Search

Fisheries co-management policy and research have been extensively reported in recent decades, with mixed results in process and outcome. Co-management has proliferated worldwide under the assumption that fisher participation in resource regimes enhances authority of decisions, reduces transaction costs, and increases compliance. The concept of legitimacy is central to this assumption, but its use in fisheries has been vague and unrelated to its political dimension. Here, legitimacy is framed through three complementary research configurations used in organization studies (as property, process, and perception) to show its relevance for fisheries co-management. Studying the congruence of decision-making with fishers’ normative expectations, funders’ judgments on validity of environmental stewardship or fishers’ perception of propriety not to comply can strengthen institutional diagnostics and influence co-management success through better planning, evaluation, or management of legitimacy attributes. A proposal is developed for addressing fisheries co-management within national boundaries, but it can also inform other environmental regimes.

Collective engagement and inclusiveness have been in growing demand particularly within the context of managing natural resources. Here, a natural and a social scientist report on a case that the two have participated over the past decade, supported by a transdisciplinary evaluation framework. With the aid of a boundary scientist external to the process, analysis focuses on the delivery and update of spatial regulation and fishery management rules in a Marine Protected Area (Marine Park professor Luiz Saldanha) in Arrabida, Portugal, the temporal dynamics in key elements of collaboration and the building up of social, intellectual and political capital in the system. Long-term collective engagement showed that the emergence of key actors and the progression towards an outcome-driven agenda might have the downside to partially demobilize less active members. Further, the increased legitimacy of group action provided by institutional recognition may diminish adaptive capacity and group resilience. Nevertheless, negotiated group proposals to alter the bundles of fishing rights in the system and shaping of boundary objects with relevance to marine sustainability demonstrate that collective action by a community of practice can operate for long periods and deliver more than a compilation of individual wish-lists or noncommittal declarations.

Converting assemblages of marine protected areas (MPAs) into functional MPA networks requires political will, multidisciplinary information, coordinated action and time. We developed a new framework to assist planning environmental representativity in a network across the marine space of Portugal, responding to a political commitment to protect 14% of its area by 2020. An aggregate conservation value was estimated for each of the 27 habitats identified, from intertidal waters to the deep sea. This value was based on expert-judgment scoring for environmental properties and features relevant for conservation, chosen to reflect the strategic objectives of the network, thus providing an objective link between conservation commitments and habitat representativity in space. Additionally, habitats' vulnerability to existing anthropogenic pressures and sensitivity to climate change were also scored. The area coverage of each habitat in Portugal and within existing MPAs (regionally and nationally) was assigned to a scale of five orders of magnitude (from < 0.01% to >10%) to assess rarity and existing representation. Aggregate conservation value per habitat was negatively correlated with area coverage, positively correlated with vulnerability and was not correlated with sensitivity. The proposed framework offers a multi-dimensional support tool for MPA network development, in particular regarding the prioritization of new habitats to protect, when the goal is to achieve specific targets while ensuring representativity across large areas and complex habitat mosaics. It requires less information and computation effort in comparison to more quantitative approaches, while still providing an objective instrument to scrutinize progress on the implementation of politically set conservation targets. Agência financiadora Número do subsídio Oceanic Observatory of Madeira M1420-01-0145-FEDER-000001-OOM national funds through FCT UID/BIA/00329/2013 UID/Multi/04326/2013 Fundacao para a Ciencia e a Tecnologia SFRH/BPD/95334/2013 CESAM - FCT/MEC through national funds UID/AMB/50017 - POCI-01-0145-FEDER-007638 FEDER FCT SFRH/BPD/94320/2013 MARE - UID/MAR/04292/2019 EU through the Cohesion Fund POSEUR-03-2215-FC-000046 POSEUR-03-2215-FC-000047 FCT national funds ECO/28687/2017 info:eu-repo/semantics/publishedVersion

The Marine Stewardship Council (MSC) is the frontrunner in fisheries certification, receiving both extensive support and strong criticisms. The increasing uptake by fisheries and markets (almost 10% of world fisheries tonnage engaged by the end of 2014) has been followed by a widening pool of stakeholders interacting with the MSC. However, the applicability of the MSC approach for fisheries in the developing world (DW) remains doubtful, reinforced by a worldwide uptake skewed towards developed world fisheries. Here, a group of MSC stakeholders, with the aid of an ad-hoc questionnaire survey, reviews constraints to MSC certification in DW fisheries, evaluates solutions put forward by the MSC, and recommends actions to improve MSC uptake by DW fisheries. Recommendations to the MSC include researching and benchmarking suitable data-limited assessment methods, systematizing and making readily available the experiences of certified fisheries worldwide and constructing specific fisheries capacity-building for regional leaders. The MSC can further review the certification cost, especially for small-scale fisheries and, in partnership with other institutions, mobilize a fund to support specific DW fishery types. This fund could also support the development of market opportunities and infrastructures likely to satisfy local conditions and needs. For wider market intervention, the MSC should consider embarking on some form of vertical differentiation. Finally, for fisheries that may never move towards certification, the group identifies tools and experiences available at MSC that can improve environmental performance and governance bearing.

River defragmentation works and an effective fishway with a monitoring station have created conditions for adaptive fishery management in the estuary of Mondego River in central Portugal. Since 2013 fishers, scientists and authorities annually meet to update data for anadromous fish and rules for the upcoming fishing season. Meetings provide an opportunity for approximately 100 licenced fishers to participate, but communication is often hindered by contradictory fisher views and uneven representation between fishers organized in associations (mainly in the lower estuary) and non-members (mainly in the upper estuary). This study presents a survey, voluntarily undertaken by fishers (n = 35) in the upper and lower estuary, aiming to facilitate communication and discursive rationalization of decisions during the annual meetings. The questionnaire includes perceptions of change in environmental and socio-economic conditions, opinions on rules and utility of the meetings and allows comparisons between the upper and lower estuary communities. Results were presented in the 2019 meeting, demonstrating that fishers agree with most rules but also have proposals for rule change and strengthening of participation. The decisions for the 2020 season suggest that the survey permitted a more focused discussion of alternatives and led to modification of rules by consensus that was previously unattained. The survey further showed that a wider governance structure will be required to resolve the emerging problem of an invasive water plant that reduces fishing opportunities and deteriorates river productivity.

