analysis. The multimetric approach here proposed can contribute to detect dredging effects on lagoonal benthic communities by disentangling the responses caused by dredging from those resulting from the system natural dynamics. society "Polls Litoral Ria Formosa"

Non-indigenous species (NIS) are increasingly widespread and abundant in coastal areas, hence being considered indicators to assess the environmental status of marine waters under the Marine Strategy Framework Directive. However, information on the effects of biological invasions on species composition and abundance is still scarce, particularly for soft-sediment benthic communities, which remain poorly understood. Therefore, the present study aimed at monitoring the benthic communities of two Portuguese estuarine systems, with a particular focus on NIS. Sampling surveys were conducted at the Tagus and Sado estuaries, in three different years. Invertebrate communities were collected at sampling stations located along the estuarine gradient, using a clam dredge, and several water and sediment parameters were measured at the same locations. NIS represented nearly one fourth (23%) of the total observed individuals across all years and estuaries, with Ruditapes philippinarum accounting for 22% of the total abundance across estuaries and years. Although both estuaries presented a similar total number of species (91 at the Tagus and 81 at the Sado), three-fold more NIS were identified at the Tagus estuary. The frequency of occurrence of the NIS Crassostrea (Magallana) gigas, Mya arenaria and Panopeus occidentalis increased significantly over the three years at the Tagus estuary and decreased significantly for Dyspanopeus sayi from 2015 to 2018. The Tagus and Sado estuaries presented distinct and diverse communities, with the abundance of R. philippinarum being eleven-fold greater at the Tagus estuary than at the Sado estuary. This study provides a baseline list of the NIS occurring in two of the main Portuguese estuarine systems, as well as an approach to estimate NIS abundance, richness, frequency of occurrence and community diversity. Although most studies on NIS impacts have focused on single species, the assessment of the environmental status of marine waters requires that overall impacts of NIS on marine ecosystems are determined. This study indicated metrics that are appropriate to evaluate changes in soft-sediment benthic communities associated to the introduction of NIS. Fundacao para a Ciencia e Tecnologia (FCT)Portuguese Foundation for Science and TechnologyEuropean Commission [UID/MAR/04292/2019] project CRASSOSADO project AQUASADO (Programa Mar 2020) project COCKLES (Interreg Atlantic) [EAPA_458/2016] project NIPOGES (Programa Mar 2020) project COASTNET [PINFRA/22128/2016] Direcao Geral de Recursos Naturais, Seguranca e Recursos Maritimos (DGRM) Instituto da Conservacao da Natureza e das Florestas (ICNF) [SFRH/BD/145746/2019]

The present study reports morphometric relationships and discusses the relative growth in the banded murex (Hexaplex trunculus) and the purple dye murex (Bolinus brandaris) from the Ria Formosa lagoon (southern Portugal). A total of 11 morphometric parameters (eight linear variables: shell length, shell width, total aperture length, aperture length, aperture width, spire length, spire width and siphonal canal length; three ponderal variables: total weight, soft parts weight and shell weight) were analysed in both species. The analyses comprised numerous individuals of both sexes and with broad size ranges (H. trunculus: 10.7–82.8 mm shell length;B. brandaris: 14.6–107.7 mm shell length), fairly representative of the populations from the Ria Formosa lagoon. In general,B. brandarisexhibited greater morphological plasticity and higher variability in shell shape compared withH. trunculus. In both species, the vast majority of morphometric relationships displayed positive allometries, distantly followed by negative allometries and by isometries. AlthoughH. trunculusandB. brandarisare known to lack external sexual dimorphism, several morphometric relationships revealed significant differences in the type of growth between sexes, which should be further confirmed using more powerful techniques, such as geometric morphometric analyses of shell shape.

Although the bivalve dredge used on the Algarve coast (southern Portugal) is highly selective for the target species, in some periods of the year the bycatch can exceed the catch of the commercial species. The present study aimed to quantify the bycatch and discards, estimate damage and mortality, and propose management measures to minimize discards and mortality. A total of 15 fishing surveys (60 tows) were performed using two types of dredges (“DDredge” targeting Donax trunculus and “SDredge” targeting Spisula solida and Chamelea gallina). Of the 85257 individuals (392.4 kg) of 52 taxa that were caught, 73.4% belonged to the target species, 22.1% to commercially undersized target species and 4.5% to bycatch species. Bycatch rates were lower for SDredge (13.5% in number and 6.3% in weight) than for DDredge (46.0% in number and 32.9% in weight). Damage and mortality rates were also lower using SDredge (1.3% and 1.0% of the total catches, respectively) than using DDredge (4.0% and 2.8% of the total catches). Survival experiments revealed the diverse vulnerability of the taxa and confirmed the influence of the damage score on the mortality rate. The results gathered in the present study encourage the adoption of a bycatch reduction device to reduce both direct and indirect mortality., Aunque la draga de bivalvos utilizada en la costa del Algarve (sur de Portugal) es altamente selectiva para las especies objetivo, en algunos períodos del año la captura incidental puede exceder la captura de las especies comerciales. En este contexto, el presente estudio tuvo como objetivo cuantificar las capturas incidentales y los descartes, estimar el daño y la mortalidad, y proponer medidas de gestión para minimizar los descartes y la mortalidad. Se realizaron un total de 15 embarques (60 arrastres) utilizando dos tipos de dragas (“DDredge” dirigida a Donax trunculus y “SDredge” dirigida a Spisula solida y Chamelea gallina). En total, se capturaron 85257 individuos (392.4 kg) pertenecientes a 52 taxones, distribuidos entre especies objetivo (73.4%), especies objetivo por debajo de la talla legal (22.1%) y especies de captura incidental (4.5%). Las tasas de captura incidental fueron menores en SDredge (13.5% número y 6.3% peso) que en DDredge (46.0% número y 32.9% peso). Las tasas de daños y mortalidad también fueron menores usando SDredge (1.3% y 1.0% de las capturas totales) que usando DDredge (4.0% y 2.8% de las capturas totales). Los experimentos de supervivencia revelaron la diferente vulnerabilidad de los taxones y confirmaron la influencia del nivel de lesiones en la tasa de mortalidad. Los resultados del presente estudio fomentan la adopción de un dispositivo de reducción de capturas incidentales (BRD) para reducir la mortalidad directa e indirecta.

