Diversity, conservation status and threats to native oysters (Ostreidae) around the Atlantic and Caribbean coasts of South America

Abstract

ABSTRACT1. Despite the extensive literature on the ecology, systematics and culture of oysters worldwide, an assessment of their diversity, distribution and conservation status for the Atlantic and Caribbean coasts (i.e. depth 550 m) of South America is lacking. Such information is crucial because of the increasing coastal development that threatens most nearshore habitats throughout the region.2. The available information on oysters on Atlantic and Caribbean coasts is reviewed with a focus on identifying regional conservation priorities based on ecological and socio-economic importance, as well as the magnitude of current or potential threats faced by oyster populations. The current status of a-taxonomy within the Ostreidae was also examined.3. Ten species of native Ostreidae (plus three introduced species) inhabit the coastal waters of the Atlantic and Caribbean coasts of South America.4. Oyster species were ranked according to their biological/ecological and socio-economic value and conservation status within 10 distinct ecoregions. Crassostrea gasar in the Eastern Brazil ecoregion, C. rhizophorae in the Central Caribbean ecoregion and Ostrea puelchana in the North Patagonian Gulfs ecoregion should receive the highest priority for immediate conservation action due to extensive loss of mangrove habitat in the two former regions and evidence of decline of one of the most important populations for the latter. The need for a standardized methodology to assess the status of oyster populations throughout the ecoregions is identified.5. On a local scale, the allocation of territorial use rights for fisheries under a collaborative/voluntary community framework is strongly advocated to fulfil management, conservation and poverty alleviation goals in these developing countries.

Decadal changes in oyster reefs in the Big Bend of Florida's Gulf Coast

“…Documented threats to the Eastern oyster (Crassostrea virginica) throughout their range include overharvest (Berrigan et al 1991, Jackson et al 2001, EOBRT 2007, Carranza et al 2009); development and pollution (Jackson et al 2001, EOBRT 2007, Mearns et al 2007); reductions in freshwater input to estuaries (Berrigan et al 1991, Bergquist et al 2006, EOBRT 2007, Buzan et al 2009); erosion from boat wakes and storm events Hine 1995, Wall et al 2005); disease (Berrigan et al 1991, Carranza et al 2009); oil spills (Hulathduwa andBrown 2006, Mearns et al 2007); and global change related trends (Wright et al 2005, EOBRT 2007, Levinton et al 2011). The Gulf is particularly vulnerable to anthropogenic oil spills due to a heavy concentration of oil production and refining in the region (Cappiello 2011) and this threat is only likely to increase with oil demand.…”

Settlement of an exotic oyster and other epibenthos on plastic substrates at a northern Brazilian mangrove island

“…However, more information on the dynamics of mangrove species is needed to make management decisions, such as limits to catches and duration and timing of harvesting periods, for example. Natural populations of oysters are often indiscriminately harvested (Alvarenga & Nalesso, 2006), leading to their decline (Carranza et al, 2009). In Pará, there is regular recruitment of spat (Marques-Silva et al, 2006) and Crassostrea gasar (Adanson, 1757) (= C. brasiliana (Lamarck, 1819), evidence from molecular studies (Lapègue et al, 2002;Pie et al, 2006;Varela et al, 2007;Lazoski et al, 2011; and see also p. 345 in Carranza et al, 2009)) is successfully cultured in the region.…”

“…Genetic evidence shows that the Pacific oyster, Crassostrea gigas, is established in the wild in southern Brazil (Melo et al, 2010b). Exotic oyster species are known to have negative effects on native populations (Carranza et al, 2009). Oyster growers in Pará have noted that Crassostrea sp.…”

Phylogeny and phylogeography of Atlantic oyster species: evolutionary history, limited genetic connectivity and isolation by distance

“…The correct identification of those oyster species is of paramount importance, because they are used in aquaculture and in biomonitoring studies (e.g. Rebelo et al 2003), and may be under environmental threat (Carranza et al 2009). …”