Regional Case Studies

The introduction and spread of aquatic invasive species (AIS) poses a threat to lakes, rivers, and other water bodies throughout North America. One pathway that has been shown to contribute to AIS spread is seaplanes. These case studies illustrate the role seaplanes can play in the spread of AIS and the negative impacts AIS establishment can have on the environment as well as seaplane safety and operations. These case studies also illustrate the important role seaplane pilots can play to prevent the spread of AIS. For a complete packet of the case studies, click here.

Elodea spp. graphic.

FAA Region: Alaska

Elodea spp. - Canadian waterweed (E. canadensis) and Nuttall's waterweed (E. nuttallii)

Elodea spp. were the first freshwater AIS reported from the State of Alaska. First reported in 1982 from Eyak Lake, a large lake in Cordova, nearly half of the known infestations in Alaska have been in seaplane-accessible water bodies. In 2015, Lake Hood, home to the world’s busiest seaplane base, was the site of a successful extensive and costly Elodea spp. eradication project by the State of Alaska. MORE

Waterfleas. Source:J. Liebig, NOAA GLERL.

FAA Region: Great Lakes

Waterfleas - Fishook waterflea (Bythotrephes longimanus) and Spiny waterflea (Cercopagis pengoi)

Waterfleas are widespread and well-established in the Great Lakes. Likely introduced in the ballast water of large ships in the 1980s and 1990s, fishhook and spiny waterfleas are a concern to the region. Efforts to reduce their spread are focused on preventing their unintentional movement into and between inland lakes by human activities. Of particular concern are lake-hopping excursions that include visits to one or more lakes containing waterfleas. MORE

Feathered mosquitofern.

FAA Region: Southern

Feathered mosquitofern (Azolla pinnata)

Feathered mosquitofern has been found in (and removed from) numerous plant nurseries in the United States. It has a limited distribution to water bodies in Florida and Hawaii. Because of its limited distribution, seaplane pilots can prevent further spread of this plant to new water bodies. MORE

Golden algae fish kill. Source: Oklahoma Department of Wildlife Conservation.

FAA Region: Southwest

Golden algae (Prymnesium parvum)

Golden algae have been found in more than 20 states, and blooms were first noted in Texas in the 1980s. During the early 2000s, algae blooms in reservoirs and rivers occurred across the southern United States. The alga occurs in brackish inland waters and coastal freshwater rivers, lakes, and estuaries. Seaplane-accessible water bodies across the Southwest may be at risk from golden algae introductions. MORE

Hydrilla.

FAA Region: Central

Hydrilla (Hydrilla verticillata)

Hydrilla was first found in the United States in Florida in 1952 and has since spread to 27 states primarily in the South and East. In the Central Region, infestations of hydrilla are concentrated in Missouri and Oklahoma. Because of its limited distribution in the Central Region, it is possible that informed seaplane pilots can prevent further spread to other waterbodies. MORE

. New Zealand Mudsnails. Photo credit: National Park Service.

FAA Region: Eastern

New Zealand Mudsnails (Potamopyrgus antipodarum)

First reported in the United States near the Snake River in Idaho, New Zealand mudsnails have spread rapidly throughout the western states, in the Great Lakes, and in lakes and streams in parts of the East Coast, including Pennsylvania and New York. The physiology and biology of mudsnails make them well-suited for human-aided introduction and spread. MORE

Giant salvinia in Texas.

FAA Region: Western Pacific

Giant salvinia (Salvinia molesta)

Giant salvinia is an invasive floating freshwater fern found in the lower Colorado River basin. It is associated with southern drainages, as well as San Luis Obispo County, California. Native to Brazil and introduced to the United States for use in aquariums and decorative ponds, giant salvinia is one of many similar species of invasive floating vegetation that blanket water bodies, choking out native plants and animals and eliminating recreational opportunities. MORE

Dreissenids at the edge of a water body.

FAA Region: Northwest Mountain

Zebra mussels (Dreissena polymorpha) and Quagga mussels (Dreissena bugensis)

Dreissenid mussels were first found in the Great Lakes Region in 1997 where they were introduced via ballast water from global shipping. They have since spread across the United States via connected water systems, trailered watercraft, and other fouled equipment. Notable reservoirs within the Colorado River Basin are infested with quagga mussels, however invasive mussels have not been detected in most of the Pacific Northwest. The 2023 discovery of dreissenids in the Snake River, Idaho resulted in a prompt eradication attempt by the State of Idaho. Seaplane-accessible water bodies across the Northwest maybe at-risk from the introduction of dreissenids by seaplanes. MORE

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Two sets of best practices were drafted and vetted with seaplane pilots - these two sets of practices, one for Alaskan seaplane pilots, and the other for seaplane pilots in the lower 48, are intended to reduce the spread of AIS.