The functional role of native freshwater mussels in the fluvial benthic environment

Abstract

1. Freshwater mussels are the dominant consumer biomass in many fluvial systems. As filter feeding grazers, mussels can remove large amounts of particulate matter from the water column and transfer these resources to the substrate as biodeposits (agglutinated mussel faeces and pseudofaeces). Mussel biodeposits are a nutrient rich and easily assimilated food source and therefore may have significant relevance to benthic community structure. This study examines the functional role of Margaritifera falcata in the South Fork Eel River, California. 2. We addressed two main questions: (i) Do mussels increase benthic resources in this system? (ii) If so, does this alter macroinvertebrate community structure? 3. Measurements and enclosure experiments in the South Fork Eel River show that mussels can play a significant role in local food webs by increasing available fine particulate matter (both organic and inorganic) on the substrate. We document increased benthic macroinvertebrate biomass for predators and collectors (Leptophlebidae) in the presence of mussels, but only in late summer.

Impacts of climate change and land-use scenarios on Margaritifera margaritifera, an environmental indicator and endangered species

“…Freshwater invertebrates received much less attention but inside this group freshwater mussels are among the species frequently used in those studies or programs, because they play an important role in the ecosystem, with some species being classified as indicator or umbrella species, and are one of the most endangered groups of animals on the planet (Bogan, 2008;Galbraith et al, 2010;Geist, 2010;Howard and Cuffey, 2006;Lopes-Lima et al, 2014;Skinner et al, 2003;Sousa et al, 2013). Due to its large size, sedentary, long life span and variable sensitivity to environmental contaminants, freshwater bivalves can also be very useful as indicators of ecological integrity and as sentinels of environmental perturbation (Farris and Van Hassel, 2006).…”

Culturally significant fisheries: keystones for management of freshwater social-ecological systems

“…However, there are now minimal modern freshwater bivalve harvests by Indigenous peoples across these nations because of severe population declines arising from habitat loss, poor water quality, and pollution (Table 4). Although the ecological consequences of such losses are yet to be fully resolved, the role of bivalves in maintaining good water quality via filter feeding (Box et al 2006, Howard and Cuffey 2006, Machtinger et al 2007) suggests cause for serious concern. Indeed, the loss of the New Zealand freshwater mussel (Echyridella menziesi) from lake systems in New Zealand has been linked to a lowering of water quality and increased toxic phytoplankton blooms (Walker et al 2001, McDowall 2002.…”

Strategies for the conservation of endangered freshwater pearl mussels (Margaritifera margaritifera L.): a synthesis of Conservation Genetics and Ecology

“…Changes of the physical structure of stream sediments by dense mussel populations, their effects on water clearance, light penetration, abundance of macrophytic plants and the resultant increase in aquatic organisms dependent on these structures for attachment, food or cover, are examples which illustrate that freshwater bivalves in general, and freshwater pearl mussels in particular can be viewed as keystone fauna of aquatic ecosystems, their presence greatly enhancing biodiversity and ecosystem functioning (e.g. Vaughn & Hakenkamp, 2001;Howard & Cuffey, 2006).…”

“…Bogan, 1993Bogan, , 1998Bogan, , 2008Williams et al, 1993;Neves et al, 1997;Strayer et al, 2004). Given the high biomass and the high original abundances (hundreds of mussels per square metre) and thus the important roles of bivalve molluscs in particle processing, nutrient release, and sediment mixing (for review see Vaughn & Hakenkamp, 2001), the decline of mussel populations can have manifold implications on the functioning of aquatic ecosystems (Howard & Cuffey, 2006). Despite their importance, there is often a lack of knowledge about their complex biology, which connects the processes that influence their rapid declines.…”