Effective conservation planning relies on understanding population connectivity which can be informed by genomic data. This is particularly important for sessile species like the horse mussel (Modiolus modiolus), a key habitat-forming species and conservation priority in Atlantic Canada), yet little genomic information is available to describe horse mussel connectivity patterns. We used more than 8000 restriction-site associated DNA sequencing-derived single nucleotide polymorphisms and a panel of 8 microsatellites to examine genomic connectivity among horse mussel populations in the Bay of Fundy, along the Scotian Shelf, and in the broader northwestern Atlantic extending to Newfoundland. Despite phenotypic differences between sampling locations, we found an overall lack of genetic diversity and population structure in horse mussels in the Northwest Atlantic Ocean. All sampled locations had low heterozygosity, very low FST, elevated inbreeding coefficients, and deviated from Hardy-Weinberg Equilibrium, highlighting generally low genetic diversity across all metrics. Principal components analysis, Admixture analysis, pairwise FST calculations, and analysis of outlier loci (potentially under selection) all showed no independent genomic clusters within the data, and an analysis of molecular variance showed that less than 1% of the variation within the SNP dataset was found between sampling locations. Our results suggest that connectivity is high among horse mussel populations in the Northwest Atlantic, and coupled with large effective population sizes, this has resulted in minimal genomic divergence across the region. These results can inform conservation design considerations in the Bay of Fundy and support further integration into the broader regional conservation network.Cite this data as: Van Wyngaarden, Mallory et al. (2024). Widespread genetic similarity between Northwest Atlantic populations of the horse mussel, Modiolus modiolus. Published: May 2025. Coastal Ecosystem Science Division, Maritimes Region, Fisheries and Oceans Canada, Dartmouth, NS.

Considered the "king" of sea lions, the Steller sea lion (Eumetopias jubatus) is the biggest of all sea lions and enjoys a lifespan of up to thirty years. In Canada, the Steller can be spotted along the rocky coast of British Columbia. This hefty mammal usually travels alone or in a small group, but wisely, it joins others for protection during the mating and birthing season. Little is known about its oceanic lifestyle; however, the good news for this sea-loving mammal is that since the Steller sea lion first became protected in 1970, the size of the adult population has more than doubled. Recent trends in the abundance of Steller sea lions (Eumetopias jubatus) in British Columbia were assessed based on a series of thirteen province-wide aerial surveys conducted during the breeding season (27-June to 06-July) between 1971 and 2013.

Historical finds of Operophtera brumata

Historical finds of Fenusa pumila

A research survey of scallops (mainly sea scallop Placopecten magellanicus, but also Icelandic Scallop Chlamys islandica) using a dredge was carried out by DFO (Fisheries and Oceans Canada) every 1 or 2 years since 1992 in the Magdalen Islands (fishing area 20). The main objective of this research survey was to assess Sea Scallop stocks. Another objective was to document taxa associated with scallop habitat according to a fixed random sampling plan. Occurrences by species (or taxon) are presented by station. The taxonomic and geographical validity of the data was checked and the World Register of Marine Species served as the taxonomic authority for naming all taxa recorded during the survey. Epibenthic invertebrates (mainly molluscs, echinoderms and crustaceans) as well as demersal fish were identified from the dredge catches. The current data starting in 2021 are available at the following link : https://open.canada.ca/data/en/dataset/6529a4b0-f863-4568-ac71-1fa26cf68679The study area is located south of the Magdalen Islands and the sampling of scallop beds is carried out at depths of 10 to 38 m, generally around 25 to 35 m. A random selection of sampling stations is carried out from a fixed station grid. Sampling is done along transects at these randomly drawn stations in the study area. Sampling is done with a lined Digby scallop dredge (20 mm mesh) over approximately 500 m along the seabed. The four baskets of the dredge are examined for all scallops. Next, a basket (the first on the starboard side) is sorted and examined for associated species. Most specimens are counted by taxon. The presence or relative abundance of undersized and numerous, or colonial, organisms is noted. Special cases are sometimes retained for taxonomic analysis, for example, ascidians (to monitor invasive species) and sponges (to document new species).