The fate of released bycatch is an issue of great interest for fisheries research and management. Survival experiments were carried out to assess the survival capacity of animals damaged and discarded during clam dredging operations. Three common bycatch species, two fish (Trachinus vipera; Dicologlossa cuneata) and one crab (Polybius henslowii), were collected during the sorting of catches from a commercial dredging boat. An arbitrary score scale was used to quantify the type and extent of damage to the organisms. Onboard, damaged individuals were placed in tanks containing seawater which were subsequently transferred to the laboratory. Survival experiments were conducted during the subsequent 48h. D. cuneata exhibited the lowest mortality after 48h (54%), followed by P. henslowii (65%) and T. vipera (81%). Despite the magnitude of the percentage mortalities determined, the average number of individuals estimated to die during a 15 minutes tow (standard commercial fishing time) was relatively small: 1.2, 3.24 and 11 for D. cuneata, T. vipera and P. henslowii, respectively. Nevertheless, when these figures are extrapolated to cover all the dredging fleet the impact of this practice on the populations of the species studied can be significant, particulary for D. cuneata. O destino de capturas acessórias rejeitadas ao mar é uma questão de grande interesse para a pesquisa e gestão das pescas. Foram realizadas experiências de sobrevivência para avaliar a capacidade de sobrevivência dos animais danificados e rejeitados durante as operações com ganchorra, uma draga utilizada na pesca de amêijoa (bivalves). Três espécies capturadas acidentalmente, dois peixes (Trachinus vipera; Dicologlossa cuneata) e um caranguejo (Políbio henslowii), foram recolhidos durante a triagem das capturas realizadas a bordo de um barco de pesca comercial que opera com ganchorra. Uma escala de pontuação arbitrária foi utilizada para quantificar o tipo e amplitude dos danos inflingidos nos organismos. A bordo, os indivíduos danificados foram colocados em tanques com água do mar, que foram posteriormente transferidos para o laboratório. Experiências de sobrevivência foram realizadas durante as 48h subsequentes. A espécie D. cuneata exibiu a menor mortalidade após 48 horas (54%), seguido do P. henslowii (65%) e T. vipera (81%). Apesar dos valores de mortalidade percentuais determinados, o número médio de indivíduos que morreram durante 15 minutos de arrasto (tempo de pesca comercial padrão) foi relativamente pequeno, 1.2, 3.24 e 11 para D. cuneata, T. vipera e P. henslowii, respectivamente. No entanto, quando esses números são extrapolados para toda a frota da ganchora o impacto desta prática sobre as populações das espécies estudadas pode ser significativo, particularmente para a D. cuneata.

The present study aimed to describe the reproductive cycle and estimate the size at sexual maturity of the Manila clam (Ruditapes philippinarum) in the Tagus Estuary (Portugal). Specimens were collected monthly from September 2013 to December 2015 during fishing surveys using bivalve dredges. The gametogenic cycle was described in detail using gonad histology and monitored throughout the study period by the monthly variation in the frequency of gonad maturation stages, mean gonadal index and mean oocyte diameter. This invasive population of R. philippinarum displayed synchronous gonadal development between sexes, with ripening occurring mainly in April and May followed by an extensive spawning period until November–December. Individuals reached the size at first sexual maturity at 29.4 mm in shell length (i.e. before 1 year old). Furthermore, the reproductive strategy, dynamics and potential were compared between the invasive R. philippinarum and the native congeneric carpet shell clam (Ruditapes decussatus). Overall, the data gathered in this study constitutes valuable baseline information to propose conservation strategies and implement management measures to minimize the harmful impacts caused by this invasive species on local ecosystems and native biodiversity, particularly over populations of autochthonous bivalves.

