Dear colleagues,

please remember today’s seminar, and note the unusual time 16:30 (due to time zone differences):

The seminar will be hosted by Sami Kivelä.

Heikki

Biology Thursday seminar 25^th Nov at 16:30 (note unusual hour!) on zoom (link below):

Dr. James Thorson, the Program lead at the Habitat and Ecologial Processes Research Program / Alaska Fisheries Science Center / National Marine Fisheries Service in Seattle, WA.

His title: Statistical models for whole-of-ecosystem understanding, and what they say about changes in the Pacific gateway to the Arctic

Topics:

Tweedie stomachs
Pacific cod movement
Whole-of-ecosystem Bering Sea synthesis

Abstract:

The central Arctic and adjacent oceans are rapidly changing due to loss of sea ice resulting from the climate crisis. Changes are apparent in planktonic advection and phenology, shifting habitat preferences for mobile consumers, as well as consumer diet and bioenergetics. However, there are few methods to synthesize spatial patterns in numerical abundance, diet, and physiological condition for multiple trophic levels, as well as how these change among seasons and years. To address this, I present three new statistical methods to facilitate whole-of-ecosystem spatio-temporal synthesis. First, I discuss a simple approach to analyze food-habits data (stomach contents, etc.) using a Tweedie generalized linear model (GLM). This GLM approximates a thinned and double-marked Poisson point process representing foraging processes, and shows multidecadal shifts in prey for a central-place forager (Middleton Island tufted puffins). Second, I introduce a “diffusion-taxis” movement model, which I fit to data from multi-decadal surveys, fishery catch-and-effort, tagging data, and output from global climate models. This model demonstrates the rapid northward movement for Pacific cod into the northern Bering Sea. Finally, I introduce a whole-of-ecosystem “empirical orthogonal function” (EOF) model for the eastern Bering Sea. This EOF demonstrates the outsize importance of cold near-bottom waters created by spring ice formation, where warm ice-free years result in detrimental conditions for Alaska pollock. Throughout, I emphasize that whole-of-ecosystem synthesis is feasible using off-the-shelf statistical software, and that the Pacific Arctic in particular is experiencing rapid changes due to climate.

Also, don’t forget that prof. Virpi Lummaa is giving a talk in the Biodiverse Anthropocenes monthly series on Friday 26^th Nov at 12-2pm at Tellus Stage (including snacks and refreshments and time to mingle!

So see you online on Thursday, and on site in Tellus on Friday,

Heikki

Heikki Helanterä is inviting you to a scheduled Zoom meeting.

Topic: Biology Thursday seminar

Time: This is a recurring meeting Meet anytime

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