Collective engagement and inclusiveness have been in growing demand particularly within the context of managing natural resources. Here, a natural and a social scientist report on a case that the two have participated over the past decade, supported by a transdisciplinary evaluation framework. With the aid of a boundary scientist external to the process, analysis focuses on the delivery and update of spatial regulation and fishery management rules in a Marine Protected Area (Marine Park professor Luíz Saldanha) in Arrábida, Portugal, the temporal dynamics in key elements of collaboration and the building up of social, intellectual and political capital in the system. Long-term collective engagement showed that the emergence of key actors and the progression towards an outcome-driven agenda might have the downside to partially demobilize less active members. Further, the increased legitimacy of group action provided by institutional recognition may diminish adaptive capacity and group resilience. Nevertheless, negotiated group proposals to alter the bundles of fishing rights in the system and shaping of boundary objects with relevance to marine sustainability demonstrate that collective action by a community of practice can operate for long periods and deliver more than a compilation of individual wish-lists or noncommittal declarations.

To provide new information on the ingress dynamics of glass eels at the Portuguese coast, the study analyzes catch per unit effort (CPUE) data from river Lis, biometric data from recruits in basins of western Portugal and meteo‐oceanographic data from the Iberian margin and shelf. Biometric data of glass eels in western Portugal are congruent with the latitudinal size gradient of leptocephali in oceanic surveys and show clear seasonality, with longest and heaviest individuals arriving from October to December. Generalized additive models fitted to CPUEs from two experimental fishing periods (1996–1997 and 2013–2014) show that availability of glass eels to the sampling gear was inversely related to lunar phase and sea wave height. CPUE was lowest from May to September, increased towards the end of the year and peaked in February–March, when recruits were almost 40% lighter than autumn arrivals. Commercial CPUE during the 1989–1990 fishing season was significantly higher than experimental fishing data in 1996–1997. Higher variance and smaller sample size in 2013–2014 prevent conclusive interdecadal comparisons. Finally, CPUE was significantly higher during the prevalence of northward current flow off western Portugal and during strong cross‐shelf westerly winds. Findings support the suggestion that eel recruitment in Portugal occurs mainly by leptocephali travelling along the Azores Current, deflected northwards through the Iberian Poleward Current, with river ingress, and possibly oceanic metamorphosis, modulated by seasonal dynamics in coastal hydrology and shelf/upper margin oceanography.

Stakeholder participation is a key feature in risk-based frameworks used to assess and promote sustainable exploitation in fishery systems, but participants usually have a limited opportunity to influence the scope and rules of interaction. Here, an extension of this approach of stakeholder engagement is described and tested in a context where the scope and rules of interaction are decided by the participants themselves. Demonstration is based on a deep-water long-line fishery for black scabbardfish (Aphanopus carbo) off mainland Portugal. Managers, scientists and fishery representatives were invited to interact within a facilitated environment with the aim of improving understanding of main problems in the system and of negotiating solutions meaningful to all participants. Mismatches between the scale of biological processes and those at which exploitation is assessed and managed across the Northeast Atlantic and other weaknesses of the fishery system were rapidly identified during an interactive workshop of benchmarking against the Marine Stewardship Council sustainability standard. Specific proposals for action were iteratively developed within the group and evaluated in terms of perceived cost and scope for action. Finally, problems were prioritized in terms of a cumulative score of gravity of anticipated impact, urgency of action and likely degradation rate during a period of inaction to highlight issues most likely to be resolved by the group. The stage-wise approach presented here can be replicated to create or to revise strategies for resolving problems in data-limited fisheries and can be extended to incorporate other critical stakeholders and other tools to stimulate group interaction and joint deliberation.

Submitted by Liliana Carvalho (lc.marestartup@fc.ul.pt) on 2019-09-04T18:50:05Z No. of bitstreams: 1 MARE_ULisboa_MarinePolicy_59_2015_61-63.pdf: 170797 bytes, checksum: a47aab71fc7ce1d3dbf64555d52d5b30 (MD5) Approved for entry into archive by Vanessa Fonseca (vffonseca@fc.ul.pt) on 2020-01-19T21:30:41Z (GMT) No. of bitstreams: 1 MARE_ULisboa_MarinePolicy_59_2015_61-63.pdf: 170797 bytes, checksum: a47aab71fc7ce1d3dbf64555d52d5b30 (MD5) Made available in DSpace on 2020-01-19T21:30:41Z (GMT). No. of bitstreams: 1 MARE_ULisboa_MarinePolicy_59_2015_61-63.pdf: 170797 bytes, checksum: a47aab71fc7ce1d3dbf64555d52d5b30 (MD5) Previous issue date: 2015 info:eu-repo/semantics/publishedVersion

Bernal, M., Stratoudakis, Y., Wood, S., Ibaibarriaga, L., Uriarte, A., Valdés, L., and Borchers, D. 2011. A revision of daily egg production estimation methods, with application to Atlanto-Iberian sardine. 2. Spatially and environmentally explicit estimates of egg production. – ICES Journal of Marine Science, 68: . A spatially and environmentally explicit egg production model is developed to accommodate a number of assumptions about the relationship between egg production and mortality and associated environmental variables. The general model was tested under different assumptions for Atlanto-Iberian sardine. It provides a flexible estimator of egg production, in which a range of assumptions and hypotheses can be tested in a structured manner within a well-defined statistical framework. Application of the model to Atlanto-Iberian sardine increased the precision of the egg production time-series, and allowed improvements to be made in understanding the spatio-temporal variability in egg production, as well as implications for ecology and stock assessment.

Bernal, M., Stratoudakis, Y., Wood, S., Ibaibarriaga, L., Uriarte, A., Valdés, L., and Borchers, D. 2011. A revision of daily egg production estimation methods, with application to Atlanto-Iberian sardine. 1. Daily spawning synchronicity and estimates of egg mortality. – ICES Journal of Marine Science, 68: . Assumptions of daily spawning synchronicity and estimation of egg mortality for Atlanto-Iberian sardine are revised in the context of daily estimators of egg production. An extensive database of ichthyoplankton surveys from 1985 to 2008, aggregated at different levels, is used, a set of mortality models is derived, and a comparison among them is carried out using standard statistical techniques. Analysis of the database shows Atlanto-Iberian sardine to be a late-evening spawner, in agreement with previous knowledge, but suggests a lengthier daily period of spawning. Comparison among the set of mortality models used suggests that estimates of mortality from single surveys for Atlanto-Iberian sardine are often unreliable, and that the mean estimates obtained after aggregating data from various years are statistically significant, more robust, and in line with existing information gathered from the literature.

We present a method for estimating the interspawning interval (ISI) in batch-spawning teleosts with indeterminate fecundity based on the rate of oocyte growth and the size of oocytes at the beginning and end of the spawning cycle. The method is accompanied by a number of prerequisites, which are tested and subsequently applied to wild collections of Atlantic sardine Sardina pilchardus (also known as European pilchard). The rate of oocyte growth and oocyte size at the end of vitellogenesis were shown to exhibit rather constant values in Atlantic sardine; thus, the ISI could be simply estimated as a factor of oocyte size at the beginning of the spawning cycle (Ob ). Given that vitellogenesis in Atlantic sardine ceases at final oocyte maturation, Ob was estimated by measuring the size of oocytes of the subsequent batch in females with hydrated oocytes. The resulting average ISI was very close to inverse values of the spawning fraction estimated through the postovulatory follicle method, which indica...

