, Volume 202, Issue 1–2, pp 61–69

Gull contributions of phosphorus and nitrogen to a Cape Cod kettle pond

  • J. W. Portnoy

DOI: 10.1007/BF00027092

Cite this article as:
Portnoy, J.W. Hydrobiologia (1990) 202: 61. doi:10.1007/BF00027092


Nutrient excretion rates and the annual contribution of P from the feces of the gulls Larus argentatus and L. marinus (and of N from L. argentatus) to the nutrient budget of Gull Pond (Wellfleet), a soft water seepage lake, have been estimated. Intensive year-round gull counts by species were combined with determinations of defecation rate and the nutrient content of feces to quantitatively assess the P loading rates associated with regular gull use of this coastal pond on a seasonal and annual basis. Total P loading from gulls was estimated to be 52 kg yr−1, with 17 kg from L. argentatus and 35 kg from L. marinus, resulting from about 5.0 × 106 h yr−1 and 1.7 × 106 h yr−1 of pond use. This compares with P loading estimates of 67 kg yr−1 from upgradient septic systems, 2 kg yr−1 from precipitation and 3 kg yr−1 from unpolluted ground water. Fifty-six percent of annual gull P loading was associated with migratory activity in late fall. Estimated annual N loading by L. argentatus was 14 kg TKN, 206 g NO3-N, and 1.85 g g NH3-N.

Key words

Gulls phosphorus nitrogen eutrophication excretion nutrients 

Copyright information

© Kluwer Academic Publishers 1990

Authors and Affiliations

  • J. W. Portnoy
    • 1
    • 2
  1. 1.Cape Cod National SeashoreSouth Wellfleet
  2. 2.M. A. SoukupNational Park ServiceBostonUSA

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