Effects of Bivalve Aquaculture on the Environment and Their Possible Mitigation: A Review

Abstract

The use of high protein microalgae obtained by increasing the content of nitrate in the culture medium is recommended to improve the performance of broodstock, larvae and juveniles in bivalve hatchery. However, the effect of these concentrations of nitrate on the composition of fatty acids in microalgae is not known and it is relevant to assess possible changes in its nutritional properties for filtering bivalves. The results of nitrate increase in Isochrysis aff. galbana (clone T-Iso) showed that in the high nitrate medium, T-Iso is high in protein and carbohydrate and low in ash, and also exhibits higher values of polyunsaturated fatty acids (PUFA), especially n-3PUFA. The best culture medium for Tetraselmis suecica would also be the one high in nitrate because of it is high in protein and lipid and low in ash, although the best values PUFA were observed in the standard nitrate medium. T-Iso was characterized by its tendency to increase the level of n-3 PUFA with the increase of nitrate, while T.suecica was characterized by no effect of nitrate on the contents of n-3 PUFA of the cells nor a PUFA pattern related to the increase or decrease of nitrate.

Interactions and management for the future of marine aquaculture and capture fisheries

“…For example, incorporating larval dispersal models into the spatial planning process could help minimize adverse effects. Similarly, it is well established that filter feeding by bivalves alters and may even control phytoplankton biomass in shallow waters (Alpine & Cloern, ; Asmus & Asmus, ; Gallardi, ). The degree to which feeding by farmed bivalves inhibits wild suspension feeders (including commercially targeted species), and how this effect scales with farm size, is a critical remaining knowledge gap.…”

“…Where water quality is poor, unfed species such as shellfish and seaweeds can help reduce coastal eutrophication through filter feeding and nutrient uptake (Gren, Lindahl, & Lindqvist, ). While unfed mariculture is generally lauded for its win–win benefits of seafood production and water filtration (Rose, Bricker, Tedesco, & Wikfors, ; Shumway et al., ), risks do exist (Gallardi, ), particularly from large‐scale, high‐intensity systems (Liu & Su, ). For example, seaweed production can affect fish landings through decreased phytoplankton net primary productivity (Préat et al., ).…”

Past, Present, and Future: Performance of Two Bivalve Species Under Changing Environmental Conditions

“…Top-down control via filter-feeding may significantly curtail phytoplankton populations (Cranford et al, 2003;Newell, 2004;Forsberg et al, 2017) potentially affecting bivalve performance itself (Dame and Prins, 1998;Bacher et al, 2003;Strohmeier et al, 2005), but also impacting other filter-feeders and grazers (Kluger et al, 2017). Filtration activity can also play an important role in regulating water quality and depth of light penetration (Gallardi, 2014;Guyondet et al, 2015;Petersen et al, 2016). Bivalves can also impose bottom-up control on plankton communities by altering fluxes of nutrients (Menge, 1992;Newell, 2004).…”

The use of shellfish for eutrophication control

“…Fahnenstiel et al 1995a, b;Caraco et al 2006;Weber et al 2010;Pires et al 2010). It is thus obvious to suggest active use of bivalve cultures to mitigate effects of excess run-off of nutrients from land (Officer et al 1982;Haamer 1996;Newell 2004;Lindahl et al 2005;Cerco and Noel 2007;Bricker et al 2014;Gallardi 2014;Kellogg et al 2014;Petersen et al 2014). Actual implementation of mussels to remove nutrients from marine waters is sparse, and to our knowledge Lysekil municipality, Sweden was in 2004 the first to use mussels to compensate for discharge of nitrogen from a sewage treatment plant during a 6-year trial period (Lindahl and Kollberg 2009;Lindahl and Söderqvist 2011).…”