Nematodes as sensitive indicators of change at dredged material disposal sites

Demonstration of the recovery of marine habitats from perturbation, or of t he effectiveness of protective measures, is dependent on the sensitivity of the target group in responding to change. This paper highlights the utilit y of the nematode component of the meiofauna as a tool for assessing distur bance from dredgings disposal. Transect surveys were conducted at three maj or dredged material disposal sites around the U.K. coast. Both gross effect s due to the direct impact of dredgings within the disposal sites and lesse r consequences arising from the transport of material away from the sires w ere evident with nematode community analyses. The same nematode species, Sa batieria pulchra group (both breviseta and punctata) and Daptonema tenuispi culum were found to dominate at all disposal sites, despite appreciable env ironmental differences between locations and variability in the nature of t he deposited dredged material. These studies have established that nematode communities can provide a sens itive indicator of change in response to dredged material disposal at a var iety of locations and have introduced a new monitoring tool for a practice that has a wide significance around the U.K. coast. The implications of the findings for the future monitoring of dredged material disposal and other waste inputs are discussed.