Seasonal variability in nutrient regeneration by mussel Mytilus edulis rope culture in oligotrophic systems

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 431:137-149 (2011) - DOI: https://doi.org/10.3354/meps09095 Seasonal variability in nutrient regeneration by mussel Mytilus edulis rope culture in oligotrophic systems Henrice M. Jansen1,2,3,*, Øivind Strand1, Tore Strohmeier1, Cathinka Krogness1, Marc Verdegem3, Aad Smaal2,3 1Institute of Marine Research, Nordnesgaten 50, 5817 Bergen, Norway 2Wageningen IMARES–Institute for Marine Resources and Ecosystem Studies, Korringaweg 5, 4401 NT Yerseke, The Netherlands 3Department of Aquaculture and Fisheries, Wageningen University, Marijkeweg 40, 6709 PG Wageningen, The Netherlands *Email: henrice.jansen@imr.no ABSTRACT: Blue mussel Mytilus edulis cultures contribute to nutrient cycling in coastal ecosystems. Mussel populations filter particulate nutrients from the water column and inorganic nutrients are regenerated by excretion of metabolic wastes and decomposition of (pseudo-)faeces. The objective of this study was to determine the intra-annual variability in nutrient regeneration by mussel rope cultures in oligotrophic fjord systems. In situ respiration and nutrient uptake and release rates of 1 m mussel ropes were measured using 250 l pelagic chambers. There was a 20-fold difference between winter and summer respiration and nutrient release rates. Inorganic nitrogen release ranged from 50 to 1000 µmol h–1 per meter rope. These variations were mainly related to mussel growth but were also related to changes in water temperature and biofouling biomass (organisms that colonized the mussel ropes). In total 24 genera of fouling organisms were observed, diversity increased over time (ranging from 2 to 12 genera m–1), and fouling biomass was mainly characterised by ascidians (max. 37 ± 14 g m–1). However, mussels dominated the culture ropes, representing >90% of total faunal biomass. The amount of organic material associated with the ropes was stable (6.9 ± 0.3 g m–1). At the scale of one mussel farm, nutrient regeneration by mussel rope cultures increased inorganic nitrogen concentrations by 20% and inorganic phosphorus concentrations by 5% during summer conditions. During winter, there was no significant effect of mussel cultures on the inorganic nutrient pools. Nutrient regeneration by mussel cultures also affected stoichiometry as nutrients were excreted in dissimilar proportions (nitrogen > phosphate > silicate). The increased nutrient availability may contribute to primary production, especially in nutrient-limited (oligotrophic) fjord ecosystems. However, fjord-scale effects are largely dependent on hydrographic conditions of the fjord system. KEY WORDS: Nutrient dynamics · Respiration · In situ · Suspended mussel culture · Biofouling · Pelagic chamber Full text in pdf format PreviousNextCite this article as: Jansen HM, Strand Ø, Strohmeier T, Krogness C, Verdegem M, Smaal A (2011) Seasonal variability in nutrient regeneration by mussel Mytilus edulis rope culture in oligotrophic systems. Mar Ecol Prog Ser 431:137-149. https://doi.org/10.3354/meps09095 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 431. Online publication date: June 09, 2011 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2011 Inter-Research.