The distribution of pelagic seabirds is often driven by oceanographic features which concentrate their prey, but the relationship remains poorly understood. As a persistent localised feature of the global Subtropical Frontal Zone, the Southland Front 20-40km off Otago, Aotearoa New Zealand, provides an opportunity to study these predator-prey interactions. Utilising the Munida Transect Time Series, a 60km cross-shelf transect, planktivorous seabirds and surface zooplankton were sampled during six transects between October 2022 and March 2024. Model-based ordination was utilised for the first time in this region to characterise the surface zooplankton assemblage, supporting previous evidence of hydrological affinities and increased abundance at the frontal zone. Planktivorous seabirds were also shown to have an association with the frontal zone and Generalised Additive Mixed Models indicated distance from the coast was an important driver of seabird distribution. The first seabird-zooplankton association offshore in Otago was identified with storm petrels positively and significantly associated to zooplankton. As zooplankton and seabirds at sea are under researched nationally and globally, this study provides a baseline understanding of offshore predator-prey dynamics.
Daragh Katie Brown (Thu,) studied this question.