Large decline in hooded seal (Cystophora cristata) pup production off of northeastern Newfoundland in 2012 and 2017

Authors

  • Charmain Hamilton Fisheries and Oceans Canada
  • Pierre Goulet Fisheries and Oceans Canada
  • Shelley Lang Fisheries and Oceans Canada
  • Arnaud Mosnier Fisheries and Oceans Canada
  • Garry Stenson Bidesuk Consulting

DOI:

https://doi.org/10.7557/3.7410

Keywords:

hooded seal, pup production, aerial survey, sea-ice decline, Newfoundland and Labrador Shelves

Abstract

Accurate data on population abundance is needed to monitor trends through time, especially for species that are commercially harvested or vulnerable to climate change related impacts. Hooded seals (Cystophora cristata) in the Northwest Atlantic whelp on drifting sea ice in three areas: Davis Strait, the southern Gulf of St. Lawrence and off of northeastern Newfoundland (“Front”), Canada, with the majority of whelping (>90%) occurring at the Front. They are harvested in Canada and Greenland but have not been assessed since 2005. Aerial surveys for harp seals (Pagophilus groenlandicus) took place at the Front in 2012 and 2017. These surveys also captured the vast majority of hooded seal whelping patches in these years and so were used to estimate hooded seal pup production at the Front. Pup production was estimated from photo (2012 and 2017) and visual (2017 only) line-transect surveys. Staging data from 2004, 2005 and 2017 were used to correct these estimates for the proportion of pups not born on the survey days, resulting in total pup production estimates of 41,129 (SE = 7,374) and 39,021 (SE = 18,334) pups in 2012 and 2017, respectively. This is a large decrease from the previous estimate, being 38% and 36%, respectively, of the pup production estimated on the Front in 2005. Extensive reconnaissance that failed to locate whelping hooded seals in Davis Strait (2024) or outside the traditional whelping area at the Front (2012, 2017), along with low sea-ice coverage in the Gulf of St. Lawrence makes it unlikely that significant whelping was redistributed to other areas. The large decline in pup production after 2005 mirrors a similar decline and continued low level of pup production for hooded seals in the Greenland Sea that occurred between 1997 and 2005/07. Although the cause of the decline in the Northwest Atlantic is unknown, it is possible that negative impacts of ecosystem change on female fecundity and juvenile survival, as has been documented for harp seals in the Northwest Atlantic, are also impacting hooded seals.

References

Andersen, J. M., Wiersma, Y. F., Stenson, G., Hammill, M. O., & Rosing-Asvid, A. (2009). Movement patterns of hooded seals (Cystophora cristata) in the Northwest Atlantic Ocean during the post-moult and pre-breed seasons. Journal of Northwest Atlantic Fishery Science, 42, 1-11. https://doi.org/10.2960/J.v42.m649

Andersen, J. M., Wiersma, Y. F., Stenson, G. B., Hammill, M. O., Rosing-Asvid, A., & Skern-Maurizen, M. (2013). Habitat selection by hooded seals (Cystophora cristata) in the Northwest Atlantic Ocean. ICES Journal of Marine Science, 70, 173-185. https://doi.org/10.1093/icesjms/fss133

Bajzak, C. E., Côté, S. D., Hammill, M. O., & Stenson, G. (2009). Intersexual differences in the postbreeding foraging behaviour of the Northwest Atlantic hooded seal. Marine Ecology Progress Series, 385, 285-294. https://doi.org/10.3354/meps08015

Biuw, M., Øigård, T. A., Nilssen, K. T., Stenson, G., Lindblom, L., Poltermann, M., … Haug, T. (2022). Recent harp and hooded seal pup production estimates in the Greenland Sea suggest ecology-driven declines. NAMMCO Scientific Publications, 12. https://doi.org/10.7557/3.5821

Bowen, W. D., Oftedal, O. T., & Boness, D. J. (1985). Birth to weaning in 4 days: remarkable growth in the hooded seal, Cystophora cristata. Canadian Journal of Zoology, 63, 2841-2846. https://doi.org/10.1139/z85-424

Bowen, W. D., Myers, R. A., & Hay, K. (1987). Abundance estimation of a dispersed, dynamic population: hooded seals (Cystophora cristata) in the Northwest Atlantic. Canadian Journal of Fisheries and Aquatic Sciences, 44, 282-295. https://doi.org/10.1139/f87-037

