title: Analysis of large-scale spatio-temporal trends of Ostrea puelchana beds in Northern Patagonian gulfs, Argentina.
abstract: Wild oyster populations have declined severely worldwide, however fluctuations of South Atlantic populations are poorly documented. We explored the changes in the abundance of Ostrea puelchana population of Northern Patagonia, Argentina, by linking data from paleontological, archaeological and informal sources, with time series data from fishing, ecological and studies of oyster pathology. The present work is the first study which includes a South Atlantic time series concerning oyster beds. The focal area for this study is the San Matías Gulf (SMG, 40° 50'-42° 15' S, 63° 5'-65° 10' W). Populations of O. puelchana were inferred from sub-fossil deposits (>700 years ago) throughout the gulf, but were documented in surveys a century ago only in the NW coast. The population has declined in the last decades. However, new populations have established recently in the NE and southern regions of the gulf. A Bonamia exitiosa epizootic was coincident with the declining trend of the abundance provided by the time series, suggesting that beds declined as a consequence of parasite infections. Dredging fisheries for scallops took place in the 1970s and 1980s on the NE coast of the gulf, in areas adjacent to the NE oyster beds. We proposed that fishing activities might have had a low impact on oyster beds, since NE beds expanded and increased during that period. The southward expansion of oyster population at latitudes beyond the historical distribution range might reflect long-term adequate environmental conditions for larval survival on the NE and S of the SMG.
authors.affiliation: Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Rivadavia 1917, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina; Instituto de Biología Marina y Pesquera "Almirante Storni", Universidad Nacional del Comahue, Güemes 1030, 8520 San Antonio Oeste, Provincia de Río Negro, Argentina. Electronic address: msdoldan@gmail.com.
authors.forename: M S
authors.initials: MS
authors.lastname: Doldan
authors.affiliation: Instituto de Biología Marina y Pesquera "Almirante Storni", Universidad Nacional del Comahue, Güemes 1030, 8520 San Antonio Oeste, Provincia de Río Negro, Argentina.
authors.forename: E M
authors.initials: EM
authors.lastname: Morsan
authors.affiliation: Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Rivadavia 1917, C1033AAJ Ciudad Autónoma de Buenos Aires, Argentina; Instituto de Biología Marina y Pesquera "Almirante Storni", Universidad Nacional del Comahue, Güemes 1030, 8520 San Antonio Oeste, Provincia de Río Negro, Argentina.
authors.forename: P C
authors.initials: PC
authors.lastname: Zaidman
authors.affiliation: Instituto de Biología Marina y Pesquera "Almirante Storni", Universidad Nacional del Comahue, Güemes 1030, 8520 San Antonio Oeste, Provincia de Río Negro, Argentina.
authors.forename: M A
authors.initials: MA
authors.lastname: Kroeck
mesh_terms: D000818:Animals; D001118:Argentina; D001267:Atlantic Ocean; D003247:Conservation of Natural Resources; D005398:Fisheries / Q000266:history; D049673:History, 20th Century; D049674:History, 21st Century; D049895:Ostrea / Q000254:growth & development / Q000502:physiology*; D011156:Population Density; D011157:Population Dynamics
keywords: Benthic ecology; Coastal zone; Contraction–expansion; Distribution; Geographic range; Metapopulation; Ostrea puelchana; Oyster; Patagonia