Noticeable changes in global temperatures, climate and ocean carbon chemistry are the result of carbon dioxide increase in the atmosphere. This increase has been mitigated by the oceans capacity to absorb one-fourth of the carbon dioxide in the atmosphere, although this CO2 intake affects oceans carbonate chemistry [i.e., ocean acidification—(OA)]. The detrimental effect of OA in the development and shell formation has been studied in several species of bivalves, although no information is available on the wedge shell Donax trunculus, a gastronomically appreciated species and an important economical resource in several southern European countries. We evaluated the effect of pCO2 increase on hatching and early life stages of D. trunculus, considering two ocean acidification scenarios (ΔpH −0.3 and ΔpH −0.6). Our results showed that elevated pCO2 caused a delay in hatching into D-larvae and reduced larvae survival. In the extreme scenario (ΔpH −0.6), some trochophore larvae persisted to day 9 of the experiment and more abnormal larvae were produced than in the ΔpH −0.3 and control treatments. At day 5, normal veligers under extreme acidification were smaller than in other treatments, but by day 9, these differences were attenuated and the average size of normal D-larvae varied inversely to the pH gradient. Possible underlying mechanisms for these complex response patterns are discussed, including the existence of phenotypic plasticity or genetic pre-adaptive capacity in this D. trunculus population to cope with future environmental changes.

The pullet carpet shell Venerupis corrugata is an economically valuable species in several European countries, however, nowadays stocks are under high fishing pressure. Hatchery production of juveniles for release is a major contributor to strengthen the stock and consequently improve the sustainability of the natural stocks. This study aimed to determine the feasibility of rearing V. corrugata larvae with different larval densities (10, 40 and 200 larvae per mL) in a recirculating aquaculture system (RAS), compared with the traditional larval rearing methodology (Batch). The mean survival, growth and metamorphic rate of V. corrugata larvae in RAS was higher (11.1%; 71.3m; 21.6% respectively) than in the Batch system, in all tested densities. The larval growth was not affected by the initial density until 40 larvae per mL, however, 200 larvae per mL decreased the larval growth in length nearly 54m. The larval rearing time was shortened in 2days in the RAS system. The physical, chemical and microbiologic parameters suggested that the tested densities were not excessive to disturb the biofilter stability of RAS. The V. corrugata larval rearing performed at high larval stocking densities in RAS system present a reduction in the operating costs to produce this species. Marinaqua (PROMAR) and Reproseed (FP7-KBBE-2009) project and acknowledge Ciência 2008 program (FCT).

The surf Spisula solida and the striped venus Chamelea gallina clams support important fisheries in Europe. These fisheries have been affected by inter-annual fluctuations in stock abundance and recruitment failures. Aquaculture could contribute to address these problems through the production of larvae or juveniles for stock-enhancement programmes. In the present study, the prerequisites to produce these species in hatchery were established. Of the different methods used to obtain gametes (thermal stimulation, scarification and flow through), C. gallina spawned in the flow through only. By its turn, the best method for obtaining gametes for S. solida was stripping. Higher survivals of D-larvae were found at 15 and 17 degrees C. The greatest larval survival and growth rates were obtained from larvae fed Isochrysis aff. galbana (T-iso). First C. gallina and S. solida pediveliger larvae were found at day 8 and day 26 respectively. The presence of metamorphosed larvae found even in the unfed treatment for C. gallina and for S. solida is an advantage for aquaculture production. After metamorphosis, the S. solida juveniles' survival was quite low, whereas there was no mortality for C. gallina juveniles reared without substrate regardless the diet provided. Juveniles fed the binary diet (Chaetoceros calcitrans - C. cal + T.iso) and the monodiet T-iso showed relatively higher growth in shell length and weight than C. cal. The hatchery production of these two species was possible, however the results of this study showed that C. gallina can be more attractive for aquaculture than S. solida.

The present study reports the growth rate of the purple dye murex, Bolinus brandaris (Gastropoda: Muricidae), estimated from mark-recapture experiments. A total of 1067 specimens (shell length = 43.4±8.1 mm, range = 14.6−78.4 mm) were marked with Dymo® tape tags and released in a semi-intensive fish culture earthen pond. After a period at liberty ranging from almost two months to around two years, 288 individuals were recaptured (shell length = 67.4±6.2 mm, range = 45.3−88.6 mm), which corresponded to a recapture rate of 27.0%. At recapture, only one specimen had lost the tag (tag loss rate < 0.1%) and all remaining tags were intact and legible. Mean monthly growth rates were 0.9±1.0 mm in shell length, 0.4±0.5 mm in shell width and 0.7±0.7 g in total weight. Growth rates showed high inter-individual variability and an evident decreasing trend with specimen size. Comparison of growth rates with similar information available for other muricids confirmed that B. brandaris is a relatively slow-growing species. This provides valuable information for both fisheries management and for assessing the potential of B. brandaris as a candidate species for molluscan aquaculture.

