Impacts of bottom fishing

About 35 percent of our EEZ lies in trawlable depths (0-1500 metres). Much of the shallower parts have been fished at some point, and some depths and certain fishing grounds are fished often. In places like these, the sea floor today will likely be different to what it once was.

One heavily modified stretch of sea floor is Foveaux Strait, where oyster boats have dragged their dredges for over a century.

The plant and animal communities that develop on the sea floor there are those that can survive this sort of regular disturbance.

In shallow waters, some types of sea floor communities can recover quite quickly from the effects of dredging or trawling. However, fragile deepwater habitats may take hundreds of years to recover from such effects.

The government has already closed a number of areas to bottom fishing. Other areas of our sea floor may also need protection. So the Ministry of Fisheries and Department of Conservation are working together to learn more about the effects of bottom fishing on a range of sea floor communities.