ESSAS Annual Science Meeting
Bridging the past and present to manage thefuture of northern fisheries and ecosystems

University of Washington

June 20-23, 2022
Fisheries Sciences Building
University of Washington, Seattle

Welcome!
On behalf of the symposium conveners, organizers, and the ESSAS Scientific Steering Committee, wewelcome you to the 2022 Ecosystem Studies of Subarctic and Arctic Seas (ESSAS) Annual Science Meeting,whether you are traveling to Seattle to participate in person or joining us virtually on the Zoom platform
with enhanced conference camera and microphone. In-person participants will meet at the Fisheries Sciences
Building on the beautiful University of Washington Campus.
We are excited to meet in conjunction with the Oceans Past Initiative (OPI) and have developed a joint
session that is meant to foster interactions and possible future collaborations between ESSAS and OPI.
Under the ESSAS umbrella, we are excited to welcome scientists representing at least 7 countries with arange of expertise about sub-arctic and arctic marine ecosystems. We look forward to an excellent mix ofboth oral and poster presentations and encourage all participants to take advantage of this unique opportunity
to exchange information, experiences and ideas with fellow marine scientists from around the Arctic. We
hope that you will also use the occasion of this ASM as an opportunity to explore the University ofWashington campus and the broader Seattle region.
We thank the Oceans Past Initiative for their enthusiastic support of a joint session and our sponsors for theirgenerous support. In particular, we thank the Integrated Marine Biosphere Research (IMBeR) project, theQuaternary Research Center (University of Washington) and the School of Aquatic and Fisheries Sciences(University of Washington).
Here is to a productive, stimulating and enjoyable meeting!
Franz Mueter, Naomi Harada, Benjamin Planque
ESSAS Co-Chairs and Convenors
Ben Fitzhugh, Alan Haynie, Ben Laurel, Franz Mueter
Local Organizing Committee & program committee

ESSAS Annual Science Meeting, June 19-23, 2022
For registration, information on housing and other details, please visit the ESSAS website

Tentative schedule
Sunday, June 19, 2022
13:00 – 16:00

ESSAS SSC meeting

16:30 – 18:30

Ice-Breaker Reception

Monday, June 20, 2022.
Session 1: Learning from the Past to inform the Future(Keynotes: 30 min, all others: 15 min, (r) denotes remote presentation, click on titles to see full abstract)
9:00 – 10:30

Welcome and Conference Opening
Jason Addison (Keynote)

Paleoproductivity records in the Subarctic North Pacific Ocean: Baseline marine
ecological data for the Holocene

Alan Haynie

Socioeconomic Scenarios in the Alaska Climate Integrated Modeling (ACLIM) Project

Sturla Kvamsdal (r)An exploratory analysis of warming effects on wealth in the Barents Sea fisheries

Alberto Rovelllini

Development and calibration of an Atlantis ecosystem model for the Gulf of Alaska

Discussion

10:30 – 11:00

Coffee/Tea Break

11:00 – 12:30

Ina Nilsen

How will climate changes affect the future Northeast Atlantic cod stock in the Nordic
and Barents Seas?

Lucie Buttay

Combining social and ecological time series to describe long-term dynamics of theNorwegian Sea ecoregion.

Al Hermann

Coupled modes of projected regional change in the Bering Sea from a dynamicallydownscaling model under CMIP6 forcing

Björn Birnir

The timing of Global Change

Discussion

12:30 – 14:00

LUNCH

14:00 – 15:30

Cheryl Barnes

Model complexity has contrasting benefits for hindcasting and forecasting species
responses to climate change

Beatriz Dias

Prince William Sound marine ecosystem under different heatwave scenarios.

Szymon Surma

Investigating food web structure and dynamics in the eastern Gulf of Alaska

Carey R. McGilliard (r)Exploring future fishery-related climate impacts to Bering Sea-Aleutian Islands
groundfish fishery using a mixed-species management strategy evaluation framework

Cecilie Hansen

Effects of snow crab in the Barents Sea – Perhaps not only negative?

Discussion

15:30 – 16:00

Coffee/Tea Break

16:00 – 17:15

Louise Copeman

Temperature-dependent survival and growth of early juvenile Bering Sea snow crab
(Chionoecetes opilio) and Tanner crab (Chionoecetes bairdi): implications for optimal
crab thermal habitat in a rapidly warming Alaska Arctic

Mary Beth Decker

Cyclic variability of eastern Bering Sea jellyfish relates to regional physical conditions

Sei-Ichi Saitoh

Sustainable use of salmon resource under changing climate using multiple satellite
datasets

Joji Oida (r)Detection of biologically productive water mass from ocean color satellite using
chromophoric dissolved organic matter (CDOM)

Discussion

Tuesday, June 21, 2022
7:30 – 9:00

Working Group Meetings / Business meetings (hybrid, as needed)

9:30 – 10:30

Session 1 (continued): Learning from the Past to inform the Future

10:30 – 11:00
11:00 – 11:30

Mats Huserbråten (r)Arctic ecosystem impact assessment of oil in ice under climate change

Irene Alabia

Pan-Arctic marine biodiversity patterns under recent climate

Benjamin PlanqueForecasting Northeast Arctic cod stock biomass from climate signal – an appraisal ofmodel skills

Elizabeth Logerwell

Winners and Losers in a Warming Arctic: Potential Habitat Gain and Loss for
Epibenthic Invertebrates of the Chukchi and Bering Seas

Coffee/Tea BreakNicole Misarti

Introduction to CAMHEP: 1000 years of interaction between Icelandic codand humans

Discussion
11:30 – 12:30

Session 2: Arctic Gadids - Past, present, and future
Maxime Geoffroy (Keynote, r) Arctic cod (Boreogadus saida) in Arctic ecosystems: recent state, ecologicalrole, and impact of climate change
Nicolas Dupont

Change in the Barents Sea Arctic food-web dynamic based on biotic and abiotic
environmental factors

Robert Levine

Climate-driven shifts in abundance, distribution, and composition of the age-0 gadid
community in the eastern Chukchi Sea

12:30 – 14:00

LUNCH

14:00 – 15:30

Carmen David (r)The interactive effects of early life traits and changing environmental conditions on
Arctic cod (Boreogadus saida) growth and recruitment in present and future scenarios

Evgeniya Chikurova (r)Phylogeographic and phylogenetic histories of two Eleginus species (Gadidae) basedon Cyt b mtDNA gene

Pavel Emelin (r)Walleye pollock (Gadus chalcogrammus) in the western Chukchi Sea: distribution,
biology, stocks and fishing

Franz Mueter

Arctic Cod (Boreogadus saida) under newly formed sea ice

Lightning talks (poster):

Genoa Sullaway, Carlissa Salant (Poster session Wednesday night)

Discussion (Session 2 and all posters)

15:30 – 16:00

Coffee/Tea Break

16:00 – 18:00

Working Group Meetings / Business meetings (hybrid, as needed)

Wednesday, June 22, 2022
Joint ESSAS/OPI sessions (see full OPI programme)(Keynotes: 30 min, all others: 15 min, (r) denotes remote presentation, click on titles to see full abstract)
9:00 -10.30

Ben Fitzhugh

Joint Welcome and Conference opening

Konstantina Agiadi (Keynote) Mesopelagic fish size response to Pleistocene climatic variability
Session I – World whaling 1
Youri van den Hurk (r)The demise of the Atlantic grey whale
Jason Colby
Devilfish coast: mapping the history of grey whales and people in the North PacificRuairidh Macleod (r)Trapped in ambergris: can preservation of digestive tract metagenomes shed light onsperm whale health and symbionts?

10:30 – 11:00

Coffee/Tea Break

11:00 – 13:00

Session II – Integrating marine historical ecology and natural resource management
Catherine West (Keynote, r) Taking the Long View: Integrating Marine Historical Ecology and Natural Resource
Management in the Gulf of Alaska
Torstein Pedersen (r)Fish otoliths from medieval archaeological excavations provide exploitation effectbaselines
Megan Victor (r)Time Trawlers: An Archaeological Examination of the Fishing Station at Smuttynose
Island and its Implications for the Ecosystem of the Isles of Shoals and the Gulf ofMaine
Ben Fitzhugh
Was there a Pleistocene North Pacific fishery? The evidence for boat use, maritime
subsistence, and subarctic settlement around the North Pacific Rim.
Guðbjörg Ásta Ólafsdóttir
Historical and contemporary concerns about the consistency of Atlantic cod ecotypes
around Iceland.
Iain McKechnie
Estimating ocean temperature trajectories from ancient Indigenous fishery catchrecords: an archaeological case study from the northeast Pacific13:00-14:30

LUNCH - EARLY CAREER RESEARCHER BREAKOUT

14:30 – 16:00

Session III – World whaling 2
John Nicholls
Nina Veira
Matthew Ayre
Sophia Nicolov
Laura Courto

Global Leviathan Database - extractions through the modern and early modern periods
Portuguese whaling history: a digital data management journey
A high-resolution historical faunal archive from British Arctic whaling logbooks
Whales at the ends of the worlds
Scrimshaw: unlocking the cultural and biological archive of sea mammal art

16:00 – 16:30

Coffee/Tea Break

16:30 – 17:30

Session IV – Multiple Stressors
Benjamin PlanqueJessica Cross
Trond Kristiansen
Discussion

EVENING
18:00 – 19:30

Stakeholder perspectives on the response of the Barents Sea to multiple pressures
The next decade of ocean acidification research in the Bering Sea: what we’ve learned
and what’s coming next
Climate change impacts on marine light in Arctic ecosystems

JOINT ESSAS AND OPI POSTER SESSION/RECEPTION (see OPI programme for additional posters)
Remote participation is encouraged. Review posters online and ask questions of any presenters
Hisatomo Waga (poster)Junghyun Park (poster)
Hikaru Hikichi (poster)Austin Flanigan (poster)
Genoa Sullaway (poster)Michele Ottmar (poster)
Kali Stone (poster)
Amalis Riera (poster)

Satellite-based monitoring of phytoplankton phenology using a parametric modelingapproach in the Northern Gulf of Alaska
Increasing Arctic River Discharge and Its Role for the Phytoplankton Responses in
the Present and Future Climate Simulations
Responses of mesozooplankton biomass to climate change in the southeastern
Bering Sea shelf during the summers of 1955–2013 (summary of T/S Oshoro-Marucruises) with special references to the taxonomic composition and normalised
biomass size spectrum for several consecutive years at each climate regime
Understanding Pacific Halibut spatial dynamics in the northern Bering Sea
Data integration to model lower trophic levels in the Eastern Bering Sea
Effects of ocean acidification and warming on fertilization, egg survival and size athatch of early life stages Polar cod (Boreogadus saida)
Growth, condition, and movement of juvenile Arctic cod (Boreogadus saida) in a
warming Alaska Arctic
Sounds of walleye pollock: a quantitative descriptionHillary Thalmann (poster)

Olga Maznikova (poster)Juvenile Pacific Cod foraging and growth in response to anomalous warming in Gulf
of Alaska nursery habitats
Covarying lipid and fatty acid profiles among phytoplankton and Arctic cod(Boreogadus saida) in the Eastern Canadian Arctic
Polar cod (Boreogadus saida) of the Siberian Arctic: distribution, stocks and biology

Casey Clark (poster)

SuessR: A new tool for applying Suess and Laws corrections to marine δ13C data

Carlissa Salant (poster)Thursday, June 23, 2022
Session 3 / Workshop: Subarctic Gadids - Past, present, and future
9:00 – 10:30

Jessica Miller (Keynote)

Thermal effects on early life stages of Gulf of Alaska Pacific Cod: shifts inphenology

David Cote

Forecasted Shifts in Thermal Habitat for Cod Species in the Northwest Atlantic andEastern Canadian Arctic

Sofia Ferreira (r)Spatio-termporal overlap of cod, haddock and capelin in the Norwegian-Barents Sea
systemEmily Geissinger

Condition, size, and winter duration affect winter survival probability in juvenile
Atlantic cod (Gadus morhua) in a coastal ecosystem

Ben Laurel

Pacific cod in the Anthropocene: an early life history perspective under changing
thermal habitats

10:30 – 11:00

Coffee/Tea Break

11:00 – 12:30

Jennifer Bigman

Predicting Pacific cod spawning habitat in a changing climate

Giancarlo Correa

Modeling the multiple action pathways of projected climate change on the Pacificcod (Gadus macrocephalus) early life stages

Steven Barbeaux

Using an Environmentally Linked Assessment for Strategic Fisheries Management
Planning

Zoe Almeida

Warmer, earlier, faster: Cumulative effects of Gulf of Alaska heatwaves on the earlylife history of Pacific Cod
Changes in spawn timing of walleye pollock and impacts on assessment surveys in
the Gulf of Alaska

Lauren Rogers (r)ABSTRACTS(all abstracts are hyperlinked from titles above)
Model complexity has contrasting benefits for hindcasting and forecasting
species responses to climate change
Cheryl L. Barnes 1, Timothy E. Essington 1, Jodi L. Pirtle 2, Christopher N. Rooper 3, Edward A. Laman 4,
Kirstin K. Holsman 4, Kerim Y. Aydin 4, James T. Thorson 4

1

School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA,e-mail: cheryl.barnes@noaa.gov
2
Alaska Regional Office, National Marine Fisheries Service (NOAA), Juneau, AK
3
F isheries and Oceans Canada, Nanaimo, BC
4
Alaska Fisheries Science Center, National Marine Fisheries Service (NOAA), Seattle, WA
Identifying and predicting species responses to climate change is a high priority in ecology. Species
distribution models (SDMs) are commonly used to quantify environmental drivers of distributions anddensities; however, we lack information about how well these models predict fine-scale population
metrics under novel conditions. We compared the performance of a suite of SDMs when hindcasting
species-habitat associations and forecasting responses to changing climates. We present two case studies
from the Bering Sea, a system that has recently undergone considerable warming. Conventional statistics(R2, % Deviance Explained, UBRE or GCV) were used to assess the performance of in-sample predictions(i.e., hindcasts) for Arrowtooth Flounder (Atheresthes stomias) and Walleye Pollock (Gadus
chalcogrammus).
Retrospective skill testing was used to compare out-of-sample predictions (i.e., forecasts) with observed
distributions or densities. The most complex models, which accounted for spatial, temporal, andspatiotemporal variation in addition to static and dynamic habitat covariates, outperformed all othermodels when hindcasting population metrics. Static models that relied on long-term mean environmental
conditions, however, exhibited greater forecast skill. Decreased forecast skill for dynamic models likely
resulted from predicting species responses to temperatures outside the range of those used in model
fitting. Thus, dynamic SDMs better reflect the amount of spatiotemporal variation in natural systems, but
static SDMs may prove more skillful when forecasting responses to novel environmental conditions. We
also found that model performance and forecast skill were dependent upon the species and population
metric of interest, suggesting a negative relationship with niche breadth. Expanding environment-only
SDMs to include spatiotemporal variation in fishing pressure, trophic interactions, and other important
context-specific drivers would likely improve forecast skill. Nonetheless, our results demonstrate support
for the use of retrospective skill testing in model selection rather than identifying forecast models a priori
based on their ability to quantify species-habitat associations from the past.

Predicting Pacific cod spawning habitat in a changing climate
Jennifer Bigman1, Lauren Rogers1, Ben Laurel1, Kelly Kearney1,2, Kirstin Holsman1, Al Hermann2,41

Alaska Fisheries Science Center, National Oceanic Atmospheric Administration
Cooperative Institute for Climate, Ocean, and Ecosystem Studies, University of Washington, Seattle, WA
3
Ocean Environment Research Division, National Oceanic Atmospheric Administration, Pacific Marine
Environmental Laboratory, Seattle, WA
2

Warming temperatures elicit shifts in habitat use and distributions of fishes, with uneven effects across life
stages. Spawners and eggs are more sensitive to environmental conditions compared to other life stages
and, thus, spawning location and egg development are often constrained spatially and temporally.
Additionally, spawning dynamics are closely tied to population dynamics and fisheries management. To
understand how temperature affects the spatiotemporal variability of spawning habitat, we predict theavailability of thermally-suitable spawning habitat for Pacific cod in the eastern Bering Sea to the end of thiscentury.
Specifically, we use bottom temperature hindcasts and projections from regionally downscaled global
climate models, coupled with an experimentally-derived relationship between hatch success andtemperature to examine how the extent, mean latitude, and consistency of spawning habitat changes overtime. We also test whether year-class strength relates to the availability of suitable spawning habitat tounderstand how changes in habitat use may be linked to changes in fisheries productivity. We find that theextent and mean latitude of spawning habitat increase over time, particularly if no climate mitigation occurs
in the future. Hotspots of spawning habitat are consistent within decades but do expand from the outer
towards the middle and inner shelf by the end of the century. We find no correlation between theavailability of suitable spawning habitat and year class abundance. Collectively, our results suggest thatspawning habitat availability for Pacific cod increases and expands spatially across the southeastern Bering
Sea shelf over time, and as such, is unlikely to affect fisheries productivity, at least in the near-term. This
work highlights the use of coupling experimental data with climate models to identify complex dynamics
among temperature, life histories, and ecology, and offers a pathway for examining life stage-specificchanges in habitat use and distribution with climate change.

