Ecological Footprint of Shrimp and Tilapia Aquaculture

摘要

The human population explosion will lead to an increasing shortage of natural resources on the globe and it is urgent that we shift to proudction systems that require less resource.s One way of directing us towards a more sustainable development is to estimate the ecosystem area, the ecological footprint-functionally required to support aquacuiture. We have estimated that a typical semiintensive shrimp farm in a coastal mangrove area needs a footprint that is 35approx190 tiems the surface area of the farm. Of this 14.5 m~/m~2 shrimp pond is required to support fish catch for pellet manufacture, 0.5m~2 is needed for vegetable ingredients, 7.2m~2 is for lagoon water and 4.2m~2 is for detritus production, 0.8approx2.5m~2 is for assimilating the CO_2 produced, while the remaining larger part is the man-grove area needed to supply shrimp seed larvae In intensive Tilapia cage farming the ecological footprint required for food production was found to be 21 000 tiimes larger, while the areas needed for BOD and P waste assimilatio were 160 times and 115 tiems larger, respectively, than the area of the cages. In a semi-in-tensive Tilapia pond farm that is run on offals from fisheries, agriculture and households, virtually no external life support area is needed and the produced waste can be assimilated within the pond.