Toxic effects of pentachlorophenol on polychaete assemblages inhabiting a seagrass meadow were studied and analyzed in various ways. Examination of the effects proceeded from a more general approach (following changes of the structure of the polychaete group) to more specific ones, which included analyses at a functional and species-specific level. The study took place in a Gulf coast seagrass meadow located at Turkey Point Shoal. The shoal is dominated by mixed stands of Thalassia testudinum and Syringodium filiforme. The effects of two PCP concentrations (10 ppm and 100 ppm) were tested, in addition to sedimentation effects due to the dosing procedure. Samples were taken for chemical, granulometric, and infaunal analyses. / This experiment showed that pentachlorophenol was highly toxic to polychaete. It was possible to determine acute toxic effects and that such effects were concentration-dependent, as they were found related only with the high dose. Detrimental effects were found when using different ecological approaches. Community-type parameters were the least sensitive to changes induced by the chemical, mainly represented by density reductions, rather than effects on number and species composition. From a functional point of view, pentachlorophenol had negative toxic effects on several polychaete functional groups. Deposit feeders in general (i.e., surface and subsurface feeders) were found to be the most affected, showing strong density reductions in the high dose treatment. Other functional groups were also affected, such as scavengers and predators, suggesting that toxic effects were generalized over the polychaete group, rather than specific on determined groups. / Species-specific toxic effects were also evident. Species such as Prionospio heterobranchia, Onuphis eremita oculata and Sphaerosyllis taylori showed significant negative effects. However, other deposit feeders, such as Mediomastus ambiseta, Aricidea philbinae did not show any adverse effects to the chemical. Moreover, some species were more affected in the juvenile stages whereas other species were more affected in the adult stages. These differences in response to pentachlorophenol were attributed to a wide range of vertical distribution of some species within the sediment matrix, reducing the probability of exposure. / Source: Dissertation Abstracts International, Volume: 49-03, Section: B, page: 0619. / Major Professor: Robert J. Livingston. / Thesis (Ph.D.)--The Florida State University, 1987.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76246 |
| Contributors | Bone, David., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 242 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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