By Professor Ray Hilborn, School of Aquatic and Fishery Sciences, University of Washington
Concerns about overfishing have existed for more than a century. But it is only relatively recently that intensive fisheries management – in some form or other – has become commonplace and effective. Today, most developed countries conduct scientific research on their fish stocks and ecosystems, restrict catch or fishing effort based on trends in stock health and have an enforcement system to make sure that regulations are obeyed. We consider these elements essential to modern fisheries management – but, with few exceptions, these elements were not in place 50 years ago.
Several factors interacted to drive the emergence of intense fisheries management. Global fishing effort expanded particularly between 1950 and 1990, leading to an increase in food production – and fishing pressure. More and more stocks became overfished. Historically, most continental shelf fisheries were open to all fishing countries, and coastal states could not control fishing beyond 12 miles. But, beginning in the late 1970s, the United Nations Convention on the Law of the Sea and the declaration of Exclusive Economic Zones (EEZs), gave states almost totally control for fisheries in a 200 nautical mile-wide band of their coastal waters.
In 1992, the highly-publicised collapse of a major Canadian cod stock focused global attention on the urgent need to stop overfishing – and better manage our fisheries. Similar declines in fish stocks have played out across major fisheries globally in the last half-century where abundance data is available: in Argentina, Canada, Chile, Europe, Japan, New Zealand, Peru, South Africa and the United States, and on the high seas, leading to the implementation of catch and effort restrictions.
The ability of science-based fisheries management to rebuild fish stocks — when it is applied — is visible in global data.
We used a database of over 1,000 stocks from across the world – with highly reliable information on their status – to track fishing pressure and fish abundance, with the results published in 2020 in Proceedings of the National Academy of Sciences.1 As the pressure rose between the 1970s and the 1990s, average fish abundance across all stocks declined. Then, in the 1990s, fisheries management as we know it today began to take shape and to intensify, reducing the fishing pressure. By 2000, we could see increases in the average abundance of the 1,000 fish stocks, and today, these stocks are, on average, well above target levels to maximize food production.
The United States provides some insight into the power of fisheries management to impact stock health. Alaska is home to the largest fisheries in the country – including pollock, cod, sole, salmon, crab, herring and halibut – many of which have sustained Alaskan communities since humans first arrived. Offshore fisheries were developed far more recently by foreign vessels, until the declaration of the United States’ EEZ in 1983. By that time, industrial fishing in the North Atlantic had already overfished many stocks, and Alaska’s managers, scientists and fishermen had seen the catastrophic consequences of poor fisheries management. As a result, managers had learned the lessons of the North Atlantic and fishing pressure never rose too high — the abundance of the fish has remained well above target levels.
In contrast to the proactive management observed in Alaska, fisheries on the Pacific west coast of the lower 48 states followed the pattern seen more broadly around the world: fishing pressure increased all the way up until the 1990s, then declined. Changes made to the Magnuson-Stevens Fisheries Management and Conservation Act in 1996 required overfished stocks to be identified and rebuilt on a strict timeline. Allowable catches were dramatically reduced, sometimes by over 90 per cent. The size of the fishing fleet declined and the abundance of the fish stocks increased — all but one of the stocks classified as overfished are now at or above management targets. Consequently, local fishing communities were devastated: processing plants closed, boats were tied up, and fishing income declined dramatically. Ironically, the proportion of the allowable catch harvested also declined dramatically, and current scientific evidence indicates that much less drastic reductions in catch would have allowed stocks to rebuild, while at the same time protecting fishing communities.2
Appropriate fisheries management tools depend on local circumstances. We know a broad suite of management measures, used collectively, successfully reduces fishing pressure and increases fish abundance. We also know that some specific management measures have a disproportionately positive impact on a stock’s recovery, including harvest control rules and rebuilding plans. Strong commitment to international fisheries agreements also strengthens fisheries management in domestic waters.3
The roadmap to fisheries sustainability is clear – where science-based management has been intensely applied, fish stocks are now healthy or improving. The problem lies in that we still lack reliable information about the health of the stocks which make up at least half of the world’s catch, thus the prognosis of their stock status is that most will continue to be overfished. These data-limited fisheries are critical for food security and micronutrient requirements in some of the world’s poorest communities. Greater investment in fisheries management systems will lead to healthier fish populations, to the benefit of all the communities that rely upon them.
Professor of aquatic and fishery science at the University of Washington. University of Washington
Ray Hilborn’s research aims to identify how to best manage fisheries to provide sustainable benefits to human society. In addition to his work on global fisheries, Ray Hilborn is one of the principal investigators for the University of Washington’s long-running Alaska Salmon Program. In recognition for his many contributions to fisheries science, he has received the Volvo Environmental Prize, the American Fisheries Societies Award of Excellence, The Ecological Society of America’s Sustainability Science Award, the International Fisheries Science Prize and the American Institute of Fisheries Research Biologists Outstanding Achievement Award. He is also an elected Fellow of the Washington State Academy of Sciences, the Royal Society of Canada, and the American Academy of Arts and Sciences.