Effects of ornamental fishing on coral reefs

Coral reefs are among the world’s most fragile and endangered ecosystems. They host an extraordinary variety of marine plants and animals and are one of the most biologically diverse ecosystems in the world.

They are a significant source of food to low-income coastal communities, a source of income and employment through tourism and marine recreation, and offer countless other benefits to humans, including unique chemicals with medicinal properties.

Despite this, coral reefs around the world are rapidly being degraded by several human activities including overfishing, coastal development, and the introduction of sewage, fertilizer and sediment.

Trade in reef species is strong additional pressure on this already highly threatened ecosystem.

Though the methods used are relatively less destructive compared to some other parts of the world, aquarium fish farming in Kuruwitu and Bofa has intensely affected the communities.

For the fish to do well in the aquariums, live corals have to be present in the glass “houses” which form the new habitat for the fish.

This means that apart from collecting the fish, the corals which also serve as the breeding areas for many marine species have to be ferried to the aquarium too.

Quite a number of the area’s inhabitants have been employed by various aquarium firms either as gogglers or divers to collect the highly valued ornamental fish.

However, it is evident that the locals are not deriving substantial benefits from the business.

The locals are paid a meagre wage that hardly supports their livelihood and are also exposed to various health hazards at sea and there is no medical or insurance cover from their employers.  

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Although the area is flooding with unemployed youth the business cannot be substituted with the promise of the sea as some fish species have already vanished from the frequented areas.

Recent studies have shown that aquarium collectors have had a significant negative impact on the fish species taken in the fishery, damaging fragile coral reef ecosystems.

Coral reefs

Among other impacts, the collection of fish for the aquarium trade causes significant declines in fish populations in their natural habitat.

The aquarium fish industry has been largely unregulated in the world, despite the potential environmental impact caused by the fishery.

Almost all of the ornamental fish are harvested before they get large enough to reproduce. Kenya ranks among the top exporters of marine aquarium fish in the Western Indian Ocean region. The aquarium fishery in Kenya, involves the collection of about 100,000–200,000 fishes.

According to the National Environmental Management Authority (NEMA), 145 licensed marine aquarium fish collectors are working full time in Kenya. Some are unlicensed. These collectors are either employed or contracted by 8 companies licensed to export marine aquarium fish.

Most of the aquarium fish caught in Kenya is exported to 15 countries: the UK, USA, South Africa, Hong Kong, Germany, France, Japan, Netherlands, Austria, Israel, Denmark, Poland, Hungary, Italy, and Romania.

Generally, aquarium fish collectors target juveniles because they are more colourful and easier to handle and airfreight.

Approximately 192 aquarium fish species belonging to 35 families are harvested and exported from Kenya; the most commonly exported species include anemone fish, angelfish, wrasses, surgeonfish, gobies, and blennies. The key species targeted by aquarium fish collectors are not targeted for food fisheries, except two species from the Lutjanidae family (Lutjanus kasmira and L. sabae), one species from the Signidae family (Siganus stellatus) and one species from the Serranidae family (Cephalopholis sp.).

A variety of marine invertebrates are also harvested for export. The collection of fish for the aquarium trade causes significant declines in fish populations. Aquarium fish collectors are highly selective and often capture large quantities of species of high value, making the potential for over-exploitation high. 80% of the catch of marine ornamentals is herbivorous fish. A reduction in the abundance of herbivores can cause algal overgrowth of coral, creating long-term impacts on coral reef health. According to fish collectors, competition is strong and many areas are being over-harvested.