Tracking Salmon Juveniles in a South Dakota Lake

South Dakota Game, Fish and Parks and the University of Nebraska at Kearney are collaborating on a research project to monitor Chinook salmon stocked at Lake Oahe in central South Dakota. Researchers are using Innovasea’s advanced acoustic telemetry solutions to answer questions related to salmon stocking, including optimal size for release, ideal release locations, where the fish travel and how they’re affected by predators.  

Challenge 

South Dakota Game, Fish and Parks manages the state’s recreational and outdoor resources and has been stocking Lake Oahe with juvenile salmon each spring and fall since the early 1980s. Within a few years, the fish can grow to 30 pounds or more, providing a unique fishing opportunity for local anglers. 

However, little is known about the survival rate, habitat use and movement of the salmon as they begin their multi-year journey from smolt to adulthood. Previously SD Game, Fish and Parks biologists used coded wire tags to study the salmon, but this method does not provide any data until the fish are recaptured.  

Solution 

Dylan Gravenhof, a fisheries biologist with SD Game, Fish and Parks, and Dr. Melissa Wuellner, associate professor at UNK, have been tasked with figuring out how to protect the state’s investment using Innovasea’s acoustic telemetry technology. This will allow them to track the salmon from the moment they’re released to get a better understanding of where the fish go, how many survive and what types of habitat they prefer. 

The new Innovasea V5D tags being used in the study offer another major benefit: they have a patented polymer membrane that dissolves in stomach acid. That means if one of the tagged salmon is eaten by a predator, researchers will know within hours.  

Result 

The aim of the project is to gather baseline data that provides long term insight into what happens to the salmon after they have been tagged and released. That information will then be used to evaluate different stocking strategies. 

The predation capabilities of the V5D ensure that researchers are tracking what they intended to track. Previously, if a predator ate a tagged fish, that predator would retain the tag for a period of time, sending bad data back to researchers.  

Fifty animals from the hatchery were tagged and released in 2021 and another 50 will be tagged in the spring of 2022.