When is a shark net not a shark net?

Well, when it’s an EXCLUSION NET, obviously. Colour me educated by the sharkspotters website:

Yesterday, 29 Feb 2012, the City of Cape Town issued a press release of a proposal to trial an exclusion net in Fish Hoek Bay (http://sharkspotters.org.za/media-release-city-to-consider-a-proposed-trial-installation-of-a-shark-exclusion-net-for-fish-hoek-beach). Almost immediately shark nets (as used in KwaZulu Natal) were confused with the proposal of the exclusion net in Fish Hoek. Below is a summary of the key differences.

What are they? 
Shark nets are large-meshed, anchored gill nets.
How do they work? They entangle and catch sharks reducing the population and numbers of sharks within the environment and thereby reduce the risk of shark attack.
Layout and structure: Nets are 213.5 – 304.8 m long by 6.3 m deep, have a black mesh of 51 cm (stretched) and are set parallel to the coast in 10-14 m of water some 300-500 m from shore.
Entanglements of marine animals: Not selective and result in by-catch of a range of other marine species such as turtles, dolphins, and whales. Risk of entanglement high
Ecological impact: Considered high.
Areas where used: KZN (South Africa), Australia
What are they? Exclusion nets are fine-meshed nets and are not gill nets.
How do they work? Nets are designed to act as a barrier, physically excluding sharks, thereby preventing them from entering an enclosed area.
Layout and structure: Net is set to enclose a specified area, and stretches from the seafloor to the surface. Mesh size is 6cm stretched (3cm x 3cm on the square). Size of net is dependent on area to be enclosed.
Entanglements of marine animals: The fine mesh of the nets prevents capture or entanglement of marine species and the net acts as a barrier. Risk of entanglement low.
Ecological impact: Considered low.
Areas where used: Usually in calm waters like in Hong Kong and Seychelles.

The City is considering this because of the much publicised recent shark attacks at Fishhoek and Clovelly and the impact on the local Fishhoek area and community, including:

  • the perception of it as an unsafe swimming area due to regular shark sightings resulting in bathers being kept out of the water;
  • the impact that this has on local businesses, especially the tourism industry;
  • the need to protect the natural environment which is a unique marine asset; and
  • the need to be aware of and respectful of the current trek net rights at Fish Hoek Beach and the importance of these rights to the livelihoods of a number of people. As such the City will work with the rights holders to ensure minimal impact on those rights should the exclusion net proceed.

I see no problem with it and it’s good to see the City reacting and considering the needs and the economics of the community without going over the top and using the environmentally damaging shark nets link those in KZN. In addition, this is a trial installation – if it doesn’t work, it gets removed. That’s what trial installations are for.

Yep – good idea.

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