Zwolinski, J. P., Oliveira, P. B., Quintino, V., and Stratoudakis, Y. 2010. Sardine potential habitat and environmental forcing off western Portugal. – ICES Journal of Marine Science, 67: 1553–1564. Relationships between sardine (Sardina pilchardus) distribution and the environment off western Portugal were explored using data from seven acoustic surveys (spring and autumn of 2000, 2001, 2005, and spring 2006). Four environmental variables (salinity, temperature, chlorophyll a, and acoustic epipelagic backscatter other than fish) were related to the acoustic presence and density of sardine. Univariate quotient analysis revealed sardine preferences for waters with high chlorophyll a content, low temperature and salinity, and low acoustic epipelagic backscatter. Generalized additive models depicted significant relationships between the environment and sardine presence but not with sardine density. Maps of sardine potential habitat (SPH) built upon the presence/absence models revealed a clear seasonal effect in the across-bathymetry and alongshelf extension of SPH off western Portugal. During autumn, SPH covered a large part of the northern Portuguese continental shelf but was almost absent from the southern region, whereas in spring SPH extended farther south but was reduced to a narrow band of shallow coastal waters in the north. This seasonal pattern agrees with the spatio-temporal variation of primary production and oceanic circulation described for the western Iberian shelf.

Marçalo, A., Marques, T. A., Araújo, J., Pousão-Ferreira, P., Erzini, K., and Stratoudakis, Y. 2010. Fishing simulation experiments for predicting the effects of purse-seine capture on sardine (Sardina pilchardus). – ICES Journal of Marine Science, 67: 334–344. To study the impact of purse-seine fishing on deliberately released sardine, two laboratory experiments were performed to explore the effect of net confinement for 10, 20, 40, and 60 min at 18 and 23°C. A third experiment considered two levels of fish density while confined for 20 and 40 min at 16°C. Analysis of cortisol and haematocrit demonstrated that stress immediately after simulated fishing was milder than in commercial fishing and did not correlate with observed delayed mortality. Scale loss was related to the probability of dying (mean values of 16.3 and 2% for dead fish and survivors, respectively), and fin erosion was a long-term stress response observed in both dead and surviving fish. Time of confinement was an important stressor, with survival rates decreasing significantly with increasing periods in the net, and temperature having an additional negative effect. Density effects were less conclusive, but there was some indication that survival correlated with biological condition (heavier fish were more likely to survive). It seems that delayed mortality after release can be substantial, although death is not certain and appropriately modified fishing operations and favourable environmental conditions may enhance the probability of sardine survival.

We investigated and compared the pattern of accumulation of recent and late atretic follicles in the ovaries of Iberian sardine, Sardina pilchardus , in relation to body size with the aim to examine whether late atresia can be used in back-calculations of individual spawning history. Oppositely to earlier stages, late atresia in sardine was shown to accumulate even at peak spawning periods in fish of larger size/age indicating a relationship between atretic intensity and the distant reproductive performance of the individuals. Despite the fact that intensity of late atresia was very high in some occasions, its accumulation was not shown to impede imminent spawning activity. Lack of dependence between imminent spawning activity and the intensity of late atresia was related to the differential pattern with which postovulatory and atretic follicles are associated to the lamellar epithelium of the ovary. Finally, the effect of the ‘reference trap’ which is a major source of bias when quantifying structures in stereological measurements, could be mediated or even completely removed by using a measure of ovarian growth, such as gonosomatic index in the present study, as a covariate when modeling variability in the intensity of atresia.

Surface velocity estimates from wind and altimeter data, together with satellite-derived sea surface temperature and chlorophyll, were used to explore the advection patterns and environmental conditions using a simple Lagrangian model. Although the model is generic (only considering the physical transport), the results are of particular interest for sardine ( Sardina pilchardus ) early life stages, due to the spawning dynamics of the species off Iberia and NW Africa. Particles were released on the shelf of the Iberian and northern African Atlantic coasts every five days from 1998 to 2004 and advected for 27-days. Trajectories were computed using combinations of three surface velocity constituents: Ekman velocity, geostrophic velocity derived from sea level anomaly maps and mean geostrophic velocity derived from two mean dynamic topographies. Daily time series of sea surface temperature, chlorophyll-a concentration and water depth where constructed for each particle trajectory. The results showed strong regional and seasonal dependence of the transport due to wind, with average seasonal cycles of the percentage of particles found in the shelf reflecting the anticipated effect of the seasonal north–south migration of the trade wind belt. The addition of the geostrophic transport led to the attenuation of seasonal cycles and higher mean/maximum values in the probability of retention within the shelf. This increased capacity for retention even during strong upwelling conditions seems to have been overlooked by theories aiming to describe the reproductive strategies of pelagic fish and understand recruitment dynamics based primarily on wind variability. On the other hand, the average surface chlorophyll values indicated a distribution area with higher primary production for particles that never leave the shelf, in comparison to those that return to it or are found in the open sea a month after release, which is in agreement with existing hypotheses that offshore advection is detrimental to larval survival mainly due to the higher risk of starvation. Finally, the exchange between adjacent shelf areas was generally small (less than 5%) within the study period, with the exception of the Gulf of Cadiz. In the latter area, up to 50% of particles released in the southern Iberian shelf reached the Moroccan shelf in several events, contradicting previous suggestions that the Strait of Gibraltar acts as a physical barrier that promotes genetic differentiation among neighbouring sardine populations in the Atlantic. Overall, these results provide useful insights for the study of sardine dynamics in the northeast Atlantic but the unexpectedly high sensitivity of summary metrics (namely retention probability) to the choice of surface velocity field preclude firm conclusions and indicate alternative routes for future studies.

The main factors that affect early survival, physical damage and stress reactions of sardine Sardina pilchardus after live capture and introduction to captivity were examined. A total of 2800 sardines were captured alive from commercial purse seiners in five trials off southern Portugal and monitored for 4 weeks in aquaculture tanks. Survival rates varied considerably between trials (from 80% after a month), with most deaths occurring in the first 5 days. Sardine early survival was affected by factors related to conditions at sea (catch composition, sea temperature and transportation density), during introduction to captivity (magnitude of thermal shock, land transportation duration and use of antibacterial treatment) and, possibly, their interaction. Physical damage was related to the probability of dying, with fish that died during the first week showing significantly higher scale loss and larger caudal fin erosion that those that were alive in the same period. For all stress variables measured (blood haematocrit, cortisol, glucose and ions in the plasma), the most extreme values were attained during introduction to captivity or in the first hours after. After 2 weeks in captivity, most variables had returned to levels close to those observed at the onset of purse-seine fishing, suggesting that maintenance conditions were adequate to permit a rapid recovery from fishing and transport stress.

