CC1: Impact of reduced ice cover in the Arctic marine environment

Date: Tuesday October 9, 2018

Location: Valtuustosali, City Hall

Time: 13:00-14:30

Current trends in the Arctic marine environment indicate that species reliant on sea ice for reproduction, resting or foraging will experience range reductions as sea ice retreat occurs earlier and the open water season is prolonged. These changes will have cascading affects throughout the entire food web. This session will explore how species interactions, behaviours, distributions, and even genetics may be changing, and the implications for human use and biodiversity monitoring and conservation. Furthermore, the session will also feature presentations that urge the expansion of our knowledge and highlight approaches and tools that strengthen our ability to gather results on Arctic change.

Chairs: Allen Pope, International Arctic Science Committee (IASC); Rolf Rødven, Arctic Monitoring and Assessment Programme (AMAP)

Format: Series of presentations, followed by question/answer and discussion

Presentations:

1. Earlier ice melt increases predation of common eider eggs by polar bears: Allison Patterson, McGill University 
   
2. What lies beneath? Melting sea ice and conservation of Arctic benthic habitats: Peter Harris, GRID-Arendal 
   
3. Polar bear life in the Russian Arctic in the light of recent research results: Andrei Boltunov, Marine Mammal Research and Expedition Center LTD 
   
4. Traditional knowledge about polar bears in East Greenland: recent changes in the catch and climate: Fernando Ugarte, Greenland Institute of Natural Resources
   
5. Book: Marine Fishes of the Arctic Region: Edda Johannesen, Institute of Marine Research 
   
6. Population structure of caribou in an ice-bound archipelago: Deborah Jenkins, Trent University 
   

Abstracts

Earlier ice melt increases predation of common eider eggs by polar bears

Allison Patterson, McGill University; Cody Dey, University of Windsor; Grant Gilchrist, Environment and Climate Change Canada

Climate change is leading to the loss of Arctic sea-ice and increases in polar bear predation of seabird nests. How this changing predator-prey relationship will impact polar bear and seabird populations is unclear. We have been conducting field studies and building predictive models to understand the impact of polar bear predation on populations of northern common eiders (Somateria mollissima borealis) in the Canadian Arctic Archipelago. Our studies suggest that polar bear predation of common eider nests will increase as sea-ice continues to decline. In response, eider hens will nest in smaller, more dispersed colonies to avoid polar bear predation. Additionally, we find that common eider population sizes should remain stable over the next 25 years because climate-driven increases in breeding propensity may compensate for increased nest predation. Together, these results suggest that northern common eider populations may be resilient to increasing polar bear predation, however changes in the spatial distribution of nesting females may make it harder for northern people to harvest eggs and down from eider colonies.

What lies beneath? Melting sea ice and conservation of Arctic benthic habitats

Peter Harris, GRID-Arendal

As the summer minimum in Arctic sea ice cover reduces in area year by year due to anthropogenic global climate change, so interest grows in the un-tapped oil, gas and fisheries resources that were previously concealed beneath. Existing marine protected areas in the Arctic Ocean (covering around 2.5% of the Arctic Ocean) offer little or no protection to many habitats and deep seafloor features that coincide spatially with areas likely to be of interest to industry. These habitats are globally unique, hosting Arctic species within pristine environments that are currently undergoing rapid adjustment to climate-induced changes in ocean dynamics, species migration and primary production. They are invaluable as reference points for conservation monitoring and assessment. The existing Arctic marine protected area network needs to be expanded in order to protect these habitats and be fully coordinated with other spatial and non-spatial measures intended to protect Arctic habitats and ensure any uses of Arctic marine or subsea resources are sustainable.

