Invertebrate bioassays with North Sea water samples. I. Structural effects on embryos and larvae of serpulids, oysters and sea urchins

Abstract

Structural effects of bottom and surface water samples from two dumping grounds in the inner German Bight on the development of three meroplanktonic organisms (Pomatoceros triqueter: Polychaeta, Psammechinus miliaris: Echinodermata and Crassostrea gigas, Mollusca) were investigated. The titaniumdioxide dumping site was sampled immediately after dumping (within the visible waste trail 1 km behind the vessel), and 10 h after dumping. Samples were taken in the sewage sludge deposition area in the intervals between the usual dumping activities, regardless of the exact dumping schedule. The preserved bioassay test organisms were inspected microscopically to count percentages of "normal" larval hatch in test water samples, reference water samples and laboratory aged control water samples (5 to 10 replicates). The relative water quality at various dumping sites was expressed in terms of "net risk--values (Woelke, 1972) compared to hatching rates observed in the controls. Larval development of P. triqueter was significantly suppressed (up to -22 % "net risk") in trail water of the titanium dioxide dump site while the development of sea urchin larvae was still affected in the 10 h surface samples. Hatching of all test organisms in bottom-water samples from the centre of the sewage sludge dump site was affected to different degrees when compared to reference areas about 4 km north or 6 km northwest of the dumping area. The general usefulness of standardized bioassay procedures in pollution monitoring programmes is discussed. The results presented here call for further verification to minimize experimental background variability and to enlarge the catalogue of suitable effects criteria. INTRODUCTIO~

Assessment of sediment contamination by spermiotoxicity and embryotoxicity bioassays with sea urchins (Paracentrotus lividus) and oysters (Crassostrea gigas)

“…Crassostrea gigas has been introduced throughout the world for aquaculture purposes, and its economic importance, widespread availability, and generalized use in bioassays is greater than that of any sea urchin species [4]. Finally, a factor of importance in routine biomonitoring studies, where numerous assessments may be needed as quickly as possible, is the time required for the test and its evaluation: The oyster embryo bioassay is conducted in 24 h (vs 48 h for sea urchins), and the determination of abnormalities is easier and more rapid in oysters [18,21].…”

“…The embryos were incubated for 48 h at 21 ± 1°C ( P. lividus ) or 24 h at 24 ± 1°C ( C. gigas ). After the incubation period, 100 μl of 40% buffered formalin were added to each vial, and the percentages of abnormalities were determined according to the criteria in His et al [21] and Klöckner et al [18] by direct observation of 100 randomly selected individuals per vial under an inverted microscope.…”

“…The utilization of bivalve larvae in assessments of marine pollution is subject of a recent review [4]. A few investigations have compared the sensitivity of bivalve and sea urchin embryos and larvae [17,18], but there is only a single study with contaminated sediments [17].…”

Gonadal lesions of female sea urchin (Psammechinus miliaris) after exposure to the polycyclic aromatic hydrocarbon phenanthrene

“…Psammechinus miliaris is a common echinoid found at depths of up to 100 m in the Atlantic from Scandinavia to the Azores including the North Sea and the Baltic Sea (Boschma et al, 1932;Campbell, 1977). This species has been used as a test organism in fertilisation and embryo development assays (Klöckner et al, 1985;Caldwell et al, 2002Caldwell et al, , 2004. In the past years, P. miliaris has gained interest as promising candidate for aquaculture especially in polyculture with the Atlantic salmon (Kelly et al, 1998).…”

“…Sea urchin gametes and embryos are widely used for evaluating biological effects of contaminants in marine environments (Greenwood, 1980;Kobayashi, 1980;Hose, 1985;Klöckner et al, 1985;USEPA, 1993). However, the underlying mechanisms resulting in reduced reproductive success of adult marine invertebrates and of sea urchins, in particular, are hardly investigated (Au et al, 2001a,b).…”