August 22, 2025 — A groundbreaking new environmental DNA (eDNA) tool is set to transform how scientists monitor rockfish populations. Rockfish are important to both commercial and recreational fisheries in Alaska. By analyzing DNA collected from water samples, this tool provides unprecedented accuracy in identifying a wide range of rockfish species. This- includes those that are closely related and hard to tell apart using previously available genetic methods.
Finding and identifying different species of rockfish in the ocean can be surprisingly tricky. Many of them have patchy distributions and live in rocky habitats making them difficult to survey using nets. While eDNA has become a popular method to sample fish biodiversity, previous methods were unable to tell apart many of the most abundant rockfish species in Alaska waters. But a new genetic tool, the Sebastes D-loop primer set, is changing that.
DNA primers match a target sequence in the eDNA and allow researchers to amplify species of interest. Primers are designed to identify multiple species of fishes, marine mammals, invertebrates, sharks, or any other organisms that might be in a water sample. In a recent study, NOAA Fisheries scientists demonstrate that the primer set can successfully identify nearly all rockfish species in Alaska waters. It offers a more accurate and efficient way to monitor these commercially important fish. A few closely related species still require extra effort to distinguish. But, this new approach marks a big step forward in monitoring rockfish populations and protecting their habitats.