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Diverse clades of fishes adapted to feeding on the benthos repeatedly converge on steep craniofacial profiles and shorter, wider heads. But in an incipient radiation, to what extent is this morphological evolution measurable and can we distinguish the relative genetic vs. plastic effects? We use the Trinidadian guppy (Poecilia reticulata) to test the repeatability of adaptation and the alignment of genetic and environmental effects shaping poecilid craniofacial morphology. We compare wild-caught and common garden lab-reared fish to quantify the genetic and plastic components of craniofacial morphology across 4 populations from 2 river drainage systems (n  = 56 total). We first use micro-computed tomography to capture 3D morphology, then place both landmarks and semilandmarks to perform size-corrected 3D morphometrics and quantify shape space. We find a measurable, significant, and repeatable divergence in craniofacial shape between high-predation invertivore and low-predation detritivore populations. As predicted from previous examples of piscine adaptive trophic divergence, we find increases in head slope and craniofacial compression among the benthic detritivore foragers. Furthermore, the effects of environmental plasticity among benthic detritivores produce exaggerated craniofacial morphological change along a parallel axis to genetic morphological adaptation from invertivore ancestors. Overall, many of the major patterns of benthic-limnetic craniofacial evolution appear convergent among disparate groups of teleost fishes. [ABSTRACT FROM AUTHOR]

The red swamp crayfish Procambarus clarkii (Girard, 1852) has been responsible for negative impacts on native benthic fauna and flora in invaded freshwater ecosystems around the world, including Japan. We need to clarify the reproductive biology in the invaded habitats as basic information to effectively control the introduced populations, but the reproductive biology of P. clarkii in Japan (especially in western Japan) has not been well studied. We conducted monthly samplings of P. clarkii from November 2015 to November 2016 in a pond (which does not freeze, even in winter) in Okayama, western Japan, both by using shrimp cage traps and by hand nets to examine aspects of the reproduction, including a form alternation (i.e. Form I and II). We also reared spawning females in the laboratory and calculated the accumulated water temperature during the period to Stage-3 juveniles after spawning. The total number of individuals caught throughout the study period was 6,319 (2,601 males and 2,777 females, with eight of unknown sex and 933 juveniles). The males were all Form I with a breeding status from September to November 2016. We first found ovigerous females in July 2016 and females carrying hatchlings in October 2016, even in January 2016. The form alternation in males was confirmed not only in the cheliped length, but in the hook length. In laboratory observations, approximately 52 days with approximately 1,222 °C degree-days of the accumulated water temperature were necessary to Stage-3 juveniles after spawning. Our results indicate that P. clarkii can reproduce within approximately five months of hatching. [ABSTRACT FROM AUTHOR]

Chitin is the most abundant natural polymer in the oceans, where it is primarily recycled by chitin-degrading microorganisms. Endozoicomonadaceae (Oceanospirillales) bacteria are prominent symbionts of sessile marine animals, particularly corals, and presumably contribute to nutrient cycling in their hosts. To reveal the chitinolytic potential of this iconic, animal-dwelling bacterial family, we examined 42 publicly available genomes of cultured and uncultured Endozoicomonadaceae strains for the presence of chitinase-encoding genes. Thirty-two of 42 Endozoicomonadaceae genomes harbored endo-chitinase- (EC 3.2.1.14), 25 had exo-chitinase- (EC 3.2.1.52) and 23 polysaccharide deacetylase-encoding genes. Chitinases were present in cultured and uncultured Endozoicomonadaceae lineages associated with diverse marine animals, including the three formally described genera Endozoicomonas, Paraendozoicomonas and Kistimonas, the new genus Candidatus Gorgonimonas, and other, yet unclassified, groups of the family. Most endo-chitinases belonged to the glycoside hydrolase family GH18 but five GH19 endo-chitinases were also present. Many endo-chitinases harbored an active site and a signal peptide domain, indicating the enzymes are likely functional and exported to the extracellular environment where endo-chitinases usually act. Phylogenetic analysis revealed clade-specific diversification of endo-chitinases across the family. The presence of multiple, distinct endo-chitinases on the genomes of several Endozoicomonadaceae species hints at functional variation to secure effective chitin processing in diverse micro-niches and changing environmental conditions. We demonstrate that endo-chitinases and other genes involved in chitin degradation are widespread in the Endozoicomonadaceae family and posit that these symbionts play important roles in chitin turnover in filter- and suspension-feeding animals and in benthic, marine ecosystems at large. [ABSTRACT FROM AUTHOR]

Cold-water corals form an important part of temperate benthic ecosystems by increasing three-dimensionality and providing an important ecological substrate for other benthic fauna. However, the fragile three-dimensional structure and life-history characteristics of cold-water corals can leave populations vulnerable to anthropogenic disturbance. Meanwhile, the ability of temperate octocorals, particularly shallow-water species, to respond to adjustments in their environment linked to climate change has not been studied. This study reports the first genome assembly of the pink sea fan (Eunicella verrucosa), a temperate shallow-water octocoral species. We produced an assembly of 467 Mb, comprising 4,277 contigs and an N50 of 250,417 bp. In total, 213 Mb (45.96% of the genome) comprised repetitive sequences. Annotation of the genome using RNA-seq data derived from polyp tissue and gorgonin skeleton resulted in 36,099 protein-coding genes after 90% similarity clustering, capturing 92.2% of the complete Benchmarking Universal Single-Copy Orthologs (BUSCO) ortholog benchmark genes. Functional annotation of the proteome using orthology inference identified 25,419 annotated genes. This genome adds to the very few genomic resources currently available in the octocoral community and represents a key step in allowing scientists to investigate the genomic and transcriptomic responses of octocorals to climate change. [ABSTRACT FROM AUTHOR]

The Roda Formation (early Eocene Ypresian, Huesca, Aragón, northern Spain) records successive levels including rich decapod faunas relevant for the understanding of Ypresian decapod assemblages. Asthenognathus fernandezi n. sp. is described from one of these levels, representing the oldest report of a fossil Asthenognathinae, and the first report from the Iberian Peninsula. Fossil members of Asthenognathinae Stimpson, 1858, are difficult to distinguish from other families, especially when they lack preserved pereiopods, sternum, and abdomen. The new taxon shows important features that include reduced pereiopods, small and sub-cylindrical carapace, and absence of protruding ornamentation. This combination of characters indicates a possible early adaptation of Asthenognathus Stimpson, 1858 to life in cylindrical cavities. Asthenognathus fernandezi n. sp. occurred on poorly consolidated siliciclastic substrates associated with a rich benthic fauna, including echinoderms, molluscs, and other crustaceans. [ABSTRACT FROM AUTHOR]

Hypoxia is presently seen as the principal driver behind the decline of the former dominating Eastern Baltic cod stock (EBC ; Gadus morhua). It has been proposed that both worsening conditions for reproduction and lower individual growth, condition, and survival are linked to hypoxia. Here, we elucidate the ecological envelope of EBC in terms of salinity stratification, oxygen content, and benthic animal biomasses, and how it has affected EBC productivity over time. The spawning conditions started deteriorating in the Gotland Deep in the 1950s due to oxygen depletion. In contrast, in the Bornholm Basin, hydrographic conditions have remained unchanged over the last 60 years. Indeed, the current extent of both well-oxygenated areas and the frequency of hypoxia events do not differ substantially from periods with high EBC productivity in the 1970s–1980s. Furthermore, oxygenated and therefore potentially suitable feeding areas are abundant in all parts of the Baltic Sea, and our novel analysis provides no evidence of a reduction in benthic food sources for EBC over the last 30 years. We find that while reproduction failure is intricately linked to hydrographic dynamics, a relationship between the spread of hypoxia and the decline in EBC productivity during the last decades cannot be substantiated. [ABSTRACT FROM AUTHOR]

