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Acute Toxicity and Sub-Lethal Effects of Non-Point Source Pollutants on Invertebrates

by Romano, Jocelyn Ann

Abstract (Summary)
Non-point source pollution is not generated from any single source, rather can

arise from a mixture of agricultural, residential, and industrial activities. As a result of

these activities millions of tons of chemicals enter into aquatic environments annually

with the potential to disrupt the fragile ecosystems existing within. Common

anthropogenic compounds most frequently seen in estuarine environments include

pesticides, antifoulants, polycyclic aromatic hydrocarbons (PAH), and industrial

solvents.

This dissertation examines the acute toxicity and sub-lethal effects of diuron,

CuPT, B(a)P, and styrene in the mud snail, Ilyanassa obsoleta, the American oyster,

Crassostrea virginica, the sea urchin, Lytechinus variegatus, and/or the barnacle,

Amphibalanus (= Balanus) amphitrite. In addition, the general effects of non-point source

pollution within the Rachel Carson Estuarine Research Reserve (RCERR) were examined

at six sites in order to gain a better understanding of the current health of this unique

habitat.

Of the four compounds tested, only the industrial solvent, styrene, resulted in an

LC50 (1341 µg L-1, I. obsoleta) that was within the range of currently reported

environmental levels. Diuron and CuPT did not elicit mortality at environmentally

relevant concentrations, but did significantly reduce fecundity in I. obsoleta and C.

virginica and fertilization success and larval development in L. variegatus. The only

notable sub-lethal effect elicited by the PAH, benzo(a)pyrene, was a significant decrease

in egg capsule production by I. obsoleta following exposure to concentrations as low as

50 µg L-1.

Within the RCERR, animals from Sites 4, 5, and 6 were observed to have

significant differences with respect to fecundity, condition index, and/or ECOD activity

when compared to conspecific organisms from control Site 1. This is most likely a

consequence of their proximity to anthropogenic sources. Large variation in mortality

(15-98.9%) was observed when families of A. amphitrite from a single population where

exposed to CuPT.

It is often difficult to extrapolate data from laboratory findings into natural

populations. Frequently the organisms used under laboratory conditions are genetically

very similar, while field population can vary with anthropogenic exposure. Caution

must be taken when developing protocols for risk assessment to ensure that actual

environmental conditions are being represented.

Bibliographical Information:

Advisor:Rittschof, Dan; McClellan-Green, Patricia; Di Giulio, Richard; Hinton, David; Bonaventura, Celia

School:Duke University

School Location:USA - North Carolina

Source Type:Master's Thesis

Keywords:diuron copper pyrithione styrene benzo a pyrene lytechinus variegatus ilyanassa obsoleta

ISBN:

Date of Publication:05/07/2007

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