Acoustic shad sampling

[Quillback]

Acoustic Sampling for Shad in Large Reservoirs in Arkansas

Gizzard and Threadfin Shad are essential species that serve as the primary food source for many sportfish in southern reservoirs. However, fisheries biologists have faced challenges in accurately estimating their populations using traditional sampling methods. As a result, they are continuously searching for more effective ways to assess the abundance of these vital forage fish.

At AGFC, we began using cove rotenone samples in the 1960s to estimate shad abundance in reservoirs across the state. However, changes made during the Environmental Protection Agency’s 2007 re-regulation process rendered rotenone impractical as a standard sampling technique. Additionally, the highly variable results from rotenone data made it difficult to use for management and monitoring, leading to the discontinuation of cove rotenone sampling in 2010.

With cove rotenone sampling no longer available, we sought a modern and reliable method to sample shad. In 2021, we partnered with Oklahoma State University (OSU) researchers to develop an acoustic survey technique. This method uses sound waves and specialized software to detect and measure the number and size of fish in a given area. Previous research by OSU showed that acoustic surveys provide more accurate estimates of shad abundance than previously used methods. However, specific technical details of this method still need to be researched to optimize shad abundance estimation. Research on Beaver and DeGray Lakes began that summer and has continued for at least three months every year since.

AGFC biologists and an OSU researcher spent 12 hours zigzagging at 3.5 mph from the Beaver Lake dam to the Nursery Pond late last month. They observed schools of shad throughout this effort, with higher abundances near the main river channel. OSU researchers will analyze the large amount of raw data collected to estimate the shad abundance and their average size. The same crew conducted a similar effort the following week at DeGray Lake and Lake Hamilton. This effort will be repeated on these three reservoirs in August and September.

Our plan to utilize modern sampling methods for shad will enhance our understanding of their populations and improve abundance estimates for managing fisheries in Arkansas reservoirs. This approach could also serve as a model for other states aiming to monitor their shad populations using similar technology and techniques. Gaining a better understanding of shad populations will lead to more informed decisions regarding forage management and sportfish stocking programs. Ultimately, these efforts will benefit both shad and sportfish populations, enhancing fishing opportunities for everyone.


Screenshot of large schools of shad (red oblong marks) near point marker 9 (36.3329416667, -93.9516533333) on Beaver Lake, July 23, 2024.


Another screenshot showing large schools of shad (red oblong marks) upstream of the Beaver Lake Highway 12 bridge (36.31904, -94.00615) collected on July 23, 2024

[Dan the fisherman]

Good info