Near-shore benthic biotopes, in the 2–30 m depth range, were analyzed and mapped using a combination of biological, sedimentary and acoustic data to interrogate the utility of these methods. The surveyed area covered approximately 270 km2, along 80 km of the Southeast coast of Portugal. The acoustic data were acquired with a single beam ground discrimination system (QTC VIEW, Series V), connected to a dual frequency echo sounder (50 and 200 kHz). Sediment grain size and macrofaunal community data were obtained by grab sampling at 88 sites. The sedimentary and the biological data were subjected to classification and ordination analysis and the acoustic data obtained with the two frequencies were analyzed individually with the QTC IMPACT (v3.4) software and classified into acoustic classes. The affinity groups obtained with the three datasets were mapped using a Geographic Information System. The study area showed an inshore-offshore pattern with sands ranging from very fine to very coarse, revealing a sediment distribution in the near-shore shelf comprised by two main areas; a very fine/fine sand area up to 7–10 m depth and a very coarse/coarse sand area offshore. In turn, the biological data also showed an inshore-offshore pattern, identifying two main biological assemblages: fine/very fine sand and coarse/very coarse sand communities. Furthermore, the biological pattern clearly reflected the hydrodynamic conditions of the area, from highly hydrodynamic shallow depth to the calmer deeper areas. Accordingly, species richness and densities were lower at shallow areas than at deeper depth. The acoustic data identified the prevailing biosedimentary gradients along the inshore-offshore direction. Overall, the results obtained here showed that the acoustic system could identify two main areas based on sediment grain size, which closely related to the two main biological communities (groups A and B). This study indicates the importance of combining several layers of information in order to increase the spatial resolution of the main biotope distribution (validating the acoustic data) and detail their sub-divisions (ground-truth sampling). Furthermore, we show that designing ground-truth samples on the basis of the acoustic diversity data allows the biological data to “speak” for itself. In general, acoustic techniques are used as a means to optimize ground-truth sampling. This will only be valid if acoustics can capture all the essence of biotope heterogeneity. If this is not the case, special attention should be given when using broad scale methods (acoustic remote sensing) devoted to biotope mapping. This work was supported by the Portuguese FCT (Fundação para a Ciência e a Tecnologia) under the project “ACOSHELF: Coastal shelf ecosystem studies using acoustics” (POCI/MAR/56441/2004 and PPCDT/MAR/56441/04) and by CESAM own research funds. Our colleague Rui Marques gave invaluable help in preparing the acoustic system and in data collection. published

16 pages, 5 figures, 2 tables, 1 appendix, [EN] Ecological aspects of 75 megabenthic bivalve species found on the south coast of Portugal (from Vila Real to Sagres) were studied based on the information provided by seasonal bivalve surveys from 2000 to 2007 (8600 hauls, simultaneously using a razor shell dredge and a clam dredge). Of the 75 species identified, 36 occurred less than 30 times, and thus were considered rare in the area. The remaining 39 bivalves were analysed according to their occurrence, bathymetric distribution, geographic preferences, seasonal preferences, burying-depth, beach exposure and river mouth proximity. All species belonging to the Pharidae and Solenidae families (razor shells) and most Tellinidae were significantly more frequent in the razor shell dredge (indicating deeper burying in the sediment), whilst the families Cardiidae and Donacidae were significantly more frequent in the clam dredge (indicating that these species are probably closer to the sediment surface). As for the season, most bivalve species occurred similarly in both seasons (19 sp; 49%), but a large proportion were more abundant during the autumn surveys (17 sp., 44%), whereas only three species were commoner during the spring surveys. Most species belonging to the families Cardiidae and Mactridae were commoner in the autumn surveys. The spatial distribution differed between species and cluster analysis identified four communities with greater geographic affinity. Species belonging to the family Cardiidae were preferably found in the western part (WB) and the eastern part (S) of the study area, whereas the families Donacidae, Mactridae and Tellinidae occurred mainly in the central area (EB) and the eastern (S) coastal sectors. Overall, shallower species (modal depth at 3-6 m) showed greater occurrences and abundances than the deeper ones, and the depth pattern observed did not change between seasons. Donacidae and Mactridae (except Mactra glauca) were represented essentially by shallow species, whereas Cardiidae (except Acanthocardia tuberculata and Cerastoderma edule) included mostly species occurring in deeper waters. Bathymetric sequence of species distribution within some families was observed, [ES] Se estudiaron algunos aspectos ecológicos de 75 especies de bivalvos megabentónicos en la costa meridional de Portugal (desde Vila Real a Sagres), basados en la información obtenida a lo largo de varios muestreos estacionales realizados entre el año 2000 y 2007 (8600 muestras). Las muestras se obtuvieron utilizando simultáneamente un rastro para capturar navajas y un rastro para capturar almejas). De los 75 taxones identificados, 36 aparecieron menos de 30 veces, considerándose raros en el área. De los 39 taxones de bivalvos restantes se analizaron los patrones de presencia, distribución batimétrica, preferencias geográficas y estacionalidad y se relacionaron con la profundidad de enterramiento, la exposición de las playas y la proximidad a desembocaduras de ríos. Todas las especies de las familias Pharidae, Solenidae (navajas) y la mayor parte de Tellinidae fueron más frecuentes en el rastro para capturar navajas, indicando una mayor profundidad de enterramiento en el sedimento, mientras que las familias Cardiidae y Donacidae fueron significativamente más frecuentes en el rastro para capturar almejas, indicando que estas especies se encuentran más cercanas a la superficie del sedimento. La mayoría de especies presentaron abundancias similares a lo largo de todo el año (19 especies, 49%), pero una gran proporción fueron más abundantes en los muestreos de otoño (17 especies, 44%), mientras que sólo 3 especies fueron más comunes en primavera. La mayoría de especies de las familias Cardiidae y Mactridae fueron más comunes en otoño. La distribución espacial fue distinta para cada especie y el análisis de clasificación jerárquica mostró 4 comunidades con mayor afinidad geográfica. Las especies pertenecientes a la familia Cardiidae se encontraron preferentemente en la parte occidental de la zona de estudio (WB) y en la oriental, mientras que las familias Donacidae, Mactridae y Tellinidae aparecieron principalmente en pelos sectores central (EB) y oriental (S) del área. Las especies de distribución más somera (profundidad modal 3-6 m) fueron más frecuentes y abundantes en general que las especies de más profundidad y este patrón no cambió entre primavera y otoño. Donacidae y Mactridae (excepto Mactra glauca) estuvieron representadas fundamentalmente por especies someras, mientras que los Cardiidae (excepto Acanthocardia tuberculata y Cerastoderma edule) estuvieron representados principalmente por especies de profundidad. En algunas familias se observó una distribución batimétrica secuencial, This work formed part of the MMR post-doc program financed by Fundação para a Ciência e a Tecnologia BPD/14935/2004

