title: Nutrient content in macrophyta collected from southern Baltic Sea beaches in relation to eutrophication and biogas production.
abstract: One of the signs of eutrophication is the excessive growth of opportunistic macroalgae, a worldwide phenomenon also observed in the Baltic Sea. Mats of macroalgae may drift long distances and accumulate at the seashore, considerably decreasing the recreational value of beaches. The matter accumulating at the shore is treated usually as waste. However, it could be used, for example, as a resource for biogas production. The aim of this work was to verify the hypothesis that collecting of macrophyta accumulating on the beach and potential usage of this material for biogas production will decrease nutrient reserves in the sea to counteract eutrophication and the increase in greenhouse effects. Samples of macrophyta were collected in 2011 and 2012 and analysed for their C, N, and P contents, and degree of degradation (% Chl-a in the sum of chloropigments-a); the results were analysed statistically. The nutrient content was studied in macrophyta accumulating on the beach (Sopot, Gulf of Gdańsk, Poland) and for comparison, macrophyta collected from their habitats in less nutrient polluted area (off the Skåre coast, Trelleborg, Sweden). The nutrient content (N, P) in macrophyta depends primarily on their morphology and only secondarily on environmental nutrient pollution. Collecting the macrophyta biomass accumulating on beaches will not significantly change the eutrophication of the Baltic as a whole; any improvements in this respect are likely to be on a local scale only. Collecting macrophyta removes more nitrogen than phosphorous, so this would decrease the N/P ratio in seawater. This macrophyta biomass is a substantial reserve of renewable energy, which could be utilized with the appropriate technology for biomass collection/preservation and biofuel production as an additive to other carbon-rich biomasses. And the biofuel production should be evaluated not only from the standpoint of economic efficiency but also from the environmental point of view.
authors.affiliation: Marine Pollution Laboratory, Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55, 81-712 Sopot, Poland.
authors.forename: K
authors.initials: K
authors.lastname: Bucholc
authors.affiliation: Marine Pollution Laboratory, Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55, 81-712 Sopot, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Szymczak-Żyła
authors.affiliation: Marine Pollution Laboratory, Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55, 81-712 Sopot, Poland.
authors.forename: L
authors.initials: L
authors.lastname: Lubecki
authors.affiliation: University of Gdańsk, Department of Econometrics, ul. Armii Krajowej 101, 81-824 Sopot, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Zamojska
authors.affiliation: Marine Pollution Laboratory, Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55, 81-712 Sopot, Poland.
authors.forename: P
authors.initials: P
authors.lastname: Hapter
authors.affiliation: Environmental Department, Trelleborg Municipality, Algatan 13, 231 83 Trelleborg, Sweden.
authors.forename: E
authors.initials: E
authors.lastname: Tjernström
authors.affiliation: Marine Pollution Laboratory, Institute of Oceanology, Polish Academy of Sciences, ul. Powstańców Warszawy 55, 81-712 Sopot, Poland.
authors.forename: G
authors.initials: G
authors.lastname: Kowalewska
mesh_terms: D056804:Biofuels; D002244:Carbon / Q000032:analysis; D017753:Ecosystem; D004784:Environmental Monitoring; D005068:Eutrophication; D019015:Geologic Sediments / Q000737:chemistry; D009584:Nitrogen / Q000032:analysis*; D009792:Oceans and Seas; D010758:Phosphorus / Q000032:analysis*; D012623:Seawater / Q000737:chemistry*; D012624:Seaweed / Q000737:chemistry*
chemical_list: D056804:Biofuels; D010758:Phosphorus; D002244:Carbon; D009584:Nitrogen
keywords: Biomass; C/N; Eutrophication; Macroalgae; Nutrients; Southern Baltic beaches