Greenland Sharks (Somniosus microcephalus) are estimated to have the highest longevity of any invertebrate (392 ± 120 years), making bycatch a significant concern (Nielsen et al. 2016). However, in the Newfoundland and Labrador (NL) region, accurate estimates of bycatch are not often available for the species (Simpson et al. 2021). To address this, species distribution models (SDMs) were generated to delineate habitat suitability for the species throughout the NL region in order to identify areas where a higher rate of bycatch is expected to occur.Observations of Greenland shark bycatch recorded by At-Sea Observers (ASOs) in NL (1983 – 2019), Spain (1999 – 2017), and by the Northwest Atlantic Fisheries Organization (NAFO) Secretariat (2014 – 2019) were compiled to generate a presence-only dataset. Multiple environmental variables were assessed for collinearity, and non-collinear variables (Bathymetry and mean monthly bottom temperature for March and November (1990 – 2015)) were retained for use in the SDM. MaxEnt (maximum entropy) software was used to model habitat suitability because it is a presence-only modelling program that is able to account for a lack of absence data by comparing the environmental conditions at occurrence locations to those at randomly selected background points. Overall, the results indicated that habitat suitability for Greenland Shark was highest in deeper waters along the shelf edge in NAFO Divisions 3OP, and the Laurentian Channel, but also extended along the edge of the Labrador shelf, the Grand Banks, and deeper areas along the continental shelf such as the Hawke Channel, Funk Island Deep, and the slopes of Saglek, Nain, and Hamilton Banks. Beyond the Economic Exclusive Zone (EEZ) and within the NAFO regulatory area (NRA), suitable habitat was also present within the Flemish Pass, and along the slope of the Flemish Cap and shelf edge in NAFO Divisions 3NO (Simpson et al. 2021). More detailed information can be found in Simpson et al. 2021.References:Nielsen, J., R. B. Hedeholm, J. Heinemeier, P. G. Bushnell, J. S. Christiansen, J. Olsen, C. B. Ramsey, R. W. Brill, M. Simon, K. F. Steffensen, J. F. Steffensen. 2016. Eye lens radiocarbon reveals centuries of longevity in the Greenland shark (Somniosus microcephalus). Science 353 (6300):702-704Simpson, M. R., Gullage, L., Konecny, C., Ollerhead, N., Treble, M.A., Nogueira, A., González-Costas, F. 2021. Spatial-temporal variation in Greenland shark (Somniosus microcephalus) bycatch in the NAFO Regulatory Area. NAFO SCR Doc. 21/028

Historical finds of Adelges abietis

Speckled Dace (Rhinichthys osculus) are listed under the Species at Risk Act (SARA) as endangered. These fresh water fish, of the family Cyprinidae, are found in Canada only in the Kettle Valley of British Columbia. Proposed critical habitat was based on minimum viable population analysis and assumed densities of fish. From October 19th to the 22nd of 2015, night time pole seining surveys were conducted to enumerate Speckled Dace in proposed critical habitat on the West Kettle River; one of three rivers containing Speckled Dace. The estimated population abundance of Speckled Dace within the survey area was 8,978 (6,143-11,814), however only 1,014 of these are estimated to be adults.

The Steller sea lion (Eumetopias jubatus) is the largest of all sea lions and enjoys a lifespan of up to thirty years. In Canada, the Steller can be spotted along the rocky coast of British Columbia. These highly mobile marine mammals typically travel alone or in small groups, but they congregate in large numbers at traditional rookeries and haul-outs during the mating and pupping season. The population was severely depleted in Canada but following its protection in 1970, the size of the adult population has more than doubled.The survey targeted Steller sea lions and sites were chosen based on knowledge of historically occupied rookeries and haul-out sites with nearby areas monitored for potential shifts in distribution. This dataset contains counts that have been collected from sightings of individuals in the 2016/2017 survey season.

The United States population of California Sea Lions (Zalophus californianus) range from southeast Alaska to the Pacific coast of central Mexico. While this population does not breed in Canada, some sub-adult and adult males migrate northwards to British Columbia during the non-breeding season with an arrival in August-October and a departure in April-May. The population in coastal BC has not been fully assessed since 1985. However, opportunistic counts suggest that California Sea Lions overwintering in BC increased in abundance from approximately 1,000 animals in the mid-2000s to several thousand individuals in more recent years.The survey targeted Steller sea lions and sites were chosen based on knowledge of historically occupied rookeries and haul-out sites with nearby areas monitored for potential shifts in distribution. The presence of California Sea Lions are based on incidental observations while surveying sites for Steller sea lion counts. This dataset contains counts that have been collected from sightings of individuals in the 2016/2017 survey season.