Data on the occurrence of sardine (Sardina pilchardus) eggs from 42 national ichthyoplankton surveys along the European Atlantic coast were collated in order to describe the spawning habitat and spawning distribution of sardine in recent decades (1985–2005). A modification of existing spawning habitat characterisation techniques and a newly developed method to compare the probability of egg presence across surveys carried out with different sampling gears were used. Results showed that sardine spawning off the Atlantic European coast is mainly restricted to the shelf area, with the main geographical range being between the Strait of Gibraltar (the southern limit of data available for this analysis) and the middle part of the Armorican shelf (latitude around 47.5° North), and along a temperature range of 12–17 °C. Spawning grounds within these limits show a nearly continuous geographical distribution, covering a large proportion of the shelf of the Iberian peninsula and adjacent waters, except for: (1) a persistent gap at the north west corner of the Iberian peninsula, (2) a small secondary break at the Spanish–French border in the inner part of the Bay of Biscay and (3) at the south west corner of the peninsula where there is a narrowing of the shelf width. These discontinuities were used to separate spawning into four nuclei and to describe the changes in spawning distribution in the time series. The relative importance of each nucleus and the degree of separation between adjacent nuclei varies between years, with the exception of the permanent gap at the northwest corner of the Iberian peninsula, which is persistent throughout the time series. Year to year changes in the proportion of the potential spawning habitat in which spawning actually occurred, changing from around 60% before the mid 1990s to around 40% thereafter, and did not show any relationship with spawning stock biomass. Evolution of potential habitat occupation over the Armorican shelf shows larger variability than that observed in the Iberian peninsula, with percentages of occupation ranging from around 30% up to nearly 80% of the shelf in recent years (within the limitations of the relatively sparse data for this region).

Zwolinski, J., Morais, A., Marques, V., Stratoudakis, Y., and Fernandes, P. G. 2007. Diel variation in the vertical distribution and schooling behaviour of sardine (Sardina pilchardus) off Portugal. – ICES Journal of Marine Science, 64: 963–972. Diel patterns in the schooling behaviour and vertical distribution of pelagic fish schools were studied by examining their echotraces from repeated acoustic survey transects at three inshore sites off the Portuguese coast. At two sites, sardine was the dominant pelagic species, and echotrace characteristics of fish schools were similar to those reported in the literature. At the third site, where there was a multispecies pelagic assemblage that included sardine, there was more variability in several of the school descriptors. At all sites, fish schools expanded after sunset, enlarging their cross-sectional area along the horizontal plane and reducing their mean internal acoustic density, while maintaining their overall mean abundance. Downward migration was rapid (within 1 h) after sunset and simultaneous with school expansion. School-like aggregations with total backscattering similar to daytime schools were present throughout the night, although the proportion of small schools and scattered fish appeared to increase at that time. At dawn, sardine rose back up the water column and rapidly reformed into the typical daytime schools. This pattern of diel vertical migration is opposite to that described for most clupeoids worldwide. The implications of this behaviour on abundance estimation by acoustic monitoring surveys for small pelagic fish are discussed.

Egg data from ichthyoplankton monitoring sites in the western English Channel (1988–2003) and northern Spain (1990–2000) and macroscopic maturity data from biological samples of purse seine landings in western and southern Iberia (1980–2004) are used to describe the spawning seasonality of sardine (Sardina pilchardus) in European waters of the northeast Atlantic using generalised additive models. The fitted models reveal a double peak in spawning activity during early summer and autumn in the western Channel, a wider spring peak off northern Spain and a broad winter season in the western and southern Iberian Peninsula. At all sites, a high probability of spawning activity was observed over at least 3 months of the year, with the duration of the season increasing with both decreasing latitude and increasing fish size. Off western and southern Iberia there are indications that the spawning season has been of longer duration in recent years for all size classes (reaching in some cases 8 months of the year for large fish). These patterns are in general agreement with existing literature and theoretical expectations of sardine spawning being driven locally by the seasonal cycle of water temperature, assuming preferences for spawning at 14 –15°C and avoidance for temperatures below 12°C and above 16°C. Regional quotient plots indicated that spawning tolerance to higher temperatures increases progressively with decreasing latitude. Despite the weak evidence for geographical differences in temperature tolerance that may have some genetic origin, the degree of spatio-temporal overlap in sardine-spawning activity within Atlantic European waters is unlikely to promote any reproductive isolation in that area.

O Parque Marinho Professor Luiz Saldanha (PMLS - Arrábida, Portugal) foi criado em 1998 e está regulado por um plano de ordenamento desde 2005. Este estudo apresenta os resultados de um inquérito que recolheu informações e opiniões de pescadores do PMLS sobre a situação ecológica, socioeconómica e de governança 4-7 anos após a implementação faseada das regras nesta área marinha protegida (AMP). As 31 perguntas sobre o sistema social-ecológico e algumas perguntas auxiliares foram presencialmente respondidas em entrevistas individuais por 23 pescadores do PMLS (cerca de um terço dos licenciados) aleatoriamente escolhidos. As informações sobre a actividade pesqueira são utilizadas para formar indicadores de estado e de tendência para parâmetros ecológicos. As opiniões relacionadas com a interacção com outros utentes, as regras do PMLS e instituições associadas formam indicadores socioeconómicos e de governança considerados relevantes para qualquer AMP. Os resultados são comparados com dados oficiais de actividade pesqueira no porto de origem (Sesimbra) e com informações de literatura publicada. No geral, a caracterização da pesca do PMLS com base nas respostas ao inquérito foi reveladora de uma maior complexidade do que anteriormente reconhecida para esta pequena frota; os resultados para os indicadores ecológicos no PMLS genericamente apontam para ausência de mudança, mas são inconclusivos, dado a ausência de padrões claros nas respostas e algumas incongruências com outras fontes de informação. Os resultados para os indicadores socioeconómicos e de governança são claros no registo maioritário de desalento, mas difusos no registo das causas e propostas de solução. Esta análise é complementada pelo estudo de Stratoudakis et al., (2015) sobre as percepções de outros utentes do PMLS relativamente à mesma temática, aonde também se cruzam os resultados dos dois inquéritos. O objectivo conjunto destes trabalhos é apoiar a avaliação da eficácia de gestão no processo da primeira revisão do plano de ordenamento do PMLS e a iniciação de um plano de monitorização longitudinal focando em metodologias participativas. The Prof. Luiz Saldanha Marine Park (PMLS - Arrábida, Portugal) was created in 1998 and is regulated by a spatial plan since 2005 (POPNA). The present study shows results from an inquiry that collected information and opinions of PMLS fishers on the ecological, socio-economic and governance conditions 4-7 years after the phased introduction of regulation in this marine protected area (MPA). The 31 questions about the social-ecological system and some auxiliary questions were re-sponded by 23 fishermen (skippers of a third of the

