Status

Vongole Clam
Katelysia scalarina

2018/19 Vongole Clam Status

A rapid and extreme decline in abundance of Vongole at Ansons Bay was apparent in 2014, with the 2015
biomass estimate of 27 t being 13% of the peak recorded biomass of 202 t in 2002 (Keane and Gardner, 2018). The most probable cause for the population collapse appeared related to both the low levels of pre-recruits observed in the 2006 – 2017 surveys, exacerbated by sporadic events of high natural mortality and cumulative fishing mortality of recruited Vongole (Tarbath and Gardner, 2015). It was noted during the 2015 survey that the density of non-commercial bivalve species (e.g., Katelysia rhytiphora, Paphies sp., Callista sp.) was remarkably low compared with previous years, indicating that an environmental factor had increased mortality of Vongole and other bivalves, rather than fishing mortality (Tarbath and Gardner, 2015). The fishery was closed to commercial catch in 2015 following the stock decline.

Market pressures had also contributed to a decline in commercial Vongole catch. The expansion of supply of product from other sources, such as New Zealand, into mainland markets and subsequent falls in price reduced the economic profitability of the Ansons Bay Vongole Clam Fishery. This economic impact was compounded by business impacts of prolonged closures from harmful algal blooms and the costs associated with monitoring and testing. 

In 2018 biomass in the Vongole Clam fishery was estimated at 23.42 t, 12 % of its peak, based on quadrat counts that are extrapolated across the defined fishable beds (Keane and Gardner, 2018). This stock was classified in 2015 as environmentally limited on the basis of severe declines in biomass associated with a flood event (Tarbath and Gardner 2015). This fishery is currently closed to commercial catch and classified as depleted.