|Trophic models for investigation of fishing effect on coral reef ecosystems|
Arias-González, J.E.; Nuñez-Lara, E.; González-Salas, C.; Galzin, R. (2004). Trophic models for investigation of fishing effect on coral reef ecosystems. Ecol. Model. 172(2-4): 197-212
In: Ecological Modelling. Elsevier: Amsterdam; Lausanne; New York; Oxford; Shannon; Tokyo. ISSN 0304-3800, more
Coral reefs; Fishing mortality; Food webs; Marine parks; Reef fish; Marine
|Authors|| || Top |
- Arias-González, J.E.
- Nuñez-Lara, E.
- González-Salas, C.
- Galzin, R.
A comparison was made using general trophic models of three coral reef slopes in the Mexican Caribbean. Two reef slopesare in semi-protected areas (Boca Paila, Tampalam) and the third is subject to more intense exploitation (Mahahual). Themass-balanced models of the three reef slopes were derived from fish biomass density data obtained directly from field measurements(fish census). Other trophic groups were derived from published sources. Initial parameters for the three reef slopeswere calculated using the Ecopath with Ecosim software. Comparisons of model outputs were done to establish differencesbetween reef slope systems that are semi-protected and unprotected from fishing activities. The most significant results include:partition of production was always lowest for the unprotected reef slope; net primary production was three times higher for thesemi-protected slopes than for the unprotected one; total catch in the unprotected reef slope was three and eight times higherthan the two semi-protected reef slopes; food chain length increased as total catch increased; the calculated trophic level of thecatch was relatively lower in the unprotected reef slope; and catch per net primary production (gross efficiency) was higher inthe unprotected reef slope than the semi-protected reef slopes. It is concluded that trophic macrodescriptors can serve as a guideto the hard-to-detect negative effects of coral reef management, aid in decision-making, and emphasize the effects that structuraldescriptors, (e.g. total fish biomass, diversity indices) do not detect.