Effects of mussel farms on the benthic nitrogen cycle on the Swedish west coast
Journal article, 2012

The biogeochemical impact of 3 long-line mussel farms (M1, M2 and M3) in Lysekil, Sweden, was investigated from before farm establishment until 1.5 yr after operation had begun. Sedimentation, benthic N flux, total oxygen uptake (TOU) and sulfate reduction rate (SRR) were all significantly increased below the mussel lines at all 3 farms. Effects of increased sedimentation rates were revealed by sediment profile imaging and were highest at Stn M2. These effects increased significantly with time of farm operation, indicating the accumulation of organic matter within sediments over time. Furthermore, more total particulate organic N deposited at farm stations was recycled into the water column compared to at reference stations (similar to 45 versus similar to 13%), indicating an increased release of dissolved inorganic N from sediment below the mussel farms. At one station (M2) with the highest increase in sedimentation rate, denitrification seemed inhibited, while at another station (M3), with a less pronounced increase in sedimentation rate, denitrification was in fact stimulated, accounting for 13% of total sediment N removal. Calculations based on estimated values of N removal through mussel harvest and direct measurements of N input through changes in sedimentation, N regeneration from sediment to the water column through benthic fluxes and changes in denitrification showed, in all cases, a net removal of N from the system, as only 26 to 40% of the total amount of harvested N had been added to the sediments during the growth period.

nitrate reduction

Denitrification

organic

Benthic mineralization

impacts

marine-sediments

shellfish aquaculture

oxygen

Nitrogen

nutrient fluxes

new-zealand

denitrification

Mussel farm

enrichment

ammonium

Author

M. S. Carlsson

University of Southern Denmark

Aarhus University

Pia Engström

Chalmers, Civil and Environmental Engineering

Odd Lindahl

The Royal Swedish Academy of Engineering Sciences (IVA)

Lars Ljungqvist

University of Gothenburg

J. K. Petersen

Danish Shellfish Centre

Linda Svanberg

University of Gothenburg

M. Holmer

University of Southern Denmark

Aquaculture Environment Interactions

1869-215X (ISSN) 1869-7534 (eISSN)

Vol. 2 2 177-191

Subject Categories

Ecology

DOI

10.3354/aei00039

More information

Latest update

12/2/2020