Zebra Mussel Farming in the Szczecin (Oder) Lagoon: Water-Quality Objectives and Cost-Effectiveness

Abstract

ABSTRACT. The Oder (Szczecin) Lagoon in the southern Baltic Sea is a heavily eutrophicated and degraded coastal ecosystem. We applied a systems approach framework to critically evaluate whether existing water-management measures achieve waterquality objectives for the river and lagoon systems. Our simulations reveal that the existing water-quality objectives for the river and the coastal waters are not sufficiently complementary. We suggest new water-quality threshold concentrations, which are in agreement with the European Water Framework Directive, and we calculate acceptable maximum nutrient loads for the Oder River. These calculations suggest that external nutrient-load reductions in the river basin alone seem insufficient to achieve good water quality in the lagoon. A comprehensive eutrophication management approach should also include internal nutrientretention and nutrient-removal measures in the lagoon. We focus on mussel farming, i.e., that of zebra mussels, Dreissena polymorpha, because they are efficient in removing nutrients and improving water transparency in the Oder Lagoon. For this purpose, the ecosystem model ERGOM is extended by a mussel module and an economic model. The economic model describes costs and benefits of mussel cultivation depending on the the farm size. We included additional potential sources of income such as water-quality tax or emission certificates. The simulations show that mussel farming in the lagoon is a suitable supportive measure and, at a load-reduction target of 50% or more, it is a cost-efficient measure for removing nutrients and for implementing the Baltic Sea Action Plan. In the Oder Lagoon, mussel farming could potentially remove nearly 1000 t of N (70 t of P)/year, or about 2% of the present N and P loads, and it would have the additional benefit of improving water transparency.

Removal of metallic elements from real wastewater using zebra mussel bio-filtration process

“…Therefore, in the exclusive case of D. polymorpha, it may be advantageous to exploit the potential of this bivalve, now almost present in all the Europe inland waters. This will not certainly be an easy process; in fact, being D. polymorpha considered a serious threat for the aquatic environment and a dangerous fouling agent of many industrial structures [46,47], is poorly perceived by the scientific community as a valid filtering factor, despite the presence of encouraging results in the depuration context [28,48,25,49,30,21]. In this regard, the construction of appropriate facilities for bio-filtration, followed by further downstream treatment aimed to contain bivalves accidentally leaked from the plant (such as the peracetic acid treatment and sand filters) would avoid the problem related to fouling.…”

The biofiltration process by the bivalve D. polymorpha for the removal of some pharmaceuticals and drugs of abuse from civil wastewaters

“…These authors also suggested that zebra mussels could be used as an on-site industrial bio-filter for water treatment. Finally, Schernewski et al, 2012 considered the opportunities of using zebra mussel cultivation in the Szczecin Lagoon (Germany) in order to improve water quality. Although these evidences based on the capability of zebra mussel to be exploited in the environmental management, no data are available until now on the possible use of this filter feeder as complementary treatment in WWTPs.…”

Development and Use of a Bioeconomic Model for Management of Mussel Fisheries under Different Nutrient Regimes in the Temperate Estuary of the Limfjord, Denmark

“…For example, Vermaat et al (2012) developed a spatial dynamic model that allowed farming decisions to be improved by taking into account present and future societal settings. Melaku Canu et al (2011) and Schernewski et al (2012) both demonstrated how SAF could be used to address sustainable bivalve farming and to reduce illegal harvesting. With the SAF, large-scale clam farming in the Venice Lagoon could be more sustainable and could achieve social and economic benefits for the local community while reducing negative environmental impacts and social conflicts (Melaku Canu et al 2011).…”