Gastrointestinal effects of crustacean shell by-products in diets for farmed Atlantic cod (Gadus morhua).

The role of northern shrimp as a key forage species in the Canadian Sub-Arctic

Non-additive phospholipidomic responses to ocean warming and acidification drive intraspecific variation in cell membrane vulnerability in a marine ectotherm.

Effect of emerging technologies on the physicochemical and colloidal properties of protein hydrolysate from Pandalus borealis side-streams

Effects of illumination and pot design on catch and bycatch when targeting northern shrimp (Pandalus borealis) using white LED PotLights

Fatty acid composition of northern shrimp Pandalus borealis in relation to salmon aquaculture locations in Northern Norway

Abstract Large Greenland sharks (Somniosus microcephalus) commonly enter bottom trawls, and in some cases this results in unintended bycatch when they become stuck in the Nordmøre grid system. Successful bycatch reduction strategies should focus on excluding species as early and quickly as possible in the capture process to prevent stress and mortality. Developing bycatch reduction devices (BRDs) that consider shark escape behaviours could reduce their bycatch while allowing for a quicker and earlier escape. This study describes Greenland shark behaviour in the Nordmøre grid system, offering insights for designing more effective BRDs. Video of Greenland sharks was collected in the offshore Northern shrimp factory-freezer trawl fishery in Eastern Canada. Greenland shark behaviours are described in qualitative and quantitative terms, including observed turns, rolls, contact and engagement with gear components, and time-to-escape. Given that the majority of Greenland sharks observed were large (∼2.5–>4.0 m), these behaviours often hindered their escape out of the escape opening of the grid system. Greenland sharks interacted with the grid itself in varying ways, 50% (n = 6) were observed sliding over the grid, and the grid quickly deflected immobile sharks out through the escape opening. Greenland sharks often became stuck in the grid system, one at the guiding panel and 6 (50%) at the escape opening and grid. Stuck individuals performed rolls and thrashes in apparent attempts to escape. Although all of the observed individuals eventually escaped in this study, that is not always the case in the fishery, and gear modifications should be considered to prevent prolonged interactions, including adding BRDs before the grid system, modifying the guiding panel, and/or increasing the dimensions of the escape opening.

Broadband acoustic classification of Atlantic cod, polar cod, and northern shrimp in in situ mesocosm experiments

In the Northwest Atlantic Ocean, northern shrimp (Pandalus borealis) play key ecological roles as mid-trophic level consumers and as prey to higher-trophic level predators, including commercial fish species. However, the effects of changing environmental conditions and biological processes on trophic interactions in sub-Arctic ecosystems, particularly on lipid storage and nutrient transfer from intermediate to high trophic levels, remain unclear. Biochemical tracer methods (i.e., fatty acids and stable isotopes) were employed to study the trophic ecology and stage-specific nutritional condition of P. borealis across different spatial and seasonal scales. Trophic markers indicated significant contributions from both diatoms and zooplankton to the diet of P. borealis and highlighted the adaptability of this species to opportunistic feeding strategies based on sinking phytodetritus. Our results revealed a strong seasonality in the lipid composition of P. borealis, with lipid dynamics being highly influenced by environmental conditions and resource availability. The primary lipid classes in P. borealis were storage triacylglycerols, accounting for over 50% of lipids observed, followed by membrane phospholipids. Eggs from ovigerous females exhibited the highest concentrations of total lipids and essential fatty acids, such as omega-3 fatty acids, underscoring the important ecological role of eggs in sub-Arctic food webs by providing high-quality lipid sources. Additionally, our findings indicated an increase in the total lipid content of shrimp eggs from spring to summer, suggesting that the early stages of P. borealis are vulnerable to changes in the timing of seasonal primary production, when females store large reserves of energy-rich lipids. This study highlights the large seasonal and temporal variability in the nutritional status of P. borealis and underlines the importance of understanding lipid dynamics in assessing the resilience of populations to environmental changes.

