Counting salmon using eDNA
eDNA—a low-cost and non-invasive option—is increasingly being used by researchers for sample collection and species monitoring.
Varying amounts of eDNA are found in the skin, scales, or waste shed by salmon into their surrounding environment. These samples have a relatively short life span, but can help detect the presence or absence of the salmon through the presence of species specific eDNA, says Marlatt.
Why it matters
Marlatt explains that the human count method for counting salmon works well, but requires labor-intensive human counters and less frequently, sonar, resulting in limited counting across streams in Canada.
“Additionally, to count spawning salmonids one must construct a fence that spans an entire river to prevent passage of salmon, except through single narrow gates, so that a human observer can count and identify the species,” she says.
“This is costly to construct and operate, thus alternatives to these labour-intensive, high-cost methods would allow more rivers to be monitored for salmon abundance, and this is where testing eDNA for salmon enumeration comes in.”
If successful, the use of eDNA can be expanded for wider commercial use across B.C.’s fisheries and aquaculture sectors.
The research is funded through Genome BC’s Sector Innovation Program, which aims to support projects that will address the needs of each key sector and have the potential to generate social, environmental and economic benefits for British Columbia in the future.