A caridean grass shrimp (Palaemonetes pugio Holthius) as an indicator of sediment quality in Florida coastal areas affected by point and nonpoint source contamination

Abstract

Grass shrimp are one of the more widely distributed estuarine benthic organisms along the Gulf of Mexico and Atlantic coasts, but they were used infrequently in contaminated sediment assessments. Early-life stages of caridean grass shrimp, Palaemonetes pugio (Holthius), were used in this baseline survey as indicators of sediment pore water quality for several Florida coastal areas affected by nonpoint and point sources of contamination. Static toxicity tests were conducted using 24 well culture plates assessing embryo and larval survival after 12 days exposure to pore water (interstitial water). Acute toxicity was observed in 28% of pore waters (15 of 53 samples) suggesting that sediment contamination was not widespread in the study area based on the response of this species. When toxicity was observed, grass shrimp pore water toxicity test was usually a more sensitive indicator of contamination than solid-phase tests conducted with the epibenthic invertebrate, Mysidopsis bahia. P. pugio embryos were more sensitive than larval form and response of different brood stocks usually were similar (P>0.05) when exposed to same pore waters. Based on all considerations, this early-life stage toxicity test shows promise being useful detecting pore water toxicity. This conclusion is based on availability of a test methodology which requires minimal space and effort, and the test species widespread geographical distribution. However, there are several remaining research needs, including the important issue of its sensitivity relative to that for other pore water test species as well as for species used in solid-phase toxicity tests. © 2000 John Wiley & Sons, Inc. Environ Toxicol 15: 234–242, 2000