NO take zones take the marine protected area one step further. They are areas e.g. New Zealand’s marine reserves, where all forms of exploitation are prohibited and severely limit human activates. Generally a No Take Zone can cover the whole MPA or specific vulnerable portions that enjoy elevated protection.
The Great Barrier Reef.
One well known reef, the Great Barrier Reef became a no take zone as part of a controversial decision in 2004. However despite initial hesitation the decision to halt commercial and recreational fishing across vast areas of the reef has proven remarkably effective for reviving coral trout numbers.
Fishing was totally banned across a third of the park, more than 100,000km2 including parts of 70 biologically distinct bioregions.
Within 18 months of the fishing ban, coral trout stocks had increased by 60% in two areas (Palm Island and the Whitsundays) within the no take zone. In contrast coral trout numbers in nearby fished areas did not change at all. In the long term it is hoped that the number build up in the protected areas and over spill and spawning means number will thus increase in unprotected areas too.
This recovery was further supported by a second team of scientists led by Hugh Sweatman of the Australian Institute of Marine Science in Townsville. They found coral trout number had increased significantly in no take zones around reefs from 32 to 200 kilometres off shore. In four of these offshore regions, numbers of coral trout were between 31 and 64% higher compared to unprotected regions nearby, just two years after the zoning took place. It is a very positive result but the full recovery of coral trout will take 10-15years to access.
The no take reserve has also seen other benefits; protecting corals reefs from the predatory starfish, Acanthaster planci is one of them. The crown-of-thorns starfish, Acanthaster planci, is a predator of corals that is a major management issue on coral reefs (Sweatman 2008). It occurs throughout the Indo–Pacific and shows boom–bust population dynamics with low background densities and intermittent outbreaks. Three waves of population outbreaks have affected Australia's Great Barrier Reef since the 1960s. The waves of outbreaks cause major losses of living coral on many reefs across a large area and dwarfing losses from other disturbances such as storms or coral bleaching over the same period. Humans can potentially influence starfish population dynamics by exploiting predators. Extensive surveys in the Great Barrier Reef Marine Park show that protection from fishing affects the frequency of outbreaks: the relative frequency of outbreaks on reefs that were open to fishing was 3.75 times higher than that on no-take reefs in the mid-shelf region of the GBR, where most outbreaks occur, and seven times greater on open reefs if all reefs were included. Although exploited fishes are unlikely to prey on starfish directly, trophic cascades could favour invertebrates that prey on juvenile starfish.
NO take zones clearly have their benefits for coral reefs but to make a significant difference more needs to be done.
A newspaper article by Eccleston (2008) states “current conservation zones ‘no take zones’ are too small, vulnerable to climate change and are in the wrong place to prevent reefs collapsing”. This statement was based upon joint research by Newcastle University and the Wildlife Conservation Society, New York. This team concluded that existing conservation zones should not be removed but new zones are urgently needed to protect coral reef and to aid their recovery from mass die offs caused by rising temperatures.
References.
Sweatman 2008: doi:10.1016/j.cub.2008.05.033
Russ et al. 2008: doi:10.1016/j.cub.2008.04.016
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