Spatially explicit models of growth rate potential
Demers, E.; Brandt, S.B.; Barry, K.L.; Jech, J.M. (2000). Spatially explicit models of growth rate potential, in: Hobbie, J.E. (Ed.) Estuarine science: a synthetic approach to research and practice. pp. 405-425 In: Hobbie, J.E. (Ed.) (2000). Estuarine science: A synthetic approach to research and practice. Island Press: Washington D.C.ISBN 1-55963-700-5. XI, 539 pp., more |
| Authors | | Top | - Demers, E.
- Brandt, S.B.
- Barry, K.L.
- Jech, J.M.
| | |
| Abstract | Estuaries are high-yield fishing areas that are characterized by spatial heterogeneity in physical and biological conditions. Models of fish production have traditionally been based on systemwide averages of environmental conditions, but habitat heterogeneity can substantially influence fish growth. Growth rate potential (GRP) provides a spatially explicit approach that integrates the heterogeneous nature of estuaries into a simple modeling framework. In this chapter, we describe and illustrate the application of GRP to compare potential growth of tWo piscivores and to determine the potential growth of a non-native species introduced into an estuary. Acoustically derived prey distributions and temperature profiles were merged in a spatially explicit analysis to estimate and compare GRP of striped bass and bluefish in Chesapeake and Delaware Bays. In this analysis, bluefish grew better in the thermal regimes and prey biomass available during midsummer while striped bass had higher potential growth during fall. This suggests that, although striped bass and bluefish use similar prey resources, they may be thermally and temporally segregated, thereby reducing competitive overlap. In our second example, GRP results indicate that the suitability of Chesapeake Bay for the growth of chinook salmon (a non-native, hypothetical invader) was very low during summer, whereas in October, water temperature and prey availability could possibly support chinook salmon growth. This spatially explicit approach proved to be a valuable tool to study fish production in estuarine systems where heterogeneous conditions can affect populations at systems levels. |
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