Arctic cod (Boreogadus saida) in Arctic ecosystems: recent state, ecological role,and impact of climate change
Maxime Geoffroy1, Caroline Bouchard, Hauke Flores, Dominique Robert, Harald Gjøsæter, Carie
Hoover, Haakon Hop, Nigel Hussey, Jasmine Nahrgang, Nadja Steiner, Morgan Bender, Jørgen Berge,
Giulia Castellani, Natalia Chernova, Louise Copeman, Carmen L. David, Alison Deary, George Divoky,
Andrey Dolgov, Janet Duffy-Anderson, Nicolas Dupont, Joël M. Durant, Kyle Elliott, Stéphane Gauthier,
Esther Goldstein, Rolf Gradinger, Kevin Hedges, Jennifer Herbig, Ben Laurel, Lisa Loseto, Sarah Maes, Felix
Mark, Anders Mosbech, Sara Pedro, Harri Pettitt-Wade, Irina Prokopchuk, Paul E. Renaud, Fokje
Schaafsma, Sarah Schembri, Cathleen Vestfals, Wojciech Walkusz

1

Fisheries and Marine Institute of Memorial University. e-mail: maxime.geoffroy@mi.mun.ca

We present a comprehensive overview of Arctic cod (Boreogadus saida) physiology, ecology, distribution,and habitats to assess how climate change affects the most abundant pelagic fish in the Arctic Ocean. This
presentation identifies vulnerabilities to climate change for different life stages across the whole
distribution range of Arctic cod. We explore the impact of environmental (abiotic and biotic) andanthropogenic stressors on Arctic cod with a regional perspective in a scenario up to the year 2050, andidentify knowledge gaps constraining predictions. We conclude that the epipelagic eggs and larvae are
more vulnerable to climate change than adults. Sea ice decline, ocean warming, change in freshwater input,changing prey field, increased competition, new predators, as well as pollution are the main stressors that
present a high or very high risk of impacting Arctic cod population dynamics. The risk from fisheries ismoderate and mainly limited to bycatch. Detrimental effects are stronger in regions with advection ofAtlantic and Pacific waters. In contrast, Arctic cod may benefit from ocean warming in colder areas of thehigh Arctic. Overall, a decrease in total Arctic cod biomass and in the abundance of ice-associatedindividuals is predicted. In most Arctic seas, the relative abundance of Arctic cod within the fish community
will likely fluctuate between cold and warm periods. A reduced abundance of Arctic cod, to the advantage
of boreal fish species, can negatively impact the abundance, distribution, and condition of certain
predators, whereas other species can successfully adapt to a more boreal diet. Management andstewardship measures adapted to specific regions of the Arctic that recognize the critical role of Arctic cod
are required to ensure that increased anthropogenic activities do not exacerbate the impacts of climatechange on northern marine ecosystems.

Phylogeographic and phylogenetic histories of two Eleginus
species (Gadidae) based on Cyt b mtDNA gene
Evgeniya A. Chikurova1,2, Alexei M. Orlov1,2,3,4,5,6, Dmitry M. Shcepetov7,8,9,
Svetlana Yu. Orlova1,3
1

Russian Federal Research Institute of Fisheries and Oceanography, Moscow, Russia.
e-mail: orlov@vniro.ru
2
A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia;
3
Shirshov Institute of Oceanology of the Russian Academy of Sciences, Moscow, Russia;
4
Tomsk State University, Tomsk, Russia;
5
Dagestan State University, Makhachkala, Russia;
6
Caspian Institute of Biological Resources of Dagestan Federal Research Center of the Russian Academyof Sciences, Makhachkala, Russia;
7
Koltzov Institute of Developmental Biology of the Russian Academy of Sciences, Moscow, Russia;
8
National Research University ‘Moscow Power Engineering Institute’, Moscow, Russia;
9
National Research University Higher School of Economics, Moscow, Russia

The fishes of the genus Eleginus (Gadidae) are typical representatives of the cold water ichthyofaunaof the northern hemisphere adapted to habitat under low temperatures. They play an important
trophic role in the ecosystems of the Arctic and adjacent Pacific Ocean and serve as targets ofcommercial and artisanal coastal fisheries in many regions of the Russian North and Far East as well as
in some coastal areas of Alaska and Japan. Their intra-species organization that is necessary for therational exploitation of the stocks remains poorly understood, while their inter-species relationships
were previously analyzed based on very limited samples. In the present report, the results of the studyof inter-species relationships and population structure of the Navaga Eleginus nawaga and saffron
cod E. gracilis are presented for the first time based on large-scale samples (986 individuals in 29
samples from the majority of the species’ ranges) using the analysis of mtDNA Cyt b gene
polymorphism. These results showed that both representatives of the Eleginus genus were independent
species well differentiated from each other. Genetic analysis of Eleginus and Microgadus species
showed that both representatives of the former genus may originate from the common ancestor
closely related to M. proximus, while the divergence in the latter genus occurred considerably
earlier. The data on haplotype diversity of the saffron cod samples within the area from Peter theGreat Bay (Sea of Japan) to Alaskan waters and of the Navaga from the White Sea to Obskaya Guba in
the Kara Sea are presented that allow for judging of phylogeographic histories of both Eleginus species
and their intra-species structures within the studied areas.

Polar cod (Boreogadus saida) of the Siberian Arctic:
distribution, stocks and biology
Olga A. Maznikova1*, Pavel O. Emelin1, Alexei M. Orlov1,2,3,4,5,6
1

2
3
4
5
6

Russian Federal Research Institute of Fisheries and Oceanography, Moscow, Russia
e-mail: maznikovao@vniro.ru
Shirshov Institute of Oceanology of the Russian Academy of Sciences, Moscow, Russia
A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia
Tomsk State University, Tomsk, Russia
Dagestan State University, Makhachkala, Russia
Caspian Institute of Biological Resources of Dagestan Federal Research Center of the Russian Academy of
Sciences, Makhachkala, Russia

Polar cod (Boreogadus saida) is a widespread Arctic fish species. Due to its relatively high abundance, polar
cod is occupying a central position in the Arctic food web, which makes it a reliable indicator of changes inhigh latitudes marine ecosystems. Polar cod biology and spatial distribution are described on the results oftrawl surveys conducted in the Siberian Arctic (Laptev Sea, Chukchi Sea and East Siberian Sea) in AugustSeptember of 2003-2018. Spatial distribution and size composition of its individuals within the study area
were characterized by similar patterns. Retreat of the polar front and a reduction in the area of ice
cover leads to a northward shift in the boundaries of polar cod distribution and, as a consequence, todecreasing of its abundance within the study area and to restructuring of Siberian Arctic marine ecosystems.
In all surveyed seas, polar cod aggregations consisted of individuals 3 to 29 cm long aged 0+ to 6+ years. The
schoolings were represented by larger individuals near the bottom and by smaller fish in the water column.
Due to the harsh climate conditions and low productivity, the smallest polar cod individuals were found in
the East Siberian Sea. In the Chukchi and East Siberian seas, its main concentrations were observed within thenear-bottom layer, while in the Laptev Sea they were recorded in the water column. The abundance andbiomass of polar cod in the Chukchi Sea in different years ranged from 514 million inds. and 0.830 thousand
tons (2008) to 8256 million inds. and 117.5 thousand tones (2003). Respective indices for the Laptev Sea
amounted to 12753 million individuals and 233 thousand tones. The abundance and biomass of the East
Siberian Sea polar cod were at a relatively low level compared to other seas (about 20 million inds. and 0.150
thousand tons).

Walleye pollock (Gadus chalcogrammus) in the western Chukchi Sea:
distribution, biology, stocks and fishing
Pavel O. Emelin1, Olga A. Maznikova1, Alexei M. Orlov1,2,3,4,5,6
1

2
3
4
5
6

Russian Federal Research Institute of Fisheries and Oceanography, Moscow, Russia.
e-mail: emelin@vniro.ru
Shirshov Institute of Oceanology of the Russian Academy of Sciences, Moscow, Russia;
A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia;
Tomsk State University, Tomsk, Russia;
Dagestan State University, Makhachkala, Russia;
Caspian Institute of Biological Resources of Dagestan Federal Research Center of the Russian Academy of
Sciences, Makhachkala, Russia

Walleye pollock is the most abundant and widely distributed species of the North Pacific.
In the Chukchi Sea, walleye pollock juveniles were first found in small quantities in its southern part in thelate 1970s. However, until recently, there was no information on the occurrence of adult fish in the
Chukchi Sea. Based on research of 7 trawl surveys conducted onboard Russian research vessels in 20032020 the data on the biology, spatial and vertical distributions of walleye pollock in the western Chukchi
Sea are provided. Spatial distribution of walleye pollock does not fundamentally differ from that in otherparts of its range. Schoolings in the water column during all the years of research were mainly
represented by juveniles (FL 5-12 cm), which proportion varied from 93 to 100%, while medium-sized andlarge individuals in catches were rare. In bottom trawl catches, walleye pollock was represented mainly byboth juveniles (FL 7-14 cm) and large-sized fish (FL 50-62 cm), and the proportion of medium-sizedindividuals was insignificant. Vertical distribution was characterized by an increase in the number of large andolder fish with a decrease in depth as well as the predominance of adult fish and juveniles at shallow depths.
The age structure of walleye pollock was significantly different from that of both the western and eastern
Bering Sea. Age groups representing recruitment of commercial stock (aged 3-5 years) were not observedin the catches. This may testify that the walleye pollock population of the western Chukchi Sea depends
on the migration activity of individuals from the Bering Sea. Bottom trawl surveys in 2019-2020 period
allowed to set for the former area a total allowable catch as 37,200 t for 2021 and 2022 fishing seasons andto start walleye pollock fishery there in 2021 when over 4,000 t were caught.

Stakeholder perspectives on the response of the Barents Sea
to multiple pressures
Benjamin Planque1, Nina Mikkelsen1,2
1
2

IMR, Tromsø, Norway, benjamin.planque@hi.no,
Arthur Valance, Ifremer, Nantes, France

Human activities, climate variability and change, and other drivers affect the structure and dynamics ofthe Barents Sea, as well as the ecosystem services it provides. Anticipating the combined effects of these
multiple drivers is required to support management decisions, but stakeholder groups, managers andscientists may hold different points-of-view on the functioning of the Barents Sea and may therefore havedistinct anticipations.
This contribution explores how stakeholders can anticipate the consequences of changes in multiple
drivers on the Barents Sea ecosystem and its associated services. The approach is based on a scoping
exercise followed by qualitative modelling. The scoping exercise was conducted with six stakeholder
groups representing different sectors (fishing, shipping, tourism, oil and gas) and interest (environmental
protection), during a 2-day workshop and subsequent dialogues. From this, several hierarchicalconceptual models of the Barents Sea were constructed. The conceptual models were then used todevelop qualitative models that predict how different components of the Barents Sea may respond tochanges in one or several driving forces. We applied selected scenarios of changes in human activities andchanges in the biomass of animal groups to assess the effects of cumulative impacts. These modelling
experiments were conducted on a synthesis model common to the stakeholder groups and on
stakeholder-specific models. The model results indicate that cumulative impacts are mostly additive. The
comparison of results across models reveals that the conclusions derived from the synthesis model arerobust and reflect well the perspectives of the various stakeholders. This suggests that there exists a
common understanding of the Barents Sea functioning across stakeholder groups and that, at least insome instances, a common representation of the system may be used to support ecosystem-based
management.

Forecasting Northeast Arctic cod stock biomass from climate signal:
an appraisal of model skills.
Benjamin PlanqueInstitute of Marine Research, Tromsø, Norway. e-mail: benjamin.planque@hi.no
Recent publications have argued for the possibility of making robust forecasts of cod stocks biomass in
the Barents Sea several years in advance. The core idea in these contributions is that the dynamic of codbiomass is partly controlled by the sea temperature regime and that sea temperature can be predicted
several years in advance. A central point to these studies is the measure of the "skill" of the model
predictions. High skill is interpreted as the opportunity to make robust predictions about the futurebiomass of cod stocks, several years in advance, and then use these predictions to support management.
In this presentation, I distinguish prediction skills from forecast skills and discuss the differences between
the two when these are used to assess the performance of a model. I explore the possibility that thereported prediction skills could have emerged by chance. I also discuss which type of skills may beappropriate if predictions are to be used to support management. A re-analysis of the data indicates ahigh risk that the originally reported prediction skills could have arisen by chance. The newly estimatedforecasting skills are generally lower than the prediction skills originally reported. Finally, forecasts from acontrol model based on persistence-only are often as good or better than the forecasts fromtemperature-base models. These results highlight the challenges in producing climate-based cod stock
forecasts that are sufficiently robust to support ecosystem-based management.

Satellite-based monitoring of phytoplankton phenology using a parametricmodeling approach in the Northern Gulf of Alaska
Hisatomo Waga1,2
1
2International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, AK, USA
Arctic Research Center, Hokkaido University, Sapporo, Hokkaido, Japan.
mail: hwaga@alaska.edu

The fundamental food source for higher trophic level animals in marine systems is the carbon produced by
the phytoplankton community. Observations and modelling studies suggest that the ocean is becoming
increasingly stratified in response to a warming climate, limiting nutrient exchange to the upper sunlit
ocean and favoring small cells able to grow in warmer, nutrient poor conditions. Phytoplankton
assemblages dominated by smaller cells are associated with longer food chains and decreased energy
transfer to higher trophic levels such as zooplankton, and ultimately, fish. In the Northern Gulf of Alaska(NGA) threats of increased water column stratification are amplified by accelerated glacial melt, a sea
surface warming trend roughly twice the global average, and more recently, recurring ‘heatwave’ events.
These changes also threaten to alter the NGA’s phytoplankton blooms, upon which numerous species rely
on for survival. Given that the NGA contains one of the largest and most valuable fisheries in the nation,
investigating these climate-driven threats and linking them to fisheries is of immense social and economic
importance. To further accurate monitoring of seasonal phytoplankton dynamics in the NGA, this study
examines the performance of a parametric modeling approach to capture phytoplankton phenology in the
NGA over the time period 2003–2021. To this end, time-series of satellite-retrieved phytoplankton
biomass were modeled using a parametric Gaussian function, as an effective approach to capture thedevelopment and decay of seasonal phytoplankton blooms. In general, the timing, duration, andamplitude of phytoplankton blooms are known to be essential features that define phytoplankton
phenology. The present study will demonstrate the robustness/uncertainties of the parametric modelingapproach for satellite-based monitoring of phytoplankton phenology in the NGA.

Effects of ocean acidification and warming on fertilization, egg survival andsize at hatch of early life stages Polar cod (Boreogadus saida)
Ottmar, M.L.1, Hicks, M.B.R.2, Laurel B.J.1, Magel C.1, Hurst, T.P.1
1

Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric
Administration, Hatfield Marine Science Center, Newport, OR, USA.
e-mail: Michele.ottmar@noaa.gov
2
Saltwater INC, Under Contract to Alaska Fisheries Science Center, National Marine Fisheries Service,
National Oceanic and Atmospheric Administration, Hatfield Marine Science Center, Newport, OR, USA

Warming temperatures and rising pCO2 levels are co-occurring and present the need for a greater
understanding of multistressor effects on marine species. Recent studies on growth and survival underelevated pCO2 suggests a species-specific response with physiological complexity not necessarily linked
to species habitat. Polar cod (Boreogadus saida), a pelagic, keystone species, serves as a high energy
food source for marine mammals and seabirds. Early life stages of Polar cod are sensitive totemperatures above 3.5°C but vulnerability to synergistic effects of elevated pCO2 levels andtemperature are unknown. We examined fertilization, hatching success and size at hatch of Polar cod in
two experiments. In one experiment, Polar cod eggs obtained from a captive broodstock were fertilized
at pH 7.6 and 8.0 with fertilization success in 3 replicates scored after 24 hours of incubation at 1°C.
Fertilization success varied across egg batches (obtained from different females), but was higher at pH
8.1 than 7.6 in 12 of the 15 batches. In a separate experiment, replication with 2 independent, mixed
parentage groups of Polar cod eggs were incubated from 5 and 8 days post fertilization (dpf) to hatch
under a factorial design of 3 pH (7.5, 7.7, 8.0) and 2 temperature (1°C, 3.5°C) treatments. The higher
temperature reduced the time to hatch and survival to hatch and resulted in higher rates ofmalformations. Higher temperatures also resulted in larvae hatching at a smaller size (length) but withincreased yolk area. Elevated pCO2 appeared to have no effect on hatching success, size at hatch or yolk
area. These observations of elevated pCO2 levels affecting fertilization success, but not egg
development, demonstrate stage-specific effects and the need to consider climate variation at all life
stages of marine fishes.

