University of New Brunswick – Dr. Allen CurryApril 3, 2018
The University of New Brunswick’s latest ASCF funded research project may not involve working out in nature and standing in cold rivers and streams, but it’s still very important to the future of Atlantic Salmon.
The university has received $6900 in funding and is writing a scientific literature review describing the feeding behaviour and prey preferences of Striped Bass during its spawning period, with emphasis on salmonids.
Samuel Andrews is one of Dr. Allen Curry’s PhD. students and is writing the literature review. He explains that within the review they are summarizing all available Striped Bass diet and smolt predation studies occurring within the native range of Atlantic Salmon.
“Through this review we are assessing Striped Bass feeding ecology in Atlantic Salmon supporting rivers, characterizing Striped Bass feeding behaviour during their pre-spawn, spawn, and post-spawn periods, describing the findings and discussing the methods of all studies having reported Striped Bass predation on Atlantic Salmon smolt and parr, and providing a method for accurate assessment of smolt predation by Striped Bass.”
Andrews adds the goal is threefold.
“We are aiming to quantify the relative predation threat of Striped Bass to Atlantic Salmon, to summarize the research approaches and studies so far conducted to describe Striped Bass predatory interactions with Atlantic Salmon smolt, and to propose study designs and methods to better evaluate the interactions between Atlantic Salmon, Striped Bass, and the fisheries that they support.”
He notes the research is important as Atlantic Salmon face numerous survival threats throughout their complex and charismatic life histories such as rising water temperatures, commercial fishing and habitat fragmentation such as that imposed by dams.
“Recovering Striped Bass populations are now also suspected to pose a threat to Atlantic salmon smolt during spring when the two species briefly overlap in river estuaries. The predator/prey relationship of Striped Bass and Atlantic Salmon however, remains poorly understood and greatly understudied.”
Andrews said all such studies conducted to date contain numerous assumptions and inconsistencies leading to inaccurate estimates of smolt predation.
“Removing Striped Bass has been proposed as being an easier solution to address estuarine smolt mortality. Though, it remains unclear if Striped Bass pose a significant threat to smolt, if Striped Bass removal would help adult salmon returns, or what the ecosystem wide consequences of a Striped Bass removal would be. Prior to making such large ecosystem altering changes, researchers must first accurately describe the Striped Bass/smolt interaction and carefully measure smolt survival, both critical steps that have yet to be accomplished. Until these knowledge gaps are bridged there is no way of knowing if the easy solution is in fact the right solution, or even a viable solution at all.”
The project is nearly complete and only requires final review and minor corrections, updates and clarifications prior to submission.
The ultimate goal?
“To better inform both our understanding of current smolt predation studies and the design of all future smolt predation studies. Through these clarifications, this review will allow for both accurate estimates of smolt loss and effective management to help mitigate smolt losses if Striped Bass predation is proven to have a significant effect.”