Deep-sea caging of the musselMytilus galloprovincialis: Potential application in ecotoxicological studies

Abstract

We experimented with caging the Mediterranean mussel (Mytilus galloprovincialis) at various depths for 69 d to measure basic physiological parameters, histological response and bio-accumulation of contaminants in a deep-sea contaminated area. In preliminary experiments, we demonstrated, under artificial pressure conditions, the ability of mussels Mytilus galloprovincialis to tolerate rapid immersion (at a speed of up to 120 m min −1 ). In situ experiments were performed using submerged lines enabling mussels to be maintained at depths ranging of 40-1550 m with survival rates ranging from 80 to 38%, respectively. No significant differences in condition indexes were observed between treated and control specimens. However, histological observations demonstrated a clear reduction in thickness of the digestive epithelium with increasing depth exposure. By determining the contaminants in caged mussels, we found the following values for chromium accumulation: 27.4 µg g −1 dry weight at 580 m depth and 9.8 µg g −1 dry weight at 1550 m. Selected stations were located downstream of an industrial effluent at 420 m. The biological and environmental consequences of deep-sea contamination demonstrate the suitability of caged mussels for monitoring contaminant accumulation.

Oceanographic moorings as year-round laboratories for investigating growth performance and settlement dynamics in the Antarctic scallopAdamussium colbecki(E. A. Smith, 1902)

“…This “caging approach” can also be used in deep waters, with cages attached to lines moored with weights and stabilized by mid-water and surface buoys. For example, specimens of Mytilus galloprovincialis Lamarck, 1819 were successfully suspended in cages in 40–1,550 m ( Galgani et al, 2005 ). This species tolerated the initial high-speed immersion (120 m min −1 ), with 38% surviving to the end of the experiment ( Galgani et al, 2005 ).…”

“…For example, specimens of Mytilus galloprovincialis Lamarck, 1819 were successfully suspended in cages in 40–1,550 m ( Galgani et al, 2005 ). This species tolerated the initial high-speed immersion (120 m min −1 ), with 38% surviving to the end of the experiment ( Galgani et al, 2005 ). However, cages attached to surface lines and buoys represent a potential navigation hazard, especially when deployed to monitor deep-water discharges or oil fields, which are often located along commercial navigation routes.…”

Active biomonitoring in Greek coastal waters: Application of the integrated biomarker response index in relation to contaminant levels in caged mussels

“…The use of deployed mussels has proved useful for large geographical scale monitoring since mussels can be immersed at any location and/or depth. (Andral et al, 2004;Galgani et al, 2005;Galgani et al, 2011).…”

Peer Review #2 of "Oceanographic moorings as year-round laboratories for investigating growth performance and settlement dynamics in the Antarctic scallop Adamussium colbecki (E. A. Smith, 1902) (v0.2)"

“…It could be argued that even in our experiment water drag during mooring retrieval could have dislodged A. colbecki juveniles that had settled on the funnel surfaces. In fact, given the high speed that these structures reach during their retrieval (~120m min -1 ; Galgani et al 2005), there could be an 'opposite bias', in this case towards smaller sizes, i.e. those that due to their minute size experience less drag and water turbulence during mooring retrieval.…”

“…For example, specimens of Mytilus galloprovincialis Lamarck, 1819 were successfully suspended in cages in 40-1550m (Galgani et al, 2005). This species tolerated the initial high-speed immersion (120m min -1 ), with 38% surviving to the end of the experiment (Galgani et al, 2005).…”