Juvenile Pacific Cod foraging and growth in response to anomalous warmingin Gulf of Alaska nursery habitats
Hillary Thalmann1, Ben Laurel2, and Jessica Miller1
1

Oregon State University, Coastal Oregon Marine Experiment Station, Department of Fisheries, Wildlife,and Conservation Sciences. e-mail: hillary.thalmann@oregonstate.edu
2National Marine Fisheries Service – NOAA, Alaska Fisheries Science Center

Pacific Cod (Gadus macrocephalus), an ecologically and commercially important fish species in the Gulf of
Alaska, is highly susceptible to warming ocean temperatures. Following two marine heatwaves in 20142016 and 2019, the population declined by ~75%, leading to the closure of the federal fishery in 2020.
Early life stages of Pacific Cod may be particularly susceptible to arming, including age-0 juveniles during
periods of rapid summer growth in coastal nursery habitats. To evaluate potential consequences ofextreme thermal variability on juvenile Pacific Cod, we assessed the size, diet composition, and recent
growth of post-settled age-0 juveniles collected from Kodiak Island in July and August, 2006 - 2019.
Juvenile Pacific Cod were ~40% larger during warmer years, with more extreme size discrepancies byAugust. Non-metric Multidimensional Scaling (NMS) ordinations of diet composition explained 86% of
overall variability in July and 76% of variability in August. Body size was correlated with axis 1 of the NMS
ordination in both July and August (r > 0.50), and temperature was correlated with axis 1 by August (r = 0.71). In both July and August, smaller prey items (e.g. copepods and cladocerans) were more common inyears prior to the heatwaves, and larger prey items (e.g. mysids, polychaetes, and shrimps) were morecommon during the heatwaves. The final three weeks of nursery growth in both July and August werestrongly influenced by fish size, ocean temperature, and year (Mixed Effects Model; p < 0.001), but NMS
axis scores did not significantly contribute to daily otolith increment width in either month. Together,patterns in size, diet composition, and recent nursery growth suggest that larger, faster-growing age-0
Pacific Cod may have a survival advantage during heatwave conditions, which likely drives their foraging
patterns in the nursery, leading to consumption of larger and more diverse prey during heatwave
conditions.

Modeling the multiple action pathways of projected climate change on the Pacific cod(Gadus macrocephalus) early life stages
Giancarlo M. Correa1*, Thomas P. Hurst2, William T. Stockhausen3, Lorenzo Ciannelli1
Trond Kristiansen4,5, Darren J. Pilcher6,7
1

College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA.
e-mail: g.moroncorrea@gmail.com
2
National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Newport, OR, USA
3
National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, USA
4
Fallaron Institute, Petaluma, CA, USA
5
Norwegian Institute for Water Research (NIVA), Oslo, Norway
6
Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, WA, USA
7
Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, WA,USA
Understanding how future ocean conditions will impact fish early life stages and the effects on population
recruitment is critical for the adaptation of fisheries communities to climate change. In this study, we used
an oceanographic (Bering10K) and a mechanistic individual-based model (IBM) for larval and juvenile fish
to analyze how climate change (warming and ocean acidification) may impact the hatch success, growth,survival, and spatial distribution of Pacific cod (Gadus macrocephalus) in the eastern Bering Sea during
2010-2100. We evaluated two emission scenarios: RCP8.5 (high emissions, low mitigation efforts) and
RCP4.5 (medium emissions and mitigation efforts). Under the high emission scenario, the Bering10K
projected an increase in temperature, pCO2 concentration, and large-bodied copepod in the cod larval
habitat, while a decrease in euphausiids and small-bodied copepods are expected. We observed thatwarmer years produced faster growth rates but decrease survival probability by increasing starvation,
which agreed with the current knowledge of the ecology of this species. Projected environmental changes
produced an increase in hatch success and growth by the end of the century; however, they also triggered
a reduction in the probability of survival and dying from starvation. Ocean warming was the main driver ofthese changes, whereas ocean acidification had negligible impacts. We also identified a larval retention
area in the southeastern Bering Sea, which also had a higher survival probability and smaller larval sizes.
Based on these results, recruitment is expected to decrease in the future, which may have ecological andsocio-economic impacts in the Alaska region. Our results support the hypothesis that starvation might be a
crucial driver of recruitment in the eastern Bering Sea as observed for other gadids.
Keywords: climate change, Pacific cod, fish, recruitment, individual-based modeling, mechanistic modelingIncreasing Arctic river discharge and its impacts on the phytoplankton response
under present and future climate simulations
Junghyun Park1, Seong-Joong Kim2, Hyung-Gyu Lim3, Jong-Seong Kug4,
Eun Jin Yang5, Baek-Min Kim1,*
1

Division of Earth Environmental System Science Major of Environmental Atmospheric Sciences, Pukyong
National University, Busan 48513, South Korea. e-mail: james70712@gmail.co
2
Division of Atmospheric Sciences, Division of Ocean Sciences, Korea Polar Research Institute, 26
Songdomirae-ro, Incheon 21990, South Korea
3
Atmospheric and Oceanic Sciences Program, Princeton University, Princeton, NJ 08540, USA
4
Division of Environmental Science and Engineering, Pohang University of Science and Technology(POSTECH), Pohang 37673, South Korea
5
Division of Ocean Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Incheon 21990, South
Korea* Corresponding author: Baek-Min Kim (baekmin@pknu.ac.kr)
Arctic amplification is known to accelerate the hydrological cycle in high-latitude landmasses, which
eventually leads to increased river discharge into the Arctic Ocean. However, the majority of climate
models in the Coupled Model Intercomparison Project 5 (CMIP5) tend to underestimate Arctic riverdischarge. This study elucidates the role of additional Arctic river discharge for the phytoplankton
responses under present and future climate simulations. In the present climate simulation, the additional
freshwater input showed a decrease in the phytoplankton in spring due to the increasing sea ice, and insummer, it showed an increase in phytoplankton due to the surplus nitrate left over from spring andinduced vertical mixing. Similar processes occurred in future climate simulations.
However, in those simulations, the major response region of phytoplankton to additional freshwater input
was altered from the Eurasian Basin to the Canadian Basin and the East-Siberian Sea. This is because thecurrent marginal ice zone in the Barents-Kara Sea, where phytoplankton mainly responds, moves toward
the East-Siberian-Chukchi Sea. We suggest that Arctic river discharge is potentially an important
contributing factor for Arctic ecosystems in both present and future climate that controls sea ice andnutrient distribution.

Spatio-termporal overlap of cod, haddock and capelinin the Norwegian-Barents Sea system
A Sofia A Ferreira1,2, Joël M Durant1, Natalia Yaragina3, and Øystein Langangen1
1

Department of Biosciences, University of Oslo, Oslo, Norway
e-mail: asofiaaferreira@gmail.com
2
Department of Biology – Aquatic Biology, University of Aarhus, Denmark
3
Polar branch of Russian Federal Research Institute of Fisheries and Oceanography, VNIRO, Murmansk,
RussiaThe Norwegian-Barents Sea (NBS) system is very productive. However, the extent to which thisproductivity is challenged remains uncertain for many species. Cod (Gadus morhua), haddock(Melanogrammus aeglefinus), and capelin (Mallotus villosus) are three key species in the NBS ecosystem. In
this study, we investigate the interaction of these three species and assess the impact their spatiotemporal overlap at their pelagic larval stages has on their survival. In this study, we ask: what is theeffect of the spatio-temporal overlap between the three species (cod, haddock, and capelin) on theirsurvival at later stages? Thus, our objectives are to quantify the overlap in both space and time, and toassess whether the overlap affects the survival of the three species. Data on larval abundances werecollected during the ichthyoplankton surveys run by the Knipovich Polar Research Institute of Marine
Fisheries and Oceanography in both spring (April−May) and summer (June−July) by using an egg net
and ring trawl. Data on survival indices were collected from the Arctic Fisheries Working Group from theInternational Council for the Exploration of the Sea. We then calculated the spatio-temporal overlap of
the three species and test it against the survival indices of each. We observed a negative effect of theoverlap between cod and the species it competes with (haddock and capelin) explaining 12 % of cod
recruitment at age 0, whereas the negative effect of overlap between haddock and the species it competes
with (cod and capelin) explain 11 % of haddock recruitment at age 0. The overlap between capelin and theother species does not show a significant result. These results improve the understanding of how these
species use their critical habitats to face emerging environmental stressors such as habitat loss, oil spills,
and climate change.

Historical and contemporary concerns about the consistencyof Atlantic cod ecotypes around Iceland.
Guðbjörg Ásta Ólafsdóttir

University of Iceland, Research Centre of the Westfjords, Hafnargata 9b, 415 Bolungarvik, Iceland.
e-mail: gaol@hi.is

Atlantic cod is a keystone species that remains among the most economically important demersal fish in
the North Atlantic despite severe stock depletion resulting from overexploitation. Throughout its
distributional range Atlantic cod is composed of populations or ecotypes that vary across environmental
gradients, such as temperature or salinity, across geographical regions and in phenotypic traits,
importantly, in migratory propensity. This variation has repeatedly been linked to genetic divergence on
several genomic inversions or “supergenes”. The origin of these supergenes is ancient and variation in cod
migratory behavior has been noted throughout historical times. This life-history variation is likely to havecontributed to the relative resilience of Atlantic cod to environmental change and exploitation. In the subarctic North Atlantic cod ecotypes exhibiting longer foraging migration and preferentially seeking cooler
temperatures, or migratory cod, are present both around Iceland and Norway. Icelandic migratory cod seek
cooler arctic waters for feeding but they are currently dependent on warmer nearshore waters forspawning, transport of eggs and larvae and, critically, growth at nursery grounds. Here, data on theconsistency, growth, foraging ecology and movement of Atlantic cod ecotypes in Icelandic waters inhistorical times will be presented and discussed in the context of how current anthropogenic stressors may
differently affect the ecotypes, specifically at early life-stages.

Change in the Barents Sea Arctic food-web dynamic based on
biotic and abiotic environmental factors

Nicolas Dupont1, Joël M. Durant1, Øystein Langangen2, Leif Chr. Stige1,3

1

Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Box 1066
Blindern, NO-0316 Oslo, Norway.
2
Section for Aquatic Biology and Toxicology, Department of Biosciences, University of Oslo, P.O. Box 1066
Blindern, NO-0316 Oslo, Norway.
3
Norwegian Veterinary Institute, 1431 Ås, Norway Contact mail: nicolas.dupont@ibv.uio.no

The Arctic part of the Barents Sea is currently facing a range of environmental changes identified as“borealization”. The phenomenon includes a decreasing sea-ice cover, increasing sea temperatures and theincreasing presence of boreal piscivorous species such as the Atlantic cod (Gadus morhua). As Atlantic cod
expands in the Northern Barents Sea, the predation level on forage fish species, otherwise preyed on by
sea-ice adapted marine mammals such harp seal (Pagophilus groenlandicus), may increase. In this context,
we focused on a key Arctic fish species and common prey for both Atlantic cod and harp seal: the polar
cod (Boreogadus saida). Varying abundance and distribution of the capelin (Mallotus villosus) stock, whichis also a common prey for both Atlantic cod and harp seal, has been previously suggested to affect the
predation of both predators on polar cod. In the light of current environmental changes, we quantified theeffects of both predators on the abundance-at-age of polar cod depending on both summer sea-ice coverand capelin stock using a threshold multilinear regression in a Bayesian framework. Using a 31-year times
series (1986-2017) of polar cod abundance, we showed that predation effects on adult polar cod varydepending on summer sea-ice cover and capelin stock conditions. Significant predation effects of bothpredators were associated with years of low capelin stock values. However, significant effects of Atlantic
cod and harp seal varied between years of low and high summer sea-ice cover. Our results suggest that the“borealization” of the Barents Sea Arctic may lead to a shift in food web dynamics. Effects of expanding
subarctic predators may alter predation pressure on lower trophic levels of the Arctic food web with
unclear ecosystem consequences.

The interactive effects of early life traits and changing environmental conditions on
Arctic cod (Boreogadus saida) growth and recruitment in present and future scenarios
Carmen L. David1, Rubao Ji2, Zhixuan Feng3, Caroline Bouchard4,5, Haakon Hop6,
Irene Alabia7, Jeffrey A. Hutchings8,9,10
1

Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada. e-mail: carmen.david@dal.ca
Department of Biology, Woods Hole Oceanographic Institution, MA 02543, USA
3
Institute of Estuarine and Coastal Research, East China Normal University, 200241 Shanghai, China
4
Greenland Climate Research Centre, Greenland Institute of Natural Resources, 3900 Nuuk, Greenland
5
Département de Biologie, Université Laval, Québec, QC, G1V 0A6, Canada
6
Norwegian Polar Institute, Fram Centre, 9296 Tromsø, Norway
7
Arctic Research Center, Hokkaido University, Sapporo, Japan
8
Norwegian Polar Institute, Fram Centre, 9296 Tromsø, Norway
9
Institute of Marine Research, Nye Flødevigen 20, 4817 His, Norway
10
Centre for Coastal Research, University of Agder, 4630 Kristiansand, Norway
2

Fish larval growth and consequently recruitment success are mediated by the interaction of early life
history traits (e.g., hatching timing, size at hatch) and environmental conditions (e.g., temperature, sea-ice
cover, food availability). Optimal growth enhances recruitment success, i.e., reaching a length thresholdcorresponding to complete metamorphosis to juvenile stage. Early hatching and larger size at hatch offer anadvantage to those larvae, while optimal temperatures and sufficient food availablility enhance their
growth. We used a bioenergetic model (BEM) as an integrative tool to simulate the growth of larval Arctic
cod (Boreogadus saida) and to test the sensitivity of modeled growth to temperature and food conditions.
To simulate realistic environmental conditions, BEM was coupled to an ocean sea-ice and transport model.
We tested different monthly hatching cohorts (March – June; 2005 – 2014) and size at hatch (4 – 7 mm).
Present conditions related to food quantity and quality were simulated based on stomach content
observations of wild larvae. Scenarios of change in food conditions were simulated by decreasing the foodconsumption in the model and/or switching to other type of prey, for example from Arctic to boreal
copepods which have a lower energetic content. Larval length at the end of summer was compared among
scenarios in two different Arctic regions and among warm and cold years. As a future Arctic warming
scenario, we tested how the lengthening of the growth season and an increase in water temperature by 1.5ºC will affect larval growth. Finally, we evaluated optimum growth and recruitment success between
present and future scenarios.

