Emerging and persistent impacts on Marine Organisms: Detection methods and action mechanisms

Editorial Marine environmental quality and biodiversity The fourth Bilateral Seminar Italy-Japan on "Physical and Chemical Impacts on Marine Organisms - For Conservation of Biodiversity and Sustainability" took place on October 25-26 2010 at Aichi Prefectural University, Nagakute, Japan, and it was quite timely regarding the international recognition of the endangered environment and the worldwide concern for the conservation of biodiversity. The seminar was divided into 5 sections: "Global warming, ocean acidification and emerging pollutants", "Xenobiotic receptors and biomarkers of exposure", "From marine biology to applied biotechnology", "Toxicology of nanoparticles on marine organisms" and "Molecular approaches to marine ecotoxicology". This special issue contains selected papers from presentations given by acknowledged experts and related to: i) actual and changing environmental conditions for marine organisms, ii) action mechanisms of pollutants and harmful chemicals, iii) validation of biological indicators of environmental hazard, iv) use of model organisms for the analysis of pollutants effects, v) introduction of new materials and methods to detect and decrease the impact of pollutants on the marine environment. On behalf of all participants of the seminar, VM and YY hope that the reported results will give a contribution to better understanding the deterioration of the marine environment, and new stimuli to investigate these matters. The first four articles are mini-reviews on hot topics and emerging hazards which have inspired concern in the scientific community. Among these, the manuscript "Global change ecotoxicology: identification of early life history bottlenecks in marine invertebrates, variable species responses and variable experimental approaches" (by Byrne) offers a timely review of methodological issues in global change ecotoxicology of fertilization, embryo and larval developments in marine invertebrates with planktonic stages. Even though the subject is relatively new, the updated review on the impacts of both ocean acidification and rising of seawater temperature is an important milestone in this field of research. The mini-review "Bivalve molluscs as a unique target group for nanoparticle toxicity" (by Canesi et al.) summarizes the effects of nanoparticles in bivalves and the utility of these organisms to assess their potential impact. The authors present the state of the art in this emerging field, elucidating some mechanisms of response exhibited by mussels toward a few types of nanoparticles. The current state of knowledge on the responses of copepods to a range of stress factors is reviewed in "Gene expression patterns and stress response in marine copepods" (by Lauritano et al.), with a particular emphasis on the molecular level. The last mini-review "Toxic effects of engineered nanoparticles in the marine environment: Model organisms and molecular approaches" (by Matranga and Corsi) provides the first valuable collection of papers and main findings specifically addressing the effects of engineered nanoparticles (ENPs) on marine organisms. The authors stressed the importance of monitoring noxious effects of emerging and often neglected pollutants, and the need to fully assess the effects of ENPs in the marine environment. In the manuscript "Algal symbiont type affects gene expression in juveniles of the coral Acropora tenuis exposed to thermal stress" (by Yuyama et al.), it is shown that expressions of stress related genes in the host coral are significantly affected by the symbiont types, with different clades resulting in different levels of gene expression. This is an important contribution toward the understanding of coral bleaching, providing a significant advancement from the application of molecular biology to this field. The paper "Modulation of CYP1A and genotoxic effects in European seabass (Dicentrarchus labrax) exposed to weathered oil: a mesocosm study" (by Della Torre et al.), represents an interesting report on the application of mesocosm studies in evaluating the medium-term toxicity of weathered oil using fish as model organism. This investigation provides an additional perspective for addressing the oil spill behavior and effects in the marine environment. The papers "Specific accumulation of organotin compounds in tissues of the rock shell, Thais clavigera," and "Vas deferens and penis development in the imposex-exhibiting female rock shell, T. clavigera" (by Horiguchi et al.), give a detailed description of the partition of TBT, TPT compounds and their metabolites in various tissues of T. clavigera, elucidating the developmental process of imposex and the vas deferens sequence (VDS) index for this gastropod. The presented findings elucidate organotin