Effects of stress on the immune system of fish

The effects of stress on the immune system of various fish species including dab Limanda limanda, flounder Platichthys flesus, sea bass Dicentrarchus labrax and gobies Zosterisessor ophiocephalus, were investigated from laboratory and field experiments, using various assays to measure immunocompetence, correlated with histological and ultrastructural observations. Modulation of the immune system was demonstrated at tissue, cellular and biochemical levels following exposure to various stressors. The spleen somatic index was depressed in dab stressed in the laboratory and gobies collected from polluted sites in the Venice Lagoon. Differential blood cell counts consistently showed an increase in phagocytes and decrease in thrombocytes in fish exposed to various stressors. Phagocytic activity from spleen and kidney adherent cells was stimulated in dab stressed by transportation but depressed in fish exposed to chemical pollutants. Respiratory burst activity in phagocytic cells was also stimulated in stressed dab but depressed in sea bass exposed to cadmium. The results are discussed in relation to current concepts on stress in fish and the regulation of the immune system

Reconstructing Reefs: Qualitative Methods and the Environmental History of the Great Barrier Reef, Australia

Given recent concerns about the degradation of coral reef\ud ecosystems world-wide, we investigated the environmental history of the Great Barrier Reef of Australia using qualitative methods. In particular,we used archival and oral history sources to reconstruct changes in coral reefs, islands and marine wildlife species for the period 1860–1970 and we evaluated the potential of qualitative methods to inform marine environmental research. Here, we argue that qualitative research offers a valuable means of reconstructing environmental changes, their drivers and their historical contexts. However, we found that qualitative methods also had important limitations. Hence we identify strategies for addressing those challenges and we suggest criteria for ensuring the accuracy and rigor of qualitative sources in marine environmental research. Overall, we argue that qualitative methods offer distinctive\ud insights into the environmental history of the Great Barrier Reef, and that qualitative reconstructions can act as important triggers for conservation of marine ecosystems