Tim Nehus and Will Methvin spent enough time out in Tennessee ditches rooting through mud with shovels looking for endangered crustaceans to know there had to be a better way. So, they created one.
Tim, a Principal in the Ecological Services, and Will, a Project Scientist, in CEC’s Nashville office are the winners of a 2022 Innovation Award for their Crayfish Extractor Pump.
The Nashville Ecological Services Practice provides a variety of species surveying and collection services for aquatic and semi-aquatic organisms. One of the species of concern is the Hatchie Burrowing Crayfish. This species is considered an endangered species in Tennessee and therefore water quality permit applications in areas where this species may occur must perform an assessment for presence/absence of the species. As the name suggests, the Hatchie Burrowing Crayfish is a burrowing species, capable of creating tunnels to the water table reaching depths of up to 6 feet.
The conventional approach for assessing the presence of species is to use a shovel to dig into the burrows visible at the surface.
“The burrows are easy to find as most are topped by a ‘little mud chimney,’ ” Tim says. The crustaceans are not communal creatures, therefore, there’s likely to only be one in each burrow.
Crayfish burrows often go in multiple directions, and digging can make it difficult to follow the main tunnel. Digging with a shovel or hand excavating gives the crayfish ample time to leave the burrow, leaving the investigator chasing empty tunnels. Multiple species of crayfish create burrows, and the destructive method of digging results in harder to identify organisms.
Tim says, in digging a hole you have to hope that you then capture the crayfish during the disruption but even more importantly avoid impact or damage to the crayfish. The crayfish has to be manually collected and in the process, there’s always a risk of grabbing hold of a snake or other creature that’s not a crayfish.
To increase the rate of successful collection, they needed a device that would allow faster execution without the destruction of the crayfish or surrounding area. While researching a better way, the yabby pump was discovered. It’s a hand pump used in Australia to extract saltwater ghost shrimp for fish bait. They needed a yabby pump for crayfish.
So after some brainstorming and trial and error, the pair did a little adjusting to an ordinary bilge pump from Lowe’s and fashioned one.
To make the pump function properly for their purposes, the one-way valve was removed so that the water and crayfish could be expelled out of the tubing rather that pulled all the way through the pump. Standard plumbing fittings were used to reduce the pump opening so that they could use tubing small enough to fit into the crayfish burrow.
It removes a few gallons of water and the crayfish from the burrows, all at the same time.
“Once you engage the pump, you can see the crayfish getting sucked up through the clear tubing,” Tim adds. Instead of manually digging down into the hole, the pump is quicker, less labor intensive (so less chance of injury for the CEC employee), safer for the crayfish, and less destructive to the burrow.
While this pump is beneficial to both CEC field staff and the crayfish, it also helps our clients. In the event that the proposed impact is in an area when a threatened or endangered crayfish may occur, then a species survey is often required as part of the application process and/or the pre-construction process.
This more effective way to assess the presence of crayfish species gets the results to the clients much faster, allowing the application to move along.
Tim and Will’s innovative idea benefits both the client and the crayfish. It is indeed a win-win for CEC.
Post a Comment