Development and calibration of an Atlantis ecosystem model for the Gulf of Alaska
Alberto Rovellini1, Isaac Kaplan2, André E. Punt1, Kerim Aydin3, Albert Hermann4, Elizabeth Fulton5,
Elizabeth McHuron4, Gemma Carroll6, Szymon Surma7, Bridget Ferriss3, and Martin Dorn3
1 School of Aquatic and Fisheries Sciences, University of Washington, USA. email: arovel@uw.edu
2 Northwest Fisheries Science Center, National Oceanic and Atmospheric Administration, USA
3 Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration, USA
4 Cooperative Institute for Climate, Ocean and Ecosystem Studies, University of Washington, USA
5 CSIRO Oceans & Atmosphere, Hobart, TAS, Australia
6 Environmental Defense Fund, USA
7 College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, USA
The Gulf of Alaska (GOA) is a large ecosystem with complex bathymetry and oceanography that supports
high fishery revenues. In the past, the GOA has been exposed to climate events, such as marine heatwaves, that have had complex effects on multiple ecosystem components, resulting in productivity
fluctuations and trophodynamic shifts. While it is unclear how the GOA ecosystem and the fisheries it
supports will respond to future climate change, ecological models can help anticipate future change
scenarios and evaluate management measures that address changes in stock and ecosystem status. We
present the development of an end-to-end, spatially explicit, deterministic, dynamic simulation
ecosystem model for the GOA using the Atlantis framework, and describe the current state of model
calibration and skill evaluation. The model area extends along the GOA continental shelf, from Vancouver
Island (Canada) to 170º W along the Aleutian Islands (Alaska), and from the tideline to 1000 m depth. The
model captures the GOA food web using 78 functional groups, including single-species groups for someecologically and commercially important species, and encompasses all size classes from nutrient pools
and plankton to megafauna. Atlantis GOA features a geophysical sub-model forced with outputs fromoceanographic models (ROMS-NPZ) for the Northeast Pacific, and as such can be used as a simulation
tool to explore ecological and fisheries responses to climate events. We present how Atlantis GOA will be
used in hindcast mode to explore the ecosystem-level effects of the 2013- 2016 marine heat wave, and in
forecast mode to simulate the effects of future climate change on ecosystem productivity, allowing us toevaluate the effectiveness of various management strategies under a changing climate. Atlantis GOA,
together with other ecological models for the GOA, can help better predict and strategically manage
outcomes for the GOA ecosystem under climate change.

Thermal effects on early life stages of Gulf of Alaska Pacific Cod: shifts in phenology
Jessica A. Miller1, L. Zoe Almeida1, Hillary Thalmann1, Lauren Rogers (2), Ben Laurel (21Oregon State University, Coastal Oregon Marine Experiment Station, Department of Fisheries, Wildlife,and Conservation Sciences. e-mail: Jessica.Miller@oregonstate.edu
2National Marine Fisheries Service – NOAA, Alaska Fisheries Science Center
Understanding the effects of environmental variability and climate change on recruitment in marine
populations is critical for conservation and management. Variation in the abundance of Pacific Cod in the
Gulf of Alaska has been related to water temperature with greater production during cooler periods;
however, the mechanisms underlying this pattern remain unclear. Furthermore, a dramatic reduction in
Pacific Cod abundance was observed after a prolonged marine heatwave from late 2014-2016. Thus, abetter understanding of thermal effects on Pacific Cod is a research priority. We combined structural
analysis of otoliths with field and laboratory data to estimate spawn timing, determine size and timing of
hatch, and reconstruct growth for fish collected during the pelagic larval and juvenile stages. We usedlarvae collected in mid-late May (7 years) and settled juveniles collected in July (11 years). Hatch dates forboth larvae and juveniles were notably earlier in the years during and after the prolonged marine heatwave(2015-2019): mean hatch dates were 14 d earlier for larvae and 23 d earlier for juveniles. Given thatwarmer temperatures increase development rates, we determined mean water temperature (at 100-250m) during embryonic development for larval and juvenile collections. Mean water temperature averaged
0.89 °C warmer during development for larvae and 1.6 °C warmer for juveniles in the years after 2014 than
before. Based on laboratory-derived development rates, these temperature differences could account for~25% of the shift in hatch dates for the larvae and up to 50% of the shift for juveniles. Therefore, otherfactors, such as changes in the timing of spawning or selective mortality, also contributed to the observed
shifts in hatch timing. Understanding how Pacific Cod respond to thermal variation will be integral for
disentangling processes regulating survival to recruitment and predicting population-level responses toclimate variation.

Combining social and ecological time series to describe long-term dynamics
of the Norwegian Sea ecoregion.
Lucie Buttay1, Hiroko Solvang2, Benjamin Planque1
12

Institute of Marine Research, Tromsø, Norway
Institute of Marine Research, Bergen, Norway Lucie.buttay@hi.no

One challenge for Integrated Ecosystem Assessments (IEAs) is to synthesize historical changes that haveoccurred in multiple components of the social-ecological system, from climate to the ecosystem and tohumans. One output of the current IEA for the Norwegian Sea is a summary of decadal changes that is
easily accessible to non-scientists. This summary primarily focuses on the physical and ecologicaldimensions of the ecosystem. In the present work, we extend the current IEA with time-series that describe
the most important sectors and activities in the ecoregion (fishing, oil and gas production, shipping andaquaculture) and some related pressures (species extractions, bycatch, contaminants, noise, etc). We use
TRend Estimation and Classification (TREC) to reveal common trends among time-series and summarise themain changes that have occurred in the Norwegian Sea ecoregion during the last three decades. In
addition, we use an extension of the TREC method to identify extreme observations in recent years that
could warrant special attention. Most of the time series of human activities presented a positive trend overthe period considered with the exception of Oil production that increased until 1996 and then decreased.
Primary production increased, zooplankton biomass decreased and while no trend was observed for mostof fish stock biomass, herring biomass decreased over the period considered. Herring catches decreased
until 2016 and then increased in recent years but the total catch value increased steadily. Our results
provide the first integrated description of changes in the Norwegian Sea from physics to humans andhighlight the potential of the TREC method to be used in IEAs to properly synthetize the information in
many different time series and provide warning for recent extremes events.

Changes in spawn timing of walleye pollock and impacts
on assessment surveys in the Gulf of Alaska
Lauren Rogers, Annette Dougherty, Martin Dorn, Kresimir Williams, Darin Jones, Cole Monnahan
Alaska Fisheries Science Center, NOAA National Marine Fisheries Service, Seattle, WA
e-mail: lauren.rogers@noaa.gov

Changes in phenology, or the seasonal timing of events, are a widely-documented response to changes inclimate. Spawn timing, in particular, has been shown to be sensitive to temperature in many fishes. Beyond
implications for recruitment and survival of offspring, climate-driven changes in the timing of spawning canaffect the availability of fish to surveys designed to monitor their abundance, complicating efforts to assess
stock status and sustainably manage fisheries through a changing climate. We analyzed changes in the
spawn timing of walleye pollock (Gadus chalcogrammus) using ichthyoplankton time-series from theWestern Gulf of Alaska (1979 – 2019). We found that warmer temperatures led to earlier spawning andlarval first feeding, consistent with expectations of advanced spring phenology under warming. However,
spawner age also played a role, with an older stock spawning earlier on average. We then investigatedwhether changes in spawn timing could be affecting the availability of pollock to one of the main
assessment surveys for the species: the winter Shelikof Strait acoustic survey. In recent years, biomass
estimates from the four surveys that monitor Gulf of Alaska pollock have diverged, giving conflicting
estimates of stock biomass and temporal trends, which have in turn increased uncertainty in the stock
assessment. We found that changes in spawn timing relative to survey timing explain a significant portionof recent and historical discrepancies in survey biomass estimates. Based on this, we developed a timeseries of covariates for survey catchability for the stock assessment model to account for changing
availability of pollock to the winter Shelikof survey. As climate change accelerates, changes in phenology
will bring new challenges for the monitoring and assessment of fish stocks. We show that knowledge ofunderlying ecological processes can guide approaches to account for these changes in assessment
frameworks, expanding our toolkit for climate-ready fisheries management.

Winners and losers in a warming Arctic: Potential habitat gain and loss
for epibenthic invertebrates of the Chukchi and Bering seas
Elizabeth Logerwell1, Muyin Wang2, Lis Jorgensen3, Kimberly Rand4

1

Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric
Administration, 7600 Sand Point Way, NE, Seattle, WA, 98115, USA. e-mial: Libby.Logerwell@noaa.gov
2
Pacific Marine Environmental Laboratory Oceanic and Atmospheric Research, National Oceanic andAtmospheric Administration 7600 Sand Point Way, NE, Seattle, WA, 98115, USA
3
Institute of Marine Research, Hjalmar Johansens gate 14, 9007 Tromsø, Norway,
4
Lynker Technologies, LLC, 202 Church Street SE, Number 536, Leesburg, Virginia 20175, USA

We examined how the epibenthic invertebrate community in the Pacific Arctic might be affected byincreased ocean temperatures. We used catch and bottom temperature data from surveys from 2009-2018
in the Bering and Chukchi seas and grouped taxa into 5 clusters according to median temperature andtemperature range. We then used an ensemble of 8 climate models to forecast bottom temperature to2050 and 2100 and to show how the amount and distribution of temperature habitat, the area that falls
within the observed temperature range of each of the 5 clusters, might change with ocean warming. We
found that by 2050 there were 50% decreases in temperature habitat for all clusters except for the clusterwith the broadest temperature range, and that temperature habitat contracted to the north. By 2100 there
was very little temperature habitat for all clusters, except the broadest range cluster, and habitat further
contracted to the north. The cluster with a cold median temperature and the narrowest range had virtuallyno temperature habitat by 2100. These “losers” were primarily gastropods and mussels which are prey for
endangered Pacific walrus, a food resource in native Alaskan communities, and for commercial
groundfishe. The cluster with the broadest temperature range had suitable temperature habitat
throughout most of the Bering and Chukchi Seas, except in the areas closest to shore. The most abundantspecies of these “winners” was the basketstar Gorgonocephalus cf. arcticus. The loss of habitat for all but
the “winners” could impact species diversity of the Bering and Chukchi Seas because the “winner” cluster
accounted for only 8% of all taxa. Our results provide the first indications that the epibenthic invertebrate
community in the Bering and Chukchi seas, which supports marine mammals, seabirds and humancommunities, may be seriously impacted by future ocean warming.

The next decade of ocean acidification research in the Bering Sea:
what we’ve learned and what’s coming next
Jessica N. Cross1, Darren Pilcher2,1, Hongjie Wang2,1, Elizabeth Siddon3, Natalie Monacci4, W.
Christopher Long5, and Esther Kennedy6
1 NOAA Pacific Marine Environmental Laboratory, Seattle, WA, USA. Email: jessica.cross@noaa.gov
2 University of Washington Cooperative Institute for Climate, Oceans, and Ecosystem Science, Seattle, WA,USA
3 NOAA Alaska Fisheries Science Center, Juneau, AK, USA
4 University of Alaska Fairbanks Ocean Acidification Research Center
5 NOAA Alaska Fisheries Science Center, Kodiak, AK, USA
6 University of California, Davis, Davis, CA, USA
Over the last decade, ocean acidification (OA) has emerged as one of the most prominent issues in Alaskan
marine research, and a possible threat to culturally and commercially important marine resources. Multiple
communities around the state are now engaged in their own OA studies and monitoring, and are asking acommon question: what risks does my region face? These are especially salient questions for Alaskans
because the intensity, duration and extent of OA events have been greater here than other ocean basins.
Given the pace of the observed changes due to OA around Alaska, the area is commonly referred to as abellwether and the proverbial “canary in the coal mine” for the rest of the global ocean. Here, we will take alook back at the last ten years of OA research in the Bering Sea, and highlight new, cutting-edge synthesis
and biogeochemical modeling, forecasting, and projection efforts that have dramatically increased ourcapacity to understand Alaskan OA from a large-scale perspective. For example, multi-decadal projections
provide spatio-temporal information for how OA conditions may evolve throughout the Bering Sea shelf andhighlight key differences between climate emissions scenarios, providing a regional perspective for the
impact of climate mitigation strategies. Meanwhile, near-term products provide fisheries stakeholders with
updated environmental information for stock assessment and the fisheries management process. This effort
recently culminated with the development of an indicator for the Eastern Bering Sea Ecosystem Status
Report (ESR) and input into the Ecosystem and Socioeconomic Profiles (ESPs) for two crab stocks. Our
vision is to continue developing and refining this approach and to expand available products to identify new
risks and emerging resilience of Alaskan ecosystems. Ultimately, we hope these products guide sound,evidence-based decisions that support sustainable marine resource management for the largest U.S. fishery.

Climate-driven shifts in abundance, distribution, and composition of theage-0 gadid community in the eastern Chukchi Sea
Robert Levine1, Alex De Robertis2, Daniel Grünbaum3, Chris Wilson2
1 Applied Physics Laboratory, University of Washington, Seattle, WA. e-mail: Leviner@uw.edu
2 Alaska Fisheries Science Center, NMFS, Seattle, WA
3 School of Oceanography, University of Washington, Seattle, WA

Age-0 Arctic cod (Boreogadus saida) have historically dominated the pelagic fish community in the Chukchi
Sea in summer, with few adults present in the region. Recently, reductions in sea ice and increases inwarming and transport have led to an increase in Pacific-origin waters on the Chukchi shelf in summer. To
examine the potential effects of these environmental changes on the pelagic community, we conductedautonomous and ship-based surveys in summer 2017, 2018, and 2019. Throughout this period, bottommoored echosounders continuously measured fish abundance and movement at several locations.
Together, these observations indicate that the abundance and composition of the pelagic community on
the Chukchi Sea shelf are highly variable over seasonal and annual time scales. Summer surveys found thatage-0 Arctic cod were the most abundant pelagic fish in all four survey years. Age-0 walleye pollock (Gadus
chalcogrammus), which were scarce and confined to the southern Chukchi Sea in previous years, were
present in high abundance throughout the Chukchi Sea shelf in 2017 and 2019. We hypothesize that thechanges in abundance and species composition are tightly coupled to recent changes in temperature andthe transport of Bering Sea waters onto the Chukchi shelf. The substantial increase in age-0 pollock inrecent years suggests that environmental conditions now allow this species to extend its northern range
into the central and southern Chukchi Sea, at least on a seasonal basis. Seasonally, fish abundance was very
low in winter, increased in May, and reached peak abundance in late summer. Age-0 gadids were displaced
to the northeast, consistent with the dominant advection on the shelf. Fish speeds and headings werestrongly correlated with local currents, providing evidence that behavior plays a limited role in thedisplacements of these populations.

Taking the long view: Integrating marine historical ecology andnatural resource management in the Gulf of Alaska
Catherine F. West
Department of Anthropology and Archaeology Program, Boston University. E-mail: cfwest@bu.edu

Natural resources across the Gulf of Alaska are under threat from climate change, invasive species
introductions, coastal erosion, and other hazards. In the face of such change, resource managers in thisregion are increasingly looking to Indigenous knowledge, historical archives, and archaeological andpaleoenvironmental data to understand long-term variability in ecosystems and human-animal interactions.
Drawing on examples from migratory bird rehabilitation, invasive species eradication, and fisheries
management in a marine historical ecology framework, this paper addresses how such interdisciplinary,collaborative work might inform management by: a) constructing a common vocabulary; b) integrating
across time scales; and c) establishing common goals based in management concerns.

Using an environmentally linked assessment for
strategic fisheries management planning
Steven J. Barbeaux
Alaska Fisheries Science Center, NOAA, 7600 Sand Point Way NE, Seattle, WA 98115.
E-mail: steve.barbeaux@noaa.gov

Modern fisheries are largely managed based on assumptions of stationarity in the productivity of stocks
consistent with a baseline time-period. As productivity depends on environmental conditions, theassumption of stationarity in productivity is dependent on future environmental conditions varying within
the bounds of the assumed baseline conditions. The climate of the earth is changing due to anthropogenic
forcing and although there are long-term objectives of minimizing these impacts, these impacts appear to
be largely unavoidable and irreversible over the next century. Therefore, it is essential that climate change isconsidered in developing fisheries management plans and harvest control rules to assure long-termsustainable fisheries.
Here we consider an ecosystem-linked single species assessment model for Gulf of Alaska Pacific cod (Gadus
macrocephalus) in which environmental conditions drive key biological elements of productivity andprojecting these models forward using forecasts generated from International Panel for Climate Change(IPCC) Representative Concentration Pathway (RCP) scenarios. Ecosystem-linked model projections assume
stationarity in the relationship between environmental conditions and biological elements contributing to
productivity instead of assuming stationarity in productivity itself. In this model sea surface and bottom
temperatures, and the occurrence of marine heatwaves are used to drive growth, natural mortality, andrecruitment. This model is used to obtain estimates of stock productivity under three IPCC RCP scenarios
using five climate models under each scenario to the end of the century. We observe significant variability
in productivity among climate model projections, however under all of the IPCC scenarios productivity is
reduced in comparison to status quo, more so under higher carbon concentration scenarios. There is much
uncertainty in the management advice that is provided from the method presented, however the greatest
source of variability in study results is among RCPs, determined by how we act, or fail to act, on controlling
global greenhouse gas emissions.

