Photoperiodic implications on visual foraging in polar marine ecosystems

This poster was featured at the 16th congress of the International Society for Behavioral Ecology, July 2016 in Exeter (http://www.isbe2016.com/) and at the YOUMARES7 conference September 2016 in Hamburg (http://www.youmares.net/)

Trophic interactions are the key link between climate-driven environmental change and community processes defining ecosystem dynamics. The accelerated loss of Arctic sea ice constitutes a drastic change to the light regime of the pelagic realm with fundamental implications for the outcome of predator-prey interactions. We used mechanistic modelling of biological and physical components along a latitudinal gradient from open water to sea-ice covered seas to investigate light-modulated impacts on seasonal predator-prey interactions involving visual predators. Less sea ice means increased light which results in more efficient visual search. Phenology of sea ice and its relative timing to the solar photoperiod was found crucial for foraging. Melting sea ice will seasonally boost visual foraging of planktivorous fish and thus strengthen top-down control of the arctic pelagic food-web. Strongly non-linear responses in foraging will likely induce light-driven regime shifts in the pelagic realm.