Examining the human-predator interface of the North Sea: interactions between man-made subsea structures, marine predators, and commercial fisheries.

The North Sea has entered a period of rapid change incorporating large-scale decommissioning of oil and gas infrastructure; increases in the marine renewable energy industry; changes to commercial fisheries management; and ongoing climate change. The North Sea is also home to globally significant populations of marine predators including seabirds, seals and cetaceans.

Predators and fishers have a complex relationship with man-made structures (MMS) and with each other. For example, mammals can be displaced during MMS construction and operation, but once installed, MMS can host artificial reefs with localised increases in fish densities, resulting in attraction of individual predators to forage at MMS (e.g. Russell et al. 2014 [1]).

MMS can also act as de facto MPAs because many exclude commercial fisheries and shipping. Some fishers preferentially operate near pipelines (Rouse et al. 2018 [2]), likely due to increased fish densities, but in general fishers are advocates for the removal of decommissioned structures. Marine predator interactions with fishers can be direct e.g. following fishers to scavenge on discards (Bodey et al. 2014 [3]) and predator by-catch [4] or indirect e.g. competition for prey resources [5]. Finally, predatory species compete, predate, and facilitate each other via multiple mechanisms.

Understanding the above relationships is critical to harmonising conservation of biodiversity with future resource management. This project will fill critical knowledge gaps by addressing four key questions (chapters):

1) What is the magnitude and spatial scale of the effect of MMS on fishing vessel activity? 2) What are the relative influences of MMS and fishing vessels on the movements of top predators? 3) What areas of the North Sea are hotspots for predators? 4) What is the spatial overlap between the North Sea distributions of top predators, commercial fisheries, and the current and future MMS landscape?