Benthic samples collected during several cruises from shelf areas along the West African coast from Morocco to Angola, have highlighted a huge diversity of magelonid species (over 20 species), many of which are undescribed. The majority of samples were taken as part of two large-scale projects in the region: the Canary Current Large Marine Ecosystem project (CCLME) and the Guinea Current Large Marine Ecosystem project (GCLME). Six magelonid species bearing posterior thoracic pigmentation have been highlighted, Magelona alleni and five species new to science: Magelona fasciata sp. nov. Magelona guineensis sp. nov. Magelona mackiei sp. nov. Magelona nanseni sp. nov. and Magelona picta sp. nov. West African magelonids and comparative material from the UK and Norway have been investigated using COI , 16S and 28S markers. An integrated taxonomic approach is used to delineate species of Magelona carrying posterior thoracic pigmentation. These species from West African waters constitute a well-supported monophyletic group, with the species M. alleni being sister to the new species herein described. Our 41 COI DNA-barcode-sequences had between species distances from 9.3 to 26.8% and were allocated to ten different BINs in Boldsystems.org. [ABSTRACT FROM AUTHOR]

Species in the brackish and estuarine ecosystems will experience multiple changes in hydrographic variables due to ongoing climate change and nutrient loads. Here, we investigate how a glacial relict species (Saduria entomon), having relatively cold, low salinity biogeographic origin, could be affected by the combined scenarios of climate change and eutrophication. It is an important prey for higher trophic-level species such as cod, and a predator of other benthic animals. We constructed habitat distribution models based occurrence and density of this species across the entire Baltic and estimated the relative importance of different driving variables. We then used two regional coupled ocean-biogeochemical models to investigate the combined impacts of two future climate change and nutrient loads scenarios on its spatial distribution in 2070–2100. According to the scenarios, the Baltic Sea will become warmer and fresher. Our results show that expected changes in salinity and temperature outrank those due to two nutrient-load scenarios (Baltic Sea Action Plan and business as usual) in their effect on S. entomon distribution. The results are relatively similar when using different models with the same scenarios, thereby increasing the confidence of projections. Overall, our models predict a net increase (and local declines) of suitable habitat area, total abundance and biomass for this species, which is probably facilitated by strong osmoregulation ability and tolerance to temperature changes. We emphasize the necessity of considering multiple hydrographic variables when estimating climate change impacts on species living in brackish and estuarine systems. [ABSTRACT FROM AUTHOR]

Ocean organisms as diverse as seaweeds and sea cucumbers exhibit life cycles in which dispersal occurs primarily via microscopic larvae or spores, with adults exhibiting limited or even no dispersal. In benthic animals, the larval stage concludes with irreversible settlement into the benthos. The decision of where and when to settle is thus one of substantial import. Prior work has shown that settlement in two shoreline echinoids (a sea urchin and a sand dollar) is unexpectedly sensitive to an environmental feature (intense fluid turbulence) that can be considered as a signal to larvae of their arrival in the neighbourhood of the hydrodynamically energetic habitats in which these taxa live as adults. Here, we used a comparative approach to explore the evolution of turbulence responsiveness in late-stage echinoid larvae. We examined three pairs of closely related sea urchins that differ in the energetic exposure of their adult habitats and found that larval responsiveness to turbulence was more pronounced in urchins that settle in more hydrodynamically exposed locations. These results raise the possibility that evolutionary differences in larval responsiveness to environmental indicators of appropriate adult habitat might reinforce or even provide a mechanism for vicariance in the ocean. [ABSTRACT FROM AUTHOR]

Man-made structures in the North Sea are known to act as artificial reefs by providing a habitat for sessile epifauna in a predominantly soft sediment environment. This epifauna is hypothesized to cast a so-called "shadow" over the soft sediment ecosystem by altering the nutrient composition in the overlying water column. In addition, the structure itself could alter currents and thereby influence the deposition and erosion of the sediments in the wake of the platform. This study aims to assess the long-term effects of a gas platform in the southern North Sea on the surrounding benthic community by both morphological and molecular identification of benthic species. The species composition and a set of abiotic factors of the sediment around a gas platform were assessed along four transects. Differences for the abiotic factors were found in the closer vicinity of the platform in the direction corresponding to the predominant currents. The number of benthic fauna families found in the molecular approach were on average three times higher than for the morphological approach. Both approaches showed that small differences occurred primarily due to changes in sedimentary organic matter content. Differences in species composition were more pronounced between transects rather than between distances from the platform. [ABSTRACT FROM AUTHOR]

Offshore marine renewable energy installations (MREI) introduce structure into the marine environment and can locally exclude destructive, bottom trawl fishing. These effects have the potential to aid restoration of degraded seabed habitats but may be constrained by timescales of ecological succession following MREI construction, and the removal of infrastructure during decommissioning. To inform managers about appropriate decommissioning strategies, a 25 km cable and associated rock armouring (Wave Hub, UK), installed on rocky reef, was monitored up to 5 years post-deployment. The epibenthic Assemblage composition, and Number of taxa remained significantly different from surrounding controls, while Abundance was similar in all survey years between the cable and controls. Six morphotaxa showed four patterns of colonization on cable plots compared to the controls: (i) Early colonization, which remained in greater abundances (Porifera), (ii) early colonization, converging (Turf), (iii) slow colonization, converging Anthozoa and Vertebrata), and (iv) slow colonization, remaining lower in abundance (Tunicata and Echinodermata). The environmental relevance of this MREI is considered relatively benign as it covers 0.01% of the surrounding bioregion, appears to be supporting similar assemblages to the surrounding habitat, and exhibited minimal evidence of invasive species (three records of two non-native species). Longer monitoring timescales are required to provide comprehensive, site-specific decommissioning advice. [ABSTRACT FROM AUTHOR]

Connectivity is a key consideration in the development of networks of marine protected areas (MPAs). However, little is known about the early life history of many of the epi-benthic animals that these spatial measures try to conserve. Here, a pragmatic approach to consider connectivity in such organisms is adopted, as part of the Scottish nature conservation MPA designation process. The primary tool for the study was a basic bio-physical model, forced by a circulation climatology. In the general absence of comprehensive ecological information, the model accounted for the main biological characteristics of the benthic organisms under consideration of relevance to connectivity, namely, presence, spawning season and pelagic larval duration (PLD). The results showed that some degree of connectivity between MPAs is possible even for species with short PLD although those organisms are more likely to be vulnerable to local pressures, particularly in the case of less widely distributed species and those inhabiting less dispersive inshore locations. For MPAs further offshore and species with longer PLD, our simulations suggested large-scale advection patterns crossing large-scale environmental management boundaries. Although the study was an appropriate contribution to the MPA designation process, further refinements encompassing better basic ecological information, enhanced oceanographic resolution, more realistic representation of biological processes (e.g. spawning, larval behaviour) in the model, species presence within and outside MPAs and substrate suitability maps would provide future useful confidence boundaries around the general patterns derived from our study. [ABSTRACT FROM AUTHOR]

Benthic and limnetic threespine stickleback (Gasterosteus aculeatus) are a classic example of ecological speciation. Behavioural and armour divergence between these species has been predicted to be the result of divergent selection driven in part by differential predation from cutthroat trout (Oncorhynchus clarki). To experimentally test this prediction, we reared split families of benthic-limnetic hybrids in the presence or absence of trout predation. Our results show that the presence of trout had little effect upon stickleback behaviour. We then compared performance in behavioural assays among stickleback that varied in armour to test if armour morphology correlates with behaviour. Our measurements revealed trait correlations between several behaviours and components of armour morphology. Trout predation did not result in an increased correlation between traits, therefore differential trout predation between benthics and limnetics is unlikely to be the cause of these correlations. The presence of trait correlations in advanced generation hybrids suggests that pleiotropy or linkage between genes underlying behaviour and armour morphology may be greater than previously appreciated. [ABSTRACT FROM AUTHOR]

The present study focuses on two apparent species: the giant thyasirid Conchocele bisecta (Conrad, 1849), which is the dominant species of the benthic community in a gas hydrate area with cold-water methane-rich vents at a depth of about 800 m on the slope off Paramushir Island (Kuril Islands, Sea of Okhotsk) and small unidentified thyasirid bivalves from this same community. An examination of the shell morphology of these thyasirids showed that the small bivalves were in fact young specimens of C. bisecta, characterized by a high individual and age variability. A transmission electron microscopic study of C. bisecta revealed gills with 'Type 3' filaments, which were extended abfrontally and had a distinct bacteriocyte zone with extracellular symbionts. The symbiotic bacteria found were spherical, similar to thiotrophic symbionts of other thyasirids. The isotopic δ13С values of C. bisecta soft tissues (from −39.6 to −33.8‰) were much heavier than those of methane in the Paramushir gas-hydrate area and matched the range characteristic of symbiotrophic bivalves harbouring sulphur-oxidizing chemoautotrophic bacteria. The variations in δ13С and δ15N recorded for large and small C. bisecta can be related to ontogenetic differences in life habit: small individuals are totally buried in the sediment, while large ones are half-buried. Data from fatty acid (FA) analysis indicate that sulphur-oxidizing symbionts constitute almost the entire nutrition of C. bisecta, with no significant contribution of symbiotic or free-living methanotrophs. Furthermore, neither FA nor isotopic compositions provided evidence for photosynthetic sources as food items for C. bisecta through filter feeding. [ABSTRACT FROM AUTHOR]