Bowen, W. D., Ellis, S. L., Iverson, S. J., & Boness, D. J. (2003). Maternal and newborn life-history traits during periods of contrasting population trends: implications for explaining the decline of harbour seals (Phoca vitulina), on Sable Island. Journal of Zoology, London, 261, 155-163. https://doi.org/10.1017/S0952836903004047

Bowen, W. D., den Heyer, C. E., Lang, S. L. C., Lidgard, D., & Iverson, S. J. (2020). Exploring causal components of plasticity in grey seal birthdates: effects of intrinsic traits, demography, and climate. Ecology and Evolution, 10, 11507-11522. https://doi.org/10.1002/ece3.6787

Buren, A. D., Koen-Alonso, M., Pepin, P., Mowbray, F., Nakashima, B., Stenson, G., … Montevecchi, W. A. (2014). Bottom-up regulation of capelin, a keystone forage species. PLoS ONE, 9, e87589. https://doi.org/10.1371/journal.pone.0087589

Buren, A. D., Murphy, H. M., Adamack, A. T., Davoren, G. K., Koen-Alonso, M., Montevecchi, W. A., … Varkey, D. (2019). The collapse and continued low productivity of a keystone forage fish species. Marine Ecology Progress Series, 616, 155-170. https://doi.org/10.3354/meps12924

Coltman, D. W., Stenson, G., Hammill, M. O., Haug, T., Davis, C. S., & Fulton, T. L. (2007). Panmictic population structure in the hooded seal (Cystophora cristata). Molecular Ecology, 16, 1639-1648. https://doi.org/10.1111/j.1365-294X.2007.03229.x

Costa, D. P., Crocker, D. E., Gedamke, J., Webb, P. M., Houser, D. S., Blackwell, S. B., … Le Boeuf, B. J. (2003). The effect of a low-frequency sound source (acoustic thermometry of the ocean climate) on the diving behavior of juvenile northern elephant seals, Mirounga angustirostris. The Journal of the Acoustical Society of America, 113, 1155-1165. https://doi.org/10.1121/1.1538248

Cyr, F., & Galbraith, P. S. (2021). A climate index for the Newfoundland and Labrador shelf. Earth System Science Data, 13, 1807-1828. https://doi.org/10.5194/essd-13-1807-2021

DFO. (2020). Stock Status of redfish in NAFO SA 2 + divs. 3K. (Advisory Report 2020/021). Canadian Science Advisory Secretariat.

DFO. (2022). Assessment of redfish in the Northwest Atlantic Fisheries Organization (NAFO) subarea 0, October 2016. (Advisory Report 2022/008). Canadian Science Advisory Secretariat.

DFO. (2023). Assessment of the Gulf of St. Lawrence (4RST) Greenland halibut stock in 2022. (Advisory Report 2023/022). Canadian Science Advisory Secretariat.

Dietz, R., Letcher, R. J., Desforges, J.-P., Eulaers, I., Sonne, C., Wilson, S., … Víkingsson, G. (2019). Current state of knowledge on biological effects from contaminants on arctic wildlife and fish. Science of the Total Environment, 696, 133792. https://doi.org/10.1016/j.scitotenv.2019.133792

Enoksen, S., Haug, T., Lindstrøm, U., & Nilssen, K. T. (2017). Recent summer diet of hooded Cystophora cristata and harp Pagophilus groenlandicus seals in the drift ice of the Greenland Sea. Polar Biology, 40, 931-937. https://doi.org/10.1007/s00300-016-2002-2

Fossheim, M., Primicerio, R., Johannesen, E., Ingvaldsen, R. B., Aschan, M. M., & Dolgov, A. V. (2015). Recent warming leads to a rapid borealization of fish communities in the Arctic. Nature Climate Change, 5, 673-677. https://doi.org/10.1038/nclimate2647

Frie, A. K., Stenson, G. B., & Haug, T. (2012). Long-term trends in reproductive and demographic parameters of female Northwest Atlantic hooded seals (Cystophora cristata): population responses to ecosystem change? Canadian Journal of Zoology, 90, 376-392. https://doi.org/10.1139/z11-140

Gardiner, K., & Dick, T. A. (2010). Arctic cephalopod distributions and their associated predators. Polar Research, 29, 209-227. https://doi.org/10.1111/j.1751-8369.2010.00146.x

Government of Greenland. (2017). Review of existing knowledge on marine mammal by-catch in Greenland (SC/24/BYC/14). Nuuk, Greenland: The Government of Greenland Ministry of Fisheries and Hunting.