Shrinking shrimp - Investigating the weight loss of northern shrimp Pandalus borealis following boiling

The aims of this study were firstly, to determine if the removal of heads and storage in a modified atmosphere (MA) extended the sensory shelf-life of chilled shell-on cooked Northern shrimp (Pandalus borealis). Secondly, the safe shelf-life of products was determined in regard to Listeria monocytogenes. Shrimp were kept whole or as tails (head region removed) at 5°C in laminar-film-bags with or without MA (40% CO2/60% N2) for 21 days. Analyses included changes in sensory properties (shelf-life), headspace CO2/O2, drip loss, pH, microbiota, total volatile nitrogen (TVN), trimethylamine-oxide (TMAO), and trimethylamine (TMA). Shrimp tails stored in MA reached the end-of-sensory-shelf-life after 21 days, followed by 18 days for whole shrimp in MA, and 14 and 11 days, respectively, for shrimp tails and whole shrimp without MA. For all four treatments, aerobic plate counts reached >8 log CFU/g at the time of sensory spoilage with Carnobacterium spp. and Pseudoalteromonas spp. dominating for shrimp with or without MA, respectively. Sensory spoilage coincided with TVN levels of 32–41 mg-N/100 g for shrimp in MA, while higher levels (66–143 mg-N/100 g) were observed for shrimp without MA. Pseudoalteromonas spp. had the strongest spoilage potential and likely contributed to the observed conversion of TMAO to TMA in shrimp stored without MA. Safe shelf-life was studied by testing the growth rate of L. monocytogenes, and the applicability of existing models to predict its growth. At 2°C–15°C, L. monocytogenes grew faster in whole shrimp than in shrimp meat. Moreover, the studied predictive model slightly underestimated growth of the pathogen. Taken together, our results show that to avoid unacceptable growth of L. monocytogenes, the safe shelf-life should be limited to less than 10 days at 5°C in MA for these ready-to-eat, cooked shell-on Northern shrimp products. Extension of product shelf-life would require research into stabilization of the products to inhibit the growth of L. monocytogenes.

Abstract Northern shrimp, Pandalus borealis Krøyer, 1838, are thought to form one biological unit, connected through larval dispersal, from Baffin Island in the north to the Grand Banks of Newfoundland and Labrador in the south. Current stock assessments suffer from misalignments in management, assessment, and biological spatial scales. To adequately manage and model stock dynamics, the spatiotemporal patterns in stock structure must be identified to the extent possible. We identified spatial patterns in density and life history traits (sex ratio and female length) using spatiotemporal modelling. Density peaked in depths near 250–300 m (along slope edges), the proportion of males declined as depth increased, and maximum female length was predicted in waters deeper than 400 m and in more northern areas. These spatial patterns were combined with updated genomic and larval dispersal patterns to illustrate underlying structure throughout the study area. We found two consistent north/south clusters through the time series, notably different from the current assessment and management areas used throughout the region. Spatial heterogeneity of northern shrimp dynamics and the resulting stock structure should be considered within northern shrimp assessment models to ensure proper model specification and appropriate management of the stock.

The northern shrimp Pandalus borealis (ice. Stóri kampalampi) is a North Atlantic crustacean of significant commercial interest which has been harvested consistently in Icelandic waters since 1936. In Icelandic waters, the length at which this protandrous species transitions from male to female differs between the inshore and offshore populations, suggesting a biologically meaningful stratification which may or may not be plastic. Using reduced representative genomes assembled from RADseq data, sampled from 96 individuals collected at two time points (2018 and 2021), we compare the level of genetic structure across a gradient extending out of Skjálfandi bay, north Iceland. These data are compared to samples from a far offshore site, some 65 km out from the bay, as well as another inshore fjord in Arnarfjörður, in northwestern Iceland. Since 1999, no harvesting of inshore populations of P. borealis in Skjálfandi has been allowed due to stock decline, but harvesting of offshore stocks has continued. Uncertainty surrounding the extent of structure between the in- and offshore aggregations has remained. Here we report distinct genetic structure defining the inshore and offshore populations of northern shrimp, but find significant admixture between the two. Most importantly, we see that genetically inshore populations of northern shrimp extend far outside the harvest boundaries of inshore shrimp, and offshore individuals may exhibit punctuated migration into the inshore areas.

