Fighting for Fisheries: In the debate concerning the future of the world's fisheries, some have forecasted complete collapse but others have challenged this view. The protagonists in this debate have now joined forces to present a thorough quantitative review of current trends in world fisheries. Worm et al. (p. 578 ) evaluate the evidence for a global rebuilding of marine capture fisheries and their supporting ecosystems. Contrasting regions that have been managed for rebuilding with those that have not, reveals trajectories of decline and recovery from individual stocks to species, communities, and large marine ecosystems. The management solutions that have been most successful for rebuilding fisheries and ecosystems, include both large- and small-scale fisheries around the world.

Fisheries data assembled by the Food and Agriculture Organization (FAO) suggest that global marine fisheries catches increased to 86 million tonnes in 1996, then slightly declined. Here, using a decade-long multinational ‘catch reconstruction’ project covering the Exclusive Economic Zones of the world’s maritime countries and the High Seas from 1950 to 2010, and accounting for all fisheries, we identify catch trajectories differing considerably from the national data submitted to the FAO. We suggest that catch actually peaked at 130 million tonnes, and has been declining much more strongly since. This decline in reconstructed catches reflects declines in industrial catches and to a smaller extent declining discards, despite industrial fishing having expanded from industrialized countries to the waters of developing countries. The differing trajectories documented here suggest a need for improved monitoring of all fisheries, including often neglected small-scale fisheries, and illegal and other problematic fisheries, as well as discarded bycatch.

How will the 10 billion people expected to be living on Earth by 2050 obtain sufficient and nutritious food? This is one of the greatest challenges humanity faces. Global food systems must supply enough calories and protein for a growing human population and provide important micronutrients such as iron, zinc, omega-3 fatty acids and vitamins. Deficiencies of micronutrients — so called because the body needs them only in tiny amounts — can increase the risks of perinatal and maternal mortality, growth retardation, child mortality, cognitive deficits and reduced immune function1. The associated burdens of disease are large. Forty-five per cent of mortality in children under five is attributable to undernutrition; nutritional deficiencies are responsible for 50% of years lived with disability in children aged four and under1. Fish are crucial sources of micronutrients, often in highly bioavailable forms. And fish populations are declining. Most previous analyses have considered only how people will be affected by the loss of protein derived from fish. We calculate that this is the tip of the iceberg. Combining data on dietary nutrition, and fish catch, we predict that more than 10% of the global population could face micronutrient and fatty-acid deficiencies driven by fish declines over the coming decades, especially in the developing nations at the Equator (see 'Troubled Waters'). This new view underlines the need for nutrition-sensitive fisheries policies. Presently, 17% of the global population is zinc deficient, with some subpopulations being particularly at risk1. Nearly one-fifth of pregnant women worldwide have iron-deficiency anaemia and one-third are vitamin-A deficient1. We estimate that 845 million people (11% of the current global population) are poised to become deficient in one of these three micronutrients if current trajectories in fish-catch declines continue. Considering nutrients found only in foods derived from animals, such as vitamin B12, and DHA omega-3 fatty acids (almost exclusively derived from meat consumption, see Supplementary Information), we calculate that 1.39 billion people worldwide (19% of the global population) are vulnerable to deficiencies because fish make up more than 20% of their intake of these foods by weight. To make this sobering new assessment, we coupled two databases from 2010, the most recent year for which both had data. The new Global Expanded Nutrient Supply (GENuS) database combines food balance sheets (total quantity of food production and imports minus livestock feed, post-harvest losses, and exports) and production or trade data from the Food and Agriculture Organization of the United Nations (FAO) with estimates of food group intake by age and sex2. It estimates per capita edible supplies for 225 foods, paired with regional food composition tables to infer nutrient supplies by country. GENuS is supported by the Bill and Melinda Gates Foundation and the Winslow Foundation. We categorized populations as nutritionally vulnerable if their nutrient supply was less than double the estimated average requirement (EAR), and if they derived from fish more than 10% of their vitamin A or zinc, or more than 5% of their iron. We chose to double the EAR for two reasons. First, even in countries where the national average intake is greater than the EAR, large variability of intake may still mean that a significant part of the population is eating less well. If we had used the EAR as our threshold, more than 50% of a nation's population would need to be deemed at risk of nutritional deficiency, which we feel is an irresponsibly high proportion required for raising an alarm. Second, our GENuS-derived estimates measure food supply rather than food intake, and are generally regarded as overestimates of true intake2. The Sea Around Us database, released in 2016, provides a portrait of marine fisheries catch between 1950 and 2010 for every coastal nation3. Over 15 years, a team of researchers in every coastal country collated information from government documents, academic research and maritime records to reconstruct the numbers of fish caught. This database measures the contribution of subsistence, artisanal and industrial marine fisheries to food supply at the country level more accurately than previous estimates3. This database was funded by the Pew Charitable Trust and the Paul G. Allen Family Foundation and is maintained by staff at the University of British Columbia in Vancouver, Canada. These global marine catch data are alarming. Conservative estimates by the FAO characterize global fisheries as stable, but acknowledge that global catch has declined by 0.38 million tonnes per year since 1996 (ref. 4). The Sea Around Us estimates summarized earlier this year3 paint a much bleaker picture, in which fish catch peaked in 1996 and has been falling by 1.22 million tonnes (roughly 1%) per year since — three times faster than the decline reported by FAO. The degradation of marine habitat by destructive fishing practices, industrial pollution, climate change and coastal development for urbanization and aquaculture is likely to further degrade ocean ecosystems and reduce fisheries yields. Such patterns call into question the ability of wild fisheries to support future demand for fish. The health impacts of fishery declines will hit some places harder than others. A perfect storm is brewing in the low-latitude developing nations. This is where human nutrition is most dependent on wild fish, and where fisheries are most at risk from illegal fishing, weak governance, poor knowledge of stock status, population pressures and climate change. Sharp declines in the health of fisheries were first described in the twentieth century in high-latitude regions where industrial fishing began, such as the northwest Atlantic Ocean. Developed countries have compensated with intensive agricultural production, by importing goods (including fish),...