[PAST EVENT] Individual-based modelling of two key polar species (Arctic Cod and Antarctic Krill)

September 18, 2013
12pm - 1pm
VIMS - Watermen's Hall, Classroom A/B
1375 Greate Road
Gloucester Point, VA 23062Map this location
Abstract: Individual-based models (IBMs) allow biological processes across all spatial and temporal scales, from individual metabolism to population dynamics, to be investigated. Adult Arctic cod Boreogadus saida are the primary prey for seals and sea-birds in the Arctic ecosystem. An IBM focused on the first 50 days of the life of Arctic cod, which simulated daily growth and survival, will be presented. Simulations were performed using a bioenergetics sub-model calibrated with laboratory measurements and validated using data from individuals collected during research campaigns. The relatively high resolution dataset enabled the effect of both the quality of daily larval samples, and the occurrence of matches and mismatches between larval first-feeding and prey blooms, to be investigated at daily timescales. A second IBM application, designed to investigate the population dynamics of Antarctic Krill Euphausia superba, on which whales, penguins and sea-birds in the Antarctic ecosystem depend, will be presented. In this case, the IBM was used to assess whether time-series of monthly Krill length frequency distributions could be used to estimate recruitment variability. Based on a coarse resolution dataset provided by observers measuring the length of Krill on-board fishing vessels, the simple IBM provided insights in the combined effect of growth, mortality and recruitment on trends in length frequency distributions. Both the Arctic and Antarctic models were based on the same framework, and demonstrate the utility of IBMs as numerical tools for the analysis of ecological data, in which levels of detail and spatial and temporal resolution may vary widely.

[[graves, John Graves]]