Native and non-indigenous boring polychaetes in Chile: a threat to native and commercial mollusc species

Abstract

Native and non-indigenous boring polychaetes in Chile: a threat to native and commercial mollusc species ABSTRACTBoring polychaetes infesting the shells of aquacultured molluscs affect host fitness and cause serious economic problems for the aquaculture industry. In Chile, knowledge of the native and non-indigenous polychaete fauna associated with mollusc hosts is limited, in spite of the fact that numerous native and nonindigenous mollusc species are actively harvested. We present the first complete list of boring polychaete species present in Chile, with a review of the information regarding each species' status as a native or nonindigenous species (NIS), together with information on native and introduced ranges, affected host species, likely vectors of introduction and donor areas. We recorded a total of nine boring polychaetes present along the Chilean coast including native and NIS. Within the NIS category we provide the first published report of the Sabellid Terebrasabella heterouncinata in South America. Boring polychaetes utilized both native and introduced host species. The finding of polychaete species which utilized multiple native and NIS hosts, indicates a potential risk for spread between aquaculture facilities and the natural environment. Our analysis suggests that aquaculture activities are probably the primary introduction vector for boring polychaete species to Chile and that this region does not differ in the magnitude of introduced boring polychaetes relative to other regions of the world. We discuss current laws and management regarding polychaete infestations and make recommendations for future management in Chile, which should contemplate a rational compromise between the socio-economic needs of the country and plans to protect and preserve the nation's biodiversity.

Polydorid polychaetes on farmed molluscs: distribution, spread and factors contributing to their success

“…SatoOkoshi & Nomura 1990, Sato-Okoshi 1999, SatoOkoshi & Abe 2012, 2013. Additionally, all of the pest polydorids associated with cultured oysters in Australia (Walker 2014), 5 of the 6 species in Chile (Moreno et al 2006) and 3 of the most important pests in South Africa (Boonzaaier et al 2014, Simon 2015, Williams 2015 are alien.…”

“…In particular, Haupt et al (2012) demonstrated that even after cleaning, oysters still harboured polydorid shellborers after translocation. Yet the records which confirm oysters and abalone as the vectors of transportation are limited; Polydora websteri and Boccardia proboscidea were transported from mainland USA to Hawai'i (Bailey-Brock & Ringwood 1982, BaileyBrock 2000, P. uncinata from Japan to Chile (Radashevsky & Olivares 2005), and probably P. websteri from Namibia to South Africa (Simon 2015, Williams 2015, while the sabellid Terebrasabella heterouncinata was transported from South Africa to California and further (Culver et al 1997, Moreno et al 2006. In some instances aquaculture may not have been the vector of introduction of a pest to a new region, but is responsible for its spread within its introduced range (e.g.…”

“…Up to 18 oyster species have been translocated to 73 countries or regions, with the Pacific oyster, Crassostrea gigas, translocated to more than 50 (Ruesink et al 2005, Lucas 2012). Gastropods are moved less frequently and there is a tendency for indigenous species to be cultured (Castell 2012, but see Culver et al 1997 andMoreno et al 2006).…”

“…The most common shellborers are members of the Polydora-complex, often re ferred to as polydorids (e.g. Blake 1969b, Moreno et al 2006, Radashevsky et al 2006, Sato-Okoshi et al 2008, Boon zaaier et al 2014. While there are rare in stances where high infestations by polydorids occur under natural conditions (e.g.…”

“…At least 5 species of oysters and 2 species of clams have been imported to, and moved among, countries in western and northern Europe for aquaculture purposes since as early as 1570 (Wolff & Reise 2002). On the west coast of North America, most of the cultured species are exotic or alien (McKindsey et al 2007) while in Chile a thriving abalone industry relies on stock originally imported from California and Japan (Moreno et al 2006). Similarly, the South African oyster industry relies on the regular importation of spat from the Americas and Europe and the local movement of stock from nursery to grow-out facilities (Haupt et al 2010(Haupt et al , 2012.…”