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MASTS Webinars with Douglas Speirs (16 June)



Douglas presented “Modeling zooplankton and fish in space and time, and under climate change”.
Marine zooplankton and fish species often have very wide, but continuous, geographic distributions in which individuals move or are transported by ocean currents over large distances. They also often have complicated life cycles involving physiologically different developmental stages. As a consequence, species can occur over an enormous range of environments, including food abundance and temperature, in which different life-history stages may respond variably. Combing these considerations in population models capable of capturing the dynamics of such species and their changing spatial distributions in response to changing environments poses serious modelling challenges. This talk will overview the development at the University of Strathclyde of an approach to combining physiological spatial structure in marine population models. Examples will be drawn from modelling and mesopelagic fish, and zooplankton in the Arctic under climate change.

QUESTIONS
1 The temperature-based model assumptions are most interesting in the regions where there’s no supporting data. Doesn’t this carry a risk for climate change simulations where temperature rises pushes the model into these unsampled regimes?
2 Estimates on the impact on the lipid pump are all based on the change in distribution on one species. Is it likely that other zooplankton species will also change in distribution and contribute to changes in the overall flux of lipid? Is a multispecies model of value for predicting future changes in the lipid pump?
3 Do you include any form of zooplankton behavior adaptation to climate change?
4 On the assumption that NEMO-MEDUSA is likely to be wrong, and to varying degrees in physics / biogeochemistry, do you know whether your climate change zooplankton forecasts are more sensitive to temperature (most likely accurate) or food availability (less likely accurate)?
5 From Adrian Martin (watching on YouTube): Is another fish likely to move in when Benthosema declines?
6 Can you say anything about how you would represent harvesting in such models
7 In Norway they model phytoplankton, zooplankton and three (or more) species of migrating fish in the Norwegian Sea. The model is called NORWECOM
8 In the Norwegian Ecological Model System (NORWECOM) they include three (or more) migrating fish in the Norwegian Sea (in addition to phyto and zooplankton)