Cyclic variability of eastern Bering Sea jellyfish relates
to regional physical conditions
Mary Beth Decker1, Richard D. Brodeur2,3, Lorenzo Ciannelli3, Lyle L. Britt4,
Nicholas A. Bond5, Bart Difiore6 and George L. Hunt, Jr.7

1 Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520-8106, USA
2 OAA Fisheries, Northwest Fisheries Science Center, Newport, OR, 97365, USA
3 College of Earth, Ocean and Atmospheric Sciences, Oregon State University, Corvallis, OR, 973315503, USA
4 NOAA Fisheries, Alaska Fisheries Science Center, Seattle, WA, 98115-0070, USA
5 The Cooperative Institute for Climate, Ocean and Ecosystem Studies (CICOES), University ofWashington, Seattle, WA, 98195-5672, USA
6 Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA
93106, USA
7 School of Aquatic and Fishery Sciences, University of Washington, Seattle, WA 98195, USA Oralpresentation
A substantial increase in jellyfish biomass, primarily Chrysaora melanaster, was documented over theeastern Bering Sea shelf throughout the 1990s. Their biomass peaked in summer 2000 and thendeclined precipitously, stabilizing at a moderate level during 2001-2008. Surveys since 2009 indicatedthat jellyfish biomass had increased once again to late-1990s levels, but then declined dramatically in2016 and 2017. The onsets of the biomass increases and declines coincided with transitions between
climatic regimes. Our previous investigations of a 27-year time series examined relationships between
jellyfish biomass and temperature, ice cover, atmospheric variables, current patterns, zooplankton
biomass, and associated fish biomass in two regions using Generalized Additive Models (GAMs). These
analyses indicated that jellyfish outbreaks during 1982-2004 were influenced regionally by interacting
biophysical variables such as sea ice cover, sea surface temperature, currents, wind mixing and foodavailability. Using updated environmental data from 1982-2017, we reran our GAM analyses todetermine if models using solely physical variables and lag of jellyfish biomass could describe accurately
the more recent increases of Bering Sea jellyfish. GAMs hindcasting jellyfish biomass for the period
1982-2017 explained a large fraction of the variance, 92.3% and 86.4%, for the southeast andnorthwest portions of the survey area, respectively. We developed more parsimonious models by
calculating the variance inflation factor for each term and dropping highly correlated terms. The
resulting GAMs continued to explain a significant portion of the variance in jellyfish biomass, i.e., 78.2%
and 73.5%, in the southeast and northwest survey areas, respectively. Jellyfish, which are bothpredators and competitors of fish, appear to be responding to changes in physical conditions and areimportant for understanding ecosystem changes in the eastern Bering Sea. Development of models
that use more readily available physical parameters is key to predicting jellyfish abundance and theirimpacts on commercially important species.

Paleoproductivity records in the Subarctic North Pacific Ocean:Baseline marine ecological data for the Holocene

Jason Addison 1, Bruce Finney 2, Naomi Harada 3, Kana Nagashima 3, Ben Fitzhugh 4, Catherine West 5

1 US Geological Survey, Menlo Park, CA (* corresponding author: jaddison@usgs.gov)
2 Idaho State University, Pocatello, ID
3 Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
4 University of Washington, Seattle, WA
5 Boston University, Boston, MA

The coastal regions of the Subarctic North Pacific Ocean (SNPO) experience some of the highest levels of
primary productivity in the global ocean. However, this area is susceptible to impacts from climate-related
ecological perturbations, such as “The Blob” marine heat wave event of CE 2015-2017. The unprecedented
impacts from this event, such as the crash of modern Pacific cod stocks and the occurrence of the largest
toxic diatom bloom ever observed, were not anticipated. Therefore, geologic records offer an opportunity
to examine past time intervals for analogues of future change to better predict and understand potential
trends and ecological impacts.
A Holocene compilation of biogenic silica (opal) data for the last 10,000 years was generated using a
combination of new laboratory measurements and literature review as an estimate of past diatom-based
phytoplankton productivity from the Gulf of Alaska (GoAK; n = 4), Bering Sea (BS; n = 5), Sea of Okhotsk (n= 10) and the Northwest Pacific (n = 5) margins of the SNPO. These data suggest contemporaneous shifts inall of these areas towards higher diatom productivity during the late-middle Holocene, particularly after~4000 cal yrs BP. A second regional increase is also seen in both the GoAK and BS regions at ~1000 cal yrs
BP.
This presentation will explore the intricacies of the SNPO Holocene opal data synthesis in conjunction withpublished studies that describe: (1) paleo-environmental records of SNPO atmospheric and oceanic
processes; and (2) paleo-ecological reconstructions of finfish abundance (Pacific salmon, Pacific cod,herring, and anchovy). As the opal-based phytoplankton data represents an important link between
physical forcing and higher trophic level dynamics, a key output from this study will be a better
understanding of how these elements have interacted in the past, which will provide new insights for the
future of the SNPO ecosystem under projected future climate change.

Investigating food web structure and dynamics in the eastern Gulf of Alaska
Szymon Surma1, Curry Cunningham1, Kerim Aydin2, Jamal Moss2,
Martin Dorn2, Albert Hermann3, Alberto Rovellini4
1

College of Fisheries and Ocean Sciences, University of Alaska Fairbanks. e-mail: ssurma@alaska.edu
Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration
3
Cooperative Institute for Climate, Ocean and Ecosystem Studies, University of Washington
4
School of Aquatic and Fisheries Sciences, University of Washington
2

The Gulf of Alaska (GOA) hosts numerous federally protected species and valuable fisheries, both of whichwere adversely impacted by a severe marine heatwave in 2014-15. The eastern Gulf of Alaska (EGOA) is
distinguished from waters to the west (WGOA) by many features of its oceanography, ecology, andfisheries. However, the EGOA has received comparatively less scientific attention than the WGOA. We
attempted to remedy this situation by developing mass-balance models of the EGOA food web in 19901993 (when reliable time series began) and 2014-15 (during the heatwave). The study area includes
federal and state waters overlying the continental shelf and upper slope (0-1000 m) from 54°40’N
northwest to 147°W, excluding Prince William Sound and the Inside Passage. The EGOA models represent
ecosystem structure as a network of biomass pools and fluxes informed by fisheries-independent surveys,
fisheries catches, and oceanographic (ROMS-NPZ) models. These models contain 72 functional groups (i.e.,
species or groups thereof sharing basic ecological traits) spanning all trophic levels and size classes. They
also include 19 fishing fleets defined mainly by gear and target species. Functional group and fleet
structure focuses on protected species and commercial fisheries. These models, developed in collaboration
with the GOA Climate Integrated Modeling, GOA Integrated Ecosystem Assessment (IEA), and Sitka IEA
projects at the Alaska Fisheries Science Center, revealed the directions and strengths of trophic
interactions in the EGOA before and during the heatwave. Furthermore, the 1990-1993 model was fitted
to time series to provide hindcasts of ecosystem dynamics. The EGOA models are also expected to support
projections of ecosystem states, as well as closed-loop simulation testing of fisheries management strategy
performance, under various scenarios of climate change. Finally, these models present an opportunity for
multi-model inference together with a mass-balanced WGOA model, a GOA end-to-end model, and a GOA
multi-species model.

Pan-Arctic marine biodiversity patterns under recent climate
Irene D. Alabia1, Jorge Garcia Molinos1, Takafumi Hirata1, Franz J. Mueter2, and Carmen L. David3,4

1 Actic Research Center, Hokkaido University, Sapporo, Japan. E-mail: irenealabia@arc.hokudai.ac.jp
2 University of Alaska Fairbanks, Juneau, Alaska, USA
3 Department of Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
4 Department of Biology, Woods Hole Oceanographic Institution, MA 02543, USA

The Arctic region is experiencing drastic climatic changes over the past decades bringing about potential
ecological surprises. Here, we explored changes in marine biodiversity and potential species co-occurrences
across eight Arctic marine areas defined by the Circumpolar Biodiversity Monitoring Program from 20002019. We compiled occurrence data for 55 marine taxa belonging to four different species guilds andenvironmental information to simulate and predict species-specific spatial distributions. From multiensemble species distribution model outputs, we examined the spatial and temporal biodiversity patterns
and potential species co-occurrences over time and between contrasting periods of region-specific summer
sea ice conditions during the last two decades. Our preliminary analyses revealed region-based differencesin species richness and potential species co-occurrences between high and low summer sea ice years. In
particular, we observed declines in the species richness and frequency of pair-wise species co-occurrence
between high and low sea ice periods in contiguous regions of the Davis-Baffin Bay and Hudson Complex. In
contrast, adjacent regions of the Pacific Arctic and Beaufort Sea as well as the Atlantic Arctic and KaraLaptev Sea highlighted increases in species richness and pair-wise co-occurrences. These spatial patterns
emerged in response to modeled northward habitat range expansions of marine species under low
summer sea ice conditions. Our initial results show contrasting regional impacts of warming and sea ice loss
across the different Arctic marine areas and could provide relevant insights on potential vulnerability of theregions to recent climate changes.

Prince William Sound marine ecosystem under different heatwave scenarios.
Beatriz S. Dias1, Thomas A. Okey2, Robert M. Suryan3, Russell R. Hopcroft1
1 College of Fisheries and Ocean Sciences, University of Alaska Fairbanks.
e-mail: bdossantosdias@alaska.edu
2 School of Environmental Studies, University of Victoria
3 NOAA Alaska Fisheries Science Center, Auke Bay Laboratories 17109 Point Lena Loop Rd., Juneau, Alaska
99801

As marine heatwave frequencies rise, understanding ecosystem responses is necessary to create
management strategies. These extreme events can have long-term impacts on ecosystems; therefore, it isimportant to understand how heatwaves persistence will affect declined small pelagic populations such as
Prince William Sound herring. Here we review past marine heatwaves in Prince William Sound to create
future scenarios. We explore how these events affect herring and consequently Prince William Sound
marine food web, and if the persistence of these events (duration and occurrence) results in biologicalregime changes. To achieve the goal, we: 1) used a mass balanced food web-based ecosystem model(Ecopath with Ecosim) to represent Prince William Sound marine ecosystem; 2) fit times series of biomass,
fishing effort and landings for the fished functional groups in Ecosim, the dynamic portion of the ecosystemmodel; 3) generated a trend using dynamic factor analysis (DFA) of past biological time series;4) developed three marine heatwave scenarios from the DFA trend result (the first uses the 2015 marine
heatwave, the second simulates two consecutive marine heatwaves, the third the persistence of threeconsecutive marine heatwaves); 5) evaluated herring response to the scenarios; and 6) used network
analysis to calculate how the marine food web is affected. This preliminary simulation work shows thevulnerability of herring to the increase of North Pacific marine heatwaves and the consequences to Prince
William Sound marine food web. Moving forward, we hope to extend the analysis to understand the links
between environmental and biological regime shifts.

Arctic Cod (Boreogadus saida) under newly-formed sea ice in the Pacific Arctic
F.J. Mueter1, A. Pinchuk1, L. Copeman4, S. Maes3, M. Geoffroy2, Z. Chapman1, J. Weems1, H. Flores5
1 College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska, USA
2 Fisheries and Marine Institute, Memorial University, Canada
3 Catholic University of Leuven, Belgium
4 Alaska Fisheries Science Center, NOAA, Newport, OR, USA
5 Alfred Wegener Institute, Bremerhaven, Germany

Arctic cod (Boreogadus saida), a key forage fish in the Arctic, may be particularly susceptible to changing
sea ice conditions, although their dependence on sea ice is poorly understood. Therefore, we examined theunder-ice distribution, abundance and condition of Arctic cod during the fall and early winter to assess
whether newly-formed sea ice provides suitable habitat for growth and survival. Ice-associated Arctic codand macro-zooplankton were sampled along the outer shelf and slope of the Chukchi and Beaufort seasusing a Surface and Under-Ice Trawl. Chlorophyll, zooplankton and fish in the underlying water column wereassessed using discrete water samples, vertical plankton tows and acoustic backscatter recorded by an EK80
echosounder, respectively. Chlorophyll concentrations were low at the bottom of the ice and throughout
the upper 50 m. Moderate abundances of zooplankton were observed in the upper 100 m of the watercolumn. Small Pseudocalanus, Oithona similis and Microcalanus sp. were numerically dominant, whilebiomass was dominated by larger calanoid copepods and chaetognaths. Stomachs of juvenile Arctic cod
contained pelagic zooplankton, several fish species and ice-associated amphipods, suggesting that juvenile
Arctic cod captured under the ice were actively feeding on both pelagic and ice-associated prey. The mean
wet weight of juvenile Arctic cod at a given length was higher in November than that of the same cohortcaught during late summer; however, their lipid content was considerably lower. Observed lipid densities
under the ice in November were at or near the level at which laboratory-reared juveniles experience highmortality, suggesting that their survival likely depends on continued prey availability. Acoustic backscattersuggests that small fish, most likely Arctic cod, were present throughout the study region and were found in
multiple layers in the water column. We found some evidence that smaller fish ascended into a warmer
subsurface layer at solar noon, presumably to feed, while the strongest backscatter indicative of fish was
typically associated with cool intermediate waters that separate the surface layer from warmer Atlantic
waters below. The use of ice-associated habitat by juvenile Arctic cod may be one strategy to accessavailable prey resources while minimizing metabolic requirements and predation.

Coupled modes of projected regional change in the Bering Sea
from a dynamically downscaling model under CMIP6 forcing

Albert Hermann1, Kelly Kearney2, Wei Cheng1, Darren Pilcher1, Kerim Aydin3, Kirstin Holsman3,
Anne Hollowed3, Emily Norton1

1

University of Washington-CICOES/NOAA-PMEL, Seattle, WA, USA. e-mail: Albert.J.Hermann@noaa.gov
University of Washington-CICOES/NOAA-AFSC, Seattle, WA, USA
3
NOAA Alaska Fisheries Science Center, Seattle, WA, USA
2

Three different global earth system models from the Coupled Model Intercomparison Project Phase 6(CMIP6) were used to explore anticipated changes in the Bering Sea under high (SSP126) and low (SSP585)
carbon mitigation scenarios (i.e. low and high emission scenarios), via dynamical downscaling. A
multivariate pattern analysis, based on Empirical Orthogonal Functions applied to monthly time series
reveals strong coupling of changes across several biophysical variables and the global forcing itself, on both
yearly and multidecadal time scales. Rising air and ocean temperatures from the global models are strongly
coupled with rising regional temperatures and reduced ice cover/thickness, as well as strong changes tothe phenology of the plankton food chain, including reduced biomass of large zooplankton in the fall. Thismethod ultimately provides a compact way to estimate the changes to many regional attributes under avariety of global change scenarios. Application of this method to a broad ensemble of the CMIP6 global
model air temperatures suggests that compared to present conditions, the Bering Sea shelf bottom
temperatures in July will warm by an average of ~4 °C by the end of the 21st century under SSP585, ascompared with ~1 °C under SSP126, with greatest warming focused on the outer northern shelf. An
extension of the method, based on Machine Learning, is also described.

Responses of mesozooplankton biomass to climate change in the southeastern Bering
Sea shelf during the summers of 1955–2013 (summary of T/S Oshoro-Maru cruises)with special references to the taxonomic composition and normalized biomass size
spectrum for several consecutive years at each climate regime
Hikaru Hikichi1, Kohei Matsuno2,3, Hiromichi Ueno2,3, Atsushi Yamaguchi2,3*
1 Graduate School of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, Hokkaido, 0418611, Japan. e-mail: a-yama@fish.hokudai.ac.jp
2 Faculty of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, Hokkaido, 041-8611,
Japan
3 Arctic Research Centre, Hokkaido University, Kita-21 Nishi-11 Kita-ku, Sapporo, Hokkaido, 001-0021,
Japan

The T/S Oshoro-Maru visited the southeastern Bering Sea shelf during the summers of 1955-2013. During
these visits, mesozooplankton samples were collected using the same methods: vertical tows of a NORPAC
net from 150 m depths or near-bottom to the surface. Wet weight biomass was measured for each sample.
Using these data, we studied yearly changes of mesozooplankton biomass and analyzed the effects ofenvironmental parameters: temperature, salinity, stratification index, pycnocline depths, and interactions
with large-scale climate indices. The mesozooplankton biomass showed common yearly changing patterns
related to climate regime shifts. Thus, as climate regime shifts during the study period, the four changing
timings have been reported: 1976/77, 1988/89, 1998/99, and 2005/06. The mesozooplankton biomasses
were the lowest for the warmest period (2000-2005). The highest biomasses were observed for the cold
period (2007-2013). The supplemental taxonomic and normalized biovolume size spectra (NBSS) data werealso obtained by ZooScan for two consecutive years in four different climate regimes. Zooplankton biomass
exhibited annual changes, with high and low values varying at each climate regime shift. ZooScan analysis
revealed anomalous zooplankton abundance during 2003/2004 dominated by Cnidaria and the lowest
abundance of whole-sized copepoda. Because of this anomalous community, the NBSS in 2003/2004 wascharacterized by the most moderate slope and lowest intercept which varied greatly from the other climate
regimes. The effects of climate index and environmental variables on zooplankton were evaluated using
structural equation modeling. Throughout the region, the significant interactions between climate indicesand zooplankton were in the following pathway: North Pacific index  ice retreat timing  temperature
above thermocline  zooplankton biomass. Through the five climate regimes, zooplankton biomass washigh in the cold regimes and low in the warm regimes. These negative interactions between zooplankton
biomass and temperature at the surface layer suggest that the concept of the Oscillating Control Hypothesis
holds true for long-term observations.

