- A benthic community is a group of organisms that live on, in or near a seabed.
- Mangroves play a crucial role in ecosystems: “The mangrove macrobenthos - those species that live in mangrove muds or depend on mangroves for all or part of their life-cycle - encompasses a number of phyla, including Porifera (sponges), Mollusca (molluscs), Arthropoda (crabs, lobsters, prawns, etc.), Annelida (segmented worms), Nematoda (roundworms), Sipunculoidea (peanutworms), Platyhelminthes (flatworms), and ascidians within the Chordata”(3-4).
- The following reasons have been presented against prawn, mollusk and crab aquaculture:
- “First, prawn aquaculture generally requires destruction of mangroves for construction of rearing ponds (Sathirathai and Barbier, 2001; Barbier and Cox, 2004; Islam and Wahab, 2005)…Second, water pollution from intensive prawn farms negatively impacts adjacent mangrove ecosystems…Third, the area of mangrove required to support a ‘fishery’ of gravid P. monodon spawners for generating prawn ‘seed’ for stocking ponds in which intensive prawn aquaculture is practiced is ∼ 11 times the pond area (Rönnbäck et al., 2003)….Fourth, white-spot syndrome virus (WSSV) is now established in shrimp ponds throughout the world”(7).
- “Although the Matang mangrove forest is managed at a constant 40 000 ha, cockle production in 2004 was only 50% of its historic high of 121 000 tonnes in 1980 and accounted for only 14%of Southeast Asian production (total production value: US $435 Million [FAO, 2006]) in that same year (Fig. 5 top)” (7).
- “Of the seven countries with significant production data in the FAO (2006) database (excluding Brunei Darussalam, Mauritius, and Sri Lanka, each of which did not produce more than 2 t/y between 1950 and 2004), five have passed their peaks of production (Fig. 6): Taiwan in 1983, Thailand in 1986, Singapore in 1993, Malaysia in 1995, and Australia in 1998”(8).
- It is difficult to stop certain forms of aquaculture because there are no economic incentives to aquaculture companies to conserve mangroves: “What is clear is that patterns of P. monodon production are similar to ‘slash-and-burn’ agriculture in rain forests…Such ‘roving bandits’ can persist because they have no connection to local communities and no incentive to manage sustainably a local resource. They cut mangroves, establish prawn ponds, exhaust them before regulators can catch up and respond appropriately, and then move on to another country and repeat the process”(7).
- The following recommendations for mangrove deforestation mitigation are given at the end of the article: “Key changes required include: the termination of economic subsidies for aquaculture; enforced, legal requirements that effluent from aquaculture ponds be treated prior to release into surrounding ecosystems; and restrictions on the ability of ‘ roving bandits’ to convert untitled mangrove forests to private aquaculture operations serving the global marketplace”(11).