Beach-cast as biofertiliser in the Baltic Sea region-potential limitations due to cadmium-content

• Macroalgal mass blooms and accumulating beach-cast are increasing problems in many coastal areas. However, beach-cast is also a potentially valuable marine bioresource, e.g. as a biofertiliser in coastal agriculture. One limiting factor in use of beach-cast as a fertiliser is uncertainty regarding the cadmium (Cd) concentration depending on beach-cast composition and location. In this study, chemical analyses were performed on beach-cast from Burgsviken Bay off Gotland, in the Baltic Sea. The results revealed large variations in cadmium concentration depending on sampling location and beach-cast composition, with levels ranging between 0.13 and 2.2 mg Cd/kg dry matter (DM). Of 15 beach-cast samples analysed, one had a cadmium content above the Swedish statutory limit for sewage sludge biofertiliser (2 mg Cd/kg DM) and four had values above the limit suggested by the Swedish Environmental Protection Agency for 2030 (0.8 mg/kg DM). Species-specific analysis revealed that eelgrass (Zostera marina) contained significantly higher cadmium concentrations than filamentous red algae species (Ceramium and Polysiphonia spp.). Avoiding eelgrass-rich beach-cast by seasonal timing of harvesting and monitoring differences in cadmium concentrations between harvesting sites could thus facilitate use of beach-cast as biofertiliser. © 2018

Ämnesord

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Naturresursteknik -- Miljöledning (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Environmental Engineering -- Environmental Management (hsv//eng)

Nyckelord

Beach-cast management

Biofertiliser

Cadmium-levels

Macro algae

Marine bioresources

Seagrass

Species composition

Zostera marina

Algae

Cadmium

Chemical analysis

Environmental Protection Agency

Fertilizers

Sewage sludge

Cadmium levels

Seagrasses

Beaches

Ceramium

Polysiphonia

Rhodophyta

Beach-cast management

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)