A new invasion of the St. Lawrence River estuary and Great Lakes ecosystems?

Abstract

In this issue, Roohi et al. (2024) describe wide-ranging food web alterations associated with the invasion of the Caspian Sea by the ctenophore Mnemiopsis leidyi. The study focuses on the southern, deepest basin of the Caspian within Iranian territorial waters but the ecosystem perturbations are broader. M. leidyi is perhaps the most-studied ctenophore species on the planet, native to the Atlantic coastal waters of North and South America but is now greatly expanding its range into the Baltic, North, Mediterranean, Black, and Caspian Seas. It is a voracious carnivore with an appetite for planktonic crustaceans, rotifers, bivalve larvae, and more. The authors suggest that it may next threaten the St. Lawrence River estuary or even the Great Lakes themselves.