I recently read a remarkable story of research done by people right at my home university at the University of Nevada, Reno. Thirty minutes from where we live is Lake Tahoe, which is a large lake which is half in Nevada, half in California. Like with many lakes, one of the largest threats to Lake Tahoe is invasive species, brought in either intentionally or unintentionally by boats, bait buckets and aquaria releases. Invasive species are a problem for any lake, as they generally out-compete the native organisms, disrupting the ecosystem.

Now, some researchers have come up with an innovative way of removing the invasive fish and not letting them go to waste. Christine Ngai and colleagues used an ‘electrofishing’ device which stuns fish temporarily, usually used in research for inspecting or sampling fishes. Once the fish are stunned, the researchers remove the invasive fish and return the native fish to the water (where they recover in a few minutes). In the past 3 years they have removed 51,000 fish. 

Christine Ngai using an electrofishing device from a boat while scooping out fish with a net. Photo: Mike Wolterbeek. 

This by itself is pretty impressive, but the researchers then gave all the larger edible fish like bass (55 pounds worth) to St Vincent’s food panty which provides food for poor and homeless people in the area. 

Christine Ngai (left) then gives the larger fish to the chef, Ray Trevino (middle) at St Vincent’s dining hall and food pantry. Photo: Auburn Harrison,

Smaller fish that aren’t suitable for filleting are then given to a wildlife shelter where they feed two bears. 

 A Black bear enjoying some fish at Animal Ark wildlife shelter in Reno. Photo: Jacqueline Bridegum

The even smaller leftovers are composted and used to fertilize the lawns of the University.

Of course, the best-case scenario would be no invasive fish in the lake at all, but given the problem, these researchers have demonstrated an innovative and waste-free solution to dealing with it.

Further reading:

"Carpe Eat'um: Invasive Asian Carp Leap into Restaurants, Grocery Stores" (July 8, 2015)

"Invasive Carp Clobber Local Catfish in Taste Test" (April 30, 2014)