Understanding Pacific Halibut spatial dynamics in the northern Bering Sea
Austin J. Flanigan1; Dawn Wehde2; Tim Loher3; Andrew C. Seitz1

1

University of Alaska Fairbanks, Fairbanks, AK, USA. e-mail: aflanigan@alaska.edu
Norton Sound Economic Development Corporation, Nome, AK, USA
3
Martingale Marine Ecology, Seattle, WA, USA
2

In recent years, the fish assemblage has been changing in the Northern Bering Sea (NBS), where risingwater temperature has correlated with increases in abundance of sub-arctic fish species. One such species
is the Pacific halibut (Hippoglossus stenolepis), a commercially important flatfish that is a potentiallyvaluable resource in the NBS. To optimize harvest opportunities of this increasingly available fish, informed
management is important, which in part requires understanding halibut movements and spatial dynamics inthe region. Currently, this information is scarce, and as such, the current management paradigm makes anumber of assumptions generalizing Pacific halibut movements within NBS management areas. To obtainspatial dynamic information for Pacific halibut in this region to better inform management decisions, popup satellite telemetry tags were attached to large, mature female Pacific halibut in two locations in the NBS.
Data recovered from these tags was used to assess movement and habitat occupancy within the region.
Preliminary findings indicate that tagged individuals remained within the NBS and Central Bering Sea, withPacific halibut crossing multiple management boundaries, including the Russian maritime border. During
the winter spawning season, Pacific halibut made long migrations to the shelf edge, ranging as far south as
the Pribilof Islands. Additionally, some individuals returned to their tagging location the following year,
an indication of inter-annual site fidelity to summer foraging areas. These findings are important to both
local stakeholders and managers when making management decisions about this increasingly available
resource.

An exploratory analysis of warming effects on wealth in the Barents Sea fisheries
Sturla Kvamsdal
SNF – Centre for Applied Research at NHH, Helleveien 30, N-5045 Bergen, Norway
e-mail: sturla.kvamsdal@snf.no

The Barents Sea and Arctic regions in general are facing significant impacts from climate change. A major
concern is increasing temperatures. I explore four different scenarios of temperature impacts on the
Barents Sea cod, its fishery, and the level of natural capital – wealth – that the fish stock represents. My
framework incorporates interaction with the main prey, capelin, under uncertainty in the population
dynamics equations and under two relevant management regimes. One regime is based on maximum
sustainable yield (MSY) and one is based on ecosystem-based management (EBM). Because of uncertainty
over how warming will impact the Barents Sea cod, the investigated scenarios include both positive andnegative impacts on parameters in the population dynamics. Wealth under MSY is surprisingly robust totemperature impacts, and only under one scenario with negative impacts is there a significant wealtheffect and then only in the long run. The EBM regime would increase wealth in all scenarios, but outcomesare more sensitive to the type and significance of the temperature impact.

Data integration to model lower trophic levels in the Eastern Bering Sea
Genoa Sullaway1*, Curry Cunningham1, David Kimmel2, Darren Pilcher3, James Thorson4
1

College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau AK.
e-mail: gsullaway@alaska.edu
2
NOAA Alaska Fisheries Science Center
3
CICOES, Pacific Marine Environmental Laboratory
4
Habitat and Ecological Processes Research (HEPR) Alaska Fisheries Science Center, NMFS

Ecosystem based fisheries management (EBFM) necessitates inclusion of environmental data and trophic
links into fisheries modeling efforts. Recognizing these links is important as bottom-up processes cansignificantly impact fish population dynamics. In the Eastern Bering Sea (EBS), changes to zooplankton
community dynamics can significantly shift fisheries productivity and changes in regional climate patterns
are likely affecting zooplankton production. Currently the Regional Ocean Modeling System for nutrients,
phytoplankton and zooplankton (ROMS-NPZ) estimates temporal and spatial variability in zooplankton
biomass in the Eastern Bering Sea. The output of the ROMS-NPZ has yet to be compared with observational
data. Model refinement can allow expanded use of ROMS-NPZ output in management decisions. We
compare biomass predictions from the ROMS-NPZ Bering 10k model for an abundant copepod, Calanus
spp., with a thirty-year time series of zooplankton field data collected by the NOAA Alaska Fisheries Science
Center. We use Calanus spp. for this initial comparison as calanoid copepods underpin the EBS food web as
an important prey item for fish, marine mammals, and birds. Using a GAM framework, we quantify the levelof agreement between survey observations and ROMS-NPZ model predictions and include covariates to
identify locations in space and time where discrepancies between the datasets may exist. Preliminary
results indicate that the ROMS-NPZ and empirical data have higher agreement than expected anddiscrepancies were predictable when a spatial smoother was incorporated into the model.
These comparisons are a first step in a data integration process to further bolster zooplankton data
availability for use in EBFM efforts. Future work will expand the species included in this comparison to
include other copepod species and euphausiids.

Condition, size, and winter duration affect winter survival probability in juvenile
Atlantic cod (Gadus morhua) in a coastal ecosystem
Emilie A. Geissinger1, Chelsea R. Bloom2, Robert S. Gregory2, Benjamin J. Laurel3, Paul V.R. Snelgrove4
1

Department of Biology and Ocean Sciences Centre, Memorial University of Newfoundland andLabrador, Canada. e-mail: eageissinger@mun.ca
2
Department of Biology, Memorial University of Newfoundland and Labrador and Ecological Science
Section, Fisheries and Oceans, Canada
3
Alaska Fisheries Science Center, NOAA, Newport, Oregon, USA
4
Department of Ocean Sciences and Biology, Memorial University of Newfoundland and Labrador,
CanadaJuvenile Atlantic cod (Gadus morhua) in coastal Newfoundland settle in nearshore habitats in 3-6 pulsed
events each year. These pulses create a broad size-structured year-class during the first year of life. The
combination of multiple pulses and variable winter harshness creates conditions of metabolic stressresulting in size-structured survival. Juveniles that settle early in the growing season potentially growlarger and produce more fat reserves prior to winter compared to individuals settling later in the season.
We hypothesized that early settling juveniles would be in better condition prior to winter facilitating theirsurvival through long, harsh winters. We use a generalized linear model with a binomial distribution(logistic ANCOVA) to evaluate changes in relative winter survival over a 20-year period, combining
juvenile cod survey data and archived juvenile cod samples with winter temperature records todetermine the impact of winter duration, body condition, and settlement time on overwinter survival.
Our analyses demonstrate the importance of condition entering winter, combined with size andsettlement timing, for overwinter survival. Effects of winter duration on survival were less than expected.
Body condition and settlement time play important roles in subsequent survival. Our findings advancethe importance of settlement time for overwinter survival in sub-arctic marine ecosystems in a changing
climate.

–46–

The Timing of Global Change
Björn Birnir1∗, Alethea B. T. Barbaro2†, Sam Subbey3‡, Warsha Singh4, Kristinn Guðnasson4, Hannah
Murphy5, Aaron Adamack5, Salah Alrabeei6

1 Mathematics and Center for Complex, Nonlinear and Data Science, University of California, Santa
Barbara, Santa Barbara, CA, USA. e-mail: birnir@math.ucsb.edu
2 Mathematical Physics Group, Delft Institute of Applied Mathematics, Delft University of Technology,
The Netherlands
3 Institute of Marine Research, Bergen, Norway
4 Marine and Freshwater Research Institute of Iceland, Reykjavík, Iceland
5 Fisheries and Ocean, St. John’s, NL, Canada
6 Western Norway University of Applied Sciences, Bergen, Norway

Because of its responsiveness to changes in the marine environment, it has been suggested by Rose in2005 that the capelin, a small pelagic fish that is key to the ecology and fisheries of the North Atlantic,
could be seen as a “canary in the coalmine” to detect signals of changes in the Arctic Ocean. We will
describe the historical data that make possible a quantitative assessment of the geographical shift
capelin migration-paths and spawning grounds undergo with increasing temperature, and the time ittakes to make these shifts long-lasting. Then we introduce recent data that make these quantitative
measurements more accurate and predictive. The Copernicus database of the European Union is used to
examine the evolution of the returning Atlantic water (from Svalbard) that is forming a warmer and saltier
boundary current under the colder and fresher East Greenland polar current. The returning Atlantic
water has a temperature range (-1 to 3 degrees Centigrade) suitable for feeding migrations of thecapelin. This current is reaching further north along the coast of North East Greenland and we use
Copernicus to simulate this evolution. We then validate the Copernicus data with measurements madein the fall expeditions of the Marine and Freshwater Research Institute, in Iceland, along the East
Coast of Greenland. We identify trends in Copernicus data showing that the returning Atlantic waterboundary current may reach the major glacier streams draining a large portion of the Greenland Glacier,in the relatively near future, and use the capelin data to predict when this may happen.

–47–

Effects of snowcrab in the Barents Sea – Perhaps not only negative?
Cecilie Hansen, Erik Askov Mousing, Carsten Hvingel
Institute of Marine Research, Norway. e-mail: Cecilie.hansen@hi.no

The invasion and continuing expansion of snow crab in the Barents Sea has provided the area with a new,valuable, harvestable resource. On the negative side, this invasion may lead to changes in the ecosystem,
including structural changes and shifts in energy pathways due to predator-prey effects. However, not all
expanding species have detrimental effects on their new environment. To explore ecosystem effects of thesnow crab in the Barents Sea ecosystem, we’ve applied an end-to-end ecosystem model; the Nordic andBarents Seas Atlantis model (NoBa). NoBa includes 53 species and functional groups, and is forced byphysical forcing from a regional ocean modellling system (ROMS). The snow crab has been added as an ageresolved component. Its simulated population development from 1995 and forward captures the slow
growth in the beginning, with a steeper increase in the 2020s, thereafter reaching a stable population levelof around 1.2 million tons. With a new ecosystem component, there are many unknowns, including
predator-prey effects and impacts of different harvest regimes. To explore the footprint of snow crab in the
Barents Sea we explored a set of different scenarios, including harvest levels on snow crab, options forlarvae dispersal and predator-prey effects. The current size restrictions in the management regime are taken
into account. Based on our simulations, snow crab might have found a niche where the benthic community isable to sustain the predation, thereby causing fewer ecosystem effects. The simulations include thepotential development of the snow crab population in the future (1995-2068).

Time trawlers: An archaeological examination of the fishing station
at Smuttynose Island and its implications for the ecosystemof the Isles of Shoals and the Gulf of Maine
Megan Rhodes Victor

Anthropology Department, Queens College, CUNY. e-mail: megan.victor@qc.cuny.edu

Humans have indeed engaged with marine ecosystems for subsistence, transportation, and profit. During
the seventh century and eighteenth centuries, when ‘cod was king,’ the codfish trade in the North Atlanticinterwove skilled knowledge of the local marine ecosystem, international trade with its promises ofsustenance and luxury, and the particular pressures of the frontier to produce a unique tableau of
information. Through community-based, collaborative archaeology, these intricate threads of data can beteased apart, as was done at the site featured in this paper: the former fishing settlement on Smuttynose
Island in the Isles of Shoals, off of the Maine /New Hampshire border (1623-1780). The team conducted the
excavations through the Shoals Marine Laboratory in partnership with the community-based Smuttynose
Island Stewardship Program. During the course of the project, which ran from 2009 to 2012, the team
examined climate change at Shoals, with a careful eye toward current conditions, while also noting changes
in the codfish populations and the larger ecosystem, including invasive species. Although rather isolated,
the project found ways to record, excavate, and preserve this archaeological site with input from thecommunity whose heritage was most tied to it. The historical and ecological impact of the fishermen at theIsles are inextricably entwined; by including the local and descendant communities in the examination andpreservation of the site, they are actively connected to its future – and the larger future of the Gulf ofMaine.

Growth, condition, and movement of juvenile Arctic cod (Boreogadus saida)in a warming Alaska Arctic

Kali Stone*1,2, Thomas Helser1, Timothy Essington2, Anne Beaudreau2,
Matthew Baker3, Louise Copeman1

1

NOAA Alaska Fisheries Science Center, Age & Growth Program, Seattle, WA, USA.
e-mail: kali.stone@noaa.gov
2
University of Washington, Seattle, WA, USA
3
North Pacific Research Board, Anchorage, AK, USA
Arctic cod (Boreogadus saida) is a highly abundant fish species in Arctic and sub-Arctic ecosystems and is an
integral component of northern latitude food webs. Warming conditions and corresponding shifts in sea-ice
extent and timing, prey quality and availability, and predator/competitor interactions have greatly
complicated established life history patterns for this species. In the face of these biotic and abiotic stressors,it has become increasingly important to expand what is known of Arctic cod ecology in the context ofclimate change. Simultaneous assessments of multiple response metrics and the underlying mechanisms
are inherently challenging and relatively limited for wild Arctic cod specimens. This study simultaneously
compares the ontogenetic growth, movement, and condition of wild-caught juvenile Arctic cod between
recent cool and warm thermal conditions in the US Arctic. In addition to providing basic age and growth
information of the juvenile life stage, otoliths were also sampled for trace elements and stable oxygenisotopes to characterize the chemical and thermal histories experienced by juvenile Arctic cod. We also
explored whether otolith trace element and isotopic signatures allow for comparisons of juvenile
movement patterns and aid in understanding the population structure during these early life stages. This
work will contribute to a larger study that combines growth outcomes with lipid data to explore whether
the growth and condition of wild Arctic cod respond to temperature in a manner consistent with laboratory
findings. Results from field and laboratory approaches may help to clarify the impacts of warming on
growth and lipid storage, both of which impact overwinter survival and thus recruitment dynamics.

Fish otoliths from medieval archaeological excavations provide
exploitation effect baselines

Torstein Pedersen1, Colin Amundsen2 and Stephen Wickler3
1

Department of Arctic and Marine Biology, UiT The Arctic University of Norway Tromsø, Norway
e-mail: Torstein.Pedersen@uit.no2
Museum of Archaeology, University of Stavanger, Peder Klows gate 30 A, 4010 Stavanger, Norway
3
Tromsø University Museum, N-9037 Tromsø, Norway

We compared stock origin, size, age and growth rates from archaeological excavation at two sites innorthern Norway to those of cod catches from the early and late part of the 20th century. Samples of wellpreserved cod otoliths were available from excavations at Storvågan in Lofoten (68° 12’N) (A.D. 1156-1285)
close to the present major spawning grounds of Northeast Arctic and another sample from ca. AD 14501680 from Værbukta (70° 57’ N). For comparison, modern otoliths were sampled from areas situated close
to Storvågan and Værbukta. Zone numbers and increments (mm) were calculated from images of the cut
otoliths and stock origin Northeast arctic cod (NAC) or coastal cod (CC) were determined. Fish lengths-atage from pre-20th century samples were back-calculated from zone increments and nonlinear relationships
between fish length and otolith size from modern cod.
The pre-20th century cod from Storvågan was dominated by NAC (mean age = 12.0 years, mean length =82.9 cm) of age 9-16 years and were much older and larger than the early cod from Værbukta which were
dominated by CC of age 2-6 years (mean age = 4.4 years, mean length = 53.4 cm). Pre-20th century cod
from Storvågan had shorter back-calculated length-at-age than modern cod from Lofoten, indicating slower
individual growth than in modern NAC. In contrast, cod from Værbukta had similar length at age as inmodern samples. Age-distributions from pre-20th century from Storvågan cod and from the 1930s from
Lofoten, suggests that both age at maturity and mortality rates were similar for these time periods, but
strongly contrast the truncated and young age-distributions of spawning NAC after 1980 that reflect thehigh fishing mortality rate after 1950 and decrease in median maturation age to approximately 7 years.

