Freshwater mussels are filter-feeding bivalves that occupy diverse freshwater environments. In the United States , mussel assemblages are declining in range, abundance, and species richness. R estoration can involve reintroduction of mussels to historical ranges. Reintroduction success (i.e. survival, persistence) depends on both habitat suitability and animal size . Juvenile mussel survival in nature is thought to be low but advances in hatchery spawning and pond rearing have significantly increased survival. Pond rearing can raise hatchery-spawned mussels to sizes appropriate for release. Ponds with appropriate water quality parameters provide the opportunity to grow mussels without external nutrient input and with minimal maintenance , vastly minimizing effort and resources required when compared to hatchery systems.
Freshwater mussels of two species native to the Delaware River Basin, Utterbackiana implicata and Sagittunio nasutus, have exhibited comparable survivorship and growth rates in large reservoirs, municipal stormwater ponds, and ponds located at botanical gardens. The tolerance of these species to a range of land use and nutrient inflows allows for many pond options in which to grow mussels , providing potential opportunities to partner with companies, governments, and private landowners.
Particulate matter composition (i.e. seston) is of particular interest for selecting an appropriate pond for grow-out. Seston composition of several municipally owned stormwater ponds (Table 1) shows a positive correlation between a high concentration of organic material in seston and mussel growth. In systems that experience problematic quantities of nutrients, pond grow-out of freshwater mussels may provide the ecosystem service of water quality uplift, filtering and transforming those nutrients. This may be of particular interest in municipal stormwater ponds which experience high nutrient inflows from residential lawns and stormwater runoff . Grow-out trials using mussels in stormwater ponds were initiated in 2019 and will be expanded upon through 2023 to refine our understanding of pond carrying capacity and the efficacy of novel aquaculture techniques.