Get started
Work

Carbon and Nitrogen Stable Isotopes as Descriptors of Fish Trophodynamics

Year: 2004
Type: dissertation
Abstract: Fisheries resources are not exploited in isolation and their removal has profound impacts on the structure of marine ecosystems. Assessments of the extent and significance of impacts rely heavily on trophodynamic studies among organisms as alteration of food-web structure should be reflected by changes in the component species’ diet. Traditional methods of dietary analysis such as gut content analysis have been successful in supporting some types of contemporary food web analysis, but provide limited support when gut contents are difficult to sample and identify or when retrospective analyses are used to describe long-term changes in food webs. Stable isotopes provide an alternative method to support trophodynamic studies, that can be applied when diet analysis is impractical or inappropriate and when retrospective studies of food webs are required. The relative abundances of carbon and nitrogen stable isotopes in an organism are thought to reflect that of the diet after slight and constant fractionation, and to remain unaltered after sampling. However, small deviations in fractionation or modification of isotopic ratio after sampling have important implications for interpretation of food web characteristics in both contemporary and retrospective studies. Research was conducted to help validate analyses of marine food web structure based on stable isotope analysis. The aims of the research were to understand the factors affecting the stable isotope ratios of soft and bony tissues in marine fishes, both during the life of the fish (ontogeny, diet, tissue type) and after death (preservation of different tissue types), and to understand biases that may affect the interpretation of stable isotope data (changes in lipid content, preservation).
Language: English
Subfield: Ecology
Open Access status: green
OpenAlex ID: W2740374881
Cites: 247
Cited by: 2
Related to: 10