metabolism in T. clavigera, providing with the VDS index a useful tool for biomonitoring of organotin contamination along the coasts of western Pacific. Lindane toxicity in fish is presented in "Lindane toxicity: histopathological, pathological and behavioral changes in Etroplus maculates (Bloch, 1795)" (by Nandan and Joseph), an actual and appropriate issue for developing countries where Lindane is still one of the most commonly employed agricultural insecticides in India and, due to its persistence, a widely distributed aquatic contaminant. The effects of organic enrichment and hypoxia on macrobenthic communities are described in "Disturbance of benthic macrofauna in relation to hypoxia and organic enrichment in a eutrophic coastal bay" (by Kodama et al.). The reported findings, despite of major concern for the Tokyo Bay, are of general interest for environmental scientists and management policy makers, since similar environmental problems of benthic degradation are increasingly reported in coastal areas worldwide. The paper "Settlement of the alien mollusc Brachidontes pharaonis in a Mediterranean industrial plant: Bioassays for antifouling treatment optimization and management" (by Garaventa et al.) is aimed at assessing the efficacy and environmental compatibility of three new biocides as antifouling compounds against invading alien species in the Mediterranean; the study explores new ways for the mitigation of the damage inflicted to both ecosystems and human economy by these species. The manuscript "Toxic effects of harmful benthic dinoflagellate Ostreopsis ovata on invertebrate and vertebrate marine organisms" (by Faimali et al.) describes the harmful effects of palytoxin-like compounds produced by the dinoflagellate O. ovata to a variety of marine organisms. Since the ecological risk of such toxic blooms is becoming of greater concern in the recent years, this investigation adds important information for monitoring the presence and consequences of these microalgae to the marine ecosystem. The article "The mechanically adaptive connective tissue of echinoderms: its potential for bioinnovation in applied technology and ecology" (by Barbaglio et al.) provides an overview enriched with original new data on the peculiarities of mutable collagen tissue (MCT) from echinoderms and its potential application in biotechnology and as biomaterial model for ecotoxicological studies. The effects of emerging pollutants, such as metallic nanoparticles, are reported in "Toxicity of metal oxide nanoparticles in immune cells of the sea urchin" (by Falugi et al.). This is the first study on the effects of nanoparticles on immune cells of the sea urchin, and the evidence that such cells can serve as detoxifying sites opens new areas of research, contributing to elucidate the toxic impact of nanoparticles in the marine environment. Cellular response of invertebrate immune cells are described also in "Long-term environmental exposure to metals (Cu, Cd, Pb, Zn) activates the immune cell stress response in the common European sea star (Asterias rubens)" (by Matranga et al.). This work validates an interesting and novel approach to evaluate the effects of long term exposure to metals on the common sea star A. rubens, showing a clear relationship between pollution levels and HSC70 expression in coelomocytes, and thus further supporting the role of echinoderms as bioindicators. The last paper of this special issue is "Isolation and characterization of a SEPALLATA-like gene, ZjMADS1, from marine angiosperm Zostera japonica" (by Kakinuma et al.). The authors present the molecular characterization of the gene involved in the specification of floral organs in the seagrass Z. japonica. Since Zostera meadows have drastically decreased along the entire coast line of Japan, this paper is significant to conservation and restoration of such seagrasses ecosystems. Lastly, Guest Editors (VM and YY) express their cordial appreciation to all the reviewers who read the manuscripts, giving appropriate and accurate comments. Their collaboration, in spite of being busy for their own scientific work, has been fundamental for the publication of this special issue. Appreciation is expressed to the Handling Editor (FR) for constant support and collaboration during the whole SI project; his positive attitude and open-minded approach has been instrumental for the success of the initiative. Finally, it is never forgotten to acknowledge that the fourth Bilateral Seminar Italy-Japan would have not been possible without sponsorships. On behalf of all participants, we express here our deep gratitude to the Japan Society for Promotion of Science, the Consiglio Nazionale delle Ricerche, the Italian Embassy in Tokyo, the Aichi Prefectural University, the Daiko Foundation, and the high patronage received by UNESCO in the frame of the COP10 year.