Decrease of the carrying capacity of the Oosterschelde estuary (SW Delta, NL) for bivalve filter feeders due to overgrazing?

The feasibility of offshore aquaculture and its potential for multi-use in the North Sea

“…30 million kg annually in the years (CBS 2014. There are indications that carrying capacity and environmental pressures may hinder further production growth in the traditional culture areas (Smaal et al 2013), and there is increasing concern about the sustainability of traditional methods for mussel seed fishing from natural beds (Smaal 2002;Walter and Liebezeit 2003). Although these concerns seem an incentive to expand both seed collection and/or production of market size mussels towards offshore areas, commercial interest is currently limited.…”

“…(7) Production is based on natural spat fall and growth estimates (Steenbergen et al 2005, Kamermans et al in prep). (8) Mussel production outside study area stays constant Aquacult Int (2016) 24:735-756 745 appears to be an incentive to search for new cultivation areas as environmental pressure hinders further production growth in the traditional culture areas (Smaal et al 2013), while at the same time market predictions indicate that higher volumes can be realized (BluePort 2012). Nonetheless, this has not yet ignited commercial interest, and to date, industry participation in offshore areas is limited.…”

Passende Beoordeling ten behoeve van experimentele oesterkweek in het litoraal van de Kom van de Oosterschelde

“…Dit correspondeert met een geschatte bestandsgrootte van 10 mln kg (Smaal et al, 2013) Door twee recentelijk opgetreden bedreigingen zijn de oesterkwekers op zoek naar nieuwe kweekmethoden (NOV, 2016;Smaal et al, 2016). Inmiddels zijn er aanwijzingen voor toenemende resistentie bij de oesters in Frankrijk Kamermans et al, 2013;Dundon et al, 2011).…”

Production efficiency of mussel bottom culture

“…The barrier is closed only during extreme storm floods, hence the tidal characteristics have been maintained despite current velocities and nutrient inflow decreasing and water residence time and light transparency increasing. Annual primary production was maintained for the first 10 years but lower values have been estimated recently (Smaal et al 2013b). …”

“…Chlorophyll-a concentrations typically fluctuated between 2 and 5 mg m -3 and TPM concentrations ranged from 4 to 10 mg l -1 (Smaal et al 2013b). Throughout history the area has been known for the culture of mussels and flat oysters; the latter has been replaced by culture of the Pacific oysters (Crassostrea gigas).…”