High-resolution acoustic and ichtyoplankton sampling with a ‘continuous under-way fish egg sampler (CUFES)’ was performed in two regions of approximately 100 square nautical miles off southern Iberian Peninsula, with the aim of studying the small scale distribution of sardine ( Sardina pilchardus ) adults and eggs during a spawning event. Very dense patches (246 eggs m − 3 ) of recently spawned eggs with dimensions (up to 3 nautical miles wide) significantly larger than daytime sardine schools were present in both regions. Egg staging and ageing showed very little intra-sample variation, indicating a synchronous spawning period at dusk. The internal structure of the patches evaluated by variography showed very low internal variability, as if they consisted of a single unit. This hypothesis is confirmed by the acoustic finding of large sardine shoals with similar dimensions to those of the patches after sunset and throughout the night. During that period, adults were found near or in contact with the bottom, suggesting that spawning occurred at depth. A distinct patch of older eggs was found in both areas, but with a few nautical miles of horizontal separation. Their characteristics (a larger area, lower egg densities and a more irregular shape) indicate that these patches were exposed to dispersion and ‘stirring’ by physical forces, reshaping their initial appearance, while mesoscale water circulation could have displaced the core of the patches away by several kilometres within a day.

Observations from the purse seine fishery off northern Portugal are used to describe the early dynamics of sardine (Sardina pilchardus) stress reactions and identify likely stressors during the commercial fishing operation. Sardine blood and muscle were sampled from the onset of fishing (school identification and encircling) to the end of fish transfer onboard (90–120 min later). The evolution of haematocrit, haemoglobin, cortisol, glucose, ionic concentrations, ATP and its catabolites were modelled using linear mixed models as a function of time spent in the net, biological (sex, reproductive state and condition) and operational variables (catch, light level and phase of fishing operation). Significant linear trends with time were detected for most stress variables and mean concentrations after 2 h in the net were similar to literature values corresponding to acute stress reactions for teleosts. Biological variables were rarely significant and explained a small proportion of variation, while operational variables were never significant. For each stress variable, levels varied considerably between trips but the temporal evolution was common across trips. Random trip effects were uncorrelated among most biochemical variables, suggesting that distinct factors affected each stress variable during the sampled trips. However, the linear trend with time spent in the net observed for most stress variables indicates that the duration of the fishing operation is an important stressor in purse seine fishing due to the progressive water volume restriction, crowding and manipulation associated to the fishing method.

We investigate spatial and temporal variations in sardine maturation patterns and discuss the implications for stock structure, using recent samples collected opportunistically across the species range and data collected regularly for the assessment of the Atlanto-Iberian stock. Maturity ogives were fitted to maturity-at-length data using Generalized Linear Models, and maturation patterns are summarized by length at first maturity (L50). Sardine attain sexual maturity at a total length of 10.9e16.8 cm. The percentage of mature small sardine increases from north to south across the Northeast Atlantic. L50 is low in the Mediterranean and Moroccan waters, but maturation is delayed towards the limits of the species’ range. Sardine mature smaller in the Gulf of Cadiz than in other areas of the Atlanto-Iberian stock, although there is no indication of a different maturation pattern north of the stock boundary. These results are not sufficient to review the stock structure of sardine, but question the hypothesis of homogeneous biological properties of sardine populations within the stock area. Sardine maturation length reduced and the spawning period extended in western Iberia during the past two decades. Associated increases in fish condition and fat reserves during the summer feeding season suggest that variations in reproductive traits may have been caused by environmentally driven changes in food availability., SI

Data from 10 acoustic surveys targeting sardine (spring and autumn), 3 acoustic surveys targeting blue whiting (spring) and 9 groundfish surveys (summer and autumn) were used to describe the distribution and relative abundance of snipefish ( Macroramphosus spp.) off Portugal and the Gulf of Cadiz in recent years (1998-2003). Snipefish (8-17 cm) were regularly found off Portugal, occasionally in large concentrations, but were absent from the Gulf of Cadiz. Off northern Portugal, snipefish were distributed along the outer shelf and upper slope, clearly separated from sardine (the most abundant species in the inner shelf) and partially overlapping with blue whiting ( Micromesistius poutassou ), the most abundant species in the upper slope. Snipefish were most abundant in the outer shelf of south-western Portugal, preferentially distributed in large aggregations around the Canyon of Setubal and partially overlapping with the distribution of boarfish ( Capros aper ) and blue whiting (both abundant in the upper slope of south-western Portugal). Off southern Portugal snipefish were almost exclusively distributed in the outer shelf and were significantly smaller than in south-western (intermediate) and northern Portugal (large). Acoustic estimates of total snipefish biomass ranged between 176 – 504 thousand tonnes within the study period, with more than half off south-western Portugal. Within the period 1998-2003, and despite the lack of directed fishing activity, a marked decline in abundance and a small but significant increase in mean length were observed, particularly off south-western Portugal.

The acoustic repertoire of captive grey gurnard Eutrigla gurnardus during competitive feeding consisted of three types of sound: knocks, grunts and growls. Knocks were audible as a single sound, whereas grunts and growls were perceived as longer, pulsed sounds to the human ear. Typically, knocks were composed of 1–2 pulses, grunts of 4–8 pulses and growls >10 pulses. Growls were longer and had shorter pulse periods than grunts. All sound types had peak frequencies of c. 500 Hz. The sequences of behaviours observed during feeding interactions suggest that grey gurnard obtain food both by scramble and contest tactics. Competing fish emitted knocks mainly while grasping a food item and also during other non-agonistic behaviour, suggesting that knock production may reflect a state of feeding arousal but could also serve as a warning of the forager’s presence to nearby competitors. Grunts were mainly emitted during frontal displays, which were the most frequent behavioural act preceding grasps, suggesting that they may play a role in deterring other fish from gaining access to disputed food items.

We found 1049 of 2409 mackerel eggs (46%) from 59 samples in the north-east Atlantic to be parasitized by the dinoflagellate Ichthyodinium chabelardi. The endogenous life cycle of the parasite is briefly described.

