An Estimation of the Possible Migration Path of the Pacific Oyster (Crassostrea gigas) Along the Northern Coast of Patagonia

DRAGANI, WALTER C.; BARÓN, PEDRO J.; WÖRNER, STEFANIA; CARRASCO, MAURO; ECHEVARRIA, EMILIO R.

ESTUARIES AND COASTS

SPRINGER

Año: 2018

1559-2723

In 1981, the Pacific oyster Crassostrea (Magallana) gigas was illegally introduced for aquaculture purposes in San Blas Bay locatedonthesoutherncoast ofBuenosAiresProvince,Argentina.ThepresenceandcolonizationofoystersnorthofRíoNegro Province,100kmtothesouthwest ofSanBlasBay,wasreportedin2005.Thereremainsacontroversyaboutwhether ornot the oysterwascapableofmigratingsouthwesttoRíoNegroProvincefromSanBlasBay,whichmotivatesthepresentinvestigation. While one part of the local community supports that the Pacific oyster migrated naturally southwestwards reaching the northern coast of Río Negro in 2005, another faction denies this hypothesis. The aim of this work is to determine whether or not the planktonic larvae of this invasive species could have reached the mouth of Río Negro. We assume that the oyster can produce larvae after 2 years of being set on the bottom and the larvae can drift as zooplankton during 1 month. Longshore mean current as considered as the single forcing in natural transporting of oyster larvae along the coast. Shallow water wave parameters were computed from deep water wave parameters obtained from the Simulated WAves Nearshore (SWAN) model driven by NCEP/ NCARIglobalreanalysis.Themigrationpathwascomputedfromlongshorecurrentintensities,whichwereestimatedusingthe modified experimental expression given by Longuet-Higgins. Results obtained in this paper support the possibility that the Pacific oyster larvae could have arrived at Río Negro Province, between 2002 and 2005.