Non-indigenous invasive bivalves as ecosystem engineers.

SOUSA R.; GUTIÉRREZ, J. L.; ALDRIDGE, D.

BIOLOGICAL INVASIONS

SPRINGER

Año: 2009 vol. 11 p. 2367 - 2385

1387-3547

Several non-indigenous bivalve specieshave been colonising aquatic ecosystems worldwide,in some cases with great ecological and economicimpacts. In this paper, we focus on the ecosystemengineering attributes of non-indigenous invasivebivalves (i.e., the capacities of these organisms todirectly or indirectly affect the availability of resourcesto other species by physically modifying theenvironment). By reviewing the ecology of severalinvasive bivalves we identify a variety of mechanismsvia which they modify, maintain and/or create habitats.Given the usually high densities and broad spatialdistributions of such bivalves, their engineering activitiescan significantly alter ecosystem structure andfunctioning (e.g., changes in sediment chemistry, grainsize, and organic matter content via bioturbation,increased light penetration into the water column dueto filter feeding, changes in near bed flows and shearstress due to the presence of shells, provision of colonisablesubstrate and refuges by shells). In addition,changes in ecosystem structure and functioning due toengineering by invasive bivalves often have very largeeconomic impacts. Given the worldwide spread of nonindigenousbivalves and the varied ways in which theyphysically modify habitats, their engineering effectsshould receive more serious consideration in restorationand management initiatives.