Polar bear life in the Russian Arctic in the light of recent research results

Andrei Boltunov; Varvara Semenova, Marine Mammal Research and Expedition Center LTD

In 2007-2017 during numerous coastal projects collection of non-invasive samples of polar bears was performed throughout the Russian Arctic: scats, shaded hairs, tissue samples from found carcasses. In 2014-2016 polar bear studies were conducted in a course of large scale complex expeditions, initiated by Oil Company “Rosneft”. Four expeditions covered all seas of the Russian Arctic: 32 polar bears were immobilized, 20 of them were tagged by ARGOS transmitters. Laboratory studies were done to analyze DNA, toxicology, microbiology. Complex view on the results of the studies provides deeper insight of the polar bear life in the Russian Arctic. Does current subdivision on three populations according to the Red Data Book of Russia, or four subpopulations according to IUCN, reflect natural structure of polar bear population in the Russian Arctic? Consideration of geographic features of various parts of the Russian Arctic, regional patterns of sea ice cover, distribution of main polar bear prey species along with results of recent studies of the species suggest that in every part of the species range there is certain balance of local resident and more large-scale nomad parts of one overall population. In this context possibly, the Kara Sea has the biggest proportion of resident bears while the Chukchi Sea being reach feeding area seasonally attracts considerable numbers of bears from adjacent regions. A vast marine area between these two distinct habitats is a kind of buffer or intermediate zone. Considering the above-mentioned comprehension of polar bears’ seasonal-spatial distribution, GAPs in knowledge, and available logistic potential, principal approaches to further research, conservation and monitoring of the species in the Russian Arctic are discussed.

Traditional knowledge about polar bears in East Greenland: recent changes in the catch and climate

Fernando Ugarte, Greenland Institute of Natural Resources; Kristin Laidre, University of Washington & Greenland Institute of Natural Resources; Allison Northey, University of Washington

In Greenland, polar bears are nutritional, economic, and cultural subsistence resources for Inuit. Traditional Ecological Knowledge (TEK) collected from subsistence hunters can provide important insights and improve management decisions when collected systematically. We report on the results of a TEK survey of subsistence polar bear hunters living in the areas around Tasiilaq and Ittoqqortoormiit, East Greenland. Twenty-five full-time polar bear hunters were interviewed between December 2014 and March 2015 in a conversation-style interview, where a local interviewer fluent in the East Greenlandic dialect asked a series of 55 predetermined questions. The primary goals were to 1) gather Inuit perspectives on polar bear subsistence quotas and hunting strategies, 2) understand how climate change is affecting the polar bear subsistence hunt, and 3) document observed changes in polar bear distribution, abundance, and biology. Approximately 40% of the Tasiilaq respondents had caught between 10-19 polar bears in their lifetime, while 67% of Ittoqqortoormiit respondents reported lifetime catches of >20 bears. In both areas, polar bears were most commonly hunted between February and April. Hunters noted large changes to the climate in the areas where they hunt polar bears. Most hunters reported loss of sea ice, receding glaciers, unstable weather, and warmer temperatures. In Tasiilaq 73% of the hunters said climate changes had affected the polar bear hunt and in Ittoqqortoormiit about 88% of respondents reported the same. Hunters indicated that sea ice loss has created more areas of open water so dog sledges have become unsafe for hunting transportation compared to 10-15 years ago (reported by 100% of hunters in Tasiilaq and 80% in Ittoqqortoormiit). In both areas hunters noted that more polar bears are coming into their communities compared to 10-15 years ago (81% of Tasiilaq hunters and 78% of Ittoqqortoormiit hunters) and pointed to the introduction of quotas and loss of sea ice as potential reasons. This study provides an important perspective on the East Greenland subpopulation of polar bears that can be used to direct science questions and inform management. This is an interview study that directly relates to policy recommendation 14 derived from the arctic Biodiversity Assessment: “Recognize the value of traditional ecological knowledge and work to further integrate it into the assessment, planning and management of Arctic biodiversity. This includes involving Arctic peoples and their knowledge in the survey, monitoring and analysis of Arctic biodiversity.”

