Shipborne nutrient dynamics and impact on the eutrophication in the Baltic Sea
Journal article, 2019

The Baltic Sea is a severely eutrophicated sea-area where intense shipping as an additional nutrient source is a potential contributor to changes in the ecosystem. The impact of the two most important shipborne nutrients, nitrogen and phosphorus, on the overall nutrient-phytoplankton-oxygen dynamics in the Baltic Sea was determined by using the coupled physical and biogeochemical model system General Estuarine Transport Model–Ecological Regional Ocean Model (GETM-ERGOM) in a cascade with the Ship Traffic Emission Assessment Model (STEAM) and the Community Multiscale Air Quality (CMAQ) model. We compared two nutrient scenarios in the Baltic Sea: with (SHIP) and without nutrient input from ships (NOSHIP). The model uses the combined nutrient input from shipping-related waste streams and atmospheric depositions originating from the ship emission and calculates the effect of excess nutrients on the overall biogeochemical cycle, primary production, detritus formation and nutrient flows. The shipping contribution is about 0.3% of the total phosphorus and 1.25–3.3% of the total nitrogen input to the Baltic Sea, but their impact to the different biogeochemical variables is up to 10%. Excess nitrogen entering the N-limited system of the Baltic Sea slightly alters certain pathways: cyanobacteria growth is compromised due to extra nitrogen available for other functional groups while the biomass of diatoms and especially flagellates increases due to the excess of the limiting nutrient. In terms of the Baltic Sea ecosystem functioning, continuous input of ship-borne nitrogen is compensated by steady decrease of nitrogen fixation and increase of denitrification, which results in stationary level of total nitrogen content in the water. Ship-borne phosphorus input results in a decrease of phosphate content in the water and increase of phosphorus binding to sediments. Oxygen content in the water decreases, but reaches stationary state eventually.

nitrogen cycle

nutrients

shipping

Modelling

The Baltic Sea

Author

Urmas Raudsepp

Tallinn University of Technology (TalTech)

Ilja Maljutenko

Tallinn University of Technology (TalTech)

Mariliis Kouts

Tallinn University of Technology (TalTech)

Lena Granhag

Chalmers, Mechanics and Maritime Sciences, Maritime Studies, Maritime Environmental Sciences

Magda Wilewska-Bien

Chalmers, Mechanics and Maritime Sciences, Maritime Studies, Maritime Environmental Sciences

Ida-Maja Hassellöv

Chalmers, Mechanics and Maritime Sciences, Maritime Studies, Maritime Environmental Sciences

Martin Eriksson

Chalmers, Mechanics and Maritime Sciences, Maritime Studies, Maritime Environmental Sciences

GMV

Lasse Johansson

Finnish Meteorological Institute (FMI)

Jukka-Pekka Jalkanen

Finnish Meteorological Institute (FMI)

Matthias Karl

Helmholtz-Zentrum Geesthacht - Zentrum für Material- und Küstenforschung GmbH

Volker Matthias

Helmholtz-Zentrum Geesthacht - Zentrum für Material- und Küstenforschung GmbH

Jana Moldanova

IVL Swedish Environmental Research Institute

Science of the Total Environment

00489697 (ISSN) 18791026 (eISSN)

Vol. 671 189-207

Sustainable Shipping and Environment of the Baltic Sea region (SHEBA)

Swedish Environmental Protection Agency, 2015-04-01 -- 2018-03-31.

Baltic Organisations' Network for Funding Science EEIG (BONUS), 2015-04-01 -- 2018-03-31.

Driving Forces

Sustainable development

Areas of Advance

Transport

Subject Categories

Earth and Related Environmental Sciences

Geochemistry

Oceanography, Hydrology, Water Resources

DOI

10.1016/j.scitotenv.2019.03.264

PubMed

30928749

More information

Latest update

8/15/2019