How Do Warm-Core Eddies Structure the Deep-Pelagic Fish Fauna of the Gulf of Mexico?
2018 Ocean Sciences Meeting, Portland, Oregon, February 11-16, 2018
Mesoscale oceanic features, such as cyclonic and anti-cyclonic eddies are important in structuring pelagic faunal assemblages by generating regions of environmental heterogeneity at scales of tens to hundreds of kilometres. In the Gulf of Mexico (GoM), anticyclonic loop-current eddies (LCEs) are major semi-permanent, upper-ocean oceanographic features that are characterised by warm, oligotrophic waters, and that typically persist in the GoM for several months. However, the extent to which they may influence oceanic fauna, and particularly the deep-living pelagic fish fauna is not well known. In the present study, we use depth-stratified trawl catches and sensor data to characterise LCEs and examine their influence on both the assemblage structure of deep-living fishes (0 - 1500 m), and the distributions of the dominant migratory and non-migratory species captured during five research surveys conducted between May 2015 and May 2017. Overall, our findings suggest that samples occurring within LCEs generally contained a different composition of fishes, and a lower abundance of fishes than those outside the LCEs, but that significant effects of the LCEs were generally restricted to the upper water column (< 1000 m). Below 1000 m, very little assemblage structure was observed. Given the increasing range of human activities that target deep-ocean resources, we anticipate that these findings will provide valuable context when attempting to assess the potential ecological impacts of those activities.
Milligan, Rosanna and Sutton, Tracey, "How Do Warm-Core Eddies Structure the Deep-Pelagic Fish Fauna of the Gulf of Mexico?" (2018). Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures. 614.