When: Friday April 5 at 1:00 pm EST
Link in Gotomeeting to register: https://www1.gotomeeting.com/register/939780257
or Webinar ID: 939780257
APECS Canada is organizing an Eastern Arctic research webinar (web-based seminar). The format will be similar to other conference seminar series. Five speakers, from differing research backgrounds, will present a 15 minute presentation using power point. This will then be followed by a 5-10 minute question period.
The webinar will be conducted using the GoToWebinar platform. Simply click on
https://www1.gotomeeting.com/register/939780257 to join us! To attend you just need your computer, an internet connection, and a headset or headphones and a built-in microphone is recommended. We are not using webcams or telephones, so you do not need a web cam or telephone to participate. GoToWebinar has been provided as an in-kind contribution from Bredbåndsfylket.
Our speakers:
Jean-Sebastien Moore
Describing the dispersal behaviour of Baffin Island anadromous Arctic char using a genetic assignment approach.
Anadromous Arctic char (Salvelinus alpinus) is subject to a commercial fishery in Cumberland Sound, Baffin Island, Nunavut. The fishery is currently managed on a river-by-river basis, assuming that most individuals home to their river of origin. Tagging data from other regions, however, suggest that straying (dispersal) is more common in this species than in other salmonids. We use genetic data to quantify dispersal in Arctic char from 15 rivers around Cumberland Sound, Nunavut. Due to low genetic differentiation among rivers, we obtained different estimates of dispersal depending on the genetic assignment method used. All estimates of numbers of dispersers, however, are fairly high and range between 16% and 45%. We also find evidence that individuals in reproductive condition are more likely to home than individuals not in reproductive condition. This higher propensity to disperse in years where they forego reproduction has interesting implications for the evolution of local adaptation in this system. Other biological traits (sex, age, fork length, weight, gonad weight, and condition factor) were not good predictors of dispersal propensity. Understanding the dispersal behavior of Arctic char will be crucial as the commercial fishery for this species intensifies.
Moritz Schmid
New perspectives in zooplankton sampling: use of in situ optical imaging to profile the vertical distributions of taxa
The bulk of energy and carbon from primary producers in the Arctic is transferred to the vertebrate fauna (such as fish, marine mammals and seabirds) via the mesozooplankton (0.2-20 mm). With the advancement of oceanographic research methods it is now clear that zooplankton can form high abundances in very thin layers (several centimeters to 3 m) of the water column. The distribution of these layers is important for the dynamics and fate of primary production, and affects the food available for higher trophic levels. However, traditional methods used to capture zooplankton (i.e. nets) only integrate or roughly stratify the water column, and do not provide the necessary resolution for studying the fine-scale vertical distribution of key zooplankton components. The lack of resolution from traditional zooplankton samplers can be overcome with devices such as the newly developed "Lightframe On-sight Key species Investigation" (LOKI) system, capable of in situ optical imaging of zooplankton species. By taking photographs of each particle that flows through the device, LOKI allows the vertical distributions of organisms in the water column to be determined with precision, and relates them to environmental data (e.g. T, S, Chl a). This study utilizes the LOKI to assess spatiotemporal variability in the coupling between primary and secondary production in the Canadian Arctic Ocean. Here we provide a first evaluation of the LOKI based on our experiences from a cruise in Hudson Bay, Canada as part of the BaySys expedition onboard the CCGS Pierre Radisson in September 2012. We will also offer an outlook on the next steps of the project, including the development of extensive databases for the automatic taxonomic classification of zooplankton using machine learning algorithms.
Heather Mariash
Implications of a changing Arctic to freshwater ecosystems: adaptions to shorter ice cover
In the arctic, the annual ice cover period is a critical denominator underlying lake metabolism. Ice cover controls much of the internal lake function, from timing of different carbon sources, to the light environment, to the subsequent phytoplankton emergence and zooplankton life history strategies. My research uses several approaches to identify the adaptations aquatic animals use to cope with the changing extent of ice cover. We are seeing changes in feeding strategies, physiology, and life history strategies. Understanding these adaptations can indicate degree of population plasticity in response to ongoing environmental change.
Cortney A. Watt
How adaptable are narwhal: a comparison of foraging behaviour among the world's three narwhal populations
How organisms will fair in the face of climate change depends on their behavioral adaptability to changing conditions. Adaptability in foraging behavior will be particularly critical as food web changes are already occurring in Arctic regions. Stomach contents from narwhals in the Baffin Bay (BB) population have suggested that narwhals (Monodon monoceros) are dietary specialists with little behavioral flexibility, but there are two other narwhal populations in the world, the Northern Hudson Bay (NHB) and East Greenland (EG) populations, of which very little is known about diet. To determine how adaptable narwhal are to changing environments we investigated whether plasticity in foraging behaviors existed among the world's narwhal populations and between sexes by comparing their isotopic values and niches, investigating dive behaviour, and running isotope mixing models to determine primary prey. Stable isotope analysis was conducted on skin collected by Inuit hunters during their subsistent narwhal hunt in Canada and Greenland. Isotope analysis on carbon (δ13C) and nitrogen (δ15N) revealed the three populations have distinct isotope values that are not expected based on geographic differences and that males in all populations had significantly higher δ13C. Isotope mixing models revealed narwhals in EG forage more on pelagic prey, particularly capelin, while those in NHB typically forage in the benthos. Males, probably because of their size and enhanced diving ability, likely feed more intensively on benthic organisms, resulting in their enriched δ13C value. Isotopic niches were similar between all males and females, and between NHB and BB, but EG narwhals had a significantly larger niche, suggesting they either forage across a larger geographical expanse, which is consistent with their hypothesized range, or they forage on a greater variety of prey. This is the first study to use isotopes to evaluate and compare diet in all three narwhal populations, which is vital for understanding how they will fair in the face of changing climate.
Jennifer Provencher
Pollution and parasites; why they both matter in marine bird conservation.
Both derived traits and environmental factors can shape the schedules of survivorship and reproduction of wild organisms. In migratory animals these traits can be especially important as they balance the costs and benefits of undertaking long range migrations to breeding areas to take advantage of seasonal resources. In ecosystems that are undergoing rapid change, such as the Canadian Arctic, it is increasingly important to understand how external factors influence reproduction; particularly in terms of how environmental changes might impact populations. Contaminants such as mercury are of growing concern in the Arctic because they are known to affect animal health, and levels are increasing in some Arctic regions. Concurrently, changing climatic conditions are predicted to increase the number and diversity of parasites found in wildlife within northern ecosystems. In addition to changes in both mercury and parasites, these two factors may interact in complex ways. For example, parasites are known to mitigate the effects of some contaminants in wildlife, while exacerbating them in others. Thus, understanding how contaminants and parasites may influence reproduction is important to conserving and managing arctic wildlife species. My PhD research investigates questions regarding how both mercury and parasites, separately and together, influence adult body condition and reproduction in an arctic seabird (the northern common eider duck;Somateria molissima).
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