Hammill, M. O., Stenson, G. B., & Myers, R. A. (1992). Hooded seal (Cystophora cristata) pup production in the Gulf of St. Lawrence. Canadian Journal of Fisheries and Aquatic Sciences, 49, 2546-2550. https://doi.org/10.1139/f92-281

Hammill, M. O., Lydersen, C., Kovacs, K. M., & Sjare, B. (1997). Estimated fish consumption by hooded seals (Cystophora cristata), in the Gulf of St. Lawrence. Journal of Northwest Atlantic Fishery Science, 22, 249-257.

Hammill, M. O., & Stenson, G. B. (2000). Estimated prey consumption by harp seals (Phoca groenlandica), hooded seals (Cystophora cristata), grey seals (Halichoerus grypus) and harbour seals (Phoca vitulina) in Atlantic Canada. Journal of Northwest Atlantic Fishery Science, 26, 1-23.

Hammill, M. O., & Stenson, G. B. (2003). Application of the precautionary approach and conservation reference point to the management of Atlantic seals: a discussion paper. (Research Document 2003/067). Canadian Science Advisory Secretariat.

Hammill, M. O., & Stenson, G. (2006). Abundance of Northwest Atlantic hooded seals (1960-2005). (Research Document 2006/068). Canadian Science Advisory Secretariat.

Hammill, M. O., & Stenson, G. B. (2007). Application of the precautionary approach and conservation reference points to management of Atlantic seals. ICES Journal of Marine Science, 64, 702-706. https://doi.org/10.1093/icesjms/fsm037

Hammill, M. O., Stenson, G. B., Mosnier, A., & Doniol-Valcroz, T. (2021). Trends in abundance of harp seals, Pagophilus groenlandicus, in the Northwest Atlantic, 1952-2019. (Research Document 2021/006). Canadian Science Advisory Secretariat.

Haug, T., Nilssen, K. T., & Lindblom, L. (2000). First independent feeding of harp seal (Phoca groenlandica) and hooded seal (Cystophora cristata) pups in the Greenland Sea. NAMMCO Scientific Publications, 2, 29-39. https://doi.org/10.7557/3.2969

Haug, T., Nilssen, K. T., & Lindblom, L. (2004). Feeding habits of harp and hooded seals in drift ice waters along the east coast of Greenland in summer and winter. Polar Research, 23, 35-42. https://doi.org/10.3402/polar.v23i1.6264

Haug, T., Nilssen, K. T., Lindblom, L., & Lindstrøm, U. (2007). Diets of hooded seals (Cystophora cristata) in coastal waters and drift ice waters along the east coast of Greenland. Marine Biology Research, 3, 123-133. https://doi.org/10.1080/17451000701358531

Hobbs, K. E., Lebeuf, M., & Hammill, M. O. (2002). PCBs and OCPs in male harbour, grey, harp and hooded seals from the Estuary and Gulf of St Lawrence, Canada. The Science of the Total Environment, 296, 1-18. https://doi.org/10.1016/S0048-9697(01)01074-9

Huntington, H. P., Danielson, S. L., Wiese, F. K., Baker, M., Boveng, P., Citta, J. J., … Wilson, C. (2020). Evidence suggests potential transformation of the Pacific Arctic ecosystem is underway. Nature Climate Change, 10, 342-348. https://doi.org/10.1038/s41558-020-0695-2

ICES. (2023a). Report of the joint ICES/NAFO/NAMMCO working group on harp and hooded seals (WGHARP). ICES Scientific Reports, 5, 96. https://doi.org/10.17895/ices.pub.24306100

ICES. (2023b). Northwestern Working Group (NWWG). Greenland halibut (Iceland and Faroes grounds, West of Scotland, North of Azores, and East of Greenland). ICES Scientific Reports, 5:64, 471-508. https://doi.org/10.17895/ices.pub.23267153

Kapel, F. O. (2000). Feeding habits of harp and hooded seals in Greenland waters. NAMMCO Scientific Publications, 2, 50-64. https://doi.org/10.7557/3.2971

Koen-Alonso, M., & Cuff, A. (2020). Status and trends of the fish community in the Newfoundland Shelf (NAFO Div. 2J3K), Grand Bank (NAFO Div. 3LNO) and southern Newfoundland Shelf (NAFO Div. 3Ps) Ecosystem Production Units. (Research Document 18/070). NAFO Scientific Council.