Hermetia illucens-derived chitosan as a promising sustainable biomaterial for wound healing applications: development of sponge-like scaffolds.

Effect of UV-Ozone disinfection on the quality of Northern shrimp (Pandalus borealis) under sudden state of cold chain transportation

Cette étude vise à comprendre les relations alimentaires de la morue franche (Gadus morhua) dans l’écosystème du fjord du Saguenay, espèce écologiquement et économiquement importante dans la région, notamment pour l’activité de pêche blanche. Un total de 256 carcasses de morue franche a été récupéré auprès de pêcheurs volontaires lors de 11 saisons de pêche récréative hivernale de 2003 à 2022 dans différents sites de pêche. Le régime alimentaire de la morue franche a été évalué par l’analyse de son contenu stomacal. Les résultats révèlent des changements alimentaires selon la taille des prédateurs et indiquent également une variabilité spatio-temporelle. Chez les petites morues (< 40 cm), les crevettes, principalement la crevette grise de sable (Crangon septemspinosa) et la crevette nordique (Pandalus borealis), ont dominé la composition du régime alimentaire. Chez les morues de moyenne (40-80 cm) et grande (≥ 80 cm) tailles, les crevettes ont progressivement été remplacées par les poissons, principalement par le sébaste (Sebastes sp.) et l’éperlan arc-en-ciel (Osmerus mordax). La présente étude offre une description exhaustive du régime alimentaire hivernal de la morue franche du Saguenay et démontre l’importance de considérer les facteurs spatio-temporels dans les futures recherches sur l’alimentation de cette espèce. Cette caractérisation du régime alimentaire représente une étape primordiale pour aider à la compréhension de l’écologie de ce prédateur clé et à la mise en place de mesures de conservation de la biodiversité du fjord du Saguenay pour assurer une pêche récréative durable selon une approche écosystémique promue par le parc marin du Saguenay–Saint-Laurent.

Changes in Atlantic cod (Gadus morhua) abundance at Flemish Cap, likely due to exploitation and perhaps also to changing environmental conditions, have been well documented since 1980s. While the ecological implications of cod fluctuations have been explored in relation to dominant and commercially important species including redfish (Sebastes spp.), northern shrimp (Pandalus borealis) and Greenland halibut (Reinhardtius hippoglossoides), the broader ecological impacts, e.g. on less abundant species, remain less well explored. This study aimed to analyse spatiotemporal variation in the distribution and abundance of cod, and identify associated changes in distribution and abundance of other species with various trophic relationships to cod. This analysis used a delta Generalized Additive Model (GAM) approach, incorporating binomial and quasi-Poisson GAMs fitted to EU bottom trawl survey data from 1993 to 2019. Trophic species and guilds were defined based on the sizes and feeding habits of each species, as established in previous studies. Atlantic cod is considered to comprise of two trophic species: cod under 46 cm and larger cod. Model predictions were used to construct distribution maps and estimate distribution range and annual total abundance. Bottom temperature was a more important predictor in abundance (quasi-Poisson) models than in presence (binomial) models. The observed decline in cod abundance was associated with contraction in the distribution range. Significant negative correlations were identified between cod trophic species and all but one of the other trophic species in the same trophic guilds, for both distribution range and abundance. Species in other trophic guilds that rely on northern shrimp as prey also exhibited negative correlations with cod. The abundances of the main prey of cod, namely juvenile redfish and northern shrimp, showed negative correlations with cod abundance but no relationship was seen for distribution range. The abundance of large Acadian redfish (S. fasciatus) and large beaked redfish (S. mentella), which are major prey species of cod, was positively correlated with that of large cod, suggesting that the abundance of these prey species depends more on external variables, such as intense exploitation, than on their predator-prey relationships. These findings highlight the importance, for fishery management, of considering both the direct effects of fishing mortality and the indirect effects via trophic relationships.

