Data from: Climate change alters the structure of arctic marine food webs due to poleward shifts of boreal generalists

Climate-driven poleward shifts, leading to changes in species composition
and relative abundances, have been recently documented in the Arctic.
Among the fastest moving species are boreal generalist fish which are
expected to affect arctic marine food web structure and ecosystem
functioning substantially. Here, we address structural changes at the food
web level induced by poleward shifts via topological network analysis of
highly resolved boreal and arctic food webs of the Barents Sea. We
detected considerable differences in structural properties and link
configuration between the boreal and the arctic food webs, the latter
being more modular and less connected. We found that a main characteristic
of the boreal fish moving poleward into the arctic region of the Barents
Sea is high generalism, a property that increases connectance and reduces
modularity in the arctic marine food web. Our results reveal that habitats
form natural boundaries for food web modules, and that generalists play an
important functional role in coupling pelagic and benthic modules. We
posit that these habitat couplers have the potential to promote the
transfer of energy and matter between habitats, but also the spread of
pertubations, thereby changing arctic marine food web structure
considerably with implications for ecosystem dynamics and functioning.