Book: Marine Fishes of the Arctic Region

Edda Johannesen, Institute of Marine Research; Arve Lynghammar, University of Tromsø, Mecklenburg, C.W., A. Lynghammar, E. Johannesen, I. Byrkjedal, J.S. Christiansen, A.V. Dolgov, O.V. Karamushko, T.A. Mecklenburg, P.R. Møller, D. Steinke, and R.M. Wienerroither.

Early 2018 "Marine Fishes of the Arctic Region" was published at the CAFF website where it can be downloaded for free. It presents fishes from both the Atlantic and Pacific Arctic over 749 pages. "Marine Fishes of the Arctic Region" is the product of a three years collaborative project between USA, Norway, Russia and Denmark. It includes individual species accounts with maps of global spatial distribution, descriptions of morphology and habitat, and comments on similar species and problems with their identification, as well as a photographic identification guide for 205 species of marine fishes. In recent years, due to more extensive survey activity, fishes previously only known from the Atlantic Arctic has also been found to occur on the Pacific side. By presenting the fish fauna from both sides of the Arctic, "Marine Fishes of the Arctic Region" will help researchers to become aware of the fauna from the opposite side of the Arctic. Since the knowledge on fish fauna in the Arctic region is fragmentary, all future research on fish in this area should benefit. The Arctic Biodiveristy Assessment (ABA 2013,chapter on marine fish in the ABA report identified knowlegde gaps on dsitribution and species identity. Marine Fishes of the Arctic Region is important step forward in filling those gaps. In the presentation we show how we worked with this project, demonstrate how we think it might be useful and give some directions on future work. 

Mecklenburg, C.W., A. Lynghammar, E. Johannesen, I. Byrkjedal, J.S. Christiansen, A.V. Dolgov, O.V. Karamushko, T.A. Mecklenburg, P.R. Møller, D. Steinke, and R.M. Wienerroither. 2018. Marine Fishes of the Arctic Region. Conservation of Arctic Flora and Fauna, Akureyri, Iceland. ISBN 978-9935-431-70-7.

Population structure of caribou in an ice-bound archipelago

Deborah Jenkins, Trent University, Canada; Glenn Yannic , University Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, Laboratoire d’Ecologie Alpine; James A. Schaefer, Trent University, Canada; James Conolly, Trent University, Canada; and Nicolas Lecomte, University of Moncton, Canada

Archipelagos provide ideal natural systems for inferring the effects of insolation and fragmentation on the genetic makeup of populations – an important consideration, given that many insular species are of conservation concern. Two theories predominate: Island Biogeography Theory (IBT) posits that the proximity to mainland drives the potential for migrants and gene flow. The Central Marginal Hypothesis (CMH) predicts that island populations at the periphery of a species range may experience low gene flow, small population size, and high rates of genetic drift. Using genetic fingerprinting, we explored caribou genetic diversity below the species level and deciphered how IBT and CMH could act in the Canadian Arctic Archipelago where isolation is highly variable due to sea-ice and open water. We used hierarchical Bayesian clustering and multivariate analysis to determine genetic groups, evaluated the influence of ecological and geographic variables on genetic diversity using linear mixed effects models, and compared diversity among mainland and island herds. Bayesian clustering revealed nine genetic clusters with differentiation among and within caribou subspecies. Genetic differentiation was predominantly explained by isolation-by-distance across all caribou, even at the scale of subspecies. Island caribou were less genetically diverse than mainland herds; individual heterozygosity was negatively correlated with distance-to-mainland and extent of the autumn ice-free coastline, and positively correlated with island size. Our findings underscore the importance of hierarchical analysis when investigating genetic population structure. Diversity and its key drivers lend support to both IBT and CMH, and highlight the pending threat of climate change and sea ice loss. Given that recommendations and goals of the Arctic Biodiversity Assessment includes - safeguarding Arctic biodiversity under changing environmental conditions - it is critical to identify and understand the distribution of diversity below the species level, as well as the key determinants of that diversity. This research provides meaningful large scale analysis of genetic diversity across the most northerly and remote terrestrial habitat in North America.