20 Fisheries
Patricia Corbett and Nikita Dubberley
Sustainable fisheries have to potential to significantly contribute to global food security alongside marine aquaculture (mariculture). There have historically been significant impacts to fisheries from things such as overfishing, bycatch, destructive fishing methods which cause environmental impacts and habitat destruction, and social impacts as a result of overfishing and depletion of fish stocks leading to unemployment, poverty and food insecurity.
Achieving sustainable fisheries and contribution to global food security requires a multi-factor approach. This includes, science based management solutions based on understanding of fish species life histories, maximum sustainable yield and minimum viable population size; technology advancements and a move away from destructive fishing techniques that reduce bycatch; fisheries management including catch and size limits, no take areas and enforcement of regulations; supporting small scale fishers and considering the social aspects of fisheries.
Impacts of fisheries
Explore and learn about the impact of fisheries. Choose to either click on and read the information below, or watch the videos, or both.
Overfishing
Overfishing
Overfishing occurs when the rate at which fish are harvested from a particular area exceeds the natural replenishment rate of the fish population. It is a severe problem that has significant consequences for all three pillars of sustainability: ecological, social, and economic. Overfishing can deplete fish stocks to a higher rate than can be replaced including as a result of taking fish too small/young to be have a chance to reproduce; disrupt marine ecosystems, and negatively impact the livelihoods of millions of people who depend on fishing for their income and food security. Statistics from the state of the World Fisheries and Aquaculture 2022 report suggest that since 1974 the percentage of overfished stocks have increased from 10% to 35.4 % as of 2019 and an additional 57.3% of fish stocks are fished at their maximum sustainable yield (MSY) and only 7.2% fished below their MSY (Fig. 1 FAO, 2023).
This figure is from “The State of World Fisheries and Aquaculture 2022 Towards Blue Transformation” by FAO, Rome, https://doi.org/10.4060/cc0461en, is licensed under CC BY-NC-SA 3.0
Bycatch
Bycatch
Bycatch refers to the unintentional capture of non-target species during fishing operations that are discarded, killed or injured as a result of fishing equipment. It is a significant issue in many fisheries worldwide and can have detrimental effects on marine ecosystems and non-target species. It is often the result of non-selective and particular types of fishing practices.
Destructive fishing practices
Destructive fishing practices
Destructive fishing practices cause significant harm to ecosystems and habitats. These practices, often result in the depletion of fish stocks and biodiversity. Practices include:
- Bottom trawling – where large, weighted nets along the seafloor to catch marine species. It is non-selective and can destroy habitats such as coral reefs, seagrass beds, deep-sea habitats as it drags along the seafloor.
- Drift Nets – where large nets that float in the water and non-selectively catch fish and other marine organisms that swim into them which can include marine mammals, seabirds and turtles.
- Explosive fishing – explosives are used to stun or kill fish, allowing for more fish to be caught in a shorter period of time and it makes them easier to catch. Unsurprisingly, it causes significant damage in the areas it is used to habitats and organisms.
- Cyanide fishing – where cyanide is sprayed by divers to stun fish and make them easy to capture. When used, the captured species are often destined for the aquarium trade. Cyanide fishing is toxic to marine organisms and can cause damage to marine environments.
- Ghost fishing – when discarded or lost fishing equipment remains in the ocean, it can continue to catch and kill marine organisms and lead to entanglement.
Social impact
Social impact
Fisheries paly a critical role in the economies of many countries with billions of people all around the world relying on fisheries as an essential source of animal protein and nutrition. Impact of overfishing has a significant social impact including:
- Through loss of income, unemployment and poverty caused by depletion of fish stocks and lower catch;
- Reduction in fish stocks threatened food security as fish is an essential food source;
- Leading to greater social inequities with large scale industry having greater resources and ability to catch fish stocks making it difficult for smaller fishers; and
- It can cause conflict and lead to illegal fishing as fish stocks decline.
Image Text Version
Figure 1: Global Trends in the state of the world’s marine fishery stocks, 1974-2019
Figure 1 is entitled ‘Global Trends in the state of the world’s marine fishery stocks, 1974-2019’.
There are 2 lines on the graph, ‘underfished’ and ‘maximally sustainably fished’. The vertical axis is labelled ‘Percentage’ beginning at 0 to 100, in increments of 25. The horizontal axis is labelled ‘Year’ beginning at 1974 to 2019, in decade increments. In the graph, the ‘underfished’ line begins at 1974 at 40 percent, steadily declining, with a sharp drop to 28 percent between 1980 and 1983. The line reaches 10 percent in 2010, remaining steady with a slight increase to 11 percent in 2014, before further decline to 9 percent for 2017, remaining steady with a marginal uptick to 10 percent in 2019. The ‘underfished’ line falls within the ‘sustainable’ range. The ’maximally sustainability fished’ line begins at 88 percent in 1974, rising marginally to 90 percent in 1978 before declining to 71 percent in 1990. the line rises sharply to 80 percent in 1992, before fluctuating, with an overall downward trend to 69 percent in 2008. The line rises to 72 percent in 2014 before declining to 63 percent in 2019. The ‘maximally sustainability fished line falls within the ‘sustainable’ range.