This study aimed to assess the influence of growth and reproductive cycle on the meat yield and proximate composition of the banded murex (Hexaplex trunculus) from the Ria Formosa lagoon (Algarve coast, southern Portugal). Samples of the edible portion (all soft-body tissues) were analysed monthly during one year. The average meat yield was 37.9±4.6%, with females containing more edible content (39.1±4.7%) than males (36.8±4.2%). The proximate composition comprised 70.7±1.4% moisture, 20.1±1.2% protein, 1.6±0.3% fat, 3.0±0.3% ash, and 4.6±1.2% carbohydrate, corresponding to an energetic value of 119.2±7.5 kcal/100 g wet weight. The meat yield was influenced by specimen size, increasing significantly during growth. Both meat yield and proximate composition presented seasonal fluctuations related to the reproductive cycle, which coincided mainly with the periods of maturation and spawning of this species in the Ria Formosa. Finally, H. trunculus meat yield and proximate composition were compared with similar information available for other marine gastropods.

The age and growth of the smooth clam Callista chione from the southwestern coast of Portugal were estimated during a 1 yr study period by using both the surface growth rings and internal shell microgrowth lines (by acetate peel method). The von Bertalanffy growth curves obtained by these 2 methods were, respectively: Lt = 91.9(1 - e - 0.18 (t + 0.22) ) and Lt = 98.1(1 - e - 0.15 (t + 0.43) ). Based on these, the counting of surface growth rings is appropriate for a quick age estimation of individuals up to 10 yr old (~75 mm shell length, SL). For older specimens, analysis of the growth lines in the cross section of shells is recommended, because close to the shell border it becomes difficult to distinguish growth rings on the shell surface. Rapid shell growth occurred in spring and summer, whereas slow growth occurred during autumn and winter, with the deposition of an annual growth ring. The over- all growth performance and the phi-prime index were used to compare growth parameters with data from literature about venerid bivalves. These parameters indicated that Callista spp. have a higher growth performance than other venerid bivalves and this is correlated with geographical latitude. The smooth clam achieves sexual maturation at 4 yr of age and reaches the minimum landing size (60 mm SL) after 5 yr.

Despite the importance of the dredge fishery in Portugal, few studies have focused on bycatch and discard mortality. Catches from three types of dredge: north dredge (ND); grid dredge (GD); and traditional dredge (TD), currently used in the Spisula solida (Bivalvia: Mactridae) fishery, were compared in order to characterize bycatch and to estimate discard mortality. In TD and ND, the catch was retained in a net bag, whereas in the GD a metallic grid cage was used. Tows were carried out on sandy bottoms at depths ranging from 5 to 10 m. Bycatch differed significantly between dredges. The ratio of bycatch abundance to S. solida was 0.22:1 for ND, 0.10:1 for GD and 0.33:1 for TD. The weight ratio was 0.15:1, 0.14:1 and 0.32:1 for ND, GD and TD, respectively. Although a lower bycatch was observed for GD, higher mortality (ND: 10%; TD: 20%; GD: 36%) was estimated for this dredge. However, taking into consideration the fishing yields obtained for each dredge combined with the fact that this fishery is managed by daily quota per vessel, our results showed that, at daily quota level, discard mortality was lower when GD was used. Our study suggests that in output-controlled fisheries, there are obvious advantages in developing dredges with rigid retention structures, such as metallic grids, because these are more selective and efficient than dredges that use net bags. At species level, the bycatch mortality to attain quota varied among dredges. A "selective" and persisting significant removal of bycatch species from biota may change benthic community structure. Therefore, clam fisheries should apply exploitation strategies that are goal-oriented and adaptive to the evolution of the macrofauna communities, which might include the use of different dredge types, thereby diversifying the bycatch and consequently avoiding the cumulative removal of specific macrofauna taxa.

