Species that are considered uncertain risk need a more in-depth assessment beyond the Risk Summary to better define the species’ risk to U.S. environments.
Stephanodiscus binderanus is a diatom first described from the Baltic Sea and is considered a Eurasian species. It has been considered invasive to North America, potentially introduced to the Great Lakes basin in ships’ ballast water (Mills et al. 1993). Recent work found fossils of this species in Lake Simcoe, Ontario from as early as 1700, throwing into question the invasive or native status of this species in North America. The history of invasiveness is uncertain. There are well documented impacts of Stephanodiscus binderanus in the Great Lakes. However, it is not certain if those impacts stem from the species being completely new to the system or a native species that
experienced a population increase with the eutrophication of the Great Lakes. The climate match is high. This species is already present in the Great Lakes basin. Its worldwide distribution is not well documented in a single location but can be found haphazardly in the
literature. The certainty of assessment is low. The overall risk assessment is uncertain.
Publication date
Type of document
Uncertain Risk
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