What is Sustainable Fishery?

A sustainable fishery is one that is harvested at a sustainable rate to ensure that the fish population does not decline over time as a result of fishing methods or practices.

The study of sustainability in fisheries combines the observation of fish population makeup with the implementation of practical strategies to sustain fish stock. Overfishing, as well as issues such as individual fishing quotas and the curtailment of destructive and illegal fishing practices are addressed.

Researchers, scientists and activists are currently taking many steps to address the issues that most affect sustainable fisheries, such as:

• Lobbying for appropriate laws and policies
• Setting up protected areas
• Restoring collapsed fisheries
• Incorporating all externalities involved in harvesting marine ecosystems into fishery economics
• Educating stakeholders and the public
• Developing independent certification programs

Ray Hilborn, of the University of Washington, has presented three ways of defining a sustainable fishery, which are widely accepted:

• Long term constant yield – this is the idea that undisturbed nature establishes a steady state. “Properly done, fishing at up to maximum sustainable yield allows nature to adjust to a new steady state,” says Hilborn – “. . .without compromising future harvests”.
• Preserving intergenerational equity – this acknowledges natural fluctuations and regards as unsustainable only those practices that damage the genetic structure, destroy habitat or deplete stock levels.
• Providing rebuilding – rebuilding takes only one generation.

The primary concerns in creating sustainability are that overexploitation and growth of recruitment overfishing are currently resulting in the loss of significant potential yield. Researchers fear that the stock structure may erode to the point where it loses its diversity and resilience. There is also concern today that ecosystems and their economic infrastructures will cycle between collapse and recovery – and that each time they do so, the systems will be less productive. This may throw the ocean’s ecosystems off balance and cause an overall collapse in the chain.

Global wild fisheries are currently in decline and ocean habitats, such as estuaries and coral reefs, are in critical condition. This is due to a number of factors – from global warming to ocean acidification. Aquaculture or farming of some fish, such as salmon, does not appear to solve the problem. Farmed fish are fed products from wild fish, such as forage fish – so farming ends up having a major negative impact on wild salmon, making this type of farming unsustainable in the long term.

Fisheries management was limited for a long time by focusing solely on target fish populations and failing to consider the effects on ecosystems. Current researchers see a correlation between the decline in species abundance and diversity and the fishing industry. Today, stock assessment scientists are working on conservation issues as a way to create sustainability, thereby supporting both marine life and the fishing industry.

There are specific ways that everyone can help support the sustainability of our fisheries:

• Social sustainability – making sustainable seafood choices is important when supporting solutions for sustainable oceans. Choosing sustainable seafood is the act of choosing sustainable products when you purchase seafood. Sustainable seafood is seafood fished or farmed in a manner that can maintain or increase production in the long term. Researchers suggest that consumers should choose seafood from sustainable capture fisheries. These have a low vulnerability to fishing pressure so they are not overfished. They have a stock structure and abundance sufficient to maintain or enhance long-term productivity. They also use techniques that minimize the catch of unwanted and/or unmarketable species.

• Sustainable fishing – commercial or subsistence fishing practices that maintain the population of fish and fish stocks. Fishing methods such as trawling can hurt other marine life because it captures species that fall outside the target catch of the fleet. Ensuring that fishing fleets use methods that do not harm the environment and that only allow for the capture of targeted seafood promotes the protection of many marine species.

• Curtail overfishing – large catches make sense economically for any fishing fleet; however, the long-term repercussions involved need to be taken into account. Fish populations that have been depleted cannot easily replenish themselves through reproduction. Removing fish species at rates where their populations cannot reproduce quickly enough has been one of the most significant causes of stock depletion over the last three decades. We have seen this in the case of the Chilean Sea Bass. In the 1990s, the Chilean Sea Bass became popular in restaurants causing an increase in demand. The fish is native to the South Pacific and South Atlantic oceans, and although fishing in this area is regulated by international agreements, they are very difficult to enforce. Illegal fishing became widespread and the Chilean Sea Bass was fished almost into extinction. Today there is a “Take a Pass on Chilean Sea Bass” campaign that activists and researchers are hoping will give the Chilean Sea Bass a chance to recover.

Currently, there is a concerted effort to ensure the sustainability of fisheries at a global level. Reducing overfishing and by-catch through fisheries management is at the forefront of these efforts. However, the management of fish populations requires cooperation at all levels of government, from local communities to the nations around the world.

Governments may soon start to look to the science community for new approaches to the tackle problem of depleted fish stocks. The viability of ocean fertilization for restoring fish populations is currently being investigated. Oceaneos is a centre of excellence in this rapidly evolving field. The company offers the required expertise and state-of-the-art technology to allow governments to conduct carefully controlled and responsible ocean fertilization initiatives under the guidelines of the UN.