12 pages, 8 figures.-- Printed version published Dec 10, 2008., From 2000 to 2006, a total of 75 bivalve species were identified, varying from 29 (spring 2001) to 54 species (spring 2005) per year. Seasonal tendencies in diversity varied according the year, thus the interpretation of long-term and regional scales is essential before drawing any conclusions in other studies. Richness and diversity consistently decreased with depth and increased with sediment grain size (from low in very coarse sand to high in coarse silt). Diversity decreased progressively from 3 to 16 m depth, thus the harsher shallower environments (due to waves and tidal air exposure) showed greater diversity than the most stable areas. Communities in finer sediments were more diverse than those in coarser sand. Evenness showed patterns opposite to diversity, overall., Diversity and evenness maps (produced with multivariate universal kriging), showed that most geographic areas with greater diversity were farer from river outflows and wastewater treatment plants. Two types of geographic pattern were observed: areas with persistently greater bivalve diversity through time and areas that changed locally from year to year. This spatial analysis can be used to establish priority conservation areas for management purposes, and to analyse the persistency of regional diversity patterns. The area with most habitat heterogeneity (Sotavento) corresponded to greatest diversity., There was a positive relationship between Spisula solida and Chamelea gallina landings and bivalve diversity 2 years and 1 year later, respectively. Possibly, local fisheries, by selectively withdrawing the commercial numerically dominant species from the ecosystem, increased diversity 1 to 2 years later, as the ecological niches of the dominants are quickly filled by several other species thereby creating a more even community. On regional scales, no significant impact was found on long-term bivalve diversity in local fisheries., This work was part of an MMR Post-doc program financed by Fundação para a Ciência e a Tecnologia BPD /14935/ 2004.

The present study compares the ability of conventional condition indices (based on weight of the whole organism, weight of its flesh, and/or its shell weight) and visual quantitative indices (based on measures of the digestive gland, gonad, and capsule gland on digitized images of sections of these organs) for the assessment of reproductive activity in Hexaplex trunculus. To estimate conventional indices, a total of 120 standard-sized specimens (50 males and 70 females) in the 60–70 mm shell length interval were analysed. To estimate visual quantitative indices, a total of 903 specimens (501 males and 402 females) were analysed for the gonadosomatic index (GSI); females were also analysed for the capsule gland index (CGI). Compared to conventional indices, the visual quantitative indices (GSI and CGI) followed seasonal variations of the species reproductive cycle and identified broad changes in reproductive development (being highly accurate in detecting the main period of gonad maturation and sp...

The gametogenic cycle of the banded murex, Hexaplex (Trunculariopsis) trunculus, from the Ria Formosa lagoon (Algarve coast, southern Portugal) was studied through macro- and microscopic analyses of the gonads during a 1-year study period (March 2003–February 2004). The overall samples presented a balanced sex ratio, with males dominating among smaller individuals and females predominating in larger size-classes. The gametogenic cycle of T. trunculus in the Ria Formosa lagoon comprised an extensive period of gonadal activity, with the simultaneous occurrence of distinct developmental stages of gametogenesis in both sexes almost year-round, and with males invariably presenting gonads in more developed stages of gametogenesis than females. Spawning occurred mainly from May to June 2003, apparently triggered by the rising seawater temperature during spring. Due to the extensive period of gonadal activity, T. trunculus exhibited a short resting phase that occurred simultaneously in both sexes between June and August 2003 and coincided with the period of warmest seawater temperatures. Considering these findings, a closed season in the fishing activity should be implemented during the main spawning period of T. trunculus (May and June), in order to protect the female broodstock and collective spawns.

The gametogenic cycle of the smooth clam Callista chione off the Arrábida region was studied throughout a 17-month period (from January 2004 to May 2005) using standard histological techniques, mean oocyte diameters and a condition index. This species showed a synchronism between sexes both in terms of gametogenic development and spawning. The results indicated that sex-ratio was not significantly different from parity. In January 2004, the gametogenic cycle had already begun and ended in late October 2004. Three spawning peaks were detected: January–March, April–May and August–October. No resting period was observed and a new gametogenic cycle began in early November, immediately after the spawning period. The analysis of the oocyte diameter enabled predicting the main spawning periods, which appear to be largely governed by seawater temperature. The condition index evolved according to the reproductive cycle of the species, with the highest values being observed prior to the main spawning periods. The size at first maturity estimated for C. chione was 50.81 mm.

