Marine animals

The invertebrate macrofauna and algal epiphytes occurring on Thalassia in three hydrographically distinct areas in southern Florida were sampled during 14 June-21 June, 1974. A total of 178 invertebrate species was collected. The dominant non-colonial invertebrate taxa were Amphipoda, Isopoda, Mollusca, Polychaeta, and Tanaidacea. These groups included 93.8% of the fauna and 70.4% of the non-colonial invertebrate species. A relatively high faunal homogeneity was observed on each site. Turbidity and the abundance of algal epiphytes were important environmental factors affecting the observed differences in the composition and density of the epifauna between sites. Similarities in diversity (H') between Chicken Key (2.75), Lake Surprise (2.89) and San Carlos Bay (2.93), were presumably due to equivalent substrates with similar degrees of environmental instability. The Thalassia epifauna showed a high degree of parallelism with the Zostera marina epifauna.

Predator-prey relationships were studied between the shrimps Latreutes fucorum and Leander tenuicornis and the predatory fishes Stephanolepis hispidus and Histrio histrio, all found within pelagic Sargassum communities. Average survival times of shrimps were compared in species, size/density, and habitat selection studies. The results showed that S. hispidus had a preference for prey species while H. histrio did not. 30 mm shrimp survived longer than the 10 mm shrimp for both S. hispidus and H. histrio. Density was a factor in the survival times of the 20 mm shrimps with S. hispidus only. L. tenuicornis survived longer in artificial Sargassum habitats with H. histrio. The larger shrimps survived longer in the artificial habitats than the smaller shrimps with S. hispidus. Both fish predators employ optimal foraging strategies with similarities and differences, the latter of which are likely related to behavioral differences in the these predator and prey.

In examining the intentional relationship between the conservationist and the shark in South Florida, this thesis considers the latter as both a scarce natural resource - caught up in what Clifford Geertz citing Weber referred to as "webs of significance" (Geertz 1973:5) - and as a reflection of dynamic human conceptions of nature : a meta shark. This complex relationship is described by interpretations of conservation discourse recorded through ethnographic interviews that demonstrate how these perceptions have been influenced by factors such as personal experiences, film and text, and broad changes in the relationship between humans and nature since the early days of the environmental movement. By linking these perceptual changes with changes in American shark conservation policy, this work not only explains a relationship between culture, perception, and policy, but also celebrates the emergence of a multispecies marine community.