© 2015 by Salmon Watersheds Lab

Dead Zones in the Lower Fraser River

While studying aquatic communities surrounding floodboxes (a reverse-dam installed in dikes to prevent flooding- depicted on the right), two NSERC USRA students, Jen Gordon and Michael Arbeider, discovered seasonal hypoxic dead zones that occur upstream of these flood boxes throughout the lower Fraser River. Hypoxic areas fall beneath the Canadian national water quality criteria minima and extended over 100m upstream. These hypoxic dead zones are a potential chemical barrier to fish movement, including salmon migrations. With an estimated 500 aging floodboxes in the lower Fraser River, there is a need to further assess the cumulative effects of floodboxes on estuary habitat. 

Read the paper here.