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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Modelling transport of chokka squid (Loligo reynaudii) paralarvae off South Africa: reviewing, testing and extending the `Westward Transport Hypothesis'

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Author(s):
Martins, Rodrigo S. [1, 2, 3] ; Roberts, Michael J. [3] ; Lett, Christophe [4] ; Chang, Nicolette [5] ; Moloney, Coleen L. [1, 2] ; Camargo, Mauricio G. [6] ; Vidal, Erica A. G. [6]
Total Authors: 7
Affiliation:
[1] Univ Cape Town, Dept Zool, ZA-7701 Cape Town - South Africa
[2] Univ Cape Town, Marine Res Inst, ZA-7701 Cape Town - South Africa
[3] Oceans & Coasts, Dept Environm Affairs, ZA-8000 Cape Town - South Africa
[4] UMI IRD 209 UPMC UMMISCO, Ctr Rech Halieut Mediterraneenne & Trop, F-34203 Sete - France
[5] CSIR, ZA-7599 Cape Town - South Africa
[6] Univ Fed Parana UFPR, CEM, BR-83255000 Pontal Do Parana, PR - Brazil
Total Affiliations: 6
Document type: Journal article
Source: FISHERIES OCEANOGRAPHY; v. 23, n. 2, p. 116-131, MAR 2014.
Web of Science Citations: 6
Abstract

Annual landings of chokka squid (Loligo reynaudii), an important fishing resource for South Africa, fluctuate greatly, and are believed to be related to recruitment success. The Westward Transport Hypothesis' (WTH) attributes recruitment strength to variability in transport of newly hatched paralarvae from spawning grounds to the cold ridge' nursery region some 100-200km to the west, where oceanographic conditions sustain high productivity. We used an individual-based model (IBM) coupled with a 3-D hydrodynamic model (ROMS) to test the WTH and assessed four factors that might influence successful transport - Release Area, Month, Specific Gravity (body density) and Diel Vertical Migration (DVM) - in numerical experiments that estimated successful transport of squid paralarvae to the cold ridge. A multifactor ANOVA was used to identify the primary determinants of transport success in the various experimental simulations. Among these, release area was found to be the most important, implying that adult spawning behaviour (i.e., birth site fidelity) may be more important than paralarval behaviour in determining paralarval transport variability. However, specific gravity and DVM were found to play a role by retaining paralarvae on the shelf and optimizing early transport, respectively. Upwelling events seem to facilitate transport by moving paralarvae higher in the water column and thus exposing them to faster surface currents. (AU)

FAPESP's process: 10/15978-8 - Modelling the larval transport of the squid Loligo plei Blainville, 1823 exploited by comercial fishing of São Paulo state coast
Grantee:Rodrigo Silvestre Martins
Support type: Scholarships in Brazil - Post-Doctorate