Date

2005

Document Type

Master's Thesis

Degree Name

Master of Science (M.S.)

Department

Moss Landing Marine Laboratories

Abstract

By understanding species and habitat associations, predictions of species composition can be made about a benthic community based on available habitat. In a kelp forest, topographic complexity can affect an organism, by modifying flow, altering food availability, altering light availability, and provide refuges and barriers that fragment the habitat. There are many qualitative ways to evaluate topographic complexity. Rugosity is a quantitative measure and is defined as the ratio of surface area to planar area. Using habitat maps developed in GIS from multibeam bathymetry data, regions of varying rugosity were mapped in southern Monterey Bay, CA. Associated benthic communities were examined to elucidate spatial patterns and similarities in community composition. In addition, transect rugosity, significant wave height (Hs), depth, the number of edges, the number of walls and the number of crevices were used to compare environmental spatial patterns with biological spatial patterns. Results from non-metric multidimensional scaling (MDS) plots and Analysis of Similarity (ANOSIM) indicated no differences among high, medium or low rugosity classes, but did indicate significant sample site differences. Results from a Biological-Environmental (BIO-ENV) analysis procedure suggest that Hs, transect rugosity and depth correlate best with community composition variation, but only explain up to 0.35 of the variation. These results suggest that variables that were previously thought to be important in predicting benthic community composition and spatial structure may in fact work in combination with other unexamined variables. By examining species/habitat associations at multiple scales and showing strong species to habitat correlation, a more accurate and detailed assessment of benthic communities can be made and allow researchers to refine spatial predictions of these communities.

Comments

Thesis (M.S.) Division of Science and Environmental Policy. Moss Landing Marine Laboratories

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