What's for dinner? Oceanographic drivers of Manx shearwater chick provisioning and growth

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Oceanographic features (e.g. fronts, gyres and eddies) are known to aggregate pelagic forage fish andthereby shape the space use of marine predators1,2. These features are dynamic and changes in theircharacteristics (e.g. strength, persistence, position) has consequences for prey availability, foraging effortand breeding success3. The NERC SHEAR project is currently quantifying how the association andinteraction between physical oceanographic features and prey availability impacts Manx shearwaterforaging energetics, a pelagic diving seabird known to forage in close association with oceanographicfeatures. However, there is a significant knowledge gap surrounding the diet composition of Manxshearwaters4 which is partly because previous methods for studying the diet of these birds have beeninvasive. DNA metabarcoding and less invasive sampling techniques are now transforming diet studies ofsuch species5. Furthermore, less is known about how variation in oceanographic features drive theavailability of specific prey species (i.e., squid and small Clupeid fish) within key foraging areas. This isimportant as prey species differ significantly in calorific value, and diets consisting predominantly of 'junkfood' have had significant consequences for the growth and survival of seabird offspring6. Thismultidisciplinary project will identify the fine-scale links between characteristics of oceanographic featuresand species of forage fish as well as quantify the key drivers of shearwater chick growth using acombination of biologging, eDNA analysis, morphometric measurements, and physical oceanography.Specifically, this project has three core questions:1. Does the characteristics of physical oceanographic features determine shearwater foraging depthand effort?2. Is meal size and diet determined by the characteristics of physical oceanographic features targetedduring foraging trips?3. Is chick growth explained by Qs 1 & 2?