Climate change impacts on marine light in Arctic ecosystems

Trond Kristiansen1,2, Øystein Varpe3, Benjamin J. Laurel4, Elizabeth Selig5, William J. Sydeman1, Michaela
I. Hegglin6, Kenneth F. Drinkwater7, Phil Wallhead2

1

Farallon Institute, Petaluma, USA. e-mail: trondkr@faralloninstitute.org
Norwegian Institute for Water Research, Oslo, Norway
3
Department of Biological Sciences, University of Bergen, Bergen, Norway
4
Alaska Fisheries Science Center, NOAA, Newport, USA
5
Center for Ocean Solutions, Stanford University, Stanford, USA
6
Department of Meteorology, University of Reading, Reading, UK
7
Institute of Marine Research, Bergen, Norway
2

Climate change will affect light across Arctic ecosystems, impacting productivity, phenology, andrecruitment. We quantify seasonal variation in light in the water column in response to changes in sea ice
and snow, storm-driven waves, cloud cover, ozone, and chlorophyll content, which change both absorption
and reflection. Using CMIP6 inputs and a simplified radiative transfer model, we find that increased open
water and ocean warming will lead to increases in both visible light (PAR) and UV light by 2100. These
increases in PAR and UV light result in greater irradiance in the water column, and changes in productivity
depending on species and life stage. These changes vary spatially and temporally across ecosystems, withgreater light in the spring and summer for the Barents Sea and in the fall for the Chukchi Sea. Changes in
the light regime in the Arctic will have major impacts on the survival and distribution of species like polar
cod by affecting sea ice, temperature, and food availability. For example, a decrease in sea ice will result inless protection and lower survival rates for eggs. Larval growth will be affected both by greater growth rates
due to temperature, but potentially less available food due to changes in productivity. Together, these
impacts will likely result in major changes to Arctic species and overall food-web structure.

Covarying lipid and fatty acid profiles among phytoplankton and Arctic cod(Boreogadus saida) in the Eastern Canadian Arctic

Carlissa Salant1, Louise Copeman2, Maxime Geoffroy3, Jean-Éric Tremblay4, Christopher Parrish1

1

Department of Ocean Sciences, Memorial University of Newfoundland, 0 Marine Lab Rd, St. John’s, NL,
A1C 5S7, Canada *cdsalant@mun.ca
2
Alaska Fisheries Science Center, National Oceanic Atmospheric Administration, 2030 SE Marine Science
Dr, Newport, OR, 97365, United States of America
3
Fisheries and Marine Institute, Memorial University of Newfoundland, 155 Ridge Rd, St. John’s, NL, A1C
5R3, Canada
4
Département de Biologie, Université Laval, 2325 Rue de I’Université, Quebec City, QC Canada, G1V 0A6

Arctic cod (Boreogadus saida) inhabit a central space in the Arctic marine food web, linking lower trophic
levels (phytoplankton and zooplankton) to higher order consumers such as fish, mammals, and birds.
Research into the biochemistry of trophic transfer remains an important component of ecosystem healthmanagement, especially in the wake of food web reorganization due to climate change. In 2019, lipid
metrics of Arctic cod and phytoplankton were measured within the Canadian Arctic. Specifically, lipid classand fatty acid profiles were analyzed in order to 1) identify possible regional differences, 2) compare theprofiles and assess if biomarkers could be traced from phytoplankton to Arctic cod within specific regions,and 3) relate lipids to spatial patterns in condition and diet of Arctic cod.
An Analysis of Similarity (ANOSIM, p > 0.05) was conducted between fatty acids (presence above 1%) in
phytoplankton and Arctic cod as a function of Canadian Arctic regions surrounding Baffin Bay. Significant
regional differences in fatty acid compositions were found between both surface phytoplankton (Clarke’s R= 0.470, p = 0.001) and Arctic cod livers (R = 0.19, p = 0.007). More detailed analysis using non-metricmultidimensional scaling (nMDS) revealed a northern and southern regional separation. For surface
phytoplankton, this north/south separation was driven by fatty acids indicative of diatoms, 20:53 and16:17, in the northern stations, and 18 carbon monounsaturated fatty acids (MUFAS) in the south.
Multivariate analyses of Arctic cod livers mirrored the patterns in phytoplankton with the north/south
separation also driven by higher diatoms in the north. Unlike phytoplankton however, 20 and 22 carbon
MUFAS dominated Arctic cod livers. These co-varying profiles of Canadian Arctic phytoplankton and Arctic
cod storage tissues give crucial insight into the transfer of lipids within Arctic food webs, and further
highlight the need for more regional specific assessments.

Sustainable use of salmon resource under changing climate
using multiple satellite datasets

Sei-Ichi Saitoh1,2,4, Yasuyuki Miyakoshi 3, Fumihiro Takahashi 1,4,
Takafumi Hirata 1, Irene D. Alabia 1

1

Arctic Research Center, Hokkaido University, *ssaitoh@arc.hokudai.ac.jp
NPO Digital Hokkaido Community
3
Kitami Salmon Enhancement Program Association 4: Green & Life Innovation, Inc.
2

Chum salmon is one of the important fishery resources in the North Pacific. Recently, under achanging climate, the return of chum salmon to Hokkaido has tended to decrease. In particular,
more precise juvenile release operation is required to adapt for warming sea temperature during its
sea entry. It is necessary for this precise operation to predict the coastal marine environment during
the release period and monitor short-term changes in coastal residency. Here, we developed asupporting information system for the optimization of salmon release operations in the Okhotsk
coast. This system was designed as a web-based visualization consisting of two site-based services,
for monitoring the marine environment (marine site) and supporting salmon release operation(release site). The coastal residence period for chum salmon is a critical phase in the early stage of its
life history. However, recent increases in water temperatures and marine heat waves in the Bering
Sea and the Gulf of Alaska posed serious concerns for the survival of migrating salmon during its
second and third year. Thus, becoming increasingly important for the sustainable harvest of salmon
under a rapidly changing climate. We utilized multiple satellite datasets and re-analysis data from anumerical forecast model to monitor the feeding and wintering environments of chum salmon atsea. This project is supported from 2022-2024 by the Japan Aerospace Exploration Agency (JAXA)/Earth Observation Research Center (EORC) under its third Research Announcement on the Earth
Observations (EORA3) for promoting research, utilization, and social implementation of data fromJAXA Earth observation satellites.

Forecasted shifts in thermal habitat for cod species in thenorthwest Atlantic and eastern Canadian Arctic

David Cote1*, Cassandra A. Konecny1, Jennica Seiden1, Tristan Hauser2,
Trond Kristiansen3,4, Ben J. Laurel5
1 Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John’s, NL, Canada
2 Wood E&IS GmbH, Frankfurt am Main, Germany
3 Farallon Institute for Advanced Ecosystem Research, Petaluma, CA, United States,
4 Norwegian Institute for Water Research, Oslo, Norway
5 Fisheries Behavioral Ecology Program, Alaska Fisheries Science Center, National Marine Fisheries Service,
National Oceanic and Atmospheric Administration, Newport, OR, United States

Climate change will alter ecosystems and impose hardships on marine resource users as fish assemblages
redistribute to habitats that meet their physiological requirements. Marine gadids represent some of themost ecologically and socio-economically important species in the North Atlantic, but face an uncertain
future in the wake of rising ocean temperatures. We applied CMIP5 ocean temperature projections to egg
survival and juvenile growth models of three northwest Atlantic coastal species of gadids (Atlantic cod,
Polar cod, and Greenland cod), each with different thermal affinities and life histories. We illustrate how
physiologically based species distribution models (SDMs) can be used to predict habitat distribution shifts
and compare vulnerabilities of species and life stages with changing ocean conditions. We also derived an
integrated habitat suitability index from the combined surfaces of each metric to predict areas and periods
where thermal conditions were suitable for both life stages. Suitable thermal habitat shifted poleward forthe juvenile life stages of all three species, but the area remaining differed across species and life stages
through time. Arctic specialists like Polar cod are predicted to experience reductions in suitable juvenile
habitat based on metrics of egg survival and growth potential. In contrast, habitat loss in boreal andsubarctic species like Atlantic cod and Greenland cod may be dampened due to increases in suitable egg
survival habitats as suitable juvenile growth potential habitats decrease. These results emphasize the needfor mechanistic SDMs that can account for the combined effects of changing seasonal thermal
requirements under varying climate change scenarios.

Estimating ocean temperature trajectories from ancient Indigenous fisherycatch records: an archaeological case study from the northeast Pacific

Iain McKechnie1, Dylan Hillis1, Robert Gustas1, Daniel Pauly2, William Cheung2, Anne Salomon3

1 Historical Ecology and Coastal Archaeology Laboratory, Department of Anthropology, University ofVictoria, Canada
2 Institute for the Oceans and Fisheries, University of British Columbia, Canada
3 School of Resource and Environmental Management, Simon Fraser University, Canada

Climate change is altering the distribution and composition of marine fish populations globally but
comparatively little is known about preindustrial fisheries with respect to climatic variability. Here, wedevelop and extend the Mean Temperature of the Catch approach (Cheung et al. 2013) to ancientIndigenous fisheries catch records at two coastal archaeological sites on western Vancouver Island, Canada.
We devised an analytical process that calculates ‘ancient Mean Temperature of the Catch’ (aMTC) fromzooarchaeological data, temperature preferences, and proportional biomass estimates. We observe an
increase in aMTC over a 5,000-year period at two contemporaneously occupied archaeological sites withcomparatively cooler catches from 5,000-3,000 cal yr BP and warmer catches during 1,800-250 cal yr BP.
These are consistent with palaeoceanographic sea surface temperature reconstructions from sedimentcores off British Columbia and in the Gulf of Alaska. Because this method requires converting measures offish bones into estimates of fish size structure, abundance, biomass, and finally aMTC, opportunities exist
to account for both variation and uncertainty at every step. Nevertheless, given that preindustrial fisheries
data are ubiquitous in coastal archaeological sites, this method has the potential to be applied globally tobroaden the temporal and geographic scale of ocean temperature baselines.

Temperature-dependent survival and growth of early juvenile Bering Sea snow crab
(Chionoecetes opilio) and Tanner crab (Chionoecetes bairdi): implications
for optimal crab thermal habitat in a rapidly warming Alaska Arctic.
Louise A. Copeman1,2, Michele L. Ottmar1, Clifford Ryer1, Trond Kristiansen3
1 Alaska Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric
Administration, Hatfield Marine Science Center, Newport, OR, 97365, USAe-mail: Louise.Copeman@noaa.gov
2 Cooperative Institute for Marine Ecosystems and Resources Studies, Hatfield Marine Science Center,
Oregon State University, Newport, OR 97365, USA
3 Farallon Institute for Advanced Ecosystem Research, 101 H Street, Suite Q, Petaluma, CA 94952, USA

Long-term laboratory studies on temperature-dependent (-1.5 to 16 °C) growth and survival in early
juvenile Alaska snow crab (Chionoecetes opilio) and Tanner crab (Chionoecetes bairdi) were conducted. A
priori we assumed that snow crab would have a stenothermal response adapted to cold conditions (< 3 ℃)
whereas Tanner crab would have a more eurythermal response. However, survival was generally similar
between the two species and decreased at temperatures above 7 °C and below 0 °C. Intervals between
molting events (inter-molt period) and the proportional change in size at each molt (molt increment) weretemperature and species dependent. Tanner crab had both shorter inter-molt durations and larger molt
increments at temperature > 2 °C, compared to snow crab. Largest molt increments for both species were
measured at temperatures between 0 °C and 5 °C, indicating efficient growth at lower temperatures.
Above 2 °C, absolute growth rates (mm day-1) were higher in Tanner crabs compared to snow crabs.
Temperature-dependent survival and growth functions were coupled to an ensemble of CMIP6 Earth
System Models statistically downscaled bottom temperature data (1/12th degree resolution) to examine
historical and future projections of thermal habitat for Chionoecetes crab in the Eastern Bering and Chukchi
Seas (1993-2100). By the end of the century, average summer bottom temperatures are projected toapproach 7.5 °C across much of the eastern Bering Sea shelf, a level beyond the optimal thermal limit for
long-term survival of Chionoecetes spp (<80% survival over 200 days). Optimal summer thermal habitat (<5 °C) will move offshore and northward and be limited to the northwest Bering Sea shelf and the central
Chukchi Sea by 2100. Different temperature - growth responses may result in juvenile Tanner crab having
a future growth advantage over snow crab across the full latitudinal extend of the Bering and Central
Chukchi seas.

How will climate changes affect the future Northeast Atlantic cod stockin the Nordic and Barents seas?
Ina Nilsen1, Cecilie Hansen1 and Isaac Kaplan2
1 Institute of Marine Research, 5817 Bergen, Norway. e-mail: ina.nilsen@hi.no
2 Northwest Fisheries Science Center, NOAA Fisheries, Seattle, WA 98112, USA

The Barents Sea currently holds the largest cod stock (Gadus morhua) in the world. The cod plays animportant role in the Norwegian economy, with the catches being worth over 7 billion NOK(Norwegian kroners). However, the future state of the stock and consequences for fisheries are
uncertain, with studies on how climate changes will affect the cod stock showing disputing
results. Warmer climate might increase suitable feeding area for cod, while at the same timecausing potential negative effects on reproduction in cod or on its prey species. Changes in spatial
distribution and/or spawning migration might influence the pattern and seasonality of thefisheries, with following impact on the economy along the coast. In this study we apply an Atlantis
ecosystem model for the Nordic and Barents seas (NoBa) to study the impact of three different
climate projections (SPP1-2.6, SSP2-4.5 and SSP5-8.5) on future fisheries with a focus on how thiswill affect the valuable NEA cod stock and potential consequences for fisheries. In all three
scenarios, we have used two different spatial management scenarios for the cod fisheries, one
where we restrict the fisheries to only harvest in the same areas where fishing occurs today, andone where harvesters can fish where the cod actually is. This will single out the spatial impact ofclimate change on the stock and the fisheries, and potential societal effects.

Arctic ecosystem impact assessment of oil in ice under climate change

Mats Huserbråten1, Frode B. Vikebø1, Elena Eriksen1, Torild Johansen1, Kai H. Christensen2,
Raymond Nepstad3, Tor Nordam3, Alf Håkon Hoel4, Malgorzata D. Smieszek4, Ben Laurel5

1 Institute of Marine Research, Norway. e-mail: mats.huserbraaten@hi.no
2 Norwegian Meteorological Institute, Norway
3 SINTEF Ocean, Norway
4 University of Tromsø, Norway
5 Alaska Fisheries Science Center, NOAA, USA

Warmer waters and retreating sea ice allow marine populations and human activities to expand
northwards, introducing multiple pressures acting in synergy on Arctic coastal and oceanic ecosystems. It isimperative to develop risk assessments that take into account not only changes in the structure andfunction of marine ecosystems induced by climate change, but also existing and new initiatives to utilize
Arctic marine ecosystem services, including living and non-living marine resources, shipping and tourism.
Society benefits from knowledge supporting sustainable management of the marine environment and its
resources by resource utilization at optimal levels with societal tolerable footprints. We address this by
studying the polar cod (Boerogadus saida), a circumpolar species that plays an essential role in iceassociated food webs, such as in the Barents Sea, linking the lower (i.e. zooplankton) and higher (e.g. otherfish, mammals, seabirds) trophic levels. We develop a data-driven mechanistic models for polar cod basedon field and lab experiments to assess cumulative impacts of climate and oil spills on the key Arctic fish
species relevant to stakeholders and policy development. The results presented here focus specifically on
the survival success of early life stages of polar cod originating from different spawning grounds and times
and the implications for population vulnerability to oil spills.