Generalized additive models (GAMs) were fitted to sardine (Sardina pilchardus) egg distribution data from three daily egg production method surveys. The results showed that the area of egg cover off Portugal decreased significantly from 11 800 km 2 in 1988 to 7000 km 2 in 1997 and 7400 km 2 in 1999. This is because of a significant reduction in sardine egg presence off northern Portugal, GAM estimated areas being similar or higher in the late 1990s for southwestern and southern Portugal. The distributional area covered by larvae was not estimated for 1988 (larval distribution extended beyond the survey area), although it was probably higher than the 9600 km 2 for 1997 and 5500 km 2 for 1999. In 1997 and 1999, the Gulf of Cadiz was also sampled, indicating extensive areas with sardine eggs and larvae (more than 50% of the total area of distribution off Portugal). Standardized data from 15 ichthyoplankton surveys between 1985 and 2000 show a decline in the mean probability of egg presence within the Portuguese continental shelf from the mid-1980s to the late-1990s, because of a marked reduction in egg presence off northern Portugal. Sardine larval data from the same surveys suggest that the reduction in mean probability of presence in the north is less marked than for eggs (although this comparison ignores the presence of sardine larvae beyond the continental shelf in the 1980s). Similar changes off northern Portugal and western Galicia are observed in commercial sardine catches and the acoustically estimated area of fish distribution. It is possible that the observed decline in spawning area off northwestern Iberia during the 1990s is indirectly reflecting the prevalence of environmental conditions detrimental to sardine recruitment (northerly winds during winter that favour coastal upwelling and offshore transport), which have reduced the spawning contribution of young fish in that area.

Observations aboard purse-seiners demonstrated that deliberate lowering of the net to allow pelagic fish to escape (“slipping”) was frequent off northern Portugal during the second semester of 2001. Some slipping occurred in 25 of 30 trips observed, and the quantities slipped were significantly higher when the net was set on dense echo-sounder marks. During the 12 weeks of the study, the sampled fleet (nine vessels) landed 2196 t and deliberately released an estimated 4979 t (CV 33.6%). More than 95% of the total catch was sardine. Data provided by the skippers in the absence of shipboard observers led to considerably lower estimates of slipped quantities. The main reason for slipping was daily quota limitations, but illegal size and mixture with unmarketable bycatch were also reported. These results demonstrate the existence and potential magnitude of slipping, but indications of large seasonal and regional variations make extrapolations for the entire fishery impractical.

Nephrops norvegicus(Norway lobster or prawn) is an important target species in demersal fisheries of the north-east Atlantic. Trawling for Nephrops is wasteful when many small fish are caught and discarded in the process. Here, data from 106 commercial fishing trips, sampled between 1982 and 1998 as part of the Scottish discard sampling programme, are used to investigate the fish bycatch and discards of Nephrops trawlers in the Firth of Clyde (west of Scotland). A large proportion of the fish caught in the Clyde is discarded, the discards mainly consisting of small demersal fish (mean length about 19 cm), particularly young whiting (Merlangius merlangus). Within the study period, annual estimates of total fish discards ranged from 318 to 3 027 tonnes, with a mean of 1 761 tonnes. Fish landings and discards biomass per unit effort both decreased over the study period. However, the decline in landings per unit effort was greater than that in discards per unit effort, corresponding to an increase in the discard rate over time. In recent years, discards have comprised about 70 % of the fish bycatch. The mean length of discarded fish was positively related to mesh size. © 2001 Ifremer/CNRS/Inra/IRD/Cemagref/Editions scientifiques et medicales Elsevier SAS bycatch / fish discards / trawling / Nephrops norvegicus / Firth of Clyde

Atresia in the ovaries of sardine Sardina pilchardus did not show clear seasonal patterns. There was high prevalance (c. 60%) and low intensity (c. 1% of gonadal area occupied by oocytes) in all months of the spawning season studied. The batch size to ovary-free mass relationship was significantly different in the mid-spawning season, with higher relative fecundity and gonadosomatic index (I G ) in January than in November and March. There was no additional effect on batch fecundity due to age or condition factor. Data from monthly market samples during 1998-1999 revealed a continuous decline of the condition factor throughout the spawning season. The market samples also revealed that the duration of the spawning season is not equal for all fish. In any month, pre-spawning fish tended to have significantly higher I G than spawners, indicating that delayed initiation of spawning can lead to larger relative fecundity. The increase in sardine relative fecundity during the first half of the spawning season is probably due to the continuous influx of new spawners and possibly to body mass loss that is initially not translated into gonad mass loss. After January when all visible fat reserves within the body cavity have disappeared, the influx of new spawners practically ceases.

The main objective of discard sampling programmes is to estimate annual total discards of fish species whose stocks are routinely assessed from catch data. The Scottish discard programme is based on a stratified random design, and a ratio estimator is used to estimate total discards independently in each stratum. Total discards are then estimated by summing across strata. However, the small number of trips that can be sampled by scientific observers from fisheries institutes creates problems with this estimator. Here, a simulated population of fishing trips is used to investigate alternative estimators of total discards for the main fish species (haddock Melanogrammus aeglefinus, whiting - Merlangius merlangus, and cod - Gadus morhua) targeted by Scottish demersal vessels in the North Sea and the West of Scotland. The results show that when the sample size in each stratum is very small, the current methodology - independent ratio estimation in each stratum - can be very biased and imprecise. However, an alternative ratio estimator that relies on a collapsed stratification has negligible bias and greater precision. We use this alternative estimator to estimate total annual discards of haddock, whiting, and cod in the North Sea and West of Scotland from 1988 to 1993.

Understanding fishers' discarding behaviour, and anticipating their reactions to changes in the biological or regulatory characteristics of a fishery, are important for dealing with the problem of discarding. In this paper, we investigate the discarding of haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), and Atlantic cod (Gadus morhua) in the North Sea, using data collected by scientific observers onboard Scottish demersal vessels. We describe discarding on each trip by species-specific discard curves and explore how these curves depend on biological and regulatory variables. There are large differences in the size of discarded fish between inshore and offshore areas, with offshore-operating vessels discarding larger fish (high-grading). Increases in legal landing size correspond to immediate increases in the size of discarded fish, particularly for haddock and cod in inshore areas. In general, discarding practices for haddock and cod are similar over time and consistent across gears, whereas decisions for the lesser valued whiting are more variable and can be affected by the catch composition.