The effects of metal contamination on estuarine macrobenthic communities were investigated using the Biological Traits Analysis (BTA). The study was carried out in the Tagus estuary (western Portugal). Samples of macrobenthic communities and associated environmental variables were taken in four surveys (September 2012, and February, May and October 2013) across the contamination gradient from three main zones: a slightly contaminated, a moderately contaminated and a highly contaminated zone. Functional traits for the most abundant species were assigned using seven categories based on “Feeding mode”, “Life span”, “Body size”, “Motility”, “Position in sediments”, “Larval type” and “AMBI ecological group”. To investigate whether the macroinvertebrate community structure was associated with the environmental parameters and biological traits an integrative multivariate analysis, combining the RLQ analysis and the fourth-corner method, was applied. Within this analysis, human-induced estuarine variables (metals) were rendered independent from natural ones (sediment fine particles) through partial correlations. Following this approach, it was possible to decouple the effects of two typically highly correlated environmental descriptors with different origins. Overall, the study identified significant relationships between sediment environmental descriptors and the functional traits of macrobenthic communities. Further, RLQ/Fourth-corner combined analysis successfully isolated the traits and corresponding species that were most correlated with the measured concentration of trace metals in sediments, supporting the knowledge that benthic organisms exhibit distinct responses to different levels of disturbance. A shift in species dominance occurred along the contamination gradient with epifaunal tolerant species with very small size, long life span, and crawling motility dominating the highest contaminated area. This area was also related with surface deposit-feeder species. The most representative species associated with this area was the gastropod Peringia ulvae. Less contaminated sites revealed large-sized specimens, carnivores and swimmers, mainly represented by the polychaete Nephtys hombergii. This finding is consistent with other studies addressing different kinds of disturbance, where a shift in dominance from carnivore/predators, long-lived and large animals to the predominance of small-size, short-lived and deposit-feeders has been observed across increasing gradients of disturbance. Our results reinforce the importance of macrobenthic functional traits analysis to assess human disturbances driven impacts in multi-stressed estuarine ecosystems. By analysing the environmental variables with different origins independently, we were able to draw conclusions about the effects of human pressures (metals) on macrobenthic traits. Such distinction can be particularly useful to isolate different environmental descriptors and assess their effects on functional diversity, making the current approach promising in evaluation the ecological effects of anthropogenic stressors in estuarine areas. This study was funded for the “Fundação para a Ciência e Tecnologia” (FCT) project “ECOAPPROACH” (PTDC/AAC-AMB/121037/2010). Special thanks are due to Dr. Alexandra Leitão for her help in the sampling design, to Dr. João Cúrdia, Dr. Paulo Vasconcelos and Dr. Marta Rufino for their valuable suggestions and comments in earlier versions of this manuscript, and to Dr. Joanne I. Ellis for proofreading the manuscript. We are also grateful to the “Estrutura de Missão para a Extensão da Plataforma Continental” (EMEPC) for the boat used during this study, and to Adolfo Lobo and Luís Bernardes for sampling assistance, as well as to Vítor Pica, and Jorge Amado, Nuno Queluz and Luís Onofre from “Bombeiros do Montijo”. We are also indebted to Dr. Joana Raimundo and Olinda Araújo for their help in the laboratory work and to Daniela Rosa for her help with the statistical analysis on R software. D.P. and A.C. benefit from grants from the above mentioned project and P.P. benefit from a Post-doctoral grant (SFRH/BPD/69563/2010) awarded by the FCT. The authors would also like to thank the reviewers and editor for their constructive comments that contributed to substantially improve an earlier version of the manuscript. We are particularly thankful to one of the reviewers for specific directions regarding the applied combined RLQ/Fourth-corner analysis. Scopus

The biology, ecology and distribution of Pennant’s swimming crab (Portumnus latipes) along the coast of Portugal in 2015 was studied. Females dominated the catches and the highest percentage of berried females was recorded between February and April. Mean fecundity values were 7711, 10 004 and 4838 eggs for development stages I, II and III, respectively. Estimated Von Bertalanffy growth parameters , K and were 34.83 mm, 0.52 year−1 and −0.41 year for males, and 27.16 mm, 0.74 year−1 and −0.39 year for females, respectively. P. latipes is widely distributed along the Portuguese coast on sandy bottom to a maximum depth of 20 m, with the highest relative abundances from the south coast near estuaries and coastal lagoon inlets. Size distributions differed significantly () between the south and the southwest and northwest regions, with larger crabs in the south. Abundance was generally correlated with abundance of Donax trunculus and Donax vittatus, supporting the hypothesis of a predator-prey relationship.

The present work aims to analyse spatial and inter-annual variability in the benthic environment within the Obidos lagoon, assessing the relationships between environmental characteristics and macrobenthic distribution patterns. Sediment samples were collected in February 2001 and 2002 for the study of macrofauna and biogeochemical parameters (sediment grain size, organic matter, organic carbon, chlorophyll a, and phaeopigments). Comparing 2001 to 2002, a general increase in the number of species, diversity and equitability indices was observed throughout the study area. Likewise, there was an increase of phytopigments and organic matter contents in the upper sediment layer. Based on the macrobenthic community patterns and environmental variables three main areas could be distinguished in both years: an outer area near the inlet mostly influenced by the sea, with very depressed number of species and abundance, and dominated by Saccocirrus papillocercus, Lekanesphaera levii, Microphthalmus similis and Nephtys cirrosa; an intermediate area located in the central part of the lagoon characterized by sandy sediment and low organic carbon, and colonized by a high diverse community with Hydrobia ulvae, Cerastoderma edule and Abra ovata as the most characteristic species; and the innermost area of the lagoon with muddy enriched sediments dominated by Heteromastus filiformis, oligochaetes, Scrobicularia plana, Cyathura carinata, Corophium acherusicum, phoronids, insect larvae and Corbula gibba. Deposit-feeders were dominant in the muddy sediments from the inner area, where suspension-feeders were also abundant. Carnivores were associated with clean sandy sediments from the inlet area and herbivores were more abundant within the central area.

