destructive nature. This, combined with heavy commercial demand, has focused criticism from both environmentalists and media. New Zealand fisheries New Zealand currently operates the largest orange roughy fisheries in the world, with a total catch of over 8,500 tonnes in the 2014 calendar year. This accounts for 95% of the total estimated catch of orange roughy. Exports of orange roughy provided an estimated revenue to New Zealand of NZ$53 million (US$37M) in 2015. Fisheries in New Zealand are managed through the Quota Management System (QMS), under which individuals or companies own quota shares for a stock of a particular species or species group. For each stock, a Total Allowable Catch (TAC) is set that maintains the stock at or above a level that can produce the maximum sustainable yield or that will move the stock toward that level. Orange roughy has been managed within the QMS since 1986. The Ministry for Primary Industries is responsible for the implementation of the QMS and its enabling legislation, the Fisheries Act 1996. Historical Fishery farming of orange roughy was initiated in the mid-1970s, but full exploitation did not begin until 1979. There was no regulation of these early catches, and records indicate that they were very high. For many fisheries, management settings allow for a "fishing down" period during which the biomass is reduced to a level that will provide the maximum sustainable yield. For example, a fishery with a hypothetical unfished biomass of 100,000 tonnes will be allowed to be fished down to a biomass of 40,000 tonnes (assuming that this is the biomass that provides for the maximum sustainable yield) over a number of years. The rate of this "fish-down" can vary depending on the objectives of the fishery, but catches would then be more strictly controlled to maintain the biomass at around 40,000 tonnes. For the New Zealand orange roughy fisheries, productivity parameters and resulting estimates of unfished biomass were incorrectly estimated in the first decade of the fishery. Catch limits exceeded recommended estimates of sustainable yields for a subsequent decade and catches were estimated to have exceeded those catch limits because of burst nets, escape windows in nets and lost gear. Catch limits were reduced in the mid-1990s, although they were increased again following indications that stocks had begun to rebuild. This was later found not to be the case and a number of fisheries were closed completely or