Length-frequency data on squid (Loligo forbesi) collected during trawling surveys in Scottish waters from 1980 to 1994 were analysed to describe temporal and spatial patterns in abundance and to examine the prospects for using survey abundance to forecast fishery abundance. Loligo was patchily distributed in space and time. Distribution patterns in the North Sea in February appeared to be strongly related to bottom temperature (squid avoided waters

Herring Clupea harengus are demersal spawners that lay their eggs in continuous, multilayer mats on coarse sediment. Although the reproductive biology of herring is extensively studied. little is known about the processes of egg deposition and development within a spawning ground. Here, the spatial distribution of developmental egg ages from a spawning ground (Ballantrae Bank, west of Scotland) is modelled using regression trees and generalised additive models. We refer to developmental, rather than absolute, ages to indicate that ageing the eggs according to the apparent state of development in the samples may underestimate t h e ~ r true age. Egg development was found to be related to the position within the egg mat (horizontal and vertical), the sampling day and the egg density in the samples. Eggs near hatching (12 to 14 d old) were mainly deposited at the eastel-n and northeastern bounds of the mat, where eggs in the top layer exceeded the developmental age of eggs in the bottom layer. Newly laid eggs (1 to 2 d old) were found in the western parts of the ground, where substrate type was less suitable and egg densities were lowest. The results suggest that spawnlng progressed in a westerly direction over a period of at least 2 wk, constrained by the availability of suitably coarse sediment. The presence of eggs in the bottom layer w t h lower developn~ental age than In the top demonstrates that multiple layering causes developmental retardation nearest to the substrate. Developmental retardation can therefore be seen as a contribut~ng factor in the reported variability in hatch~ng lengths of herring larvae.

Recent studies have shown differences in life history features of long rough dab Hippoglossoides platessoides among populations of the North Atlantic. Here, length frequency distributions from commercial catches and age information from otolith readings are used to compare long rough dab from the North Sea and the West of Scotland. Catch data from the Scottish demersal fisheries show differences in the length distribution of long rough dab between the 2 areas, with large fish (>20 cm) more prevalent in the North Sea. The maximum length of long rough dab observed in commercial catches is 8 cm greater in the North Sea, where otolith readings indicate that the species has a greater longevity. Growth models suggest that long rough dab of age 3+ are significantly smaller in the West of Scotland. Potential explanations for the observed contrasts in hie history features include spatial differences in temperature-related metabolic costs, food availability, sex ratios (males tend to be smaller), or age-specific loss rates (emigration or mortality). Of these, we conclude that the hypothesis involving temperature-dependent metabolic costs is the least likely explanation.

Barangé, Manuel ... et al., The assessment and management of small pelagic fish (SPF) stocks is particularly difficult and uncertain because their short life expectancy, characteristic aggregative behavior, rapid response to climate and environmental signals and large and variable natural mortality make them less tractable through traditional population dynamic models and assumptions. In this review we summarize the assessment and management approaches applied in 29 SPF stocks or management units (12 anchovy, 10 sardine, 4 herring, and 3 sprat). The review demonstrates that the assessment and management of SPF varies substantially in its approach and performance between stocks and regions. Most stocks have a scientific assessment program in place and a management approach that generally takes into account assessment results, but in some stocks management practices deviate substantially from scientific advice and in some, assessment and management processes are largely disconnected. It is concluded that only properly tailored scientific assessment and management programs can provide the speed of response and the flexibility of management that highly variable SPF demand. The most effective monitoring programs are based on fishery-independent surveys (daily egg production or/and hydroacoustics), while analyses based on catch per unit effort offer limited value. Most assessments, defined as what management uses to base its decisions on, rely on catch-at-age or yield per recruit models. Harvest strategies range from those driven by harvest control rules to those derived from outputs of best assessment runs. Some stocks use operating models based on age–structure model outputs or forward VPA. On the issue of scientific uncertainty some practitioners propose reducing it through additional science and measures, while others promote the development of management procedures robust to uncertainty

Silva, A., Skagen, D. W., Uriarte, A., Massé, J., Santos, M. B., Marques, V., Carrera, P., Beillois, P., Pestana, G., Porteiro, C., and Stratoudakis, Y. 2009. Geographic variability of sardine dynamics in the Iberian Biscay region. – ICES Journal of Marine Science, 66: 495–508. The spatio-temporal variability in the distribution, demographic structure, recruitment, and mortality of sardine within the Iberian Biscay region is described using area-disaggregated data collected during acoustic surveys and at ports since the mid-1980s. Multiple regression models were used to describe log numbers-at-age obtained annually in ten areas covered by three surveys to test the existence of geographic differences in selectivity-at-age, recruitment strength, and mortality and to infer plausible migration routes. Within Iberian waters, sardine biomass was mainly concentrated off western Portugal and the Gulf of Cadiz. In the Bay of Biscay, biomass levels were comparable with those off western Portugal. Recruitment was localized in a few areas (northern Portugal and the Gulf of Cadiz and Bay of Biscay), intermingling with areas dominated by older fish. Recruitment was generally asynchronous among areas, although some recruitment peaks were noticeable across wider regions. Spatial patterns related to strong and weak year classes and year-class slopes were also noted. Clearly distinct dynamics were not evidenced within the Atlanto–Iberian sardine stock area, but the validity of the northern limit was questioned by the connection between sardine dynamics in the Bay of Biscay and the Cantabrian Sea. The results provided some evidence consistent with the hypothesis of sardine movement from recruiting grounds to areas farther along the coast as they grow.

The fate of fish deliberately released (slipped) during purse seining is poorly studied and estimating unaccounted mortality rates in pelagic fisheries has been difficult and imprecise.

This study describes broad-scale spatial variations in sardine growth across the northeastern Atlantic and Mediterranean waters using opportunistic samples collected in recent years. More detailed information on spatial, decadal and seasonal growth variations is provided for the Iberian-Biscay region using data collected in acoustic surveys since the mid-1980s. Growth curves are fitted to annual or monthly length-at-age data using a robust Von Bertalanffy model; parameters for recent samples are compared with literature information using an auximetric plot while differences between areas within the Iberian-Biscay region are tested by log-likelihood ratio tests. Sardine growth performance is generally lower in the Mediterranean and declines across the northeastern Atlantic from the English Channel to north Morocco but increases sharply off Mauritania. Lower growth of Mediterranean sardines is possibly associated to the overall oligotrophy of this Sea while differentiation from the Atlantic is likely sustained by reproductive isolation between populations from the two areas. Within the northeastern Atlantic, size- and age related migrations may partly explain differences in maximum length/age and mean length-at-age between neighbouring areas but the broad-scale latitudinal decline in growth is consistent with adaptation to the north–south decline in seasonal temperature gradients and to the annual cycles of plankton production. Within the Atlantic Iberian waters, sardine grows and improves in condition during spring and summer when the allocation of energetic resources for gonad development cease, temperature is close to the annual maxima and plankton production is high. Variation in sardine length-at-age and growth within the Atlanto-Iberian stock area has implications for stock structure and needs to be taken into account in the calculation of weight and maturity-at-age for assessment purposes. No evidence of broad temporal changes in sardine growth within the Iberian-Biscay region is obtained., SI

Release of excess/unwanted catch in many commercial fisheries results in some immediate fish mortality and an unknown post-release fate for most escapees.