Summary Some authors have studied and described different aspects of the reproductive cycle of Hexaplex (Trunculariopsis) trunculus, but most data are quite ancient and fragmented, lacking information in important respects on the reproductive cycle of this species. Based on several individual and collective spawns deposited in laboratory aquaria, this study provides additional and more detailed information on the spawning behaviour and egg-laying pattern, description of the general morphology and dimensions of the spawns, egg capsules, eggs, embryos and early post-metamorphic juveniles, as well as the first data available on the growth rate of T. trunculus hatchlings and juveniles (until 4 months old). Females deposited an average of 118 ± 89 tongue-shaped egg capsules per individual spawn, measuring on average 5.5 mm length x 4.7 mm width x 2.6 mm thickness. These egg capsules contained 723 ± 66 eggs with an average diameter of 240 ± 8 μm. T. trunculus is a direct developer species (metamorphosed hatchli...

The effect of dredging on bottom structure was assessed, to estimate the damage inflicted on the benthic macrofauna left on the dredge path and to evaluate aggregations of scavengers within the track. Sediment suspended during dredging rapidly resettled both on sand and sandy-mud bottoms. Dredge tracks were deeper on sandy-mud sediments and persisted longer than in sandy sediments. The disappearance of tracks in both sediment types depended both on current strength and wave action. Damage and mortality induced by dredging on the macrobenthic animals left on the dredge path was relatively low. Post-fishing SCUBA diver observations showed that damaged animals left on the dredge path rapidly attracted scavengers, mainly Ophiura albida. Immediately after the tow ophiuroids reached densities eight times greater in the track region than in the background. However, they dispersed again rapidly because only few damaged fauna were available on the dredge tracks. Undamaged or slightly damaged shellfish started to rebury immediately after escaping from the dredge.

The white clam Spisula solida is harvested along the entire coast of Portugal using mechanical dredges. In this study, the total direct mortality of the macrobenthic community caused by three types of clam dredges (north dredge—ND, traditional dredge—TD, and the metallic grid dredge—GD) used in the S. solida fishery was determined and compared. The relationship between mortality and catching efficiency for each type of dredge was also assessed. Our results showed significant differences for total direct mortality between the ND and both the GD and TD dredges. This difference was largely attributed to the mortality of animals that died in the dredge track as a direct result of the physical damage inflicted by the dredge passing. It was also found that the damage to uncaught individuals is directly related to gear efficiency. The lower catching efficiency of the ND (64%) led to a higher proportion of damaged individuals being left in the dredge path, when compared with the more efficient GD (98%) and TD (90%) dredges. Short and long-term implications of the impact of dredging on the composition of benthic communities are discussed. From fisheries management and ecological points of view, there are obvious advantages to introduce into the bivalve dredge fisheries more efficient and selective dredges in order to reduce the number of damaged individuals and by-catch, and consequently decreasing the impact on the macrobenthic communities.

During 1998, a study of the European hake (Merluccius merluccius) static gear fishery was undertaken in southern Portugal. This study aimed to compare long-line and gill net catches within the same area in terms of catch composition, fishing yield, by-catch and discards, and specifically for hake, catch size frequency distribution and quality of the fished product. At least 35 species of fish and invertebrates were caught, with hake dominating the catches in terms of both weight and number. The by-catch represented 23% and 15% of the catch in weight for long-lines and gill nets respectively. No illegal sized hake (under 27 cm total length) were caught in either gear during the study period. Discards of non-commercial species were similar for both gears and considered to be negligible (< 3% by weight). Hake discards were significantly different between gears (7% for long-lines and 42% for gill nets, by weight), due to fish deterioration related to soaking time. Higher daily yields were obtained for long-lines (258.37 kg / 9,000 hooks) compared with those for gill nets (127.12 kg / 10 km net). These findings will help to improve the management and conservation of this valuable hake fishery. Durante 1998 se realizó un estudio de la pesquería estática de merluza europea (Merluccius merluccius) en el sur de Portugal. Este estudio estuvo dirigido a comparar las capturas de las redes de enmalle y del palangre dentro de la misma área, en términos de composición, rendimiento pesquero, captura secundaria y descartes. Específicamente para la merluza, se comparó además la distribución de frecuencias de talla y calidad del producto pescado. Se capturaron, por lo menos 35 especies de peces e invertebrados, con la merluza como especie dominante en las capturas, tanto en peso como en número. Las capturas colaterales representaron el 23% y 15% del total de la captura en peso para los palangres y redes de enmalle respectivamente. Durante el periodo de estudio no se capturaron merluzas de talla ilegal (menos de 27 cm de talla total) en ninguna de las artes de pesca. Los descartes de especies no comerciales fueron similares para ambas artes de pesca y se consideraron insignificantes (< 3% en peso). Los descartes de merluza fueron significativamente distintos entre artes de pesca (7% y 42% en peso para palangre y redes de enmalle respectivamente), debido al deterioro de los peces relacionado con el tiempo de permanencia de las artes de pesca en el agua. Se obtuvieron rendimientos diarios más altos para los palangres (258.37 kg / 9,000 anzuelos) que para las redes de enmalle (127.12 kg / 10 km de red). Estos resultados contribuyen a mejorar la gestión y conservación de esta valiosa pesquería de merluza.