Valve movement response of the mussel Mytilus galloprovincialis to metals (Cu, Hg, Cd and Zn) and phosphate industry effluents from Moroccan Atlantic coast

Abstract

Valve activity was measured in the Mediterranean mussel Mytilus galloprovincialis in response to sublethal concentrations of four metals (Hg, Cu, Zn and Cd) and two phosphate industry effluents from the Atlantic coast of Morocco. Valve movements were monitored using a proximity inductive sensor which could display all activity figures from full closure to wide opening of the shell valves. In a 1 h exposure experiments, all metals induced a decrease in the time of normal opening and the appearance of sequences of stress behaviour, including enhanced valve adductions and complete closure at high concentrations. Mercury (tested from 5 to 75 microg Hg l(-1)) was the most toxic to the valve activity, with a threshold effective concentration at 10 microg Hg l(-1) and full valve closure occurring at 50 microg Hg l(-1). Copper (15-150 microg Cu l(-1)) showed a toxic effect starting at threshold concentration of 20 microg Cu l(-1) and induced full valve closure at 150 microg Cu l(-1). Zinc (100-500 microg Zn l(-1)) was effective in reducing the time of normal opening (threshold concentration at 100 microg Zn I(-1)) but no complete closure was recorded in any of the tested concentrations. For cadmium (1000-5000 microg Cd l(-1)), the valve activity was insensitive for exposures under 2000 microg Cd l(-1). Results for the testing of several samplings of the phosphate industry effluents (Safi and Jorf Lasfar) showed that their toxicity varied over the time. The effluent of the Jorf Lasfar plant (2-9.4%) was, however, more toxic than that of Safi (1-25%). In the light of these results, the sensitivity of the valve activity of Mytilus galloprovincialis to pollutants and its usefulness for in situ monitoring of coastal pollution in Morocco are discussed.

The Application of Long-Lived Bivalve Sclerochronology in Environmental Baseline Monitoring

“…Several studies (e.g., Manley and Davenport, 1979;Kramer et al, 1989;Huebner and Pynnönen, 1992;Markich et al, 1996;Fdil et al, 2006;Schwartzmann et al, 2011) have confirmed that valve movement behavior can be used to sensitively quantify biological reactions in real-time (Figure 10) for assessing the toxicological effects of metal exposures. The observations found that upon exposure to toxic concentrations of metals, bivalves have the ability to reduce the exposure of their soft tissues for extended periods by closing their valve (Manley and Davenport, 1979;Kramer et al, 1989;Salánki and Balogh, 1989;Huebner and Pynnönen, 1992).…”

Marine Invertebrate Xenobiotic-Activated Nuclear Receptors: Their Application as Sensor Elements in High-Throughput Bioassays for Marine Bioactive Compounds

“…Interestingly, there is evidence that natural selection associated with bitter taste perception may have influenced the evolution of bitter taste receptor gene repertoire sizes in vertebrate genomes [ 20 , 21 , 22 ]. In the marine environment, avoidance of toxic/unpalatable prey by coral reef fish is well-documented [ 23 , 24 , 25 ], while bivalve molluscs can limit their exposure to toxic compounds using behavioral responses, such as shell closure and restriction of filtration rate [ 8 , 26 , 27 , 28 ]. Despite avoidance behaviors, the diet of many animals will inevitably contain bioactive, and potentially toxic, chemicals that need to be metabolized and eliminated from their bodies [ 29 , 30 , 31 , 32 , 33 ].…”

Valve movement response of the freshwater clam Corbicula fluminea following exposure to waterborne arsenic

“…The use of bivalve as a surrogate species in metal toxicity testing has supported the hypotheses that bivalve is a viable indicator of impairment in aquatic ecosystems (Tran et al 2003;Liao et al 2005;Ait Fdil et al 2006;Jou and Liao 2006). Newton and Cope (2007) pointed out that valve activity in freshwater bivalves has promise as a biological response to contaminants because it is relatively easy and inexpensive to monitor, mirroring responses at environmentally realistic concentrations.…”