Ecosystem management requires an integrated understanding of ecological interactions. In the Gulf of Maine (GoM), trophic information pertaining to commercially important groundfishes and nearshore prey communities is lacking. We characterized nearshore communities and groundfish diets using data collected from nearshore surveys (864 bottom trawls and 3638 stomach samples of six groundfish species) conducted biannually (spring and fall) in Midcoast Maine and Penobscot Bay from 2012 to 2022. Groundfish diets were dominated by some of the most available nearshore prey (gadiform and clupeiform fishes and pandalid and crangonid shrimps). Shifts in relative prey availability over environmental gradients (e.g., depth and position along the coast), across seasons, and over years corresponded with parallel patterns in prey contributions to groundfish diets in specific predator–prey interactions. Negative trends in the relative availability and diet occurrence of signature GoM prey taxa (Northern shrimp Pandalus borealis, Atlantic herring Clupea harengus, and euphausiids) indicate that broader ecosystem changes, such as steady rises in water temperature and shifts in species distributions, are impacting nearshore trophic dynamics in the GoM. These observations provide timely information on mechanisms that underlie groundfish productivity and warrant inclusion of nearshore trophic dynamics in relevant ecosystem models.

ABSTRACTThe Gulf of Maine (GOM) northern shrimp, Pandalus borealis, once supported a significant winter fishery, but a moratorium has been placed on the fishery since 2014 because of a population collapse and recruitment failures that have been attributed to unfavorably warm water temperatures. The GOM is at the southernmost end of the northern shrimp's range, suggesting its population dynamics and distribution may be vulnerable to warming water temperatures. In this study, we used survey data to estimate spatial indicators for GOM northern shrimp at four life history stages to identify possible temporal trends and examine relationships between the indicators and northern shrimp abundance and bottom temperature. We observed patchier distributions over time, which were related to declining population abundance, and a distributional shift northward that was associated with warming bottom water temperatures. Northern shrimp habitat distribution was strongly associated with bottom temperature. Shrimp of all life stages were found in bottom waters cooler than the station's average bottom temperature.

This study uses telemetry and stomach content analysis to describe the ringed seals’ dive pattern and prey selection within Kangia (Ilulissat Icefjord), Greenland, where the ringed seals are known to be exceptionally large and genetically distinct. Data from twenty-four ringed seals (Pusa hispida) tagged in Kangia, with satellite relay data loggers from 2012 to 2020, were used to describe the dive patterns. The transmitters were active between 28 and 270 days and showed that subadults most frequently dove to around 150 m. Adult males frequently dove to this depth, but they also had a second frequently visited depth at around 400 m, some adults significantly deeper. Adult males generally dove deeper than females and adult seals showed deeper dives during the winter, a feature that was less prominent in subadults. The stomach content from ringed seals (n = 108) harvested in Kangia by subsistence hunters revealed that polar cod (Boreogadus saida), capelin (Mallotus villosus), mysids (Mysis oculata, M. littoralis, M. Polaris) and shrimps (mainly Pandalus borealis) were the dominant prey. Shrimps were observed more often in adults, likely due to the frequently visited dive depth of around 400 m, whereas mysids were more observed in small subadult seals. The stomach content from harp seals (Pagophilus groenlandicus) and Greenland halibut (Reinhardtius hippoglossoides) caught in Kangia also showed a strong niche overlap with the ringed seals. These findings outline the unique ecological adaptations and the importance of Kangia as a critical habitat of ringed seals.