Inaccuracy in the aging of postovulatory follicles (POFs) and in estimating the effect of temperature on the resorption rate of POFs may introduce bias in the determination of the daily spawning age classes with the daily egg production method (DEPM). To explore the above two bias problems with f ield-collected European pilchard (Sardina pilchardus, known regionally as the Iberian sardine), a method was developed in which the time elapsed from spawning (POF age) was estimated from the size of POFs (i.e., from the cross-sectional area in histological sections). The potential effect of the preservative type and embedding material on POF size and the effect of ambient water temperature on POF resorption rate are taken into account with this method. A highly significant loglinear relationship was found between POF area and age; POF area shrank by approximately 50% per day. POFs were also shown to shrink faster at higher temperatures (approximately 3% per degree), but this temperature effect is unlikely to be an important source of bias in the assignment of females to daily spawning classes. The embedding material was also shown to influence the size of POFs, the latter being significantly larger in resin than in paraffin sections. In conclusion, the size of POFs provides an indirect, reliable estimation of the time elapsed from spawning and may thus be used to test both the validity of POF staging criteria for identifying daily classes of spawners and the effect of other factors (such as temperature and laboratory processing) in applications of the DEPM to S. pilchardus and other fish species.

Spawning temperature preferences for sardine (Sardina pilchardus) in the eastern North Atlantic were determined from egg survey data. These were compared with climatological temperature cycles (1986–2002) derived from satellite observations, by geographical region, to predict spawning seasons. Optimum spawning temperatures were determined as 14.0–15.0°C from the English Channel to Portugal and 16.0–18.0°C for all north-west African regions. Spawning seasons were closely related to the general latitudinal trend of the annual temperature cycle, with modification by upwelling in the western Iberian and north-west African regions. Some differences between temperature-based spawning season predictions and field observations were related to variations in seasonal plankton production. Correlations in the annual time-series of favourable spawning temperatures suggested relatively strong linkages between the southern areas from Portugal to Senegal. There was no consistent relationship between annual variations in extent of temperature-predicted spawning seasons and observed field abundance of eggs.

More than 120 surveys over 25 years suggest that appropriate use of the daily egg production method (DEPM) provides unbiased but rather imprecise estimates of spawning biomass (coefficient of variation generally above 30%). Knowledge of species reproductive biology and early life history and a survey design adapted to local population dynamics are required to optimize DEPM performance in terms of bias, precision and cost. Clupeoid applications dominate worldwide (mainly for anchovies and sardines) and estimates are often used to tune indirect assessment models or to calibrate other fisheries-independent methods. The method seems better adapted to the life history of anchovies than of sardines, leading to more precise estimates of anchovy spawning biomass and facilitating extensions of the method to estimate total biomass and numbers at age. The continuous underway fish egg sampler is often used as a secondary sampler in the ichthyoplankton survey of the DEPM to reduce the cost and improve the precision of egg production. Multinomial models were recently developed to analyse egg incubation data and used in a Bayesian procedure for egg ageing and delimitation of daily cohorts. These were incorporated in model-based estimators to get spatially explicit estimates of egg production, daily fecundity parameters and spawning biomass that can improve the precision of DEPM. Uncertainty in daily fecundity estimation of clupeoids is mainly because of spawning fraction estimation by the post-ovulatory follicle (POF) method. Exploration of recent histological and molecular techniques for POF characterization and laboratory experiments to test the effect of temperature on POF degradation can help to improve spawning fraction estimation. Available estimates of egg production and mortality, daily fecundity, spawning area and biomass from different populations, species and ecosystems are being used to improve the understanding of clupeoid spawning dynamics, their relation with ecosystem productivity and to build comprehensive population models. Finally, a counter-intuitive finding of this review is that, although the DEPM is almost exclusively applied to clupeoids, recent evidence indicates that it may be easier and cheaper to use in other teleost families, including demersal species.

Data from 10 acoustic surveys targeting sardine (spring and autumn), 3 acoustic surveys targeting blue whiting (spring) and 9 groundfish surveys (summer and autumn) were used to describe the distribution and relative abundance of snipefish (Macroramphosus spp.) off Portugal and the Gulf of Cadiz in recent years (1998-2003). Snipefish (8-17 cm) were regularly found off Portugal, occasionally in large concentrations, but were absent from the Gulf of Cadiz. Off northern Portugal, snipefish were distributed along the outer shelf and upper slope, clearly separated from sardine (the most abundant species in the inner shelf) and partially overlapping with blue whiting (Micromesistius poutassou), the most abundant species in the upper slope. Snipefish were most abundant in the outer shelf of south-western Portugal, preferentially distributed in large aggregations around the Canyon of Setubal and partially overlapping with the distribution of boarfish (Capros aper) and blue whiting (both abundant in the upper slope of south-western Portugal). Off southern Portugal snipefish were almost exclusively distributed in the outer shelf and were significantly smaller than in south-western (intermediate) and northern Portugal (large). Acoustic estimates of total snipefish biomass ranged between 176 – 504 thousand tonnes within the study period, with more than half off south-western Portugal. Within the period 1998-2003, and despite the lack of directed fishing activity, a marked decline in abundance and a small but significant increase in mean length were observed, particularly off south-western Portugal. Datos de 10 cruceros acústicos dirigidos a la sardina (Sardina pilchardus) (primavera y otoño), 3 cruceros acústicos dirigidos a la bacaladilla (Micromesistius poutassou) y 9 cruceros demersales (verano y otoño) fueron utilizados para describir la distribución y abundancia relativa del trompetero (Macroramphosus spp.) en la costa portuguesa y Golfo de Cádiz en los últimos años (1998-2003). El trompetero (con tallas comprendidas entre 8 y 17 cm) estuvo presente frecuentemente en aguas portuguesas, en ocasiones en elevadas concentraciones y ha estado ausente del Golfo de Cádiz. En las aguas del Norte de Portugal, el trompetero estuvo presente sobre el exterior de la plataforma continental y la parte superior del talud, claramente separado de la sardina (la especie más abundante de la plataforma interior) y sobrepuesto parcialmente a la bacaladilla, la especie más abundante del talud superior. El trompetero fue más abundante en el exterior de la plataforma continental del Sudoeste de Portugal, encontrándose preferencialmente en elevadas densidades alrededor del cañón de Setúbal, solapándose parcialmente al ochavo (Capros aper) y a la bacaladilla, ambos abundantes en el talud superior del sudoeste de Portugal. Al sur de Portugal, el trompetero se encontró casi exclusivamente en la plataforma exterior, siendo los individuos significativamente más pequeños que en el sudoeste (medianos) y en el norte (mayores). La estimación acústica de la biomasa del trompetero osciló entre 176000-504000 toneladas en el periodo estudiado, con más de mitad en la zona sudoeste de Portugal. En el periodo de 1998-2003, se verificó un descenso acentuado en la abundancia y un ligero aumento del tamaño medio de los individuos, especialmente en el sudoeste de Portugal.