Members of the Status of Stocks and Multispecies Assessment (SSMA) program participated in the 28th Lowell Wakefield Fisheries Symposium "Responses of Arctic Marine Ecosystems to Climate Change" which was held at the Hotel Captain Cook, Anchorage, Alaska, 26–29 March 2013. Franz Mueter of the University of Alaska Fairbanks, Juneau was Chair of the steering committee and is the symposium contact. A description of the symposium follows.
The Arctic Ocean and its adjacent seas are undergoing rapid environmental changes, most notably in the extent and duration of sea ice cover. The biological consequences of these changes and their impacts on humans are complicated and therefore difficult to predict. For example, larger areas and a longer season of open water are likely to increase primary production, while low nutrient availability and more storm events may limit any such increases. Changes in the abundance and spatial distribution of some fish, birds, and mammals have been documented, but whether subarctic species will expand into the Arctic and how arctic species will respond to an extended ice-free season is highly uncertain.
This symposium sought to advance our understanding of present and future responses of arctic marine ecosystems to climate change at all trophic levels from plankton to marine mammals to humans, by documenting and forecasting likely changes in environmental processes and the responses of species to those changes. We encouraged contributions that focused on collaborative approaches to understanding and managing living marine resources in a changing Arctic and to managing human responses—locally, regionally, and globally—to changing arctic marine ecosystems. We believe that important insight and innovation will come from residents of the affected arctic communities.
Dr. Libby Logerwell of the AFSC's Fisheries Interaction Team is a member of the steering committee and co-chaired a session on Marine Fish Resources of the Arctic in a Changing Climate. This session encompassed the biology and ecology of arctic fishes, distributional shifts of fishes into arctic waters, the capacity of local species to adapt to changing conditions, fisheries potential of the Arctic Ocean, and approaches to managing fisheries resources in the Arctic from local to pan-arctic scales. Anne Hollowed, Program Manager for SSMA, was an invited speaker for this session; Libby Logerwell also presented a talk within this session. The abstracts of their talks follow.
Potential Movement of Fish and Shellfish Stocks from the Subarctic to the Arctic Ocean
Anne B. Hollowed, NOAA Fisheries, Alaska Fisheries Science Center, Seattle, WA
Harald Loeng, Institute of Marine Research, Bergen, Norway
Benjamin Planque, Institute of Marine Research, Tromsø, Norway
An assessment was conducted on the likelihood that 17 fish stocks, shellfish stocks, or stock groups will move from subarctic areas into the Arctic Ocean. We assess the vulnerability of fish and shellfish stocks to expected exposure to climate-induced environmental changes in arctic and subarctic ecosystems resulting from climate change. We assess the sensitivity and adaptability of 17 stocks from five ecosystems: Barents Sea, Eurasian shelves of the Arctic, Bering Sea, Chukchi Sea, and Beaufort Sea. These comparisons reveal that several species are considered candidates to migrate into the high Arctic in the future, but it is anticipated that only six stocks have a high probability of establishing viable resident populations in the region. The ability of species to survive in the Arctic depends on how they respond to the physical and biological conditions of the region.
Marine fauna that currently reside in the area exhibit adaptations that make them well suited for the challenging conditions of the Arctic. Examples of these adaptations include: 1) capability of rapid growth to maximize the benefit of a short production season; 2) specific physiological characteristics to survive in cold conditions; 3) capability of inhabiting deep-ocean conditions to avoid ice in winter; 4) diversity of diets; 5) broad spawning range, with low site fidelity; 6) high migration/dispersal rates; and 7) phenotypic plasticity.
Oceanographic Characteristics of the Habitat of Benthic Fish and Invertebrates in the Beaufort Sea
Elizabeth Logerwell and Kimberly Rand, NOAA Fisheries, Alaska Fisheries Science Center, Seattle, WA
Thomas J. Weingartner, University of Alaska Fairbanks, School of Fisheries and Ocean Sciences, Institute of Marine Science, Fairbanks, Alaska
We relate the spatial variability in the distribution of benthic taxa of the Beaufort Sea to oceanographic characteristics of their habitat, with the goal of illustrating potential mechanisms linking climate change to arctic marine communities. Offshore fish of the Beaufort Sea have not been surveyed since 1977, and no synchronous measures of fish distribution and the oceanographic characteristics of their habitat have been made previously. A survey was conducted during August 2008 in the western Beaufort Sea, Alaska. The distribution and abundance of benthic fish and invertebrates were assessed with standard bottom trawl survey methods.
Oceanographic data were collected at each trawl station and at several locations between stations. The dominant benthic taxa, polar cod (Boreogadus saida), eelpouts (Lycodes sp.), and snow crab (Chionoecetes opilio), were associated with cold (<–1.5°C), high salinity (>33) water found offshore of the shelf break, derived from the Chukchi Sea. These waters are expected to be high in secondary productivity, such that we hypothesize that the distribution of fish and crab was driven by conditions favorable for successful foraging. Predictions of the impacts of climate change require an understanding of the mechanisms linking the distribution and abundance of marine organisms to their oceanographic habitat. Our study documents the association of dominant benthic fish and invertebrates of the Beaufort Sea with specific water mass types and is thus a step toward this understanding.