The values above the ‘maximally sustainably fished’ line, up to 100 percent, from 1974 to 2019 fall within the ‘overfished’ range. All data is approximate.
End Image Text Version
Will the ocean ever run out of fish?
In the TED-Ed video below, Ayana Elizabeth Johnson and Jennifer Jacquet explore the evolution and impacts of modern commercial fishing practices and what this means for sustaining marine environments and organisms into the future.
Ocean Alert: Overfishing
The video below, from the Khaled bin Sultan Living Oceans Foundation, highlights the hidden impacts of overfishing practices on marine ecosystems, alongside possible strategies for restoring balance and system sustainability.
Achieving sustainable fisheries
Achieving sustainable fisheries and work towards global food security requires a holistic management approach. Open the sections below to explore possible solutions.
Science based management solutions
Science based management solutions
High quality science investigating fisheries species life history to understand reproductive rate and age, ecosystem requirements, and population dynamics; and identifying maximum sustainable yield and minimum viable population size to ensure that species are sustainably harvested and are able to regenerate at the same level (or greater) than they are being extracted, and regularly assessing fish stocks. Conservation measures including no take marine protected areas, remediation and habitat restoration measures to increase biodiversity and fish stocks.
Innovative fishing practices
Innovative fishing practices
Advancement in fishing practices to move away from non-selective, destructive fishing methods that target a specific species is required. This will reduce bycatch and increase productive fisheries.
Fisheries management
Fisheries management
Fisheries management is the process of regulating and controlling fishing activities to ensure the sustainable use of fishery resources. It involves the application of scientific data, ecological understanding, and socioeconomic considerations to make informed decisions aimed at maintaining fish populations including setting and enforcing catch and size limits, protecting marine ecosystems, and supporting the livelihoods of fishing communities including combating illegal fishing. Effective fisheries management is essential to prevent overfishing, protect biodiversity, and maintain the health of marine ecosystems.
Socially inclusive
Socially inclusive
Improving fish stocks through effective fisheries management and conservation measures can bring various social benefits to communities and society as a whole. These include:
- Increased food security – Healthy fish stocks provide a reliable and sustainable source of protein and nutrition for billions of people globally, and are particularly important for people in coastal regions and small island nations where fish is a dietary staple. Improved fish stocks can help improve food security and nutrition.
- Support livelihoods – sustainable fisheries create livelihood for people around the world by allowing fishers to catch more fish and provide for their families. Healthy fisheries creates employment for fisher people, marketing, transportation, tourism and other industries supporting local communities and reducing unemployment.
- Improved recreation – sustainable fisheries provide greater recreational resources through recreational such as fishing, snorkelling and diving.
David Attenborough Explains What We Need to Do to Stop Over-Fishing
Watch the below video from the World Economic Forum where David Attenborough outlines what can be done to stop over-fishing and enable more sustainable systems.
How More Efficient Fishing Can Protect the Ocean
Watch the video below from the National Geographic, which discusses sustainable and unsustainable fishing practices, their impacts and the need for global fisheries management.
Activity: Test your Knowledge
Test your knowledge in the quiz below:
Activity Text Version
Activity: Test your Knowledge
This exercise invites readers to answer questions to test their knowledge, based on the fisheries information above. Questions and answers are listed below.
Question 1
Which of the following are impacts related to fisheries?
Select all that apply from: overexploitation, habitat destruction, by-catch of non target species, and ghost fishing.
Answers to question 1
Overexploitation, habitat destruction, by-catch of non target species, and ghost fishing.
Question 2
Overfishing has the potential to impact which pillar or pillars of sustainability?
Select all that apply from: environmental, economic, and social.
Answers to question 2
Environmental, economic, and social.
Question 3
Which of the following will help achieve sustainable fisheries?
Select all that apply from:
- Fishing at or below the maximum sustainable yield
- Social inclusion ensuring food and livelihoods
- Continuing fisheries as it is currently done, and
- Innovative fishing practices such as developing fishing gear that only captures the target species
Answers to question 3
- Fishing at or below the maximum sustainable yield
- Social inclusion ensuring food and livelihoods
- Innovative fishing practices such as developing fishing gear that only captures the target species
End Activity Text Version
