Overfishing is one of the greatest threats our oceans face. By catching more than the seas can sustain, humanity trespasses the limits of the environment and compromises the well-being of future generations. According to FAO, overexploitation of fish stocks has reached levels of 31% supported by unprecedented increases in production and global consumption . Moreover, overharvesting the oceans imposes serious constraintsto the proper development of natural ecosystems. In fact, fish stocks are dynamic and profoundly interconnected with different types of habitats, so exhaustive fishing can result in fragile ecosystems and also in a substantial decrease in the population of non-target animals .
This article will focus on unsustainable scaleas the main cause of overfishing and will provide some elements that explain the strong connection that exists between both. Scale refers to the magnitude of the economic activity in relation to the planet, which is a bigger system that supports the economy . A sustainable scale is met when the economy operates within the limits of the natural ecosystem without affecting its ability to replenish the resources employed .
The first element is the development conception that prioritisesgrowth over the preservation of the oceans. In many countries, fishery industry has been considered as a development engine . Nevertheless, the creation of new markets, technological advances and high investments in fleets not only has brought economic progress but also the inestimable destruction of ocean species . The scale created by this economic model has been far from sustainable because fishing activity has crossed the boundaries of the marine ecosystems and has reduced their capacity to recover. Likewise, fisheries production cannot be separated from the environment that sustains it, otherwise,the stability of the communities that depend on it might be disrupted as well.
Second, catching beyond the limits is also caused by an unsustainable scale due to the inherent characteristics of fish stocks. Fisheries are common-pool resources, meaning that given their size, it is not easy to prevent people from utilisingthem . In fact, since their access is usually unrestricted, the more users they have, the more resources could be overexploited . Therefore, the nature of the fisheries may give rise to an unsustainable practice. Such practice is characterisedby individuals that disregard the benefits fish stocks can supply in the long term because they can take immediate profit from the capture and transfer the real cost of overharvesting to society .
The third element that links unsustainable scale with this issue is the behaviourof fishers and can be illustrated through what is commonly called the race to fish. This situation arises when fishers need to complete certain levels of capture in a season and they rival with others to reach the amounts required. Such behaviourcreates high pressures on the seas in the short run and leads to a dramatic decline in fish populations . It also motivates individuals to purchase fishing gears that impacts the capacity of habitats to regrowth over time, reduce benefits and increment costs .
To solve this problem is necessary to establish a limit on the amount of fishes that can be taken from the ocean. This level is sustainable if the speed of the restoration process of fish stocks is not surpassed by the rate of capture . The policy instrument that meets these conditions is the Individual TransferableQuota (ITQ). ITQs are considered effective mechanisms to halt the depletion of fisheries resources and promote their regeneration . These schemes are based on a total allowed catch (TAC) that is split into quotas by the government and allocated to different actors . A TAC is a key component of this policy because it solves scale failures by defining a maximum level of capture according to the ecosystem composition. Participants can buy or sell their quotas in the market. These transactions offer fishers a right to catch that gives them adaptability to variable conditions and permits their decisions to match with conservation aims . Furthermore, evidence has proved that ITQ mechanisms stimulate efficiency, diminish costs, and have the potential to reduce fishing effort by extending seasons .
On the other hand, aspects such as unintentional catches, allocation problems,and unclear information provided by fishers should be considered in detail to apply an integrated solution . In this regard, continuous supervision and appropriate enforcement are fundamental to ensure the success of this policy . For instance, by purchasing existing quotas in markets and relocating them, regulators can make sure ecological and social objectives are accomplished .
Overall, as the elements discussed have shown, an unsustainable scale has significant repercussions on fish stocks. Policies to address this environmental issue need a holistic approach and should be designed according to the context, the local communities, and the institutions that intervene in our society . Therefore, unless we apply coordinated programs that tackle the scale and motivate the replenishment of resources, we may run out of fish in the future.