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Chemical Pollution (chemical + pollution)
Selected AbstractsChemical pollution as a factor affecting the sea survival of Atlantic salmon, Salmo salar L.FISHERIES MANAGEMENT & ECOLOGY, Issue 6 2001D. Scott The catch of Atlantic salmon Salmo salar L., from ocean and coastal fisheries since 1960 is described and the decline starting in 1973 noted. This decline continued despite cessation of some fisheries, and evidence indicates a marine locus for the decline. Oceanic pollution has received little attention, and ozone loss has caused an increase in UV radiation reaching the surface of the North Atlantic. Direct effects of this increase include negative impacts on the food chain. Photo-induced toxicity of polycyclic aromatic hydrocarbons (PAH) is a possible effect, but concentrations of these compounds in oceanic waters are low. Chlorinated organic compounds are widely distributed in the North Atlantic, and their persistence, lipophilicity, bioaccumulation potential and toxicity represent a potential hazard to salmon. The suggested causes of decline are likely to be complementary rather than exclusive. [source] Pollution by conspecifics as a component of intraspecific competition among Aedes aegypti larvaeECOLOGICAL ENTOMOLOGY, Issue 1 2005Stéphanie Bédhomme Abstract., 1. The role of pollution by conspecifics in the costs associated with larval intraspecific competition was investigated for Aedes aegypti (Diptera: Culicidae). 2. The growth of larval A. aegypti mosquitoes reared in clean water and water in which another larva had previously grown was compared; this procedure eliminates interactions through food consumption between competitors and allows the effects of other processes to be expressed. 3. A cost of growing in polluted water was found: this cost was expressed as an increase in developmental time and a reduction of adult longevity when starved, starved adult dry weight, and wing length. 4. Contrary to previously reported results of an experiment allowing for competition for food, these costs were not expressed in a sex-specific manner and were independent of the sex of the polluter. 5. It was thus demonstrated that competition arises from both resource depletion and other effects that result in deterioration of the environment, with chemical pollution of the environment being the most likely cause. [source] Toxicity of nonylphenol on the cnidarian Hydra attenuata and environmental risk assessmentENVIRONMENTAL TOXICOLOGY, Issue 4 2006S. Pachura-Bouchet Abstract Alkylphenols and their derivatives, alkylphenol polyethoxylates (APEs), are synthetic chemicals of concern owing to their endocrine properties. Nonylphenol (NP) is a critical APE metabolite because of its recalcitrance to biodegradation, toxicity, and ability to bio-accumulate in aquatic organisms. Studies of NP effects in vertebrates demonstrated estrogenic disrupting properties in fish, birds, reptiles, and mammal cells in which NP displaces the natural estrogen from its receptor. Less is known on its toxicity toward invertebrates. Effects on reproduction have been reported, but toxicity on development has been poorly documented thus far. We investigated NP toxicity on survival and regeneration of the freshwater coelenterate Hydra attenuata. Hydra is known for its regenerative capacity and its sensitivity to chemical pollution. It has been used for over 20 years to screen for teratogenicity of chemicals (Johnson et al. (1982) Teratog Carcinog Mutagen 2:263,276). Our results showed that hydra appeared as one of the most sensitive species to acute and chronic toxicity of NP compared to several freshwater invertebrates. Regeneration was disrupted at NP concentrations lower than those affecting survival. Toxicity thresholds of NP for aquatic vertebrates and invertebrates are also reported and discussed in the context of environmental risk assessment and of water quality objectives recommended for surface waters in industrialized countries. NP levels have decreased during the last decade because of a voluntary agreement of surfactant producers and users. At present, concentrations of NP found in surface waters are far below 1 ,g/L in Europe, but can reach several ,g/L when wastewater treatment plant inefficiency occurs. © 2006 Wiley Periodicals, Inc. Environ Toxicol 21: 388,394, 2006. [source] Understanding ,hot-spot' problems in catchments: the need for scale-sensitive measures and mechanisms to secure effective solutions for river management and conservationAQUATIC CONSERVATION: MARINE AND FRESHWATER ECOSYSTEMS, Issue S1 2010Malcolm Newson Abstract 1.Regulatory progress in controlling point sources of chemical river pollution has progressively thrown the attention of public policy towards anthropogenic physical impacts, many of which are scaled to the catchment via the runoff/sediment system. At the same time, concern over diffuse chemical pollution has reinforced ,catchment consciousness': land-use and land-management planning and control must be considered to conserve or restore river ecosystem integrity. 2.The scientific, political and legal elements of this scale change are, however, complex and uncertain: ,myths' abound. Landscape-scale consideration of ,pressures' suggests an unequal distribution of regulatory costs and benefits and large uncertainties in the evidence from a ,land-use hydrology' and fluvial geomorphology perspective. 3.,Hydrological connectivity' brings together a number of knowledge themes about catchment spatial organization which facilitate applying mitigation measures to much smaller areas, helping to offset uncertainty and reduce costs. 4.Instead of blanket ,remedies', more practical use is needed of process evidence from hydrology and fluvial geomorphology; this tends to suggest that ,hot-spots' dominate risks and impacts of factors such as leaching, surface flow generation and silt entrainment. 5.Set in a realistic policy framework, from strategic spatial planning to grant-aided best practice, a ,catchment acupuncture' approach to measures provides a cost-effective contribution to improving ecological status and may also increase resilience to the impacts of climate change. 6.The European Union's Water Framework Directive (WFD) encourages ,joined-up thinking' on this issue but it remains to be seen whether spatial scales, structures and concepts already enshrined in the WFD and the relevant UK national policies for land use and nature conservation can be exploited to permit the much-needed practical uptake of this new riparianism. Copyright © 2010 John Wiley & Sons, Ltd. [source] | |||||||||||||