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Rapid respiratory responses of the deep-water sponge Geodia barretti exposed to suspended sediments
Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
2013 (English)In: Aquatic Biology, ISSN 1864-7790, Vol. 19, no 1, 65-73 p.Article in journal (Refereed) Published
Abstract [en]

Sponges often dominate deep-water benthic faunal communities and can comprise up to 90% of the benthic biomass. Due to the large amount of water that they filter daily, sponges are an important link between benthic and pelagic ecosystems. Across the Tromso-flaket, Barents Sea, Norway, there are high biomasses of deep-water sponges. This area is also an important fishing ground, with fishing activity in some areas >27000 trawl hours yr(-1). Bottom trawling suspends large quantities of sediment into the water column, with measured concentrations up to 500 mg l(-1). This is the first study on the effects of suspended sediment exposure on deep-water sponges. In a laboratory experiment, Geodia barretti (Bowerbank 1858) (Class: Demospongiae) was exposed to 5 different sediment concentrations (0, 10, 50, 100 and 500 mg l(-1)). Respiration rates were measured before, during and after the exposure period. The results demonstrate that G. barretti physiologically shuts down when exposed to concentrations of 100 mg l(-1) (86% reduction in respiration), with thresholds of responses occurring between 10 to 50 mg l(-1). However, rapid recovery to initial respiration levels directly after the exposure indicates that G. barretti can cope with a single short exposure to elevated sediment concentrations. Given the high bottom-trawling frequency in Tromso-flaket, sponges may be frequently exposed to suspended sediments. Therefore, it is important that further investigations on the effects of suspended sediments on filter feeding organisms focus on the effects of repeated and long-term suspended sediment exposures to evaluate the overall ecological impacts.

Place, publisher, year, edition, pages
2013. Vol. 19, no 1, 65-73 p.
Keyword [en]
Continental shelf, Porifera, Turbidity, Bottom trawling, Fisheries
National Category
Biological Sciences
URN: urn:nbn:se:su:diva-94871DOI: 10.3354/ab00522ISI: 000324199700007OAI: diva2:656587


Available from: 2013-10-16 Created: 2013-10-16 Last updated: 2014-01-14Bibliographically approved
In thesis
1. Sediment resuspension: Impacts and extent of human disturbances
Open this publication in new window or tab >>Sediment resuspension: Impacts and extent of human disturbances
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Resuspension of sediment by anthropogenic disturbances is a concern due to the impacts it has on organisms and ecosystems. Bottom trawling is one major cause of sediment resuspension. A field study showed that a small trawl created a sediment plume 120 - 150 m wide and 15-18 m high (Paper 1). The sediment in the same study was highly contaminated. Blue mussels exposed to the sediment plume showed an increased uptake of contaminants and after 1 month reached levels toxic for human health (Paper 1). In the Baltic Proper, bottom trawling is the main cause of sediment suspension in waters >73 m, where resuspension by wind induced waves is minimal. Compared with dredging, bottom trawling annually resuspends 23-88 times more sediment in this area (Paper 4).

Bottom trawling is expanding to deeper waters where sediment resuspension is expected to have larger impacts on organisms compared with shallow water. Deep water sponges create important habitats that are attractive fishing grounds. A laboratory experiment (Paper 3) showed that deep water sponges had a rapid respiratory response to short exposure of elevated turbidity.

Boat activities in harbours are another major cause of sediment and contaminant remobilisation to the water column. A laboratory experiment showed that suspension of sediment with high TBT concentrations induced higher mortality in blue mussels, Mytilus edulis, and faster growth inhibition of the alga Ceramium tenuicorne than unsuspended sediment (Paper 2).

This thesis clearly shows that resuspension due to human activities, in particular bottom trawling, is widespread and can have impacts on a range of organisms. However, there are large differences in management of these activities as they are covered by different legislative frameworks. When managing dredging, it is the most cited concern, whereas it is not considered in the management of bottom trawling.

Place, publisher, year, edition, pages
Stockholm: Department of Ecology, Environment and Plant Sciences, Stockholm University, 2014. 42 p.
National Category
Research subject
Marine Ecotoxicology
urn:nbn:se:su:diva-98640 (URN)978-91-7447-842-6 (ISBN)
Public defence
2014-02-14, föreläsningssalen, Institutionen för ekologi, miljö och botanik, Lilla Frescativägen 5, Stockholm, 14:00 (English)
Baltic Ecosystem Adaptive Management (BEAM)
Formas, 2006-1018

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 4: Manuscript.

Available from: 2014-01-23 Created: 2014-01-08 Last updated: 2014-01-24Bibliographically approved

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Tjensvoll, Ingrid
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