Freshwater mussels are an ancient group of molluscs that are considered ecosystem engineers because of the many important functions they perform, two of these being biofiltration and biodeposition. Worldwide, freshwater mussels are in decline, and are one of the most threatened groups of organisms. Sedimentation is considered a major threat to freshwater mussels, and although associations between mussel declines and increased sedimentation are well documented, the direct effects of suspended sediment (SS) concentrations on mussel functioning is poorly understood. In the summer of 2018, laboratory experiments were run on the river mussel, Alathyria jacksoni, to test the effects of increasing SS concentrations on the filtration rates and production of biodeposits. Filtrations rates were estimated using two methods: flow cytometry and chlorophyll a. Increasing SS concentrations did not have a significant effect on the filtration of algae, with filtration rates ranging from 0.035 - 0.721 L mussel-1 h-1, when estimated using chlorophyll a, and from 0.033 - 0.438 L mussel-1 h-1, when estimated using flow cytometry. Increasing SS concentrations did have a significant effect on the filtration of sediment. There was also a significant effect of increasing SS concentrations on the production of biodeposits, with inorganic and organic content in the biodeposits increasing with sediment concentrations. These findings suggest that, as SS concentrations increase, A. jacksoni reduces its ingestion of algae, and has to clean its gills from excess particles by rejecting more inorganic and organic material, in the form of pseudofaeces. This added maintenance work may result in an energetic cost to the mussel, and have potential consequences for growth, reproduction, and survival.
|Number of pages||1|
|Publication status||Published - 01 Dec 2019|
|Event||Australian Freshwater Sciences Society & New Zealand Freshwater Sciences Society Joint Conference - Deakin University, Waurn Ponds, Australia|
Duration: 01 Dec 2019 → 04 Dec 2019
|Conference||Australian Freshwater Sciences Society & New Zealand Freshwater Sciences Society Joint Conference|
|Period||01/12/19 → 04/12/19|