High frequency (hourly) variation in vertical distribution and abundance of meroplanktonic larvae in nearshore waters during strong internal tidal forcing

TitleHigh frequency (hourly) variation in vertical distribution and abundance of meroplanktonic larvae in nearshore waters during strong internal tidal forcing
Publication TypeJournal Article
Year of Publication2016
AuthorsMacTavish A.L, Ladah L.B, Lavin M.F, Filonov A., Tapia F.J, Leichter J.
JournalContinental Shelf Research
Volume117
Pagination92-99
Date Published2016/04
Type of ArticleArticle
ISBN Number0278-4343
Accession NumberWOS:000374607000009
Keywordsbenthic invertebrates; bores; coral-reef; cross-shelf transport; dispersal; Fronts; internal waves; Meroplankton; onshore transport; planktonic larvae; surface slicks; waves; Zooplankton
Abstract

We related the vertical distribution and abundance of nearshore meroplankton at hourly time scales with internal tidal wave events. We proposed that significant changes in plankter abundance would occur across internal tidal fronts, and that surface and bottom strata would respond in opposite fashions. First mode internal tidal bores propagating in the alongshore direction were detected in water-column currents and baroclinic temperature changes. Surface and bottom currents always flowed in opposite directions, and abrupt flow reversals coincided with large temperature changes during arrival of bores. Crab zoeae and barnacle cyprids were more abundant in the bottom strata, whereas barnacle nauplii showed the opposite pattern. Significant changes in vertical distribution and abundance of target meroplankters occurred across internal tidal fronts, especially for crabs at depth, with surface and bottom organisms responding in opposite fashions. Changes in plankter abundance were significantly correlated with current flows in the strata where they were most abundant. The manner in which plankters were affected (increasing or decreasing abundance) appeared to be modulated by their vertical position within the water column. The significant differences found at the high frequencies of this study, maintained across sampling days, suggest that nearshore meroplankton populations may have greater and more consistent temporal and vertical variability than previously considered. (C) 2016 Elsevier Ltd. All rights reserved.

DOI10.1016/j.csr.2016.02.004
Short TitleCont Shelf Res
Student Publication: 
No