Study of factors influencing the invasion of Golden Mussels (Limnoperna fortunei) in water transfer projects

Abstract

Water transfer projects are effective measures to solve the uneven distribution of water resources in China. However, these projects create highways for Golden Mussels (Limnoperna fortunei), which are aquatic invasive species, to invade new habitats. This has caused a series of problems such as structure corrosion, enhanced flow resistance, pipe blocking, and water pollution. In order to design remediation strategies, it is important to understand the factors influencing the Golden Mussel invasion. This paper investigates the invasion of Golden Mussels in the East River Water Source Project and the Northern Inter-basin Water Transfer project in China. The maximum densities of Golden Mussel attachment in these projects are about 10 000 ind. m−2. Flow velocity was found to be a significant influencing factor: the optimal flow velocity for attachment is in the range of 0.3 to 0.9 m s−1. Water temperature was also an important factor: the water temperature in the cold season influences the density of Golden Mussels and additionally, their growth and shell size are related to food competition between different individuals and water temperature. There was no obvious relationship between the pressure and the attachment density of Golden Mussels. Because all data was obtained during an infrequent pause in the water transfer projects, the data of this study is limited and the conclusions are preliminary descriptive observations. For future management decisions, more rigorous studies should be conducted to develop quantitative models aimed at providing a confident basis for controlling Golden Mussel invasion in water transfer projects.