Enhanced Growth Rates of the Mediterranean Mussel in a Coastal Lagoon Driven by Groundwater Inflow

Abstract

Groundwater discharge is today recognized as an important pathway for freshwater, nutrients and other dissolved chemical substances to coastal systems. While its effect on supporting primary production in coastal ecosystems is increasingly recognized, its impact on growth of animals at higher trophic level (primary and secondary consumers) is less well documented. Here, we investigate the impact of groundwater discharge on the growth of the Mediterranean mussel (Mytilus galloprovincialis) in a coastal lagoon. Growth rates and condition index (tissue weight/shell weight) of mussels growing at groundwater-exposed sites and at a control site in Salses-Leucate lagoon (France) were measured. The mussels in this lagoon produce circadian (daily rhythm) growth increments in their shell, as opposed to semi-diurnal increments in tidally influenced systems. Mussels from groundwater-influenced sites have higher growth rate and condition index compared to those from a control site. Importantly, growth rates from groundwater-influenced sites are amongst the highest rates reported for the Mediterranean region (41 ± 9 µm d −1 ). The higher growth rates at groundwaterinfluenced sites are likely a consequence of both the higher winter temperatures of lagoon water as a result of groundwater discharging with relatively constant temperatures, and the groundwater-driven nutrient supply that increase the food availability to support mussel growth. Overall, this study demonstrates that groundwater discharge to Mediterranean lagoons provides favorable environmental conditions for fast growth of mussels of high commercial-quality.

Microencapsulated diets using thraustochytrids and macroalgae side streams for nursery rearing of Mytilus galloprovincialis spat

“…field may have contributed to a different periodicity of tissue growth and shell accretion between the lab and field populations (Andrisoa et al, 2019;Karayücel et al, 2010;Okaniwa et al, 2010;Orban et al, 2002). Similar values of growth rates and condition index to those we recorded at Mutriku have been reported for M. galloprovincialis mussels grown in other coastal lagoons (Andrisoa et al, 2019).…”

The influence of natural vs anthropogenic factors on trace metal(loid) levels in the Mussel Watch programme: Two decades of monitoring in the Spanish Mediterranean sea

“…The net flow, resulting from the inputs to and outputs from the Mediterranean Sea was calculated and integrated for the two years previous to the mussels sampling date (around 15 May). Andrisoa et al (2019) showed that the age of 3-4 cm mussels in this area may be around 2 years.…”

Step in Time: Biomineralisation of Bivalve’s Shell

“…The 60 days pattern observed in the shell of the deep species Bathymodiolus thermophilus might reflect current velocity changes in the hydrothermal habitats induced by ridge-crest jets (Nedoncelle et al, 2013;Nedoncelle et al, 2015). The five and three days patterns of the mussel M. galloprovincialis observed in the Mediterranean lagoon of Salses-Leucate (France) could be due to regular wind events occurring in this area (Andrisoa et al, 2019).The two-day periodicity recorded in the shell of the tropical Comptopallium radula could be synchronised with temperature or sea level pressure as both of these parameters display two-day cycles (Thébault et al, 2006). Although a synchronism with environmental variables appears, the precise origin of growth increments is still discussed in literature.…”