The extent to which convergent adaptation to similar ecological niches occurs by a predictable genetic basis remains a fundamental question in biology. Threespine stickleback fish have undergone an adaptive radiation in which ancestral oceanic populations repeatedly colonized and adapted to freshwater habitats. In multiple lakes in British Columbia, two different freshwater ecotypes have evolved: a deep-bodied benthic form adapted to forage near the lake substrate, and a narrow-bodied limnetic form adapted to forage in open water. Here, we use genome-wide linkage mapping in marine × benthic F2 genetic crosses to test the extent of shared genomic regions underlying benthic adaptation in three benthic populations. We identify at least 100 Quantitative Trait Loci (QTL) harboring genes influencing skeletal morphology. The majority of QTL (57%) are unique to one cross. However, four genomic regions affecting eight craniofacial and armor phenotypes are found in all three benthic populations. We find that QTL are clustered in the genome and overlapping QTL regions are enriched for genomic signatures of natural selection. These findings suggest that benthic adaptation has occurred via both parallel and nonparallel genetic changes. [ABSTRACT FROM AUTHOR]

This study provides an inventory of the recent benthic macrofaunal communities in the entire Baltic Sea. The analyses of soft-bottom benthic invertebrate community data based on over 7000 locations in the Baltic Sea suggested the existence of 10 major communities based on species abundances and 17 communities based on species biomasses, respectively. The low-saline northern Baltic, characterized by silty sediments, is dominated by Monoporeia affinis, Marenzelleria spp., and Macoma balthica. Hydrobiidae, Pygospio elegans, and Cerastoderma glaucum dominate the community in sandy habitats off the Estonian west coast and in the southeastern and southern Baltic Sea. Deep parts of the Gulf of Finland and central Baltic Sea often experience hypoxia, and when oxygen levels in these regions recover, Bylgides sarsi was the first species to colonize. The southwestern Baltic Sea, with high salinity, has higher macrofaunal diversity compared with the northern parts. To spatially interpolate the distribution of the major communities, we used the Random Forest method. Substrate data, bathymetric maps, and modelled hydrographical fields were used as predictors. Model predictions were in good agreement with observations, quantified by Cohen's K of 0.90 for the abundance and 0.89 in the wet weight-based model. Misclassifications were mainly associated with uncommon classes in regions with high spatial variability. Our analysis provides a detailed baseline map of the distribution of benthic communities in the Baltic Sea to be used both in science and management. [ABSTRACT FROM AUTHOR]

From 1994 to 2002, five major year-round closed areas were established in the Gulf of Maine and on Georges Bank to promote recovery of groundfish species, including Atlantic cod (Gadusmorhua). Here, we present life-history data for cod sampled within and next to four of the five closed areas to test the hypothesis that closed areas benefit cod. We found a positive effect of closure status on cod age, length and growth for three of the four closed areas; contrary results for the fourth area (Jeffreys Ledge)may be due to recreational fishing pressure. Diet results were not consistent across closed areas, but for the two areas farthest from shore (Cashes Ledge and Closed Area II), cod tended to have higher gut fullness and higher trophic niche breadth (based on stable isotopes) inside vs. outside. Body shape analysis revealed a consistent effect of closure status on cod morphometry with cod inside closed areas exhibiting less streamlined bodies. We discuss this apparent selection for more sedentary cod with lower productivity potential but highlight the demographic result (i.e. higher age and greater size inside closed areas) as critical considerations for resource managers that are designing or altering the configuration and/or scale of closed areas to protect and rebuild demersal fish species. [ABSTRACT FROM AUTHOR]

Trawling has been reported worldwide to alter seabed structure, and thus benthic habitats and ecosystems. Usually, a decrease in species richness and biomass is observed, and community structure is modified towards more opportunistic species. The Gulf of St Lawrence (Canada) has been intensely exploited since the 17th century, including net, longline, dredge and trawl fishing activities. Recently, the collapse of groundfish stocks induced a shift in fishing practices toward shrimp trawling, which is currently considered a sustainable fishing activity in the region. However, no long-term study has evaluated the potential effects of trawling disturbances on benthic mega-invertebrates. We investigated whether shrimp trawling had long- (ca. 20 years), mid- (ca. 10 years), and short-term (ca. 4 years) impacts on benthic mega-invertebrate taxa richness, biomass, and community structure. Scientific and fishery trawling data analyses showed that no significant long-, mid-, or short-term effect was detected on taxa richness. Significant but weak effects on biomass and community structure were detected at the mesoscale, i.e. at the scale of fishing grounds. In this long-exploited ecosystem, we suggest that a critical level of disturbance was attained by the first gear passages, which occurred decades ago and had irreversible impacts on the seabed by removing vulnerable taxa and structures that provided three-dimensional habitats. It is likely that benthic communities have subsequently reached a disturbed state of equilibrium on which current trawling disturbance has limited or no further impacts. [ABSTRACT FROM AUTHOR]

This paper investigates the relations between the diet structure of predaceous adult water beetles from the Dytiscidae family and the structure of macrofauna inhabiting the same environments. The field studies were carried out from April until September in 2012 and 2013 in 1-mo intervals. In total, >1,000 water beetles and 5,115 benthic macro-invertebrates were collected during the whole period of the study. Subsequently, 784 specimens of adult water beetles (70.6% out of the total sampled) with benthic macro-invertebrates found in their proventriculi, were subject to analysis. The predators were divided into three categories depending on their body size: small beetles (2.3-5.0 mm), medium-sized beetles (13-15 mm), and large beetles (27-37 mm). All adult Dytiscidae consumed primarily Ephemeroptera and Chironomidae larvae. Although Asellidae were numerically dominant inhabitants of the sites, the adult water beetles did not feed on them. The analysis of feeding relations between predators and their prey revealed that abundance of Ephemeroptera, Chironomidae, and larval Dytiscidae between the environment and the diet of adult Dytiscidae were strongly correlated. [ABSTRACT FROM AUTHOR]

Assessing the vulnerability of biological communities to anthropic pressures in marine systems may be challenging because of the difficulty to properly model each species' response to the pressure due to lack of information. One solution is to apply factor-mediated vulnerability assessment which combines (i) information on species ecological traits and conservation status organized in a matrix of so-called "vulnerability factors", (ii) a conceptual model of how these factors affect species vulnerability, and (iii) data on the spatial distribution and abundance of each species issued from at-sea surveys. Such factor-mediated vulnerability assessment was originally introduced in the seabird-wind farm context by Garthe and Hüppop (2004. Scaling possible adverse effects of marine wind farms on seabirds: developing and applying a vulnerability index. Journal of Applied Ecology, 41: 724-734) and has since then been expanded to many case studies. However, the mathematical formulations that were proposed at that time are overly simplistic and may overlook critical components of the impact assessment. Our study briefly reviews the original approach and highlights its hidden assumptions and associated interpretation problems, for example, the overestimation of disturbance pressure to the detriment of collision, or the very high contribution of log abundances in vulnerability maps. Then, we propose a revised framework that solves these issues and permits easy transposition to other community-pressure case studies. To illustrate the usefulness and generality of the revised framework, we apply it to two case studies, one concerning the vulnerability assessment of a seabird community to offshore wind farms in the Bay of Biscay, and another focusing on the vulnerability assessment of the benthic megafauna community to trawling pressure in the Barents Sea. [ABSTRACT FROM AUTHOR]

