Cottrell, RS and Black, KD and Hutchinson, ZL and Last, KS, The influence of organic material and temperature on the burial tolerance of the blue mussel, Mytilus edulis: considerations for the management of marine aggregate dredging, PLoS ONE, 11, (1) Article e0147534. ISSN 1932-6203 (2016) [Refereed Article]
Rationale and Experimental Approach
Aggregate dredging is a growing source of anthropogenic disturbance in coastal UK waters and has the potential to impact marine systems through the smothering of benthic fauna with organically loaded screening discards. This study investigates the tolerance of the blue mussel, Mytilus edulis to such episodic smothering events using a multi-factorial design, including organic matter concentration, temperature, sediment fraction size and duration of burial as important predictor variables.
Results and Discussion
Mussel mortality was significantly higher in organically loaded burials when compared to control sediments after just 2 days. Particularly, M. edulis specimens under burial in fine sediment with high (1%) concentrations of organic matter experienced a significantly higher mortality rate (p<0.01) than those under coarse control aggregates. Additionally, mussels exposed to the summer maximum temperature treatment (20°C) exhibited significantly increased mortality (p<0.01) compared to those in the ambient treatment group (15°C). Total Oxygen Uptake rates of experimental aggregates were greatest (112.7 mmol m-2 day-1) with 1% organic loadings in coarse sediment at 20°C. Elevated oxygen flux rates in porous coarse sediments are likely to be a function of increased vertical migration of anaerobically liberated sulphides to the sediment-water interface. However, survival of M. edulis under bacterial mats of Beggiatoa spp. indicates the species’ resilience to sulphides and so we propose that the presence of reactive organic matter within the burial medium may facilitate bacterial growth and increase mortality through pathogenic infection. This may be exacerbated under the stable interstitial conditions in fine sediment and increased bacterial metabolism under high temperatures. Furthermore, increased temperature may impose metabolic demands upon the mussel that cannot be met during burial-induced anaerobiosis.
|Item Type:||Refereed Article|
|Keywords:||mussels, sedimentation, aggregate dredging, marine, reefs|
|Research Division:||Environmental Sciences|
|Research Group:||Pollution and contamination|
|Research Field:||Environmental biogeochemistry|
|Objective Group:||Environmentally sustainable construction activities|
|Objective Field:||Environmentally sustainable construction activities not elsewhere classified|
|UTAS Author:||Cottrell, RS (Dr Richard Cottrell)|
|Web of Science® Times Cited:||10|
|Deposited By:||Ecology and Biodiversity|
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