Allometric length-weight relationships for benthic prey of aquatic wildlife in coastal marine habitats
McKinney, R.A., Glatt, S.M. & Williams, S.R. 2004: Allometric lengthweight relationships for benthic prey of aquatic wildlife in coastal marine habitats. - Wildl. Biol. 10: 241-249.
We developed models to estimate the soft tissue content of benthic marine invertebrates that are prey for aquatic wildlife. Allometric regression models of tissue wet weight with shell length for 10 species of benthic invertebrates had r² values ranging from 0.29 for hermit crabs Pagurus longicarpusto 0.98 for green crabs Carcinus maenas. As a class, bivalves had the highest r² values (0.84) and crustaceans the lowest (0.48). Energy and nutrient content of soft tissue is also presented for the 10 benthic species. The energy content was lowest in crabs, and ranged within 2.20-4.71 kcal g-1 dry weight. Fat content was highly variable (range: 3.5-16.0%), and protein content ranged within 43.1-68.1% and was highest for shrimp Palaemonetes pugio. Comparison between classes of organisms of the amount of soft tissue per unit shell length showed that crustaceans yield five times more soft tissue per unit shell length than bivalves, and four times more than gastropods. The models we present use simple measures, such as the length of shell or wet weight of the entire animal, to quantitatively estimate the amount of available soft tissue in benthic prey that are usually consumed in total (with shell and soft tissue intact) but for which only the soft tissue is used for nutritional gain. This information can be combined with energy and nutrient content data to calculate energy or nutrient based carrying capacities that can help assess available resources for shorebirds, waterfowl and marine mammals.
Key words: allometric scaling, aquatic wildlife, energy-based carrying capacity, marine invertebrates
Richard A. McKinney, US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, 27 Tarzwell Drive, Narragansett, Rhode Island 02882, USA - e-mail: mckinney.rick@epa.gov
Sarah M. Glatt, Department of Life Sciences, Brandeis University, Waltham, Massachusetts 02454, USA - e-mail: sglatt@brandeis.edu
Scott R. McWilliams, Department of Natural Resources Science, University of Rhode Island, Kingston, Rhode Island 02881, USA - e-mail: srmcwilliams@uri.edu
Corresponding author: Richard A. McKinney
Received 9 May 2003, accepted 10 November 2003
Associate Editor: Jan Lindström