As part of a large impact study in a wind farm (OWEZ) in the Dutch coastal zone, the effects of exclusion of bottom trawling on the benthic community were studied by comparison with nearby reference areas which were regularly fished. In addition to a standard boxcorer for common macro-fauna, a Triple-D dredge was used to collect longer-lived, more sparsely distributed infauna and epifauna. Multivariate analysis did not reveal any difference between the assemblages in and outside OWEZ with respect to abundance, biomass, and production after a 5-year closure. The Shannon-Wiener diversity index pointed to a significantly higher diversity in OWEZ compared with some of the reference areas. A minority of the bivalve species assumed to be sensitive to trawling showed higher abundances (Spisula solida) or larger sizes (Tellina fabula, Ensis directus) in OWEZ than in some of the reference areas. In general, samples collected with the Triple-D showed more differences between areas than boxcore samples. No evidence was also found that the species composition in OWEZ relative to the reference areas had changed in the period between 1 (2007) and 5 (2011) years after closure. The change observed in all areas between 2007 and 2011 was mainly due to relatively small variations in species abundances. In conclusion, 5 years after the closure of OWEZ to fisheries, only subtle changes were measured in the local benthic community, i.e. a higher species diversity and an increased abundance and lengths of some bivalves. Depleted adult stocks, faunal patchiness, and a limited time for recovery (5 years) might explain that a significant recovery could not be found. The current study shows that designation of large-scale marine protected areas as planned for the North Sea will not automatically imply that restoration of benthic assemblages can be expected within a relatively short period of years. [ABSTRACT FROM AUTHOR]

Benthos plays a significant role as substrate, refuge from predation and food for a wide variety of fish and invertebrates of all life stages and should therefore be considered in the ecosystem approach (EA) to management. Epibenthos from trawl catches, used in annual assessments of commercial fish stocks, was identified and measured on-board. The 2011 dataset present the baseline mapping for monitoring and included 354 taxa (218 to species level) analysed with multivariate statistical methods. This revealed four main megafaunal regions: southwestern (SW), banks/slopes in southeast and west (SEW), northwestern (NW), and northeastern (NE) which were significantly related to depth, temperature, salinity, and number of ice-days. The SW region was dominated by filter-feeders (sponges) in the inflow area of warm Atlantic water while the deeper trenches had a detritivorous fauna (echinoderms). In the SEW region, predators (sea stars, anemones and snow crabs) prevailed together with filtrating species (sea cucumber and bivalves) within a mosaic of banks and slopes. Plankton-feeding brittlestars were common in the NW and NE region, but with increasing snow crab population in NE. Climate change, potentially expanding trawling activity, and increasing snow and king crab populations might all have impacts on the benthos. Benthos should therefore be a part of an integrated assessment of a changing sea, and national agencies might consider adding benthic taxonomic expertise on-board scientific research vessels to identify the invertebrate “by-catch” as part of routine trawl surveys. [ABSTRACT FROM PUBLISHER]

The mud crab Scylla serrata (Forskal, 1775) (Portunidae) is a commercial species in the Indo-West-Pacific. Despite its high fishery value, the microhabitat of its early juvenile stages remains unknown. We studied microhabitat use by the 'early benthic stage' (EBS, between 3 and 30 mm carapace width, CW) at two sites in eastern Australia by two types of artificial benthic collectors and baited traps. 92% of EBS mud crabs were captured in muddy areas, compared to 8% on sandy habitats. The majority of the EBS mud crabs (87%) was found in intertidal areas within the mangrove fringe, only few individuals (13%) were found on unvegetated mud flats seawards to the mangroves. EBS from the mudflat (including first instars of 3-4 mm CW) were significantly smaller (p < 0.001) than those from the mangrove habitat. This indicates an active migration from the mud flat towards the mangrove fringe as the crabs grow. The recapture of mud crabs in close proximity to their tagging site at the mangrove fringe suggest that EBS-crabs have a small home range. Cannibalism is considered a major driver in the distribution patterns of EBS mud crabs, which may explain, why EBS-crabs stay at the more sheltered site near the mangrove fringe. By identifying the microhabitat of the critical early benthic stages of S. serrata in eastern Australia, our findings may contribute to the development of appropriate management and conservation strategies for this commercially important species. [ABSTRACT FROM AUTHOR]

Frank, K. T., Leggett, W. C., Petrie, B., Fisher, J. A. D., Shackell, N. L., and Taggart, C. T. 2013. Pelagic fish outbreak in the Northwest Atlantic - reality or illusion? – ICES Journal of Marine Science, 70: .The collapse of Northwest Atlantic groundfish in the early 1990s yielded a “natural experiment” within which to explore responses of ecosystems to a major perturbation. The “Pelagic Outburst” hypothesis was developed to explain an up to 900% increase in the abundance of small-bodied forage fishes and macroinvertebrates following this collapse and a subsequent trophic cascade extending across four trophic levels. Recently, this theory has been challenged and an alternative “Suprabenthic Habitat Occupation” (SHO) hypothesis has been advanced; it proposes the prey outburst associated with the forage fish component was an illusion created by changes in the vertical distribution of small pelagic fishes after the cod collapse in favour of a more bottom-oriented distribution that increased their vulnerability to bottom trawls. We evaluated the SHO hypothesis as it applied to the relationship between changes in the biomass of cod and the vertical distribution of herring and sand lance, the major small pelagic species of the Scotian Shelf ecosystem off eastern Nova Scotia. Contrary to predictions of the SHO hypothesis our initial conclusion that a pelagic outburst occurred in that ecosystem was confirmed and we found no evidence of a predator effect on vertical distributions of these species. We also explored the acoustic survey design and execution that generated the data that form the cornerstone of the SHO hypothesis, and the coherence between the behaviour depicted in these data and catch rates in the surface-oriented purse-seine fishery for herring operating at the time of these surveys. In combination, the results of our re-analysis of the population dynamics and behaviour of herring on the eastern Scotian Shelf, lead us to conclude that the SHO hypothesis, at least as it relates to the post-cod collapse dynamics of the affected Northwest Atlantic ecosystems, is not supported. [ABSTRACT FROM PUBLISHER]

Predators capture prey in complex and variable environments. In the ocean, bottom-dwelling (benthic) organisms are subjected to water currents, waves, and turbulent eddies. For benthic predators that feed on small animals carried in the water (zooplankton), flow not only delivers prey, but can also shape predator–prey interactions. Benthic passive suspension feeders collect prey delivered by movement of ambient water onto capture-surfaces, whereas motile benthic predators, such as burrow-dwelling fish, dart out to catch passing zooplankton. How does the flow of ambient water affect these contrasting modes of predation by benthic zooplanktivores? We studied the effects of turbulent, wavy flow on the encounter, capture, and retention of motile zooplanktonic prey (copepods, Acartia spp.) by passive benthic suspension feeders (sea anemones, Anthopleura elegantissima). Predator–prey interactions were video-recorded in a wave-generating flume under two regimes of oscillating flow with different peak wave velocities and levels of turbulent kinetic energy (“weak” and “strong” waves). Rates of encounter (number of prey passing through a sea anemone’s capture zone per time), capture (prey contacting and sticking to tentacles per time), and retention (prey retained on tentacles, without struggling free or washing off, per time) were measured at both strengths of waves. Strong waves enhanced encounter rates both for dead copepods and for actively swimming copepods, but there was so much variability in the behavior of the live prey that the effect of wave strength on encounter rates was not significant. Trapping efficiency (number of prey retained per number encountered) was the same in both flow regimes because, although fewer prey executed maneuvers to escape capture in strong waves, more of the captured prey was washed off the predators’ tentacles. Although peak water velocities and turbulence of waves did not affect feeding rates of passive suspension-feeding sea anemones, increases in these aspects of flow have been shown to enhance feeding rates and efficiency of motile benthic fish that lunge out of their burrows to catch zooplankton. Faster, more turbulent flow interferes with the ability of prey to detect predators and execute escape maneuvers, and thus enhances capture rates both for passive suspension-feeding predators and for actively swimming predators. However, prey captured in the mouths of fish are not washed away by ambient flow, whereas prey captured on the tentacles of suspension feeders can be swept off before they are ingested. Therefore, the effects of flowing water on predation on zooplankton by benthic animals depend on the feeding mode of the predator. [ABSTRACT FROM PUBLISHER]

