Ecotoxicology of tropical marine ecosystems

Abstract

Abstract-The negative effects of chemical contaminants on tropical marine ecosystems are of increasing concern as human populations expand adjacent to these communities. Watershed streams and ground water carry a variety of chemicals from agricultural, industrial, and domestic activities, while winds and currents transport pollutants from atmospheric and oceanic sources to these coastal ecosystems. The implications of the limited information available on impacts of chemical stressors on mangrove forests, seagrass meadows, and coral reefs are discussed in the context of ecosystem management and ecological risk assessment. Three classes of pollutants have received attention: heavy metals, petroleum, and synthetic organics such as herbicides and pesticides. Heavy metals have been detected in all three ecosystems, causing physiological stress, reduced reproductive success, and outright mortality in associated invertebrates and fishes. Oil spills have been responsible for the destruction of entire coastal shallow-water communities, with recovery requiring years. Herbicides are particularly detrimental to mangroves and seagrasses and adversely affect the animal-algal symbioses in corals. Pesticides interfere with chemical cues responsible for key biological processes, including reproduction and recruitment of a variety of organisms. Information is lacking with regard to long-term recovery, indicator species, and biomarkers for tropical communities. Critical areas that are beginning to be addressed include the development of appropriate benchmarks for risk assessment, baseline monitoring criteria, and effective management strategies to protect tropical marine ecosystems in the face of mounting anthropogenic disturbance.

Effects of copper on development and survival rate of Paphia malabarica Chemnitz larvae under low saline condition

“…Ecotoxicological studies on clams have mostly been carried out on juveniles (Blidberg et al 1999;Elfwing et al 2002), where both copper (5 μg Cu2 + l −1 ) and low salinity have been shown to be sub lethal but negatively affect the physiological performance. However, copper concentrations much higher than this has been reported in reef waters (Peters et al 1997). It is very likely that copper in higher concentrations than investigated in this study may further increase the mortality in P. malabarica larvae.…”

“…Copper is an anthropogenic pollutant known to be harmful in aquatic environment and several sources such as coastal runoffs and anti-fouling paint affects non-target organisms (Peters et al 1997). Short neck clam, Paphia malabarica (Family: Veneridae) is widely distributed in the Vembanad Lake and Ashtamudi estuary, south west coast of India.…”

Florida seagrass habitat evaluation: A comparative survey for chemical quality

“…T. testudinum is considered an index or keystone species (Peters et al, 1997) and it and H. wrightii are common to the northwest and southern coasts of Florida (Iverson and Bittaker, 1986). After uprooting and removal of sediments, the plants were thoroughly rinsed at least twice on site with seawater to remove remaining inorganic particles.…”

“…The contribution of toxic chemicals to seagrass declines, the focus of this study, is largely unknown and has been investigated less frequently than the effects attributable to nutrient enrichment which is considered the primary cause of seagrass declines. However, some consider the impact of anthropogenic chemicals to be significant and worthy of increased investigation (Catsiki and Panayotidis, 1993;Short and Wyllie-Echeverria, 1996;Peters et al, 1997;SchlacherHoenlinger and Schlacher, 1998;Bester, 2000;Ralph, 2000).…”

A review of nickel toxicity to marine and estuarine tropical biota with particular reference to the South East Asian and Melanesian region

“…Anthropogenic activities including industry, urbanisation and land development (agriculture and mining) are having a major impact on tropical coasts through an increase in sedimentation and input of nutrients and chemical contaminants (Peters et al 1997). Tropical ecosystems are valuable and unique, with greater than 80% of the global ecological diversity found in these regions (Biodiversity Futures, JCU 2015).…”