Document Type
Article
Publication Date
9-17-2020
Department
Coastal Sciences, Gulf Coast Research Laboratory
School
Ocean Science and Engineering
Abstract
© Inter-Research 2020. Freshwater input into nearshore continental shelf waters from coastal river-estuarine plumes can greatly alter the physical and trophic environments experienced by fish larvae. However, the biological consequences of plume encounter on larval fish survival remain equivocal, largely due to the extreme variability of these systems but also because traditional sampling techniques alone are too coarse to effectively characterize the dynamic biophysical environment at spatiotemporal scales relevant to individual larvae. Using a multidimensional approach, we simultaneously collected in situ imagery and net samples of larval fishes and zooplankton from the Mobile Bay plume (Alabama, USA) and ambient continental shelf waters during a high discharge event (8-11 April 2016). We measured the effects of plume encounter on growth and condition of larval striped anchovy Anchoa hepsetus and sand seatrout Cynoscion arenarius, 2 prominent nearshore species in the northern Gulf of Mexico. Size-frequency distributions of both species indicated that larger individuals were present in shelf waters but absent from plume waters. Otolith microstructure analysis revealed that recent growth of both focal species was significantly lower for plume-collected larvae during the last few days prior to capture. Furthermore, plume larvae were in poorer morphometric condition (skinnier at length) than their shelf counterparts, despite the fact that there were higher concentrations of zooplankton prey in plume water masses. Taken together, these results suggest that elevated prey concentrations do not necessarily translate to higher growth and condition. High turbulence and turbidity within the plume may physically inhibit the prey capture ability and feeding success of fish larvae.
Publication Title
Marine Ecology Progress Series
Volume
650
First Page
63
Last Page
80
Recommended Citation
Axler, K.,
Sponaugle, S.,
Hernandez, F.,
Culpepper, C.,
Cowen, R.
(2020). Consequences of Plume Encounter On Larval Fish Growth and Condition In the Gulf of Mexico. Marine Ecology Progress Series, 650, 63-80.
Available at: https://aquila.usm.edu/fac_pubs/18219
Comments
Published version available at 10.3354/meps13396.