Benthic marine invertebrates live in a multistressor world where stressor levels are, and will continue to be, exacerbated by global warming and increased atmospheric carbon dioxide. These changes are causing the oceans to warm, decrease in pH, become hypercapnic, and to become less saturated in carbonate minerals. These stressors have strong impacts on biological processes, but little is known about their combined effects on the development of marine invertebrates. Increasing temperature has a stimulatory effect on development, whereas hypercapnia can depress developmental processes. The pH, pCO2, and CaCO3 of seawater change simultaneously with temperature, challenging our ability to predict future outcomes for marine biota. The need to consider both warming and acidification is reflected in the recent increase in cross-factorial studies of the effects of these stressors on development of marine invertebrates. The outcomes and trends in these studies are synthesized here. Based on this compilation, significant additive or antagonistic effects of warming and acidification of the ocean are common (16 of 20 species studied), and synergistic negative effects also are reported. Fertilization can be robust to near-future warming and acidification, depending on the male–female mating pair. Although larvae and juveniles of some species tolerate near-future levels of warming and acidification (+2°C/pH 7.8), projected far-future conditions (ca. &geq;4°C/ &leq;pH 7.6) are widely deleterious, with a reduction in the size and survival of larvae. It appears that larvae that calcify are sensitive both to warming and acidification, whereas those that do not calcify are more sensitive to warming. Different sensitivities of life-history stages and species have implications for persistence and community function in a changing ocean. Some species are more resilient than others and may be potential “winners” in the climate-change stakes. As the ocean will change more gradually over coming decades than in “future shock” perturbation investigations, it is likely that some species, particularly those with short generation times, may be able to tolerate near-future oceanic change through acclimatization and/or adaption. [ABSTRACT FROM PUBLISHER]

Bučas, M., Bergström, U., Downie, A-L., Sundblad, G., Gullström, M., von Numers, M., Šiaulys, A., and Lindegarth, M. 2013. Empirical modelling of benthic species distribution, abundance, and diversity in the Baltic Sea: evaluating the scope for predictive mapping using different modelling approaches. – ICES Journal of Marine Science, 70: 1233–1243.The predictive performance of distribution models of common benthic species in the Baltic Sea was compared using four non-linear methods: generalized additive models (GAMs), multivariate adaptive regression splines, random forest (RF), and maximum entropy modelling (MAXENT). The effects of data traits were also tested. In total, 292 occurrence models and 204 quantitative (abundance and diversity) models were assessed. The main conclusions are that (i) the spatial distribution, abundance, and diversity of benthic species in the Baltic Sea can be successfully predicted using several non-linear predictive modelling techniques; (ii) RF was the most accurate method for both models, closely followed by GAM and MAXENT; (iii) correlation coefficients of predictive performance among the modelling techniques were relatively low, suggesting that the performance of methods is related to specific responses; (iv) the differences in predictive performance among the modelling methods could only partly be explained by data traits; (v) the response prevalence was the most important explanatory variable for predictive accuracy of GAM and MAXENT on occurrence data; (vi) RF on the occurrence data was the only method sensitive to sampling density; (vii) a higher predictive accuracy of abundance models could be achieved by reducing variance in the response data and increasing the sample size. [ABSTRACT FROM PUBLISHER]

The circadian clock is a molecular network that translates predictable environmental signals, such as light levels, into organismal responses, including behavior and physiology. Regular oscillations of the molecular components of the clock enable individuals to anticipate regularly fluctuating environmental conditions. Cnidarians play important roles in benthic and pelagic marine environments and also occupy a key evolutionary position as the likely sister group to the bilaterians. Together, these attributes make members of this phylum attractive as models for testing hypotheses on roles for circadian clocks in regulating behavior, physiology, and reproduction as well as those regarding the deep evolutionary conservation of circadian regulatory pathways in animal evolution. Here, we review and synthesize the field of cnidarian circadian biology by discussing the diverse effects of daily light cycles on cnidarians, summarizing the molecular evidence for the conservation of a bilaterian-like circadian clock in anthozoan cnidarians, and presenting new empirical data supporting the presence of a conserved feed-forward loop in the starlet sea anemone, Nematostella vectensis. Furthermore, we discuss critical gaps in our current knowledge about the cnidarian clock, including the functions directly regulated by the clock and the precise molecular interactions that drive the oscillating gene-expression patterns. We conclude that the field of cnidarian circadian biology is moving rapidly toward linking molecular mechanisms with physiology and behavior. [ABSTRACT FROM PUBLISHER]

Rousi, H., Laine, A. O., Peltonen, H., Kangas, P., Andersin, A-B., Rissanen, J., Sandberg-Kilpi, E., and Bonsdorff, E. 2013. Long-term changes in coastal zoobenthos in the northern Baltic Sea: the role of abiotic environmental factors – ICES Journal of Marine Science, 70: 440–451.We investigated site-specific changes in a coastal zoobenthic community during 1964–2007 in the northern Baltic Sea. Multivariate analysis indicated that the community structure had changed. The amphipods Monoporeia affinis and Pontoporeia femorata decreased drastically in the late 1970s–early 1980s, and by the early 1990s P. femorata vanished and M. affinis abundance was low. The decline of M. affinis and P. femorata was followed by an increase of the bivalve Macoma balthica and the arrival of the polychaete genus Marenzelleria in the 1990s. Trend analyses showed a rising trend for near-bottom temperature from the late 1960s. There was a significant decline in salinity during the early 1980s, which stabilized during the early 1990s. A negative trend was observed for oxygen concentration during the entire study period. There were interannual variations in the phosphorus and nitrogen concentrations, and a step-like increase in phosphorus concentration at the beginning of the 21st century. The correlations of temperature, salinity, oxygen, total phosphorus and nitrogen with zoobenthic communities were examined using Constrained Correspondence Analysis. Temperature was the most highly correlated explanatory variable for the benthic species. The study highlights the importance of long-term data sets in assessing the state and ecological processes of zoobenthic systems. [ABSTRACT FROM PUBLISHER]

Many copepod species rely on pheromone cues to find partners. Some parasitic and benthic copepod males are able to distinguish between females of different reproductive states. Here, we demonstrate that the swimming activity and velocity of males of a pelagic copepod, Oithona davisae, increases in the presence of virgin when compared with mated females and that the cue is waterborne. The ability to distinguish between virgin and mated females may reduce male mortality during mate search and the cost related to mating behaviour (precopula) in both sexes. We estimate that at realistic population densities the ability of males to distinguish between virgin and mated females saves them several hours per day of dangerous and energetically expensive fast female tracking. [ABSTRACT FROM AUTHOR]

Barrio Froján, C. R. S., MacIsaac, K. G., McMillan, A. K., del Mar Sacau Cuadrado, M., Large, P. A., Kenny, A. J., Kenchington, E., and de Cárdenas González, E. 2012. An evaluation of benthic community structure in and around the Sackville Spur closed area (Northwest Atlantic) in relation to the protection of vulnerable marine ecosystems. – ICES Journal of Marine Science, 69: 213–222.The benthic macrofaunal community structure is investigated within and around a closed area at Sackville Spur in the Northwest Atlantic to ascertain whether continued exclusion of bottom fishing can be justified. This and other similar closed areas have been introduced by the Northwest Atlantic Fisheries Organisation (NAFO) to protect areas of likely occurrence of taxa that are indicative of vulnerable marine ecosystems (VMEs) from the damaging effects of bottom-contact fishing gear. Results reveal subtle yet significant differences in macrofaunal assemblage composition and community structure between inside and outside the closed area, between above and below the 1200-m depth contour (i.e. the historical depth limit of fishing), and between areas where dense sponge spicule mats are either present or absent. Differences were observed in many assemblage metrics; however, the most revealing was the greater abundance, biomass, diversity, and number of VME indicative taxa inside the closed area than outside. Overall community composition is also significantly different between treatments. Depth, sediment temperature, and the proportion of clay within sediments are important in shaping the faunal assemblage. The importance of the effects of fishing is discussed, although it is not possible to ascertain if fishing is the direct cause behind observed differences in the macrofaunal assemblage. A continued closure of the area is recommended, as well as options for streamlining the evaluation process of other closed areas. [ABSTRACT FROM PUBLISHER]

