An estimate of the energy budget between cultivated biomass and the environment around a mussel-park in the northwest Mediterranean Sea

Grenz, C., Masse, H., Morchid, A. K., and Parache, A. 1991. An estimate of the energy budget between cultivated biomass and the environment around a musselpark in the northwest Mediterranean Sea. - ICES mar. Sei. Symp., 192: 63-67. This theoretical approach deals with a culture unit of Mytilus galloprovincialis in subtidal conditions (50 suspended ropes, 3 m long). The culture cycle lasted 480 days; 180 days from spat to seed size and 300 days from seed to market size. The mean hydrobiological conditions considered in this study were taken from monthly measurements collected over four years. The flow through the system was estimated as 30 x 106m 3, carrying 331 t of particulate matter containing 1201 of particulate organic matter, equivalent to an energy of 336 x 109 J. The retention by mussels was estimated at 7 7 1 of particulate matter containing 2 8 1 of organic material, equivalent to 78 x 109 J. The culture unit produced 10.791 of biodeposits containing 1.76 1 of organic matter, equivalent to 10 x lO’ J; 5.421 of mussels containing 276 kg of dry tissues, equivalent to 6 x 101 ' J and 130 kg of gametes (dry weight) accounting for an energy of 3 x 10< J J. These results are discussed at the level of the whole suspended culture system of an estimate of carrying capacities.