Detection of biologically productive water mass from ocean color satellite using
chromophoric dissolved organic matter (CDOM)
Joji Oida1, Toru Hirawake2,1, Youhei Yamashita3,4, Hiroto Abe5, Jun Nishioka4,6,
Hisatomo Waga7,8, Daiki Nomura7,5,8, Shigeho Kakehi9

1 Department of Polar Science, The Graduate University for Advanced Studies, SOKENDAI, Japan,
e-mail: oida.joji@nipr.ac.jp
2 National Institute of Polar Research, Japan
3 Faculty of Environmental Earth Science, Hokkaido University, Japan
4 Graduate School of Environmental Science, Hokkaido University, Japan
5 Faculty of Fisheries Sciences, Hokkaido University, Japan
6 Pan-Okhotsk Research Center, Institute of Low Temperature Science, Hokkaido University, Japan
7 Field Science Center for Northern Biosphere, Hokkaido University, Japan
8 Arctic Research Center, Hokkaido University, Japan
9 Shiogama Field Station, Fisheries Stock Assessment Center, Fisheries Resources Institute, Japan Fisheries
Research and Education Agency, JapanThe northwestern Pacific and shelf region of the Bering Sea are one of the most biologically productive
regions in the world. This feature is attributed to mixing of warm water with eutrophic cold water. Recent
warming, freshening and sea ice decline, however, might change the distribution and properties of water
masses that are important for ecosystems in these regions. Therefore, long-term and wide observationthat capture recent changes in water masses are important for predicting future changes in marine
resources and ecosystems. In this study, we have developed a method to derive water mass distribution
from ocean color satellite using light absorption spectrum (aCDOM(λ)) of chromophoric dissolved organic
matter (CDOM). We classified waters in the area into seven water masses (WMs) using in situ ultraviolet
aCDOM(λ) obtained during summers in 2006–2021. A classifier was created by machine learning using theWM number as the objective variable and temperature and the visible (VIS) aCDOM(λ) as the explanatory
variables. Distribution of the WMs were observed from MODIS-Aqua satellite by inputting sea surface
temperature and VIS aCDOM(λ) from the satellite to this classifier. The WMs distribution presented seasonalchanges in surface water likely due to vertical mixing in winter and expansion of water with high CDOM
concentration from spring to summer. This high CDOM water found only in April had a positive chlorophyll
anomaly. It suggests that the method in this study could detect the water mass with a potential to induce
high biological production in the study regions. In addition, it can be expected to extend the knowledge on
the biogeochemical cycles and mechanism of primary production from local to regional or basin scale
based on water mass. Therefore, it will be useful for verification of predictions from ecosystem models inthe sub-Arctic seas.

Was there a Pleistocene North Pacific fishery? The evidence for boat use, maritime
subsistence, and subarctic settlement around the North Pacific Rim.
Ben Fitzhugh
Department of Anthropology, University of Washington, Seattle, WA, USA

This talk reviews the available evidence for maritime adaptations around the coasts of Northeast Asia from40,000 years ago to the end of the last Ice Age. Drawing on the archaeological records of Northeast Asia
and recent genetic and palaeoceanographic discoveries, I examine the probability of cryptic Maritime
Beringian occupation in the Late Glacial Maximum (LGM) – whether it could have been a continuation ofearlier more temperate and subtropical coastal adaptations or where it could have formed, if not. Recent
evidence suggests the LGM North Pacific climate was milder in both winter and summer than thecontinental interiors of Beringia, making it plausible for maritime communities to form in areas of above
average productivity such as the now submerged Pacific coasts of Hokkaido, Kamchatka and the northshore of the Alaska Peninsula/eastern Aleutians. With circumstantial evidence leaning heavily on the side ofa coastal route for post-glacial settlement of the Americas, the question is no longer whether or not a
Maritime Beringian population existed in the LGM but how people crossed the Bering Land Bridge, and – ifby boat – how they manufactured their watercraft in a Beringian environment lacking abundant live trees.
Future work - including by members of the PESAS WG - could focus on: improved physical models of theNortheast Asian/Beringian paleoshorelines and ocean dynamics to refine predictions on likely places toprospect for submerged evidence; marine coring of submerged but protected paleolakes, ponds andlagoons in those locations in search of evidence of human presence in the most likely productive “hotspots”
for maritime settlement (e.g., sterols, sedDNA, etc.); and refinement of submarine archaeological
techniques to survey those locations for positive archaeological evidence.

Sounds of walleye pollock: a quantitative description
Amalis Riera1, Rodney Rountree1,2, Francis Juanes1
12

University of Victoria, Victoria, BC, Canada. email: ariera@uvic.ca
The Fish Listener, 23 Joshua Lane, Waquoit, Massachusetts, USA

We present the first quantitative description of walleye pollock (Gadus chalcogrammus) sounds based onover 67 h of audio recordings of captive specimens at the Hatfield Marine Sciences Center (Oregon). Over
6000 sounds attributed to walleye pollock were recorded in April 2018. Preliminary measurements on 436
sounds revealed an average duration of 152 ms, a frequency range of 18 to 839 Hz, and an average peakfrequency of 84 Hz. Quantification of the acoustic parameters of walleye pollock is an essential precursor to
the implementation of passive acoustic monitoring (PAM) surveys for the species. The ability to include
PAM surveys in studies of walleye pollock distribution would greatly enhance ongoing efforts to document
how rapid changes in the species distribution due to climate change are affecting the Arctic and North
Pacific ecosystems. In particular, there is concern about possible negative interactions with Arctic cod(Boreogadus saida) which has also recently been shown to be soniferous.

Pacific cod in the Anthropocene: an early life history perspective
under changing thermal habitats
Ben Laurel1, Alisa Abookire, Zoe Almeida, Steven Barbeaux, Louise Copeman,
Janet Duffy-Anderson, Tom Hurst, Mike Litzow, Trond Kristiansen, Jessica Miller,
Wayne Paulson, Hillary Thalmann, Sean Rooney, Lauren Rogers
1

NOAA Alaska Fisheries Science Center, Hatfield Marine Science Center Newport, OR, USA

The rapid decline in Pacific cod biomass following a recent Gulf of Alaska (GOA) marine heatwave (201416, 2019) may be one of the most dramatic documented changes in a sustainably managed marine fishery.
As such, fisheries managers are exploring new recruitment paradigms for Pacific cod under novel
environmental conditions. In this review, we address the challenges of managing and forecasting Pacific
cod populations in the Eastern Pacific where thermal habitats for early life stages are undergoing varying
rates of change across space and time. We use observational data and thermal habitat models to examinechanges in distribution, abundance and demographics of the population from 1993 to 2020. Results indicatethat reduced spawning habitat and early life stage abundance may be a precursor to regional population
decline, but the apparent increases in size-at-age of larval and juvenile cohorts following warming represent
potential climate resilience in the Gulf of Alaska. We contend that monitoring of thermal habitat and earlylife stages will need to consider how potential changes in phenology and growth impact later survival andpotential recruitment into the adult population i.e., ‘carry over effects.’ These include complex size- andtemperature-dependent energetics spanning seasonal habitats and through the first winter. Pacific cod
management in the Anthropocene will therefore require new process investigations beyond those that can be
conducted from single-season surveys focused on one life stage.

Socioeconomic Scenarios in the Alaska Climate Integrated Modeling (ACLIM) Project
Alan C. Haynie, Amanda Faig, Kirstin Holsman, Anne Hollowed, Stephen Kasperski,
Jonathan Reum, Andy Whitehouse, Jim Ianelli
NOAA Alaska Fisheries Science Center, Seattle, WA, USA

The Alaska Climate Integrated Modeling (ACLIM) project is an interdisciplinary effort to examine how
predicted warming may impact the Bering Sea ecosystem – and to ensure that the management system is
as prepared as possible for change (Hollowed et al., 2020). ACLIM integrates emissions scenarios with asuite of biological models – ranging from climate-enhanced single-species models to spatial ecosystemmodels. Each model includes different levels of ecosystem and fishing complexity and, which lets us
examine the interaction of sources of climatic and biological variability, change, and uncertainty and how
current and potential management measures influence the system. Central to projecting how future
warming may affect the ecosystem and fisheries is having realistic catch projections. Realized catch is a
result not just of the allowable biological catch (ABC) of each species, but the total allowable catch (TAC)
allocated to each species under the ecosystem cap and to the harvest of each species given those TACs.
For many species, catch is constrained not by the ABC or TAC, but by bycatch limitations or the lack ofprofitable targeting opportunities, given prices, costs, and management measures. Here we discuss the
ATTACH model and socioeconomic scenarios that have been developed and new scenarios that are indevelopment with stakeholder input. ATTACH retrospectively models how the North Pacific Fishery
Management Council sets the TAC and how the fishery has been able harvest different species. ATTACH isthen coupled with emissions scenarios and ecosystem models to project harvest. We show results of
ATTACH coupled with an existing suite of socioeconomic scenarios and then the current process ofdeveloping expanded socioeconomic scenarios that will make the management system more resilient in
the face of future change.

Exploring future fishery-related climate impacts to Bering Sea-Aleutian Islands
groundfish fishery using a mixed-species manageme
Carey R. McGilliard1, Jim Ianelli1, André E. Punt2, Andrea Havron2,
Anne B. Hollowed1, Alan Haynie1, Sophia Wassermann2
1
2

NOAA Alaska Fisheries Science Center, Seattle, WA, USA
School of Aquatic and Fisheries Sciences, University of Washington, Seattle,WA, USA

The multi-species groundfish fishery in the Bering Sea and Aleutian Islands (BSAI) is a large-scale fishery
driven by trawl and longline catches, as well as several constraints. These constraints include a two million
ton multi-species cap on total catches and bycatch limits for species such as Pacific halibut and Chinook
salmon. As shifts in climate occur, the distribution of the component species and the targeting behavior of
the fisheries is expected to change, leading to changes in the species composition of catches. Here we
present new and expected developments in a management strategy evaluation (MSE) framework for themulti-species groundfish fishery in the BSAI where the constraints are modeled explicitly. We developed amodel-based clustering method (R package clustTMB) to explore how species composition of catches may
be changing over space and time, with plans to apply the method to BSAI groundfish data and to integrate
modeling results into the MSE. Additionally, work is in progress to expand the number of species includedin the current MSE model, along with relevant linkages between population dynamics and environmental
variables such as temperature. With these new components, the MSE framework will be poised tosimulate the dynamics of the multi-species groundfish fishery under a variety of future climate and fisherypathways, and to evaluate potential climate-ready harvest control rules.

Warmer, earlier, faster: Cumulative effects of Gulf of Alaska heatwaves
on the early life history of Pacific Cod
L. Zoe Almeida1, Ben Laurel2, Hillary Thalmann1, Jessica Miller1
1

Oregon State University, Coastal Oregon Marine Experiment Station, Department of Fisheries, Wildlife,and Conservation Sciences. e-mail: almeidle@oregonstate.edu
2National Marine Fisheries Service – NOAA, Alaska Fisheries Science Center

Global warming can alter fish early-life phenology and growth through individual, daily processes thatscale up to populations. Recent marine heatwaves (MHWs) in the North Pacific Ocean dramaticallyreduced Pacific Cod (Gadus macrocephalus) populations in the Gulf of Alaska, with fewer but larger postsettlement juveniles observed during MHWs than before. Preliminary analyses indicated that these size
shifts were due to changes in both hatch timing and growth during MHWs. To quantify the effect oftemperature on hatch date and growth, we examined daily otolith increments of post-settlement age-0
juveniles collected during July near Kodiak Island, Alaska across 11 years before (2007, 2009-2010, 20122014), during (2015, 2016, 2019), and between (2017-2018) MHWs. Hatch dates differed due to heatwave
status (P < 0.001). Mean hatch dates were 13 d earlier during and 23 d earlier after MHWs than before;
however, significant differences in hatch dates only occurred between the periods before and between
MHWs (P = 0.02). Individual growth estimated based on otolith increment widths and back-calculated
growth showed similar trends; growth was positively correlated with temperature early in life with limited
effects of temperature on growth later in life (P < 0.001). Hatch date also interacted with age to influence
growth (P < 0.001), with later hatching individuals appearing faster growing than earlier hatching
individuals between 1-2 months of life. Overall, we found that warming affected age-0 Pacific Cod throughboth earlier hatching and faster apparent growth, with the greatest effect of temperature on growthearlier in life. Interestingly, the only significant shift in hatch phenology from years before the recent
MHWs occurred between MHWs (2017-2018), potentially indicating lingering effects of MHWs. Our results
will advance understanding of how MHWs alter growth and performance of Pacific Cod, which helps
explain and anticipate changes in size-structure and recruitment potential in near-future climates.

Introduction to CAMHEP: 1000 years of interaction between Icelandic cod and humans
Nicole Misarti1, Steven Campana2, Mary Efird3, George Hambrecht3,
Árni Daníel Júlíusson4, Habiba Moshfeka1
1

University of Alaska Fairbanks, Fairbanks, Alaska, USA, email: nmisarti@alaska.edu
University of Iceland
3
University of Maryland
4
Reykjavik Akademy
2

Atlantic cod (Gadus morhua; cod) has had a powerful influence on Iceland’s cultural, economic and evenpolitical development for the last 1100 years. Archaeological and historical sources make it clear that cod
and Icelandic society have been in a mutually constituted, integrated socio-environmental system long
before the advent of the modern era, and that any ecological studies in the present day will have to takethis long-term integration into account. Archaeology and historical ecology are in a unique position to
analyze the long-term consequences of human/natural interactions. This is especially true when
isogeochemical techniques including stable isotope analyses (SI), zooarchaeological techniques (such as
size and age assessments), and historical documents are combined. These methods can be used toinvestigate interactions between human subsistence, commercial harvests, and marine ecosystems. To
examine these links, this project will use SI signatures (δ13C, δ18O and δ15N bulk and compound specific),
allometric measurements of cod cranial elements, sea surface temperature (SST) reconstruction, growthrate, size-at-age estimates, and mortality rates from otoliths, as proxies to help determine changes introphic position, productivity, foraging locations, and stock size and health over time. This is a fairly new
project but to date we have examined 185 otoliths for size and age data and have begun to process over
150 cod premaxilla including fork length and bulk carbon and nitrogen isotope analyses.

SuessR: A new tool for applying Suess and Laws corrections to marine 13C data

Clark, C.T.1,2, Shapley, M.D.3, Mueter, F.J4., Finney, B.P.5, Cape, M.R.6, Misarti, N.2

1

University of Washington, Joint Institute for the Study of Atmosphere and Ocean, 3737 Brooklyn Ave NE,
Seattle, WA 98105, USA. email:ctclark@uw.edu
2
University of Alaska Fairbanks, Water and Environmental Research Center, 1764 Tanana Loop, Fairbanks,
Alaska 99775, USA. email:nmisarti@alaska.edu
3
University of Minnesota, CDSCO/National Lacustrine Core Facility, 116 Church Street SE, Minneapolis,
Minnesota 55455, USA. email: shap0029@umn.edu
4
University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, 17101 Point Lena Loop Rd,
Juneau, AK 99801, USA. email: fmueter@alaska.edu
5
Idaho State University, Departments of Biological Sciences and Geosciences, 921 S 8th Avenue, Pocatello,
Idaho, USA. email: finney@isu.edu
6
University of Washington, School of Oceanography, 1503 NE Boat Street, Seattle, WA 98195, USA.
email:mcape@uw.edu
Anthropogenic CO2 emissions have altered baseline atmospheric and oceanic 13C values. This decrease in13C, referred to as the Suess Effect, is incorporated into biological systems via photosynthesis andpropagates throughout food webs. In aquatic and marine systems, 13C discrimination by phytoplankton isfurther impacted by changes in water temperature, salinity, and aqueous CO2 concentrations, aphenomenon called the Laws Effect. In combination, these two factors may confound the results ofresearch using 13C to study marine ecosystems. Efforts have been made to mathematically correct for the
Suess and Laws effects with varying degrees of success; however, a standardized approach has not been
adopted by ecologists. SuessR is a new tool for applying corrections to marine 13C data, and is available as
an R package and a web-hosted Shiny app. This open-source platform builds on the most effective
published Suess and Laws corrections, using online repositories of historic sea surface temperature,salinity, and atmospheric CO2 data to calculate region-specific 13C corrections for samples collected from1850–present. Version 1.0.0 contains three built-in regions in the North Pacific (Gulf of Alaska, AleutianIslands, and Bering Sea); however, users can input their own environmental data to generate corrections
for their region, and are encouraged to submit these data to the developers for incorporation into futureversions of SuessR. Though considered by many to be a problem affecting only historical ecology andarchaeology, corrections generated by SuessR indicate that, for samples collected only 8 years apart (2013vs. 2020), the combined Suess and Laws effects exceed the typical instrument error for stable isotope
analysis (±0.2‰). By providing a simple, easy to use tool for applying Suess and Laws corrections to marine
13C data, SuessR will improve the interpretability of stable isotope data in future research and will allow
for greater comparability among studies.