Similarly, oxygen consumption rates are higher in summer.
Reproduction seems to require a massive use of energy stores.
Chemical pollutants and suspended solids may impair metabolic activity by interfering with respiratory, feeding, and reproduction. Distribution and Habitat Mussels are principally distributed throughout the Mississippi River drainage and river systems in eastern North America. Freshwater bivalve distribution is also related to stream size or order. The number of unionacean species in drainage systems is not, however, related to drainage area size. Other environmental variables that may effect species richness include surface geology and soil porosity, water flow stability, oxygen concentrations, and reduced silt loading.