Kovacs, K. M., Lydersen, C., Overland, J. E., & Moore, S. E. (2011). Impacts of changing sea-ice conditions on Arctic marine mammals. Marine Biodiversity, 41, 181-194. https://doi.org/10.1007/s12526-010-0061-0

Kovacs, K.M. (2018). Hooded seal: Cystophora cristata. In B. Würsig, J. G. M. Thewissen, & K. M. Kovacs (Eds.), Encyclopedia of Marine Mammals (3rd Ed.) (pp. 477-480). London, United Kingdom: Academic Press.

Laidre, K. L., Stern, H., Kovacs, K. M., Lowry, L., Moore, S. E., Regehr, E. V., … Ugarte, F. (2015). Arctic marine mammal population status, sea ice habitat loss, and conservation recommendations for the 21st century. Conservation Biology, 29, 724-737. https://doi.org/10.1111/cobi.12474

Laidre, K. L., & Regehr, E.V. (2018). Arctic Marine Mammals. In B. Würsig, J. G. M. Thewissen, & K. M. Kovacs (Eds.), Encyclopedia of Marine Mammals (3rd Ed.) (pp. 34-40). London, United Kingdom: Academic Press.

Lydersen, C., & Kovacs, K. M. (1999). Behaviour and energetics of ice-breeding, North Atlantic phocid seals during the lactation period. Marine Ecology Progress Series, 187, 265-281. https://doi.org/10.3354/meps187265

Mansfield, A. W. (1967). Seals of arctic and eastern Canada. Bulletin of the Fisheries Research Board of Canada, 137, 1-30.

Marine and Freshwater Research Institute (MFRI), Iceland. (2024). Greater silver smelt Argentina silus Technical Report. Retrieved from https://www.hafogvatn.is/static/extras/images/19-gss_techreport_en.html

Mood, A. M., Graybill, F. A., & Boes, D. C. (1974). Introduction to the Theory of Statistics (3rd Ed.). Toronto, Ontario, Canada: McGraw-Hill.

Mosnier, A., den Heyer, C. E., Stenson, G. B., & Hammill, M. O. (2023). A Bayesian birth distribution model for grey seals and an evaluation of timing of the harvest. (Research Document 2023/052). Canadian Science Advisory Secretariat.

Øigård, T. A., Haug, T., & Nilssen, K. T. (2014). Current status of hooded seals in the Greenland Sea. Victims of climate change and predation? Biological Conservation, 172, 29-36. https://doi.org/10.1016/j.biocon.2014.02.007

PAME. (2021). Underwater noise pollution from shipping in the Arctic Report. Protection of the Arctic Marine Environment Working Group (PAME). Tromsø, Norway: Arctic Council.

Post, E., Bhatt, U. S., Bitz, C. M., Brodie, J. F., Fulton, T. L., Hebblewhite, M., … Walker, D. A. (2013). Ecological consequences of sea-ice decline. Science, 341, 519-524. https://doi.org/10.1126/science.1235225

Potelov, V., Nilssen, K. T., Svetochev, V., & Haug, T. (2000). Feeding habits of harp (Phoca groenlandica) and hooded seals (Cystophora cristata) during late winter, spring and early summer in the Greenland Sea. NAMMCO Scientific Publications, 2, 40-49. https://doi.org/10.7557/3.2970

R Core Team. (2023). R: A language and environment for statistical computing. R Foundation for Statistical Computing. Vienna, Austria.

Reiling, S. J., Measures, L., Feng, S., Boone, R., Merks, H., & Dixon, B. R. (2019). Toxoplasma gondii, Sarcocystis sp. and Neospora caninum¬-like parasites in seals from northern and eastern Canada: potential risk to consumers. Food and Waterborne Parasitology, 17, e00067. https://doi.org/10.1016/j.fawpar.2019.e00067

Ringuette, M., Devred, E., Azetsu-Scott, K., Head, E., Punshon, S., Casault, B., & Clay, S. (2022). Optical, chemical and biological oceanographic conditions in the Labrador Sea between 2014 and 2018. (Research Document 2022/021). Canadian Science Advisory Secretariat.

