Nonlinear effects of body size and optical attenuation on Diel Vertical Migration by zooplankton

TitleNonlinear effects of body size and optical attenuation on Diel Vertical Migration by zooplankton
Publication TypeJournal Article
Year of Publication2016
AuthorsOhman MD, Romagnan J.B
JournalLimnology and Oceanography
Volume61
Pagination765-770
Date Published2016/03
Type of ArticleArticle
ISBN Number0024-3590
Accession NumberWOS:000372166500020
Keywordscalifornia current system; climate-change; Copepods; intensification; Micronekton; model
Abstract

We adopt a trait-based approach to explain Diel Vertical Migration (DVM) across a diverse assemblage of planktonic copepods, utilizing body size as a master trait. We find a reproducible pattern of body size-dependence of day and night depths occupied, and of DVM. Both the smallest surface-dwelling and the largest deeper-dwelling copepods refrain from migrations, while intermediate-sized individuals show pronounced DVM. This pattern apparently arises as a consequence of size-dependent predation risk. In the size classes of migratory copepods the amplitude of DVM is further modulated by optical attenuation in the ocean water column because increased turbidity decreases encounter rates with visually hunting predators. Long-term changes in the ocean optical environment are expected to alter the vertical distributions of many copepods and thus to affect predator-prey encounters as well as oceanic carbon export.

DOI10.1002/lno.10251
Student Publication: 
No