The relationship between meroplankton distribution and spatio-temporal variability of coastal mesoscale hydrological structure was investigated in the northern Bay of Biscay, North-East Atlantic. For the three coastal polychaetes studied, i.e. Pectinaria koreni, Owenia fusiformis and Sabellaria alveolata, the highest larval abundances were sampled in low-salinity, low-density and high-temperature river plume waters. For two species (P. koreni and O. fusiformis), maximal abundances were observed in the surface and thermocline layers due to ontogenic migrations. Variance partitioning based on multiple regression and redundancy analyses was used to assess the relative roles played by the hydrological environment alone, the geographical space alone and their interactions, i.e. the spatial structure of the hydrological environment. These analyses demonstrate the key role played by the hydrological spatial structure in the distribution of larval abundances. The hydrological environment alone was insignificant, whereas geographical space alone explained a significant part of the variability in meroplankton distribution, probably in conjunction with ecological processes. For species whose benthic populations are spatially structured, the distribution and the size of adult populations and the timing of spawning events can significantly affect larval distribution and dispersal. [ABSTRACT FROM AUTHOR]

Plasticity in hatching potentially adjusts risks of benthic and planktonic development for benthic marine invertebrates. The proportionate effect of hatching plasticity on duration of larval swimming is greatest for animals that can potentially brood or encapsulate offspring until hatching near metamorphic competence. As an example, early hatching of the nudibranch mollusk Phestilla sibogae is stimulated by scattering of encapsulated offspring, as by a predator feeding on the gelatinous egg ribbon. When egg ribbons are undisturbed, hatching is at or near metamorphic competence. Disturbance of an unguarded benthic egg mass can insert 4 or more days of obligate larval dispersal into the life history. As another example, the spionid annelid Boccardia proboscidea broods capsules, each with both cannibalistic and developmentally arrested planktivorous siblings plus nurse eggs. Early hatching produces mainly planktivorous larvae with a planktonic duration of 15 days. Late hatching produces mainly adelphophages who have eaten their planktivorous siblings and metamorphose with little or no period of swimming. Mothers actively hatch their offspring by tearing the capsules, and appeared to time hatching in response to their environment and not to the stage of development of their offspring. Higher temperature increased the variance of brooding time. Females appeared to hatch capsules at an earlier developmental stage at lower temperatures. Species that release gametes or zygotes directly into the plankton have less scope for plasticity in stage at hatching. Their embryos develop singly with little protection and hatch at early stages, often as blastulae or gastrulae. Time of hatching cannot be greatly advanced, and sensory capabilities of blastulae may be limited. [ABSTRACT FROM AUTHOR]

Thirteen years ago in a review that appeared in the American Zoologist, we presented the first survey of the chemical and ecological bioactivity of Antarctic shallow-water marine invertebrates. In essence, we reported that despite theoretical predictions to the contrary the incidence of chemical defenses among sessile and sluggish Antarctic marine invertebrates was widespread. Since that time we and others have significantly expanded upon the base of knowledge of Antarctic marine invertebrates’ chemical ecology, both from the perspective of examining marine invertebrates in new, distinct geographic provinces, as well as broadening the evaluation of the ecological significance of secondary metabolites. Importantly, many of these studies have been framed within established theoretical constructs, particularly the Optimal Defense Theory. In the present article, we review the current knowledge of chemical ecology of benthic marine invertebrates comprising communities along the Western Antarctic Peninsula (WAP), a region of Antarctica that is both physically and biologically distinct from the rest of the continent. Our overview indicates that, similar to other regions of Antarctica, anti-predator chemical defenses are widespread among species occurring along the WAP. In some groups, such as the sponges, the incidence of chemical defenses against predation is comparable to, or even slightly higher than, that found in tropical marine systems. While there is substantial knowledge of the chemical defenses of benthic marine invertebrates against predators, much less is known about chemical anti-foulants. The sole survey conducted to date suggests that secondary metabolites in benthic sponges are likely to be important in the prevention of fouling by benthic diatoms, yet generally lack activity against marine bacteria. Our understanding of the sensory ecology of Antarctic benthic marine invertebrates, despite its great potential, remains in its infancy. For example, along the WAP, community-level non-consumptive effects occur when amphipods chemically sense fish predators and respond by seeking refuge in chemically-defended macroalgae. Such interactions may be important in releasing amphipods from predation pressure and facilitating their unusually high abundances along the WAP. Moreover, recent studies on the sensory biology of the Antarctic keystone sea star Odontaster validus indicate that chemotactile-mediated interactions between conspecifics and other sympatric predatory sea stars may have significant ramifications in structuring community dynamics. Finally, from a global environmental perspective, understanding how chemical ecology structures marine benthic communities along the WAP must increasingly be viewed in the context of the dramatic impacts of rapid climatic change now occurring in this biogeographic region. [ABSTRACT FROM AUTHOR]

The pelagic environment is characterized by unevenly distributed resources and risks. Such unpredictability presents adaptive challenges to diverse planktonic organisms including the larvae of benthic marine invertebrates. Estimates of mortality during planktonic development are highly variable, ranging from 0% to 100% per day. Predation is considered a significant source of this mortality, but what explains the variability in estimates of the mortality of marine invertebrate larvae? While differential exposure of larval prey to predators may explain these widely variable estimates, adaptations that reduce vulnerability of marine larvae to predators may also be important. Although there are excellent reviews of predation upon larvae and of larval mortality and defenses, nearly 15 years have elapsed since these topics were formally reviewed. Here, we highlight recent advances in understanding the behavioral, chemical, and morphological defenses that larvae possess and assess their effectiveness in reducing the risk of predation. While recent work confirms that larval mortality is generally high, it also demonstrates that larvae can reduce their risk of predation in several ways, including: (1) temporarily escaping the benthos during vulnerable early stages, (2) producing chemical compounds that reduce palatability, (3) possessing morphological defenses such as spines and shells, and (4) exhibiting induced defensive responses whereby larvae can alter their behavior, morphology, and life histories in the presence of predators. Taken together, these studies indicate that marine invertebrate larvae possess a sophisticated suite of defensive phenotypes that have allowed them to persist in the life cycle of benthic invertebrates for eons. [ABSTRACT FROM AUTHOR]

Many benthic marine invertebrate animals release larvae that are dispersed by ocean currents. These larvae swim and can respond to environmental factors such as chemical cues. However, larvae are so small (generally 0.01–1 mm) that they are often assumed to be passive particles whose trajectories are determined by the motion of the water in which they are riding. Therefore, marine larvae are useful model organisms to study the more general question of how the locomotion of very small animals in complex, variable natural habitats is affected by the motion of the fluid (water or air) around them. Studying larval locomotion under conditions of water flow encountered in nature is challenging because measuring the behavior of an individual microscopic organism requires high magnification imaging that is difficult to do in the field. The purpose of this article is to synthesize in one place the various approaches that we have been using to address the technical challenges of studying the locomotion of microscopic larvae in realistic ambient flow. The steps in our process include: (1) measuring water flow in the field; (2) mimicking realistic water movement in laboratory flumes to measure larval scale fluctuations in velocity of flow and concentration of chemical cues; (3) mimicking fine scale temporal patterns of larval encounters with a dissolved chemical cue to record larval responses; (4) using individual-based models to put larvae back into the larger scale environmental flow to determine trajectories; and (5) mimicking fine scale spatial and temporal patterns of larval encounters with water velocities and shear to determine the instantaneous forces on larvae. We illustrate these techniques using examples from our ongoing research on the settlement of larvae onto fouling communities and from our published work on settlement of larvae onto coral reefs. These examples show that water velocities and concentrations of chemical cues encountered by microscopic organisms can fluctuate in fractions of a second and vary over scales of less than a millimeter. [ABSTRACT FROM AUTHOR]

Alfaro, A. C. 2010. Effects of mangrove removal on benthic communities and sediment characteristics at Mangawhai Harbour, northern New Zealand. – ICES Journal of Marine Science, 67: 1087–1104.The spread of mangroves at many locations in temperate northern New Zealand provides a stark contrast to the well-documented trend in mangrove forest decline recorded through the tropics and subtropics. To explore this difference, improved understanding is needed of New Zealand's mangrove ecosystems and how they respond to anthropogenic disturbance. The effect of mangrove removal on the community ecology of mangrove stands and adjacent habitats was investigated within Mangawhai Estuary, northern New Zealand, between March 2004 and September 2006. The vegetation, benthic macrofauna, and sediments were sampled within habitats (marshgrass, mangrove stands, pneumatophore zones, sandflats, and channels) at a treatment site (mangroves removed) and two undisturbed sites, before and after mangrove-removal activities. Mature mangrove habitats had less total abundance and fewer taxa than all the other habitats sampled and were dominated by pulmonate snails (Amphibola crenata) and mud crabs (Helice crassa). Whereas faunal composition varied seasonally as a result of life-history dynamics, temporal changes could be attributed to mangrove-removal activities. Mangrove eradication was followed by immediate changes in the sediment from a muddy to sandier environment, which favoured an overall increase in the abundance of crabs, snails, and bivalves. However, unexpected topographic catchment reconfigurations in late 2005 may have caused a subsequent increase in the delivery of silt and organic content to the study area and an overall decrease in faunal density in March and September 2006. The study provides direct evidence of the effect of mangroves on sediment and benthic faunal characteristics and the importance of catchment-derived imports to estuarine ecosystems. [ABSTRACT FROM PUBLISHER]

