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close this bookEnvironmental Handbook Volume II: Agriculture, Mining/Energy, Trade/Industry (GTZ, 1995, 736 p.)
close this folderAgriculture
close this folder32. Fisheries and aquaculture
View the document1. Scope
View the document2. Environmental impacts and protective measures
View the document3. Notes on the analysis and evaluation of environmental impacts
View the document4. Interaction with other sectors
View the document5. Summary assessment of environmental relevance
View the document6. References

1. Scope

Activities for the purpose of obtaining food and other products from water bodies involve catching and gathering as well as farming and raising aquatic organisms (above all fish, crustaceans, molluscs and algae). Annual worldwide production in the fishery and aquaculture sector amounts to around 95 million tonnes.

The principal forms of activity are:

- capture fisheries
- aquaculture
- stocking and ranching

All three types of activity can be carried out in seawater, brackish water and fresh water and in both coastal and inland waters. Deep-sea operations primarily involve capture fishery, with aquaculture playing only a very small role. Stocking and ranching may include use of deep-sea areas in that fish released near the coast (e.g. salmon) may spend their growth phase in the open sea.

While inland and inshore fisheries and aquaculture are predominantly artisanal, deep-sea operations are primarily on an industrial scale where capture fisheries are concerned and exclusively so in the case of aquaculture.

Capture fisheries utilise natural stocks of aquatic organisms. Such activities influence the stocks not only by catching them but also by means of conservation measures (closed seasons, protected areas, catch quotas, use of selective gear). In aquaculture measures are taken to directly influence at least the growth stage and if possible also the reproductive stage, above all by controlling water quality (through the conditions under which the organisms are kept), nutrition (through feeding and pond fertilising) and health (by means of prophylactic and therapeutic measures). The reproductive stage can be controlled by influencing maturation, egg and sperm production, hatching and larva raising. The characteristics of the organisms bred can be genetically influenced (e.g. by means of selection, crossing or genetic engineering).

Stocking and ranching combine aquaculture with fishery (culture-based capture fisheries). Natural or artificial bodies of water are stocked with young organisms which were hatched under supervision and spent the particularly critical early stages of their life cycle under controlled conditions. When the stocks created or augmented in this way reach the end of their growth stage, they are fished using normal capture-fishery techniques.

Between the "production" process - carried out under natural conditions (fisheries) or controlled conditions (aquaculture) - and consumption of the products there are a number of other stages which may likewise have environmental impacts: keeping fresh, processing, packing, transporting and marketing.

Fisheries and aquaculture can be divided into five main areas:

- artisanal small-scale fisheries
- small-scale aquaculture
- fisheries and aquaculture in artificial lakes
- fishery in the 200-mile exclusive economic zone
- fisheries and aquaculture in mangrove swamps

In the first two areas, emphasis must be on supporting low-income groups of the population and ensuring that appropriate technologies are applied. These two aspects likewise form the focus of attention in the use of artificial lakes for fisheries and aquaculture. By contrast, activities involving fishery in the 200-mile exclusive economic zone - predominantly at industrial scale - centre on preservation of resources and on managing and monitoring their use. Particular importance must be attached to environmental protection and resource conservation when the intention is to utilise mangrove swamps for fisheries and aquaculture, as measures involving the use of this fragile ecosystem should aim from the very outset to ensure that adverse environmental impacts are avoided altogether or kept to an absolute minimum.