Spatial Aggregation, Precision, and Power in Surveys of Freshwater Mussel Populations

  title={Spatial Aggregation, Precision, and Power in Surveys of Freshwater Mussel Populations},
  author={John A. Downing and William L. Downing},
  journal={Canadian Journal of Fisheries and Aquatic Sciences},
  • J. DowningW. L. Downing
  • Published 1 May 1992
  • Environmental Science
  • Canadian Journal of Fisheries and Aquatic Sciences
We studied aggregation in 76 populations of freshwater mussels from relatively homogeneous surroundings in a wide range of habitats. Chi-square tests for spatial aggregation found only 53% of mussel populations significantly (p   1. The number of replicate samples () required to estimate mussel abundance with a given level of precision (D = SE/m) is approximately m−0.5D−2. Sampling mussels with large quadrats requires between 5 and 25 samples for 20% precision. Sampling designs to determine… 

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