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Introduction | Identification | Impacts | Causes | Actions | More Info
|What are some of the biological and physical impacts to coral reefs?|
The overharvesting of desirable fish, invertebrate, and coral species for aquaria can have devastating effects on coral reef communities by disturbing the balance between interconnected species on the reef. Mechanical destruction of the reef also occurs as large areas of branching corals are broken apart to retrieve targeted fish (Mous et al. 2000). An estimated 0.4% reef loss per year is attributed to aquarium fishing (McManus et al 1997).
The use of cyanide – used to stun fish and make them easier to capture – is of particular concern. Cyanide not only injures targeted species but also can kill other non-target fish and invertebrates. According to one report, an estimated 50-60% of the Philippines aquarium fish and 90% of the Indonesian aquarium fish imported into the United States were captured with cyanide (Cesar 1996). Training fishermen to use nets rather than cyanide has reduced but not completely eliminated cyanide fishing (Rubec et al. 2001). This may be partly due to the fact that trained fishers could not obtain better prices for net-caught fish (Rubec and Cruz 2002). The Marine Aquarium Council is attempting to address this problem through a certification scheme that will allow buyers to easily identify net-caught fish and a public awareness program to educate buyers about the effects of cyanide on targeted and non-targeted organisms. The United States is the largest market for the marine ornamental trade (USCRTF 2000). Germany, France, Netherlands, United Kingdom, and Japan (MAC 2002) also import large numbers of aquarium fish and live corals.
What are the impacts to local communities and economies?
For many coastal communities that are dependent on local reefs for subsistence and income, the damage caused by overharvesting reef species and cyanide use, in addition to other human impacts, will eventually lead to the inability of these ecosystems to sustain local people and businesses. In addition, as aquarium species become more difficult to find due to overfishing, fishers will have to dive deeper and for longer periods in order to harvest desired species. The improper use of diving equipment has led to serious diving accidents and health problems in many communities. Injuries as a result of improper decompression are becoming more and more frequent as fishers push divings time and depth limits to harvest a diminishing population of aquarium species (Best 2002). On the Miskito Coast of Central America, close to 100 percent of divers show signs of neurologic damage, likely due to inadequate decompression and improper use of diving equipment (Best 2002).
On the other hand, a well-managed marine ornamental trade has many socioeconomic benefits. Collecting and exporting marine aquarium organisms can create jobs and additional income for rural, low-income communities in developing countries with limited resources and economic options (Holthus 1999 in Bunting et al. 2003). There are an estimated 7,000 aquarium fish collectors in the Philippines, many of them supporting families. A UNESCO report estimates that as many as 50,000 people in Sri Lanka are directly involved in the export of reef animals (Kenchington 1985 in Bunting et al. 2003). Marine ornamentals are one of the highest value-added products that can be harvested sustainably from coral reefs, bringing a higher economic return than most other reefs uses. For example, live coral in the marine ornamental trade is estimated to be worth about US$3.50 per pound, while the use of harvested coral for lime production yielded only about 3 cents per pound (Green and Shirley 1999 in Bunting et al. 2003). The figures for reef fish are even more striking. Reef fish harvested for food from one island country were valued at US$3 per pound. Aquarium fish from the same country realized a return of more than US$248 per pound (Food and Agriculture Organization 1999 in Bunting et. al. 2003).
Therefore, the marine ornamental trade can give fishers and their families an economic incentive to ensure their reefs are healthy, protected, and productive. Consequently, collectors of marine ornamentals and their communities often become active reef stewards. They guard these valuable resources against destructive uses and sometimes create informal management systems or de facto conservation areas (Bunting et al. 2003). In addition, an increasing number of collector communities are seeking to become MAC certified. This process requires the development of a formal reef management plan that is community-based, involves many users of the coral reef resource, and encourages the inclusion of no-take replenishment areas. This is particularly important because many reefs where aquarium fish collecting occurs are often located in remote areas where resource management and law enforcement by the national government is difficult. In many instances, MAC certification will provide the incentive and opportunity to bring reef management and no-take zones to areas that previously lacked them. Without sustainable uses of coral reefs—such as the responsible collection of aquarium animals and the incentives that this creates for local resource stewardship—reefs would quite probably become open to more destructive uses.
|Butterflyfish, Chaetodon trifascialis, during a night dive.
Location: Pulau Laut, Anambas & Natuna Archipalego, Indonesia
Photo by: Yusri bin Yusuf
(from ReefBase: http://www.reefbase.org)|