Rolland, R. M., Parks, S. E., Hunt, K. E., Castellote, M., Corkeron, P. J., Nowacek, D. P., … Kraus, S. D. (2012). Evidence that ship noise increases stress in right whales. Proceedings of the Royal Society B, 279, 2363-2368. https://doi.org/10.1098/rspb.2011.2429

Romano, T. A., Keogh, M. J., Kelly, C., Feng, P., Berk, L., Schlundt, C. E., … Finneran, J. J. (2004). Anthropogenic sound and marine mammal health: measures of the nervous and immune systems before and after intense sound exposure. Canadian Journal of Fisheries and Aquatic Sciences, 61, 1124-1134. https://doi.org/10.1139/F04-055

Rotander, A., van Bavel, B., Polder, A., Rigét, F., Auðunsson, G. A., Gabrielsen, G. W., … Dam, M. (2012). Polybrominated diphenyl ethers (PBDEs) in marine mammals from Arctic and North Atlantic regions, 1986-2009. Environmental International, 40, 102-109. https://doi.org/10.1016/j.envint.2011.07.001

Salberg, A.-B., Haug, T., & Nilssen, K. T. (2008). Estimation of hooded seal (Cystophora cristata) pup production in the Greenland Sea pack ice during the 2005 whelping season. Polar Biology, 31, 867-878. https://doi.org/10.1007/s00300-008-0425-0

Satterthwaite, F. E. (1946). An approximate distribution of estimates of variance components. Biometrics, 2, 110-114. https://doi.org/10.2307/3002019

Sergeant, D. E. (1974). A rediscovered whelping population of hooded seals Cystophora cristata Erxleben and its possible relationships to other populations. Polarforschung, 44, 1-7. https://doi.org/10.2312/polarforschung.44.1.1

Sergeant, D.E. (1976a). History and present status of populations of harp and hooded seals. Biological Conservation, 10, 95-118. https://doi.org/10.1016/0006-3207(76)90055-0

Sergeant, D. E. (1976b). Research on hooded seals Cystophora cristata Erxleben in 1976. (Research Document 76/X/126). International Commission for the Northwest Atlantic Fisheries.

Sergeant, D. E. (1977). Research on hooded seals in the western North Atlantic in 1977. (Research Document 77/XI/57). International Commission for the Northwest Atlantic Fisheries.

Sergeant, D. E. (1991). Harp seals, man and ice. Canadian Special Publication of Fisheries and Aquatic Sciences, 114.

Stenson, G.B. (1994). The status of pinnipeds in the Newfoundland region. NAFO Scientific Council Studies, 21, 115-119.

Stenson, G. B. (2006). Hunt induced mortality in Northwest Atlantic hooded seals. (Research Document 2006/066). Canadian Science Advisory Secretariat.

Stenson, G. B., Ni, I.-H., Myers, R. A., Hammill, M. O., Warren, W. B., & Kingsley, M. C. S. (1991). Aerial survey estimates of pup production of harp seals (Phoca groenlandica) in the Gulf of St. Lawrence and off Newfoundland during March 1990. (Research Document 91/83). Canadian Science Advisory Secretariat.

Stenson, G. B., & Sjare, B. (1996). Newfoundland hooded seal tag returns in the Northeast Atlantic. Northwest Atlantic Fisheries Organization Scientific Council Studies, 26, 115-118.

Stenson, G. B., Myers, R. A., Ni, I.-H., & Warren, W. G. (1997). Pup production and population growth of hooded seals (Cystophora cristata) near Newfoundland, Canada. Canadian Journal of Fisheries and Aquatic Sciences, 54 (Supplement 1), 209-216. https://doi.org/10.1139/f96-168

Stenson, G. B., Hammill, M. O., Lawson, J., & Gosselin, J. F. (2006). 2005 pup production of hooded seals, Cystophora cristata, in the Northwest Atlantic. (Research Document 2006/067).

Stenson, G. B., & Hammill, M. O. (2014). Can ice breeding seals adapt to habitat loss in a time of climate change? ICES Journal of Marine Science, 71, 1977-1986. https://doi.org/10.1093/icesjms/fsu074

Stenson, G. B., Hammill, M. O., Lawson, J. W., & Gosselin, J.-F. (2014). Estimating pup production of Northwest Atlantic harp seals, Pagophilus groenlandicus, in 2012. (Research Document 2014/057).

