© 2015 by Salmon Watersheds Lab

Assessing flood box designs to balance flood protection and fish biodiversity

Rebecca's broad research interest involves learning how humans can manage and balance our own needs with biodiversity conservation, particularly in aquatic ecosystems. For her Master's degree, she looked at how different designs of flood boxes, a common but often forgotten flood prevention mechanism, relate to fish biodiversity in tidal creeks in BC's Lower Mainland. These flood boxes can prevent salmon and other fish from moving into small tributary streams, which can act as important breeding, feeding, and nursery habitat. There have been some attempts to improve these flood boxes through better designs, such as fish-friendly pumps and self-regulating tide gates, but there is little information on how these improvements affect fish diversity and aquatic ecosystems. 

 

Her research explored how these different types of conventional and improved flood boxes affect fish diversity. She collected fish and water quality measurements upstream of 25 flood box sites, to learn if and how water quality, fish abundance and diversity differ among these different flood box designs. Due to global sea level rise and changing flow patterns in the Fraser River, municipalities will soon need to construct and upgrade many more of these flood boxes. Her project informs which flood box structures have lower impacts on fish diversity, in hope that municipalities in Canada and worldwide can protect their lands from flooding in a way that maintains fish biodiversity in our streams and rivers.

Rebecca Seifert