The fauna of benthic shell-bearing gastropods on the continental slope off western Norway is described, based on material collected during the 1980s. Almost 3,000 specimens belonging to 96 species have been studied. The existence of a specific gastropod fauna restricted to the upper slope is documented, and the fauna is compared with that of the shelf, the ‘lower’ slope and the abyssal (below c. 2,000 m) depths of the Norwegian Sea. Possible dependence of the slope fauna on the negative temperature of the Norwegian Sea water and on internal waves in the region of the thermocline is discussed. Some species found on the upper slope are illustrated. [ABSTRACT FROM PUBLISHER]

Mat-forming benthic cyanobacteria are widespread throughout New Zealand rivers, and their ingestion has been linked to animal poisonings. In this study, potentially toxic benthic cyanobacterial proliferations were collected from 21 rivers and lakes throughout New Zealand. Each environmental sample was screened for anatoxins using liquid chromatography-MS (LC-MS). Thirty-six cyanobacterial strains were isolated and cultured from these samples. A polyphasic approach was used to identify each isolate; this included genotypic analyses [16S rRNA gene sequences and intergenic spacer (ITS)] and morphological characterization. Each culture was analysed for anatoxins using LC-MS and screened for microcystin production potential using targeted PCR. The morphospecies Phormidium autumnale was found to be the dominant cyanobacterium in mat samples. Polyphasic analyses revealed multiple slight morphological variants within the P. autumnale clade and highlighted the difficulties in identifying Oscillatoriaceae. Only one morphospecies (comprising the two strains CYN52 and CYN53) of P. autumnale was found to produce anatoxins. These strains formed their own clade based on partial 16S rRNA gene sequences. These data indicate that benthic P. autumnale mats are composed of multiple morphospecies and toxin production is dependent on the presence of toxin-producing genotypes. Further cyanobacteria are also characterized, including Phormidium murrayi, which was identified for the first time outside of Antarctica. [ABSTRACT FROM AUTHOR]

Clements, A. J., Strong, J. A., Flanagan, C., and Service, M. 2010. Objective stratification and sampling-effort allocation of ground-truthing in benthic-mapping surveys. – ICES Journal of Marine Science, 67: 628–637.The application of statistical procedures for objective stratification of sampling effort during map ground-truthing is presented. Marine benthic mapping is usually undertaken in two stages: a remotely sensed acoustic survey followed by ground-truthing to confirm ground-type and habitat classification. The objective of this study was to assess the application of optimum allocation analysis (OAA) through the use of remotely sensed data to direct expensive ground-truthing sampling effort. At an offshore site in the Irish Sea, classification of remotely sensed data, namely bathymetry and slope angle, generated six predicted ground-types. Calculated data variances within each ground-type were assumed to be a predictor of substratum heterogeneity, and these were used in an OAA to apportion ground-truthing effort objectively within each ground-type in order to achieve a set level of sampling precision. The sampling effort recommended by the OAA was realistic and practical with regard to video footage, but the collection of grabs was limited by resource constraints. The coefficient of variation (CV) of the video ground-truthing data matched that estimated by OAA, but the inability to collect all the recommended grabs resulted in CVs greater than expected for sediment grain-size parameters. The efficient identification of substratum classes using OAA represents a first stage whereby this method could direct ground-truthing that could ultimately be used for habitat mapping. [ABSTRACT FROM PUBLISHER]

Ricard, D., Branton, R. M., Clark, D. W., and Hurley, P. 2010. Extracting groundfish survey indices from the Ocean Biogeographic Information System (OBIS): an example from Fisheries and Oceans Canada. – ICES Journal of Marine Science, 67: 638–645.Scientific trawl surveys have been conducted in different regions of the world and by a variety of countries and agencies since the mid-1900s. Although the data are collected in a scientifically and statistically appropriate context and represent an important source of fishery-independent information for agency-specific stock assessments, their use and dissemination has often been limited to the agencies conducting the surveys. In recent years, Internet data portals such as the Ocean Biogeographic Information System have provided an arena for the wider distribution and use of marine fish data. Despite the increased accessibility of such data, their scientific acceptability has been limited by a lack of reproducibility in data analyses. We present a methodology for the computation of time-series of groundfish stock indices using publicly available trawl survey data derived from the Canadian Department of Fisheries and Oceans Maritimes region. Potential pitfalls associated with the computation of time-series are discussed and proper stratified random estimates of temporal abundance trends are compared with other methods for a selected subset of species. Also, the broader applicability of the methods for datasets collected under similar sampling designs is discussed, along with the reproducibility of the analyses and results. [ABSTRACT FROM PUBLISHER]

Desprez, M., Pearce, B., and Le Bot, S. 2010. The biological impact of overflowing sands around a marine aggregate extraction site: Dieppe (eastern English Channel). – ICES Journal of Marine Science, 67: 270–277.The study investigates the physical impact of sediment deposition associated with aggregate dredging at a site off Dieppe, and the consequences for benthic fauna. Sampling stations were sited across potential zones of impact classified as high, moderate, and low deposition, depending on their proximity to dredging activities and their position relative to the net sediment transport route. Samples were also taken west of the dredge site outside the zone of likely impact (no deposition). A strong gradient was observed from the sediments dominated by fine sands in the high and moderate deposition zones, through to coarse sands and gravels in the low and no deposition zones. The benthic fauna sampled from the deposits of fine sand in the high and moderate deposition zones were sparse compared with the coarser deposits sampled from the low and no deposition zones. There was a strong correspondence between the distribution of different sediment fractions and the associated benthic fauna, with a weighted Spearman rank correlation of 0.638, higher than reported in related studies. This suggests that in deposition areas such as this, biological interactions play a less important role in shaping communities than the changes in the physical environment, which may have a greater impact on the biological communities. [ABSTRACT FROM PUBLISHER]

Morphological deformities in parts of the head capsule of Chironomus spp. larvae inhabiting three polluted rivers (Permatang Rawa [PRR], Pasir [PR], and Kilang Ubi [KUR]) in the Juni River Basin, northeastern peninsular Malaysia, were studied. Samples of the fourth-instar larvae at one location in each river were collected monthly from November 2007 to March 2008 and examined for deformities of the mentum, antenna, mandible, and epipharyngis. At each sample location, in situ measurements of water depth, river width, water pH, dissolved oxygen, and water temperature were made. Samples of river water and benthic sediments were also collected monthly from each larval sample location in each river and taken to the laboratory for appropriate analysis. Total suspended solids (TSSs), ammonium-N, nitrate-N, phosphate-P, chloride, sulfate, and aluminum content in water were analyzed. Total organic matter and nonresidual metals in the sediment samples were also analyzed. Among the three rivers, the highest mean deformity (47.17%) was recorded in larvae collected from KUR that received industrial discharges from surrounding garment and rubber factories, followed by PRR (33.71%) receiving primarily residues of fertilizers and pesticides from adjacent rice fields, and PR (30.34%) contaminated primarily by anthropogenic wastes from the surrounding residential areas. Among the various head capsule structures, deformity of the mentum was strongly reflective of environmental stress and amounted to 27.9, 20.87, and 30.19% in the PRR, PR, and KUR, respectively. Calculated Lenat's toxic score index satisfactorily explained the influence of prevailing environmental variables on the severity of mentum deformities. Redundancy analysis and forward selection selected TSSs, sediment Zn, Mn, Cu, and Ni, and water pH, dissolved oxygen, water temperature, total organic matter, nitrate-N, chloride, phosphate-P. ammonium-N, sulfate, and aluminum as parameters that significantly affected some proportion of deformities. The total deformities correlated closely with deformities of mentum but only weakly with deformities in other parts of head. The total deformity incidence was strongly correlated with high contents of sediment Mn and Ni. The mentum and epipharyngis deformities incidence was highly correlated with an increase of TSSs, total aluminum, and ammonium-N and a decrease in pH and dissolved oxygen. [ABSTRACT FROM AUTHOR]