Stenson, G. B., Buren, A. D., & Koen-Alonso, M. (2016). The impact of changing climate and abundance on reproduction in an ice-dependent species, the Northwest Atlantic harp seal, Pagophilus groenlandicus. ICES Journal of Marine Science, 73, 250-262. https://doi.org/10.1093/icesjms/fsv202

Stenson, G. B., Buren, A. D., & Sheppard, G. L. (2020). Updated estimates of reproductive rates in Northwest Atlantic harp seals and the influence of body condition. (Research Document 2020/057). Canadian Science Advisory Secretariat.

Stenson, G. B., Haug, T., & Hammill, M. O. (2020). Harp seals: monitors of change in differing ecosystems. Frontiers in Marine Science, 7, 569258. https://doi.org/10.3389/fmars.2020.569258

Stenson, G. B., Gosselin, J.-F., Lawson, J. W., Buren, A., Goulet, P., Lang, S. L. C., … Hammill, M. O. (2022). Pup production of harp seals in the Northwest Atlantic in 2017 during a time of ecosystem change. NAMMCO Scientific Publications, 12. https://doi.org/10.7557/3.6214

Stroeve, J., & Notz, D. (2018). Changing state of Arctic sea ice across all seasons. Environmental Research Letters, 13, 103001. https://doi.org/10.1088/1748-9326/aade56

Tinker, M. T., Stenson, G. B., Mosnier, A., & Hammill, M. O. (2023). Estimating abundance of Northwest Atlantic harp seal using a Bayesian modelling approach. (Research Document 2023/068). Canadian Science Advisory Secretariat.

Treble, M. A., Nogueira, A., & Hedges, K. J. (2022). Assessment of the Greenland Halibut stock component in NAFO Subarea 0 + 1 (offshore). (Research Document 22/022).

Tucker, S., Bowen, W. D., Iverson, S. J., Blanchard, W., & Stenson, G. B. (2009). Sources of variation in diets of harp and hooded seals from quantitative fatty acid signature analysis (QFASA). Marine Ecology Progress Series, 384, 287-302. https://doi.org/10.3354/meps08000

Úbeda, J., Nogueira, A., Tolimieri, N., Vihtakari, M., Elvarsson, B., Treble, M., & Boje, J. (2023). Using multivariate autoregressive state-space models to examine stock structure of Greenland halibut in the North Atlantic. Fisheries Management and Ecology, 30, 521-535. https://doi.org/10.1111/fme.12639

Vacquié-Garcia, J., Spitz, J., Hammill, M., Stenson, G. B., Kovacs, K. M., Lydersen, C., …Jeanniard du Dot, T. (2024). Foraging habits of Northwest Atlantic hooded seals over the past 30 years: Future habitat suitability under global warming. Global Change Biology, 30, e17186. https://doi.org/10.1111/gcb.17186

Villanger, G. D., Gabrielsen, K. M., Kovacs, K. M., Lydersen, C., Lie, E., Karimi, M., … Jenssen, B. M. (2013). Effects of complex organohalogen contaminant mixtures on thyroid homeostasis in hooded seal (Cystophora cristata) mother-pup pairs. Chemosphere, 92, 828-842. https://doi.org/10.1016/j.chemosphere.2013.04.036

Walkusz, W., Atchison, S., Hedges, K., & Deslauriers, D. (2019). Assessment of potential impacts of bycatch mortality on the Arctic cod (Boreogadus saida) populations from the Northern (Pandalus borealis) and striped (Pandalus montagui) shrimp fisheries in Shrimp Fishing Areas 1, 2, and 3. (Research Document 2019/073).

Welch, B. L. (1947). The generalization of ‘student’s’ problem when several different population variances are involved. Biometrika, 34, 28-35. https://doi.org/10.1093/biomet/34.1-2.28

Wolkers, H., Hammill, M. O., & van Bavel, B. (2006). Tissue-specific accumulation and lactational transfer of polychlorinated biphenyls, chlorinated pesticides, and brominated flame retardants in hooded seals (Cystophora cristata) from the Gulf of St. Lawrence: applications for monitoring. Environmental Pollution, 142, 476-486. https://doi.org/10.1016/j.envpol.2005.10.031

Downloads

Published

2024-12-18

How to Cite

Hamilton, C., Goulet, P., Lang, S., Mosnier, A., & Stenson, G. (2024). Large decline in hooded seal (Cystophora cristata) pup production off of northeastern Newfoundland in 2012 and 2017. NAMMCO Scientific Publications, 13. https://doi.org/10.7557/3.7410

Most read articles by the same author(s)