Overfishing
Bycatch
Habitat Damage
IUU Fishing
Flags of Convenience (FOC)
Loss of Biodiversity
Increasing fish contamination
Aquaculture

Overfishing

Taking too many fish is a simple definition of overfishing. Overfishing has affected oceans in every region of the world, making it an issue of global concern.

Overfishing plays a leading role in the decline and extinction of many species. When overfishing occurs, few mature fish remain to breed and replenish stocks which can upset the balance of ecosystems. Overfishing also removes species from the food chain which affects predatory-prey relationships, lowers biodiversity, and eliminates food sources for other marine organisms.

Overfishing also costs jobs and reduces incomes. When fish populations are declining, it is difficult for fishermen to make a living. When one species of fish is no longer plentiful, individuals are forced to fish elsewhere or move on to new species. That, in turn, can lead to the loss of other species.

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Bycatch

Bycatch, also known as incidental catch, is the unintentional take of unwanted and often unused species of fish, seabirds, and marine mammals.

According to the UN Food and Agriculture Organization, one in four animals caught in fishing gear dies as bycatch. Bycatch is a problem because it removes marine organisms from their environment. Bycatch usually consists of organisms that are too small or are of no commercial value. Consequently, bycatch is thrown back into the ocean either injured or dead.

Many populations of marine life are being threatened as a result of bycatch; some populations are facing extinction because of bycatch.

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Habitat Damage

Habitats are the places where marine organisms live, breed, grow and avoid predators. Marine organisms can also live in a variety of habitats depending on the purpose. Fish, for example, may use one habitat for food and another to spawn.

Damage to habitats upsets the natural processes of marine organisms that use the areas. Certain fishing practices are extremely detrimental to marine habitats.

Trawling, for example, is an extremely destructive form of fishing. Trawling involves large ships that drag cone-shaped nets behind them. The net is dragged at midwater levels (pelagic trawling) as well as bottom levels (bottom trawling) depending on the species of fish targeted. Bottom trawling nets are fixed with chains that drag along the seabed. This is bad for the ocean environment because the net disturbs and takes with it everything in its path. In areas frequented by fishing, the seafloor never gets a chance to recover. Without a healthy habitat, fish cannot survive.

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IUU fishing

IUU fishing stands for Illegal, Unreported, and Unregulated Fishing

In response to shrinking and increasingly regulated fisheries, fishermen seek to avoid regulations by failing to report the amount of fish caught and fishing illegally. IUU fishing usually occurs within international waters because of the lack of resources available to police the activities of every fishing vessel operating in these waters.

IUU fishing severely undermines conservation and management efforts and can lead to the collapse of a fishery. It can also impair efforts to rebuild depleted stocks.

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Flags of Convenience (FOC)

Similar to IUU fishing, Flags of Convenience are a technique vessels select to avoid strict fishing regulations. Vessels obtain flags of another country to fly other than the country of ownership. Most FOC countries have minimum social and environmental standards, which make them appealing to those who disregard fishery regulations and the need to protect declining fish stocks.

There are a number of motivating factors for vessels who seek FOC’s, including cheap registration fees, low or no taxes and freedom to employ cheap labour.

Minimum social standards or trade union rights are not enforced by FOC countries. Individuals who work on FOC (seafarers) ships find themselves on ships that are older and often deemed unseaworthy. Seafarers work for low wages, long hours, receive inadequate medial attention, and live in extremely poor conditions. They are essentially denied basic human rights.

FOC countries include:

To learn more, visit the International Transport Workers’ Federation
Flags of Convenience Campaign

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Loss of Biodiversity

Overfishing, habitat damage, and bycatch affect the processes that drive biodiversity. According the World Conservation Union (IUCN), WWF, and the UNEP, biodiversity is the variety of life in all its forms, levels and combinations. It includes ecosystem diversity, species diversity, and genetic diversity.

Understanding the importance of biodiversity is fundamental to proper management of the world’s fisheries.

Biodiversity allows the ecosystem to adapt to changing conditions. When an area experiences a loss in its biodiversity, the stability of that ecosystem is jeopardized. Biodiversity is essential to healthy ocean environments because it can potentially help to alleviate current and future commercial fishing pressures.

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Increasing fish contamination

Tragically, our oceans are polluted with industrial pollutants from activities such as pulp and paper, burning garbage and fossil fuels, and mining operations. Heavy metal contamination is the most prevalent issue. Mercury exists in two forms, elemental mercury and methyl mercury. Both have negative side affects in the aquatic environment; methyl mercury is most problematic because it binds tightly to proteins and bio-accumulates in fish tissue. The level of mercury found in a fish is directly proportional to the amount in the environment and its place in the food chain. Mercury also accumulates in the food chain, so larger fish are more problematic because big fish eat smaller fish, thereby getting a greater dose of accumulated mercury.

Methyl mercury has the power to alter normal brain function and development, affect the nervous system, and is especially harmful to infants. Consuming too much fish contaminated with methyl mercury before and during pregnancy, or during the breastfeeding period, could cause birth defects and learning disabilities. Evidence for mercury's effect on adults is less clear-cut. However, extreme mercury exposure can lead to personality changes, tremors, vision changes, deafness, loss of co-ordination, memory loss, intellectual impairment and death.

The Canadian Food Inspection Agency advices limited consumption of shark, swordfish, and fresh and frozen tuna to one meal per week. For small children, pregnant women, and women of child-bearing age, consumption should be limited to one meal per month.

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Aquaculture

Aquaculture, also known as fish farming, is the cultivation of marine animals for food. Today, more than one-third of our seafood comes from aquaculture.

When practiced unsustainably, aquaculture can have serious implications for the ocean environment. Open-netcage farming is one technique that can negatively impact the marine environment. It involves giant nets that float in the ocean. There are several problems associated with open-netcage farming including:

Sewage from the farms: Excrement and unused feed have serious implications for the health of wild and farmed fish.

Drugs: Medications are used to maintain the health of the farmed fish. The drugs are administered through the feed. The medication however, enters the marine environment through fish excrement and uneaten feed which can affect wild populations.

Escapes: Farmed fish that escape can threaten wild fish populations. Farmed fish can carry parasites and disease that pose serious threats. Breeding can have serious consequences as well because of the genetic diversity between farmed and wild stocks. If farmed fish breed with wild fish, the genetic diversity of wild fish may be lost and could affect the long term viability of population.

For more information on farmed seafood, visit the David Suzuki Foundation.

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