Spatial variability of larval fish in relation to their prey and predator fields:

Interactions from cm to 10s of km in a subtropical, pelagic environment

(OSTRICH: Observations of Subtropical Ichthyoplankton)

PIs: Robert Cowen, Su Sponaugle
Funding source: National Science Foundation

The spatial pattern of organisms within pelagic marine environments has long been recognized to be of significant ecological importance, and this is particularly true for larval fishes. The degree to which larvae can survive their time in the plankton depends on successful feeding and avoidance of predation, yet we know little of these interactions on the scales of relevance to the larval fish.

Patchy prey and predator environments should lead to variation in predator-prey interactions, which underlie variation in larval fish growth and survival. Yet, dissecting the components of these overall outcomes is complex, due in large part to the broad range of spatial scales involved, and technological challenges with adequately sampling the various processes simultaneously. This NSF-sponsored study used new technology (the In Situ Ichthyoplankton Imaging System – ISIIS) to simultaneously measure the in situ, fine-scale distribution of larval fishes in relation to their prey and their planktonic predators. A novel combination of detailed in situ sampling of the horizontal and vertical distributions of plankton, targeted fine-scale net sampling, and analyses of individual-level recent daily larval growth enabled Miram Gleiber to identify the role of prey and predator patchiness on growth and survival of the larvae of coral reef fishes (Gleiber et al. 2020).

Her work on larval tunas examined growth over two years of contrasting prey conditions (Gleiber et al. in revision), and an additional chapter explored fine-scale differences in the zooplankton and larval fish community (Gleiber et al. in prep.). Kelly Robinson analyzed how patchiness varied among different taxa (Robinson in prep.). Mo Schmid examined how the distribution of larval fishes was influenced by a mesoscale eddy (Schmid et al. 2020) and he is continuing a study on diel vertical migration. Jessica Luo is finalizing a study on how zooplankton communities change during a series of Lagrangian sampling efforts (Luo et al. in prep.). We also compared our collection of larval lionfishes (pictured above) during this project to previous sampling efforts (Sponaugle et al. 2019). Together these studies will provide a quantification of the patterns and consequences of the fine-scale to sub-mesoscale distributions of larval fishes, their prey, and their predators near and across a major western boundary current passing through the Straits of Florida.

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This video was created by Waterlust and uses footage and photos from the OSTRICH Project.


Data are archived at BMO-DCO.