Molecular biomarkers and toxic consequences of impact by organic pollution in aquatic organisms

Organic contaminants are readily bioaccumulated by aquatic organisms. Exposure to and toxic effects of contaminants can be measured in terms of the biochemical responses of the organisms (i.e. molecular biomarkers). The hepatic biotransformation enzyme cytochrome P4501A (CYP1A) in vertebrates is specifically induced by organic contaminants such as aromatic hydrocarbons, PCBs and dioxins, and is involved in chemical carcinogenesis via catalysis of the covalent binding of organic contaminants to DNA (DNA-adducts). Hepatic CYP1A induction has been used extensively and successfully as a biomarker of organic contaminant exposure in fish. Fewer but equally encouraging studies in fish have used hepatic bulky, hydrophobic DNA-adducts as biomarkers of organic contaminant damage. Much less is known of the situation in marine invertebrates, but a CYPlA-like enzyme with limited inducibility and some potential for biomarker application is indicated. Stimulation of reactive oxygen species (ROS) production is another potential mechanism of organic contaminant-mediated DNA and other damage in aquatic organisms. A combination of antioxidant (enzymes, scavengers) and pro-oxidant (oxidised DNA bases, lipid peroxidation) measurements may have potential as a biomarker of organic contaminant exposure (particularly those chemicals which do not induce CYP1A) and/or oxidative stress, but more studies are required. Both CYP1A- and ROS-mediated toxicity are indicated to result in higher order deleterious effects, including cancer and other aspects of animal fitness

Chesapeake Bay research initiatives at the Virginia Institute of Marine Science of the College of William and Mary : accomplishments for the 1986-1988 biennium

This biennium report for 1986-1988 presents the accomplishments achieved through the Commonwealth\u27s Chesapeake Bay Initiative for Research. In addition to those projects. the volume describes our progress on three additional initiatives funded by the General Assembly during the biennium: --Three-Dimensional Hydrodynamic Model --Wetlands Management --Estuarine Research Reserve System

2017 Texas Bays and Estuaries Meeting

Program for the 2017 Texas Bays and Estuaries Meeting held in Port Aransas, Texas, April 12-13, 2017.Coastal Bend Bays & Estuaries Program, Coastal Bend Bays Foundation, The University of Texas Marine Science Institute, Sea Grant Texas at Texas A&M University, Harte Research Institute for Gulf of Mexico Studies, and Mission Aransas National Estuarine Research Reserve.Marine Scienc

Metallothionein as an indicator of water quality: assessment of the bioavailability of cadmium, copper, mercury and zinc in aquatic animals at the cellular level

The study of metallothioneins (MTs) has greatly improved our understanding of body burdens, metal storage and detoxification in aquatic organisms subjected to contamination by the toxic heavy metals, Cd, Cu, Hg and Zn. These studies have shown that in certain organisms MT status can be used to assess impact of these metals at the cellular level and, whilst validation is currently limited to a few examples, this stress response may be linked to higher levels of organisation, thus indicating its potential for environmental quality assessment. Molluscs, such as Mytilus spp., and several commonly occurring teleost species, are the most promising of the indicator species tested. Natural variability of MT levels caused by the organism's size, condition, age, position in the sexual cycle, temperature and various stressors, can lead to difficulties in interpretation of field data as a definitive response-indicator of metal contamination unless a critical appraisal of these variables is available. From laboratory and field studies these data are almost complete for teleost fish. Whilst for molluscs much of this information is lacking, when suitable controls are utilised and MT measurements are combined with observations of metal partitioning, current studies indicate that they are nevertheless a powerful tool in the interpretation of impact, and may prove useful in water quality assessment

Division of Research and Economic Development Annual Report for FY2003

Annual report for the Division of Research and Economic Development of the University of Rhode Island for the year 2002-2003. Includes statistics of project proposals, expenditures, URI Foundation Awards, previous annual report summaries and awards received by individual academic and administrative departments

Relations of environmental contaminants, algal toxins, and diet with the reproductive success of American alligators on Florida Lakes

(113 page document

Fish biomarkers for environmental monitoring within the Water Framework Directive of the European Union

International audienceIn the past 25 years, numerous biomarkers have been developed with the objective to apply them for environmental biomonitoring. Recently, the Water Framework Directive (WFD) of the European Union specified monitoring programs required to assess the achievement of good chemical and ecological status for all water bodies by 2015. This article reviews the potential of biomarkers for ecotoxicological status assessment in WFD monitoring programs. For this purpose, we define the roles and the functions of biomarkers as biomonitoring tools. We also highlight the importance of defining a clear reference system to be confident that biomarkers represent a quantitative assessment of the effects of contaminants

