Coastal upwelling and Oikopleura occurrence (“slub”): a model and potential application to inshore fisheries

• Main Author: Kenneth T Frank
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1987
• Subjects: Gadus morhua; Newfoundland; Terre-Neuve
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.546.5341; http://www.phys.ocean.dal.ca/~taggart/Publications/Taggart-Frank_CJFAS44_1987.PDF

Var iat ions in the occurrence of Oikopleura spp. were st rongly l inked to the wind f ie ld and ensuing water temperatures in an inshore region o { eastern Newfoundland ur ing June-August of 1979 and 1981-43. Oikopleura foul inshore f ish ing gear wi th thei r d iscarded houses ("s lub") and f luctuate in abundance f rom day to day as a funct ion of wind-dr iven upwel l ing. Densi t ies of Oikopleura in cold upwel l ing water dur ing four years ranged between 20 and 800/m3. Oikopleura densi t ies <1 lm' occurred when upwel l ing ceased and warmer water occupied the inshore region. A s imple model incorporat ing adai ly averaged wind vector, Ju l ian day, and growing degree-day expla ined 62"/ " o { the dai ly var iat ion in Oikopleura abundance in 1979. The model y ie lded densi ty est imates that were signi f icant ly (p<0.05) corre lated wi th observed densi t ies in each of the other three years. We provide ev idence that net foul ing by Oikopleura in the inshore and maximum At lant ic cod (Gadus morhua) catch is co inc ident and suggest hat an annual h indcast index of s lub in tensi ty may help determine the impact of s lub condi t ions on the inshore f ishery. De ju in i r ao0t 1979 et 1981-1983, les var iat ions de la f r6quence de Olkopleura spp. 6ta ient for tement l i6es i la v i tesse du vent et d la temp6rature de l 'eau dans une r6gion cdt idre de l 'est de Terre-Neuve. Les cocons abandonn6s de Oikopleura encrassent les engins de p€che cdt idre; l 'abondance de cet