ISSN:
1365-2109
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
Notizen:
A model for dynamic simulation of the growth of the Nile tilapia, Oreochromis niloticus (L.), in relation to food amount and composition, temperature, and dissolved oxygen concentration was applied to tilapia ponds. To model food competition between stocked fish and fingerling recruits, a pond food module was added. Data for model calibration were from uniform experiments with all-male O niloticus ponds fertilized with inorganic fertilizers and chicken manure in Honduras, Rwanda and Thailand. Calibration consisted of iterative determination of two model parameters: (1) CONLEV, the consumption rate without food or oxygen limitations; and (2) TPFS, the total daily food supply by the pond. Calibration results showed that, in most ponds, final fish weight could be simulated with acceptable values for CONLEV and TPFS. Both CONLEV and TPFS were related to natural productivity indicators (net primary production and chlorophyll a concentration). For each pond, an estimate of the degree of food and/or oxygen limitation could be given. Validation of the model with independent data from Indonesia and Panama was unsuccessful. The relationships used to estimate values of CONLEV and TPFS from primary productivity measurements were not satisfactory. A more detailed approach to modeling food competition and oxygen limitation under these conditions is necessary. The model provides a conceptual framework for the analysis of fish growth in ponds, tying together effects of food quantity and composition, temperature, and dissolved oxygen concentration.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1365-2109.1996.tb01276.x
