New hope for marine ecosystems

Scientists have collaborated on a shocking assessment of the state of the marine fish and marine ecosystems. This two-year study, led by University of Washington University's Dalisousie and Ray Hilborn Boris Worm with a group of 19 co-authors, shows the early successes of methods of curbing fishing abuse. at 5 out of 10 large marine ecosystems.

The article, published in the July 31 issue of Science, provides new hopes for rebuilding the marine fisheries.

The study has two objectives: to look at current trends in the abundance of fish and the challenge rate (the amount of fish caught) and to identify the tools managers can applied in efforts to rebuild the ocean's depleted fish resources. This study is an important step because it shows that the rate of fishing has decreased in some areas around the globe, so there are some signs of recovery.In addition, this study is also a proof that proper management can contribute to rebuilding marine fish resources.

This is good news for some areas in the United States, Iceland and New Zealand. Hilborn said: 'These tightly managed ecosystems are improving. However, there is still a lot of work ahead: in all the fish sources we test, 63% are still below the set target and still need reconstruction efforts. '

Worm added: 'If we look overall, we still see a worrying trend of decreasing marine fish stocks. However, this article shows that our ocean is not completely hopeless. The encouraging result is that the rate of exploitation - the main factor leading to the depletion of marine fish resources - is declining in half of the 10 ecosystems that are assessed in detail. This means that management in those areas is creating the basis for ecological and economic recovery. This is just the beginning - but it gives hope that we will have enough ability to control fishing abuse. '

The authors also warn that their analysis is mostly confined to well-managed fisheries in developed countries, where scientific data on the abundance of fish are collected.They also point out that fishing abuses simply move to countries with weaker legal systems and enforcement.

While most advances in some marine ecosystems are due to the management of some wealthy countries, there are exceptions. For example, in Kenya, scientists, managers and local communities have teamed up to close some important areas not to catch, and to ban some fishing equipment. This leads to an increase in the number and size of marine fish, and thus leads to an increase in income for fishermen. Tim McClanahan of Kenya's Wildlife Conservation Association said: 'These successes are local - but also inspire other places to follow.'

Co-author Jeremy Collie of the University of Rhode Island, said: 'We know that we can exploit more fish and leave less environmental consequences, if we slow down and let the fish recuperate. Scientists and managers, not only in Iceland and Kenya, have achieved initial success in reducing abuses of fishing and rebuilding marine fish resources despite difficult challenges. '

The authors emphasize that management solutions are available to help rebuild marine fish resources. They found that a combination of methods, such as community quotas and fishing quotas coupled with the closure of some strategic fishing areas, zoning, selective fishing equipment, and Economic incentives will bring promise for the recovery of marine fisheries and ecosystems. However, co-author Beth Fulton of CSIRO from Oceans Flagship in Australia, said: 'lessons from a place that need to be carefully applied in a new area, no solution is perfect for all. . Management efforts need to be changed in a way that is consistent with the situation and people '.

According to the analysis of authors, Alaska and New Zealand are leading the world in management success by not waiting until urgent measures are needed to preserve, restore and rebuild. marine resources.Some other areas are slowly recovering from fishing abuses: fish abundance has increased above the average for a long time in Iceland, Northeastern United States and California Current.

Fishing boat. The methods of curbing fishing abuse have achieved initial success in 5 out of 10 large marine ecosystems. (Photo: iStockphoto / Grant Dougall)

This is a follow-up study of the 2006 report in the Science of WORM and other authors, emphasizing the global trend towards depleting marine fish stocks. The results of that report led to a disagreement between Worm and Hilborn. However, through later discussions the two scientists realized they both had a common purpose. They decided to cooperate to assess more of the world's marine fish resources, and brought together the most talented fish and ecological scientists in a two-year study at the Center. National synthesis and ecological benefits (NCEAS) in Santa Barbara, California.

Ana Parman is part of Centro Nacional Patagónico in Argentina, explaining: 'Before this study, global community and marine fish stock assessment was based on catch records, so there was a lack of better options. The results are controversial because fishing trends do not provide an accurate picture of the trend of fish abundance. This is the first attempt to synthesize the best available data on the state of the marine fish industry and trends in catch rates, a major breakthrough that allows scientists to reach a consensus on status of marine fisheries and necessary measures'.

The analysis includes catch records, stock assessments, scientific scans, small-scale fishing data and model results.The authors used the strategy of 'Russian dolls', with each data layer adding to the persuasion and the value of the overall.

Looking at the tools used to reduce the rate of extraction, the authors note that 'the most impressive recovery efforts include bold experiments with closure of some areas, or prohibition of use. use some kind of device, and new methods to distribute and enforce fishing. ' Laws that prohibit fishing abuses, clear rules and specific goals are considered prerequisites, for example in the United States.

While the study considers that these tools have long-term benefits, they also bring some damage to fishermen in the short term. Trevor Branch, a co-author from the University of Washington, said: 'Some places have chosen to prohibit fishing abuse altogether. That option could damage fishermen in the short term, but in the long run it benefits fish, fishermen and our marine ecosystem. '

The key to the team's recommendations is to catch at a level lower than the total acceptable catch volume (MSY), a long-standing standard that has been widely accepted in the international arena. Researchers believe that MSY should be interpreted as an upper bound, not a goal.

The authors used ecological models to compute multiple species MSY (or MMSY).That analysis shows that catching below MMSY has many ecological benefits including minimizing species collapse, increasing fish size and abundance.

The team also said that in addition to reducing the catch rate below MMSY, there are still other methods that can influence the impact of fishing on the ecosystem. Heike Lotze, co-author from Dalhousie University explains: 'Catching with the maximum quantity that comes with a girl has to pay is species collapse. However, even low catch rates can change marine ecosystems and lead to the decline of some vulnerable species. That's why we need a combination of measures, including restricting fishing equipment and closing important areas, to achieve conservation and fishing goals'.

The authors also warn that there is still a lot of work to be done to end global fishing abuses, because a large part of the global marine fish resource is still unmanaged and reported. the right way. Especially outside the rich industrialized countries, the ability to reduce fishing is often difficult unless the fishermen have a different source of food and income.Therefore, the authors emphasize the need for a more holistic view of marine fish reconstruction.

Pamela Mace, co-author from the New Zealand Ministry of Fisheries, said: 'Fishing managers who are currently responsible for depleted marine fish resources should follow the successes described in this study. We need to act faster to be able to rebuild fish resources as well as ecosystems that we are also part of. '

The study was conducted at the National Center for Ecological Analysis and Synthesis (NCEAS), funded by the National Science Foundation and the University of California, Santa Barbara.