Potential Impact of Filter-feeding Invaders on Temperate Inland Freshwater Environments

Gustavo Darrigran

doi:10.1023/a:1020521811416

Abstract

Since the 1990s, biological invasions have captured the attention of the scientific community as an important element of global change and a major threat to biodiversity. The inland waters of South America provide two examples of biological invasions. This review examines bivalve invasions in South America, summarizes the research results for two species, the Asian clam (Corbicula fluminea) and the golden mussel (Limnoperna fortunei), and suggests further studies. The rapid expansion of invasive bivalves into these environments involves significant changes. Until now, C. fluminea, the Asian clam, did not produce generalized macrofouling in the Neotropical region, as is common in the Holarctic region. However, the first specific cases of macrofouling by C. fluminea were recently detected in heat interchangers of power stations in Brazil. On the other hand, L. fortunei is provoking new economic impacts in South American freshwaters through macrofouling. Before the invasion by the golden mussel, macrofouling was recorded only in the marine and estuarine environments of the Neotropical region. The impact caused by invasive bivalves in this region is not only economic, however. Rapid changes in the benthic community, favoring the presence of Oligochaeta and Hirudinea, as well as the displacement of native species of mollusks, are among the problems related to the presence of the golden mussel. Another issue is the settlement of golden mussels on native bivalves. This bivalve is now a new element in the diet of some native fish species, being the main food item in some cases.

Highlights

Species distribution changes naturally over time, human activities greatly increase the rate and the spatial scale of these changes by accidentally or deliberately moving organisms across the world (Ricciardi and MacIsaac 2000)
This review examines and summarizes the research results of the introduction, spread, biology and environmental and economical impacts of two invasive freshwater bivalves, L. fortunei and C. fluminea in the Plata Basin, South America, and suggests further studies
Invasive freshwater bivalves of the Neotropical region considered in this study, especially the golden mussel, produce significant abiotic and biotic changes either directly or indirectly: (1) the introduction at specific coastal locations resulted in their dispersion through drainage systems with unpredictable consequences for the native biota (Darrigran et al 2000); (2) the alteration of natural ecosystems, since larval, juvenile and adult stages act at different levels of the same ecosystem, even producing changes in the diet of native species (Darrigran and Colautti 1994; Penchaszadeh et al 2000); and

Summary

Introduction

Species distribution changes naturally over time, human activities greatly increase the rate and the spatial scale of these changes by accidentally or deliberately moving organisms across the world (Ricciardi and MacIsaac 2000). Many human activities, such as agriculture, aquaculture, recreation and transportation promote both the intentional and accidental spread of species across their natural dispersal barriers (Kolar and Lodge 2001). The first step for such species concerns the transport pathway (e.g. in the ballast water of a ship). During this stage, specimens can either die or survive. These interactions, along with other factors, determine whether the non-indigenous species becomes established

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Conclusion