Dredging (oysters) - Foveaux Strait
Issue
Damage to the sea bed habitat from oyster dredging.
Risk
Oyster dredging reduces the biodiversity of the Foveaux Strait area in the short-term. Longer-term effects of oyster dredging are less well known.
Extent of the issue
Repetative dedging in the Foveaux Strait oyster fishery over the past 130+ years will have had a major impact on all fished grounds. It is likely that in their virgin state, some of these grounds were important both ecologically and to local fisheries. However these impacts and the fishery's recovery from them are not well understood.
Trends
Repetative dredging in the fishery over many decades will have substantially modified much of the habitat. However reduced fishing effort and area closures in the past 1-2 decades (because of reduced oyster numbers due to parasite infestation) may be allowing some recovery of seabed habitats.
Current management
This fishery is currenlty small with informal rotational fishing. Fishers avoid seafloor areas where there are lots of biogenic structures (like bryozoan beds).
Future management
A Fisheries Plan has been prepared for the Foveaux Strait oyster fishery. Effects of dredging on the seabed here are considered as part of this plan.
Documents / links
Foveaux Strait Oyster Fisheries Plan; Marine Protected Areas Policy and Implementation Plan, Jake Rice, global analysis - Kaiser 2006.
