A Better World - Volume 6

[ ] 45 Lif e Below Water T he resurrection of jack mackerel fisheries in the South Pacific, following a virtual collapse in the mid-2000s, is a success story that demonstrates how efficient fisheries management is underpinned by science- based decisions. The story began in 2006, when participating states in a series of international consultations established a regional fisheries management organization in which effective conservation and management measures are based on the best scientific informa- tion available, together with the application of a precautionary and ecosystem approach to fisheries management. The Chilean jack mackerel ( Trachurus murphyi , Nichols 1920) is widespread throughout the South Pacific, chiefly along the shelf and oceanic waters adjacent to Ecuador, Peru and Chile, as well as the Subtropical Convergence Zone, in what has been described as the “jack mackerel belt”, stretch- ing from the coasts of Chile to New Zealand within a 35º to 50º S variable band across the Pacific. In the mid-1980s, owing to large recruitment influxes, the jack mackerel stock size reached approximately 14 million tonnes of spawning biomass, one of largest fish stocks in the world, sustaining catches up to 5 million tonnes per year until the mid-1990s. However, due to the large fishing fleets operating in the area in combination with low recruitment, the stock size began to diminish and, by the mid-2000s, the stocks were badly overfished and heading for collapse. A population once estimated to be reaching 14 million tonnes dropped to less than 2 million tonnes in just two decades. The fate of jack mackerel therefore became a case study of the consequences of lacking a robust international manage- ment regime. As a consequence, in 2006, Australia, Chile and New Zealand initiated a process of consultation to enable states to cooperate in addressing the gap in international conservation and management of non-highly migratory fisheries, and the protection of biodiversity in the marine environment in high seas areas of the South Pacific Ocean. The process resulted in a series of international meetings with the objective of discharging the duty of states under international law to cooperate in the conservation and management of living resources in those areas of the high seas. Through these international meetings participants decided to establish a regional fisheries management organi- zation with the ongoing responsibility for this task. In 2009, the 8th International Meeting adopted the Convention on the Conservation and Management of High Seas Fishery Resources in the South Pacific Ocean, together with a resolution to hold a preparatory conference to assist the efficient onset of the work of the Commission of the South Pacific Regional Fisheries Management Organization (SPRFMO) established by the Convention. The SPRFMO was officially established and entered into force in 2012. A paradigm shift The first Commissionmeeting of the SPRFMOwas held in New Zealand in 2013, at which point the jack mackerel stock was seriously overfished, with levels ranging between 8 and 17 per cent of estimated unfished levels. The SPRFMO Commission expressed concern at the poor state of the stock and decided that catches in 2013 needed to be restrained to levels that, in accordance with scientific advice, provided a reasonable Successful science-based fisheries management in the South Pacific Dr. Sebastián Rodríguez Alfaro, Executive Secretary; Osvaldo Urrutia S., Chairperson, South Pacific Regional Fisheries Management Organisation (SPRFMO) Estimated trajectory for jack mackerel under high and low productivity 1970–2015 Phase plane or “Kobe” plot of the estimated trajectory for jack mackerel under high and low productivity, with reference points set to F msy (the maximum rate of fishing mortality — the proportion of a fish stock caught and removed by fishing, eventually resulting in a population size of B msy ) estimated for the time series 1970–2015, and B msy (the biomass that enables a fish stock to deliver the maximum sustainable yield) set to 5.5 million tonnes F/F msy B/B msy 0.0 0.5 1.0 1.5 2.0 2.5 2019 1970 6 5 4 3 2 1 0 Source: SPRFMO