Harris, P. T., Heap, A. D., Anderson, T. J., and Brooke, B. 2009. Comment on: Williams et al. (2009) “Australia's deep-water reserve network: implications of false homogeneity for classifying abiotic surrogates of biodiversity”. ICES Journal of Marine Science, 66: 214–224. – ICES Journal of Marine Science, 66: 2082–2085.Williams et al. (2009) report on new multibeam sonar bathymetry and underwater video data collected from submarine canyons and seamounts on Australia's southeast continental margin to “investigate the degree to which geomorphic features act as surrogates for benthic megafaunal biodiversity” (p. 214). The authors describe what they view as deficiencies in the design of the Marine Protected Areas (MPAs) in the southeast region of Australia, in which geomorphology information was employed as a surrogate to infer regional-scale patterns of benthic biodiversity. This comment is designed to support and underscore the importance of evaluating MPA designs and the validity of using abiotic surrogates such as geomorphology to infer biodiversity patterns, and also seeks to clarify some of the discrepancies in geomorphic terminologies and approaches used between the original study and the Williams et al. (2009) evaluation. It is our opinion that the MPA design criteria used by the Australian Government are incorrectly reported by Williams et al. (2009). In particular, we emphasize the necessity for consistent terminology and approaches when undertaking comparative analyses of geomorphic features. We show that the MPA selection criteria used by the Australian Government addressed the issues of false homogeneity described by Williams et al. (2009), but that final placement of MPAs was based on additional stakeholder considerations. Finally, we argue that although the Williams et al. (2009) study provides valuable information on biological distributions within seamounts and canyons, the hypothesis that geomorphic features (particularly seamounts and submarine canyons) are surrogates for benthic biodiversity is not tested explicitly by their study. [ABSTRACT FROM PUBLISHER]

Gaspar, M. B., Carvalho, S., Constantino, R., Tata-Regala, J., Cúrdia, J., and Monteiro, C. C. 2009. Can we infer dredge fishing effort from macrobenthic community structure? – ICES Journal of Marine Science, 66: 2121–2132.The effects of commercial fishing effort (FE) on macrobenthic community structure were analysed in geographically related fishing grounds separated into three groups: non-exploited (NE), moderately exploited (ME), and highly exploited (HE). Number of species, abundance, Margalef species richness, and Shannon–Wiener diversity were significantly higher in NE than in exploited areas. The first two were also significantly higher in HE than in ME areas. Measures of taxonomic diversity differed depending on whether annelids, molluscs, and crustaceans were combined or analysed separately. Crustaceans seemed to be the most vulnerable to bivalve dredging because significantly lower values were observed for them in the HE areas than in the ME and NE areas for this group. Although the samples were taken at the end of the closed season, macrobenthic communities still showed differences that may be related to FE, especially in trophic structure. Carnivory was particularly dominant in HE areas. The ratio of carnivory to filter-feeding was significantly correlated with FE, with higher values being observed in HE areas and lower values in NE areas. [ABSTRACT FROM PUBLISHER]

Luna, B., Valle Pérez, C., and Sánchez-Lizaso, J. L. 2009. Benthic impacts of recreational divers in a Mediterranean Marine Protected Area. – ICES Journal of Marine Science, 66: 517–523.The features of many Marine Protected Areas (MPAs) have increased scuba diving tourism in these areas. Impacts caused by recreational scuba activity vary widely among different divers with differing underwater behaviour. We studied diver underwater behaviour, the effects on the natural environment, and the characteristics that may influence diver behaviour. In all, 181 recreational divers were followed, and contacts and the effects produced were recorded. Information on diver profile and dive features was recorded. Field sampling revealed that 175 of the divers observed (96.7%) made at least one contact with the seabed, with a mean contact of 41.20 ± 3.55 (mean ± s.e.) per diver per 10 min. Flapping was the most frequent type of contact, and the main damage by this action was to raise sediment. Contact with the seabed was greater for males than for females, inexperienced divers than for experienced divers, camera or lantern (dive light) users than for non-users, and divers unaccompanied by a dive leader or who had not been briefed about avoiding seabed contact before undertaking a dive than for accompanied or briefed divers. A greater understanding of the causes of harmful behaviour may be useful for stricter management, reducing diving damage and assuring the sustainability of this activity in MPAs. [ABSTRACT FROM PUBLISHER]

Although generally assumed to be filter feeders, branchiopod crustaceans of the laevicaudatan genus Lynceus O.F. Müller, 1776 possess no filters and do not collect food by filtration. Investigated species of these bivalved, multi-limbed animals have basically benthic habits and collect particulate food, mostly detritus, by scraping or sweeping it from surfaces with suitably armed trunk limbs. L. simiaefacies Harding, 1941, known only from a desert pool in Yemen, has trunk limbs that are armed with particularly robust scrapers and much of the complexity of these limbs and their armature is related to the collection and manipulation of detrital food by mechanical means. Material collected by scrapers borne distally on the more anterior limbs – although the anteriormost is very lightly armed – is swept posteriorly and dorsally, assisted by the armature of the more proximal endites, towards the posterior end of a deep food groove, whence it is passed anteriorly by the substantial gnathobases of the trunk limbs... [ABSTRACT FROM AUTHOR]

Aims: To exploit the cyanobacterial diversity of microbial mats growing in the benthic environment of Antarctic lakes for the discovery of novel antibiotic and antitumour activities. Methods and results: In all, 51 Antarctic cyanobacteria isolated from benthic mats were cultivated in the laboratory by optimizing temperature, irradiance and mixing. Productivity was generally very low (≤60 mg l−1 d−1) with growth rates ( μ) in the range of 0·02–0·44 d−1. Growth rates were limited by photosensitivity, sensitivity to air bubbling, polysaccharide production or cell aggregation. Despite this, 126 extracts were prepared from 48 strains and screened for antimicrobial and cytotoxic activities. Seventeen cyanobacteria showed antimicrobial activity (against the Gram-positive Staphylococcus aureus, the filamentous fungus Aspergillus fumigatus or the yeast Cryptococcus neoformans), and 25 were cytotoxic. The bioactivities were not in accordance with the phylogenetic grouping, but rather strain-specific. One active strain was cultivated in a 10-l photobioreactor. Conclusions: Isolation and mass cultivation of Antarctic cyanobacteria and LC-MS (liquid chromatography/mass spectrometry) fractionation of extracts from a subset of those strains (hits) that exhibited relatively potent antibacterial and/or antifungal activities, evidenced a chemical novelty worthy of further investigation. Significance and impact of the study: Development of isolation, cultivation and screening methods for Antarctic cyanobacteria has led to the discovery of strains endowed with interesting antimicrobial and antitumour activities. [ABSTRACT FROM AUTHOR]

The distribution of effect sizes of genes underlying adaptation is unknown ( Orr 2005 ). Are suites of traits that diverged under natural selection controlled by a few pleiotropic genes of large effect (major genes model), by many independently acting genes of small effect (infinitesimal model), or by a combination, with frequency inversely related to effect size (geometric model)? To address this we carried out a quantitative trait loci (QTL) study of a suite of 54 position traits describing body shapes of two threespine stickleback species: an ancestral Pacific marine form and a highly derived benthic species inhabiting a geologically young lake. About half of the 26 detected QTL affected just one coordinate and had small net effects, but several genomic regions affected multiple aspects of shape and had large net effects. The distribution of effect sizes followed the gamma distribution, as predicted by the geometric model of adaptation when detection limits are taken into account. The sex-determining chromosome region had the largest effect of any QTL. Ancestral sexual dimorphism was similar to the direction of divergence, and was largely eliminated during freshwater adaptation, suggesting that sex differences may provide variation upon which selection can act. Several shape QTL are linked to Eda, a major gene responsible for reduction of lateral body armor in freshwater. Our results are consistent with predictions of the geometric model of adaptation. Shape evolution in stickleback results from a few genes with large and possibly widespread effects and multiple genes of smaller effect. [ABSTRACT FROM AUTHOR]