Designing an integrated environmental monitoring plan for land-based marine fish farms located at exposed and hard bottom coastal areas.

The increase in aquaculture activities in the last few decades has not been accompanied by a corresponding increase in environmental controls and regulations. In this context, the application of environmental monitoring plans (EMPs) has become necessary to assess the environmental impact associated with fish farming wastes. The objective of this review paper is to evaluate the suitability of experimental and analytical procedures as monitoring tools for inclusion in EMPs for intensive land-based marine fish farms (LBMFFs). The strong hydrodynamics and, in particular, the lack of sediment on the rocky coasts where LBMFFs are usually located, greatly limit the monitoring tools that can be used. We propose EMPs that employ a weight-of-evidence approach to evaluate: contamination, trophic and toxic effects, and ecological integrity. Laboratory tests, in situ bioassays and field surveys of local species are presented as key tools for assessing the impact of LBMFFs on ecosystems. The δ(15)N signal along a spatial gradient is proposed for evaluating exposure to contaminants. Trophic effects can be determined by growth of transplanted macro- and microalgae. Toxic effects can be evaluated by responses at different levels of biological organization, including biochemical and histological changes, physiological alterations and survival, in species from different trophic levels. Fouling tests and analysis of community structures are recommended for assessing ecological integrity. This review contributes to the development of environmental controls for intensive LBMFFs, and for other activities that discharge wastewater to rocky shores.

Identification of specific malformations of sea urchin larvae for toxicity assessment: application to marine pisciculture effluents.

Standard toxicity screening tests are useful tools in the management of impacted coastal ecosystems. To our knowledge, this is the first time that the sea urchin embryo development test has been used to evaluate the potential impact of effluents from land-based aquaculture farms in coastal areas. The toxicity of effluents from 8 land-based turbot farms was determined by calculating the percentage of abnormal larvae, according to two criteria: (a) standard, considering as normal pyramid-shaped larvae with differentiated components, and (b) skeletal, a new criterion that considers detailed skeletal characteristics. The skeletal criterion appeared to be more sensitive and enabled calculation of effective concentrations EC(5), EC(10), EC(20) and EC(50), unlike the classical criterion. Inclusion of the skeleton criterion in the sea urchin embryo development test may be useful for categorizing the relatively low toxicity of discharges from land-based marine fish farms. Further studies are encouraged to establish any causative relationships between pollutants and specific larval deformities.

Acute toxicity measured in the amphipod Ampelisca brevicornis after exposure to contaminated sediments from Spanish littoral.

Sediment toxicity of different areas of Spanish littoral was evaluated using an internationally recommended 10 day acute toxicity test with the amphipod Ampelisca brevicornis. Sediment samples from Santander Bay (N Spain), Las Palmas of Gran Canaria (SW Spain), Algeciras Bay (S Spain) and Ría of Huelva (SW Spain) were collected and organic carbon, fines, metals Zn, Cd, Pb, Cu, Ni, Co and Hg, PAHs and PCBs were analyzed for their characterization. Significant toxic effects compared with control site (P < 0.05) were observed after exposure to the sediments from Las Palmas of Gran Canaria port, from 83.3% of the sites studied in Algeciras Bay and from Ría of Huelva. These effects were associated (P < 0.05) with PCBs and metals Zn, Cd, Pb and Cu in Ría of Huelva and to Ni and Co in the rest of sites. Chemical measurements were compared with international sediment quality guidelines and site-specific guidelines were derived.