Academic Journals Database
Disseminating quality controlled scientific knowledge

Wake sorting, selective predation and biogenic mixing: potential reasons for high turbulence in fish schools

ADD TO MY LIST
 
Author(s): Jay Willis

Journal: PeerJ
ISSN 2167-8359

Volume: 1;
Start page: e96;
Date: 2013;
VIEW PDF   PDF DOWNLOAD PDF   Download PDF Original page

Keywords: Wake sorting | Ecosystem engineering | Ocean turbulence

ABSTRACT
There has been debate about animals’ contribution to ocean circulation, called biomixing, or biogenic mixing. The energy input of schooling fish is significant but the eddies may be too small; so energy is dissipated as heat before impacting oceanic structure. I suggest that high turbulence caused by some very large aggregations of small animals has an important impact via a more direct ecosystem feedback process than overall ocean circulation. In the model presented here, large schools exhibit cooperative behavior and act like giant sieves grading zooplankton through individual swimmer’s wakes, which focus the best prey in predictable positions. Following schoolers exploit these patterns. Then schools leave, in their wakes, chaotic turbulence enhancing growth of the smaller zooplankton and phytoplankton which has been graded out by the school. The result is a different community structure of plankton than would exist without such biomixing. Changes to plankton abundance and community structure on oceanic scales over the past century are correlated to overfishing and are consistent with this concept.
Affiliate Program     

Tango Rapperswil
Tango Rapperswil