5.4.6 Capture fisheries and aquaculture: marine and inland waters
World capture production of fish, crustaceans and molluscs in 2004 was more than twice that of aquaculture (Table 5.5), but since 1997 capture production decreased by 1%, whereas aquaculture increased by 59%. By 2030, capture production and aquaculture are projected to be closer to equality (93 Mt and 83 Mt, respectively) (FAO, 2002). Aquaculture resembles terrestrial animal husbandry more than it does capture fisheries and therefore shares many of the vulnerabilities and adaptations to climate change with that sector. Similarities between aquaculture and terrestrial animal husbandry include ownership, control of inputs, diseases and predators, and use of land and water.
Table 5.5. World fisheries production in 2004 (source: FAO, Yearbook of
|World production in Mt ||Inland ||Marine ||Total |
|Capture production ||Fish, crustaceans, molluscs, etc. ||8.8 ||85.8 ||94.6 |
|Aquaculture production ||Fish, crustaceans, molluscs, etc. ||27.2 ||18.3 ||45.5 |
|Aquatic plants ||0.0 ||13.9 ||13.9 |
Some aquaculture, particularly of plants and molluscs, depends on naturally occurring nutrients and production, but the rearing of fish and Crustacea usually requires the addition of suitable food, obtained mainly from capture fisheries. Capture fisheries depend on the productivity of the natural ecosystems on which they are based and are therefore vulnerable to changes in primary production and how this production is transferred through the aquatic food chain (climate-induced change in production in natural aquatic ecosystems is dealt with in Chapter 4).
For aquatic systems we still lack the kind of experimental data and models used to predict agricultural crop yields under different climate scenarios; therefore, it is not possible to provide quantitative predictions such as are available for other sectors.