ST. LAWRENCE EASTERN LAKE ONTARIO PARTNERSHIP FOR REGIONAL INVASIVE SPECIES MANAGEMENT
Golden clam (Corbicula fluminea), also known as Asian clam or Asiatic clam, is a small, freshwater bivalve mollusk in the basket clam family (Cyrenidae). It lives partially buried in sediment and feeds by filtering plankton and organic particles from the water. Golden clams threaten native freshwater mussels, aquatic food webs, and water quality. Dense populations compete with native species for food and space, alter nutrient cycling, and can hinder infrastructure such as clogging water intake pipes.
The golden clam is native to eastern and southeastern Asia, including China, Japan, Korea, and parts of Southeast Asia. It was first detected in the United States in 1938 in the Columbia River, Washington, likely introduced through imports for food or accidentally with aquaculture species. Since then, it has spread rapidly across much of North America through waterways and human activity.
Golden clams can reach extremely high densities, dramatically reduce plankton availability and negatively affect native mussels and other filter feeders. Their waste products increase nutrient availability, sometimes contributing to algal and cyanobacterial blooms.
Golden clams pose high costs for management and maintenance tied to infestations as they are notorious for blocking water intake pipes, causing overheating in boat engines and damage to municipal, industrial, and power generation systems.
Golden clam is established in New York State, with confirmed populations in the Hudson River, Lake George, the Champlain Canal, Finger Lakes, Erie Canal, and portions of the Adirondack region. In 2024, the species was confirmed for the first time in Lake Champlain, which drains toward the St. Lawrence system, raising concerns for spread into the SLELO region. Though Golden clam has been detected in all surrounding PRISM regions, it has yet to be found in SLELO making it a Tier 1 species making early detection efforts.
Golden clams inhabit lakes, rivers, streams, canals, and reservoirs, preferring sand, gravel, or mixed mud and sand substrates. They tolerate a wide range of temperatures and water conditions and can thrive in both still and flowing water, making them highly adaptable.
Identification:
Native fingernail clams (Sphaerium spp.) — Much smaller, thinner shells, lack heavy concentric ridges.
Eastern Elliptio (Elliptio complanata) – One of New York’s many native freshwater mussels. This common, ecologically crucial mussel is distinguished from the invasive golden clam by its large size (up to 5 inches), elongated rectangular or trapezoidal shape, smooth dark brown/black exterior, and often purple or salmon-colored inner shell.
Prevention
Manual / Mechanical Control
Take a clear, close-up photo, note the location (GPS coordinates are best), and report observations to NYiMapInvasives or directly to the SLELO PRISM’s Aquatic Restoration and Resiliency Coordinator, Adrien Owens, Adrien.Owens@tnc.org.
Education and stewardship are the most effective ways to prevent invasive species from establishing. Join our Water Protector’s Program to support early detection of this and other aquatic invasive species. Participants learn to identify and report priority species to NYiMapInvasives and adopt a waterbody for annual monitoring
SLELO PRISM also offers the Aquatic Invasive Species Learning Experience (AISLE), a three‑part training held annually that includes a virtual ID session, a hands‑on workshop, and a guided paddle.