New Zealand shark fisheries: development, size and management

New Zealand's shark fisheries have increased steadily since 1975 to reach 17000-19000 t per year. Commercial fisheries catch mainly spiny dogfish (Squalus acanthias), school shark (Galeorhinus galeus), skates (Raja nasuta and R. innominata), ghost sharks (Hydrolagus novaezealandiae and Hydrolagus sp.), rig (Mustelus lenticulatus) and elephantfish (Callorhinchus milii). School shark, rig and elephantfish fisheries have long histories, and catches are limited by individual Transferable Quotas. Fisheries for spiny dogfish, skates and ghost sharks have only developed since 1979. Spiny dogfish and skate landings are partially regulated by total quotas. Other sharks are prohibited target species. Blue (Prionace glauca), porbeagle (Lamna nasus) and mako (Isurus oxyrinchus) sharks are taken as by-catch of the tuna longline fishery. There is a small recreational catch of spiny dogfish, school shark, rig, mako shark and blue shark. Historically important Maori fisheries for spiny dogfish, school shark and rig are now minor. A beach netting programme has operated off Dunedin beaches since 1969 to protect swimmers from shark attacks. Fisheries management measures include commercial quotas, prohibitions on target fishing many species, recreational bag limits, limits on set-net length, mesh size and soak time, and closure of many inshore waters to set-netting, trawling and Danish seining.