The Rhode Island Marine Fisheries Council: Stewardship in Need of Goals and Objectives

In the State of Rhode Island, marine fisheries are managed through the Marine Fisheries Council, a citizen-based regulatory body of nine members from either the commercial or recreational fishing industries or experienced with the conservation and management of fisheries resources. To ostensibly help this group make informed decisions, biological data and scientific advice are provided by the State Division of Fish and Wildlife. This thesis examines the decision-making process of this Council. More specifically, it provides a case study of how this body has attempted to manage the State\u27s winter flounder stocks-an economically-valuable species which confines its life cycle mostly within state jurisdictional waters. Specific attention is paid to the manner in which scientific recommendations are incorporated into the Council\u27s decisions. Through carefully examining the minutes of monthly council meetings and annual stock assessments of the past ten years, a detailed chronology is presented of the stewardship of this species. Upon an analysis of this information, it is concluded that the Council has generally failed to take timely action to prevent the collapse of this fishery despite being forewarned of its demise, and even worse, has occasionally acted in direct contradiction to the Division\u27s findings and recommendations. Any attempt to revamp the Council\u27s decision-making process must provide a framework to better incorporate scientific advice. In recognition of this, this thesis starts with the premise that the fundamental purpose of any management system-public or private-is to work towards the realization and accomplishment of an organization\u27s goals (as specified through objectives). Through a careful review of the State\u27s environmental laws, it has been determined that a critical omission in Rhode Island\u27s marine fishers management program is the failure to clearly define its stewardship goals. As things currently stand, it is uncertain as to whether or not the Council is even supposed to prevent overfishing. Consequently, to the detriment of the State\u27s fishery resources, important decisions are routinely delayed or postponed indefinitely as various factions within the Council work towards dissimilar or diametrically opposite goals. Given this state of affairs, it is therefore not surprising that the Council has been largely ineffective in preventing the devastating collapse of the State\u27s winter flounder stocks despite an abundance of data forewarning of such an occurrence. To remedy this situation, it is recommended that the State unequivocally recognize that conservation, not allocation, is the foremost goal of its management program. Additionally, to help meet this goal, strategies should be developed to more consistently incorporate scientific data into the decision-making process. This study further recommends that the system of adaptive management, as specified under the Atlantic States Marine Fisheries Commission Striped Bass Management Plan, serve as a model to better include biological data in the decision-making process. An underlying precept of such a program is the need to constantly monitor stock conditions and make adjustments when necessary. In specific reference to the State\u27s winter flounder fishery, year class abundance as determined through the Division of Fish and Wildlife\u27s inshore trawl survey can survey as an early indicator to help reach more timely and effective management decisions. By adopting these recommendations the State can take a giant step towards ensuring that its marine fisheries remain a viable and sustainable resource for future generations to enjoy

Genetic alterations and cancer formation in a European flatfish at sites of different contamination burdens

Fish diseases are an indicator for marine ecosystem health since they provide a biological end-point of historical exposure to stressors. Liver cancer has been used to monitor the effects of exposure to anthropogenic pollution in flatfish for many years. The prevalence of liver cancer can exceed 20%. Despite the high prevalence and the opportunity of using flatfish to study environmentally induced cancer, the genetic and environmental factors driving tumor prevalence across sites are poorly understood. This study aims to define the link between genetic deterioration, liver disease progression, and anthropogenic contaminant exposures in the flatfish dab (Limanda limanda). We assessed genetic changes in a conserved cancer gene, Retinoblastoma (Rb), in association with histological diagnosis of normal, pretumor, and tumor pathologies in the livers of 165 fish from six sites in the North Sea and English Channel. The highest concentrations of metals (especially cadmium) and organic chemicals correlated with the presence of tumor pathology and with defined genetic profiles of the Rb gene, from these sites. Different Rb genetic profiles were found in liver tissue near each tumor phenotype, giving insight into the mechanistic molecular-level cause of the liver pathologies. Different Rb profiles were also found at sampling sites of differing contaminant burdens. Additionally, profiles indicated that histological “normal” fish from Dogger sampling locations possessed Rb profiles associated with pretumor disease. This study highlights an association between Rb and specific contaminants (especially cadmium) in the molecular etiology of dab liver tumorigenesis