Spearguns and Powerboats Harm Reef Biodiversity
Trophy Hunting for Specimen Fish Alters Ecosystems
Feb 15, 2009
The removal of top predators causes lasting damage to coral reefs and is even more serious a threat than overfishing.
Affluence and Coral Reef Biodiversity
- In an article, originally published by 'Cell Press' in the February 10th, 2009 issue of Current Biology, entitled ‘Rise or fall of reef fish driven by both economy and ecology’ Joshua Cinner of James Cook University in Australia argues that: ‘Overfishing on coral reefs isn't simply caused by too many people … the biomass of fish found on coral reefs in the western Indian Ocean depends mostly on the complexity of the reefs themselves and the socioeconomic status of the people living on the shores’.
- He goes on to blame moderate wealth without sufficient fishery regulation, citing the use of engine-powered boats and spearfishing as examples of technologies that come with affluence and selectively damage reef communities.
Fishing efficiency is limited by the range of the boats that are used. Paddling or sailing does not allow quite as much overfishing as is possible when engine-powered boats can be afforded. Even relatively poor communities can now use motorised vessels, and that means that the catch per person will go up – but while this over-exploitation will reduce the fish population it is not as damaging as the selective hunting for trophy fish that is possible when spearguns and powerboats are available.
Powerboats
- With coastal populations (living near coral reefs) become moderately wealthy their increased affluence will often attract even more well-off tourists. Powerboats, or at least motorised pleasure boats, will appear in the docks. These allow visitors to range far-and-wide, and fishing for the larger (and often rarer) ‘specimen fish’ becomes commonplace. A good example would be the search for large Potato Groupers (see: ‘Green Turtle, Potato Grouper and Giant Tortoises’).
- Here we are removing top predators selectively, and this will cause knock-on effects throughout the whole ecosystem.
When the hunt for trophy fish attracts spearfishermen to coral reefs they are able to target larger (and rarer) fish very effectively indeed. Boating rapidly to the more remote reefs, combined with the use of scuba gear and spearguns, can cause enormous damage to communities by removing a crucial part of the ecosystem.
Top Predators and Biodiversity
- Coral Reefs have some of the greatest biodiversity on the planet. Thousands of species are involved in a complex web of relationships, and the top predators (usually large fish which can be seen as good trophies) are important in retaining the balance.
- Removing these large fish lowers the level of biodiversity, and this in turn will lower the productivity of the reef and its ability to regenerate if pressures change in the future.
- Spearfishing from powerboats causes long-term damage which can be even more serious than simple overfishing.
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