title: Application of nitrogen stable isotope analysis in size-based marine food web and macroecological research.
abstract: Interacting human and environmental pressures influence the structure and dynamics of marine food webs. To describe and predict the effects of these pressures, theoretical advances need to be supported by a capacity to validate the underlying models and assumptions. Here, we review recent applications of nitrogen stable isotope analysis in marine food web and macroecological research, with a focus on work that has paralleled a resurgence of interest in the development and application of size-based models. Nitrogen stable isotope data have been used to estimate intra- and inter-specific variation in trophic level, predator-prey size ratios, transfer efficiency, food chain length, relationships between predator and prey species diversity and the dynamics of energy use. Many of these estimates have contributed to the development, testing and parameterisation of food web and ecosystem models, some of which have been used to establish baselines for assessing the scale of human impacts. The interpretation of results depends on assumed fractionation but, when supported by sensitivity analyses and experimental validation, nitrogen stable isotope data provide valuable insights into the structuring of marine communities and ecosystems.
authors.affiliation: Centre for Environment, Fisheries and Aquaculture Science, Pakefield Road, Lowestoft NR33 0HT, UK. simon.jennings@cefas.co.uk
authors.forename: Simon
authors.initials: S
authors.lastname: Jennings
authors.forename: Carolyn
authors.initials: C
authors.lastname: Barnes
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Sweeting
authors.forename: Nicholas V C
authors.initials: NV
authors.lastname: Polunin
mesh_terms: D000818:Animals; D017753:Ecosystem; D005399:Fishes / Q000378:metabolism; D020387:Food Chain; D006801:Humans; D008386:Marine Biology; D013058:Mass Spectrometry; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism*; D009587:Nitrogen Isotopes / Q000032:analysis; D010839:Phytoplankton / Q000378:metabolism; D015048:Zooplankton / Q000378:metabolism
chemical_list: D009587:Nitrogen Isotopes; D009584:Nitrogen