Ministry of Fisheries Seabirds and marine mammals are killed during commercial fishing operations. Many of the species which are caught in New Zealand waters, such as white-capped albatross, are from threatened or vulnerable populations and it is important that these mortalities are minimised. Fisheries observers record bycatch incidents, and from this dataset we are building Bayesian statistical models of the seabird and marine mammal mortality. This will be used to estimate the total catches of frequently caught species within the New Zealand Exclusive Economic Zone. The analysis will also allow a better understanding of the factors associated with incidental catch rates.
We have also carryied out boatramp surveys, in conjunction with Blue Water Marine Research, exploring whether seabirds get hooked or tangled by recreational fishers. While fishers have informally reported catching birds such as penguins, shags and gannets, there is very little known about how often this happens.
Department of Conservation Albatross and other seabirds are attracted to fishing trawlers by the discharge of scraps and discards. The birds may then be hit by the trawl warps and killed. One way to reduce this mortality is to decrease the discharge of waste while the vessel is fishing. We are working on a project that is looking at ways of processing the factory waste so that it is less available to seabirds. An effective method is to convert it to fishmeal. The waste is then retained on board and fewer birds are attracted to the vessel. Another approach, which has had mixed results, is to mince all waste to a fine paste so that the albatross are unable to eat it.
Ministry of Fisheries Kina in New Zealand are harvested by customary, recreational and commercial fishers. In this project we will characterise the kina fisheries, summarising available catch and effort data for kina. The project will also involve discussions with customary and commercial fishers, to gain a better understanding of how the kina fisheries are currently managed, and to make recommendations on how best to manage kina fisheries in the future.