Stoichiometry, growth, and fecundity responses to nutrient enrichment by invertebrate grazers in sub-tropical turtle grass (Thalassia testudinum) meadows

Authors

Lesley P. Baggett, Dauphin Island Sea Lab; Department of Marine Science, University of South AlabamaFollow
Kenneth L. Heck Jr., Dauphin Island Sea Lab; Department of Marine Science, University of South AlabamaFollow
Thomas A. Frankovich, Marine Science Program, Department of Biological Sciences and Southeast Environmental Research Center, Florida International UniversityFollow
Anna R. Armitage, Marine Science Program, Department of Biological Sciences and Southeast Environmental Research Center, Florida International University; Department of Marine Biology, Texas A&M University at GalvestonFollow
James W. Fourqurean, Marine Science Program, Department of Biological Sciences and Southeast Environmental Research Center, Florida International UniversityFollow

Abstract

Although the effectiveness of herbivores in mitigating the effects of nutrient enrichment is well documented, few studies have examined the effects of nutrient enrichment on components of consumer fitness. Enclosures were deployed in shallow turtle grass (Thalassia testudinum) beds in Florida Bay, Florida in fall 2003, spring 2004, and fall 2004 to measure the effects of nitrogen and phosphorous enrichment on the growth, fecundity, and stoichiometry of three invertebrate epiphyte grazers commonly associated with T. testudinum. The gastropod Turbo castanea exhibited significantly greater wet weight gain and lower C:P and N:P in enriched than in ambient treatments. Although nutrient enrichment did not have any significant effects on the growth of caridean shrimp (treatment consisted of several different caridean shrimp species), their C:N was significantly lower in enriched treatments. The final size and stoichiometry of the hermit crab Paguristes tortugae was not significantly affected by nutrient enrichment, nor did nutrient enrichment significantly affect the fecundity of P. tortugae, the only grazer in which gravid individuals or egg masses were present. Our study demonstrated that nutrient enrichment of primary producers can positively affect the growth of marine invertebrate grazers and alter their stoichiometry; however, these effects were species-specific and may be dependent upon the life stage, specific diets, and/or compensatory feeding habits of the grazers.

Comments

The definitive publisher-authenticated version is available online at http://dx.doi.org/10.1007/s00227-012-2075-6

This material is based upon work supported by the National Science Foundation through the Florida Coastal Everglades Long-Term Ecological Research program under Cooperative Agreements #DBI-0620409 and #DEB-9910514. Any opinions, findings, conclusions, or recommendations expressed in the material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Recommended Citation

Baggett, L.P., K.L. HeckJr., T.A. Frankovich, A.R. Armitage, J.W. Fourqurean. 2013. Stoichiometry, growth, and fecundity responses to nutrient enrichment by invertebrate grazers in sub-tropical turtlegrass (Thalassia testudinum) meadows. Marine Biology 160(1): 169-180. DOI: 10.1007/s00227-012-2075-6