Saving Seafood

Counting salmon is a breeze with airborne eDNA

December 1, 2025 — During the annual salmon run last fall, University of Washington researchers pulled salmon DNA out of thin air and used it to estimate the number of fish that passed through the adjacent river. Aden Yincheong Ip, a UW research scientist of marine and environmental affairs, began formulating the driving hypothesis for the study while hiking on the Olympic Peninsula.

“I saw the fish jumping and the water splashing and I started thinking — could we recover their genetic material from the air?,” he said.

The researchers placed air filters at several sites on Issaquah Creek, near the Issaquah Salmon Hatchery in Washington. To their amazement, the filters captured Coho salmon DNA, even 10 to 12 feet from the river. Scientists collect environmental DNA, or eDNA, to identify species living in or passing through an area, but few have attempted to track aquatic species by sampling air.

This study, published Nov. 26 in Scientific Reports, shows that eDNA can move between air and water — a possibility scientists hadn’t accounted for even though aquatic animal DNA sometimes appears in airborne study data.

The researchers then merged air and water eDNA with the hatchery’s visual counts in a model to track how salmon numbers rose and fell during the fall migration. Although the amount of salmon DNA in the air was 25,000 times less than what was observed in the water, its concentration still varied with observed migratory trends.

“This work is at the edge of what is possible with eDNA,” said senior author Ryan Kelly, a UW professor of marine and environmental affairs and director of the eDNA Collaborative. “It pushes the boundaries way further than I thought we could.”

Read the full article at UW News

Establishing Maine as a leader in environmental genetics

September 10, 2025 — Awarded in 2019, the NSF EPSCoR RII Track-1 Maine-eDNA project has reached the conclusion of its NSF funding. The program, which investigated Maine’s coast, inland lakes and the waterways in between, championed environmental DNA (eDNA) as a powerful and cost-effective approach to monitoring an environment as small as a stream to as large as Maine’s coastline. Maine-eDNA Co-PI Michael Kinnison, University of Maine professor of evolutionary applications remarked, “The real power that we were seeing for eDNA is being able to look at the biology of the Maine coast at not just local but by very large scales that span habitats. That sort of snapshot of the coastal system is broadly something that’s really hard to get a handle on with other approaches.”

Bigelow Laboratory for Ocean Sciences Senior Research Scientist and Geomicrobiologist David Emerson served as a Co-PI for Maine-eDNA and authored the white paper that developed into the project’s proposal. “There are three things that really excite me about eDNA. Scientifically, it is the opportunity to study all organisms, from microbes to whales, within an ecosystem to see how they interconnect; collaboratively, it is the opportunity to work together with researchers from many different disciplines using a common language, DNA, and practically, it is the opportunity to develop an important new tool for ecosystem management and sustainability,” explained Emerson.

This genetic tool leverages the DNA shed by organisms in their environment. Researchers take a sample from the environment, in the case of Maine-eDNA as little as a liter of water, and, depending on method, identify the likely presence of a specific species or range of species in the vicinity. While like any technology there are tradeoffs, this allows researchers to accurately detect species presence in a relatively unobtrusive manner that does not rely on visual identification.

Researchers across Maine saw potential in the technology. “We saw an opportunity to push an emerging technology forward, become a leader in the field and benefit the lives of Mainers,” explained Kody Varahramyan, Maine-eDNA PI and UMaine Vice President for Research and Graduate Studies. “Maine-eDNA’s achievements exemplify the power of partnership and collaboration.”

eDNA technology has developed quickly over the past decade. When the original proposal for Maine-eDNA was in its infancy, researchers were exploring the capabilities of eDNA and interested in finding more applications, but the depth of real-world applications was limited. Fast-forward to 2024 and the President’s Office of Science and Technology Policy released their National Aquatic Environmental DNA Strategy which directs government offices to invest resources in the technology. During the interim years it was projects like Maine-eDNA that pushed the technology forward by improving methodologies, standardizing approaches, making data accessible to others, and pushing the scope of application into new areas.

Maine in many ways was a perfect testing ground as the technology offered a way for researchers to survey the vast expanse of Maine’s waters over the course of several years at a fraction of the price presented by other approaches. A survey of this size also demands the standardization and ground truthing the technology needed. Maybe most importantly, the project put eDNA technology in the hands of students, researchers, resource managers, businesses and other stakeholders through outreach and collaboration.

Read the full article at University of Maine

NOAA Fisheries embracing eDNA tool for rockfish management

August 26, 2025 — NOAA Fisheries has developed an improved environmental DNA (eDNA) tool that will enable scientists to better understand rockfish species and could inform management of the U.S. commercial fishery.

Environmental DNA tools test for genetic material in collected water samples, allowing scientists to detect the presence of various animals. NOAA Fisheries has worked to adopt eDNA tools to help improve its species management, especially with fish that are difficult or cost prohibitive to track otherwise. Rockfish, for instance, live in rocky areas that are not conducive to trawling and are not distributed evenly. By using eDNA, scientists can get a better picture of where rockfish are present in a body of water.

Read the full article at SeafoodSource

Improved eDNA Primer Enhances Rockfish Species Identification in Alaska

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.

Read the full article at NOAA Fisheries 

eDNA uncovers salmon winter habitat usage in Northeast Pacific Ocean

July 29, 2025 — An international team of fisheries scientists studying data gathered during the oceanic winter of 2022 in the Northeast Pacific Ocean has identified distinct ocean biomes impacting the marine survival of Pacific salmon species.

Their report, based on an ecosystem-wide environmental DNA (eDNA) survey across 2.2 million square kilometers of open ocean habitat, found that salmon exhibited species-specific distribution across the Northeast Pacific. These distributions were associated with swirling ocean currents known as mesoscale anticyclonic eddies—currents that rotate clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere, characterized by a high-pressure center. These eddies play a significant role in ocean circulation by transporting heat, salt, and other properties, and by influencing biological activity.

Ocean biomes are aquatic ecosystems characterized by saltwater and include the Pacific Ocean, the largest and deepest of the world’s oceans, known for its diverse marine life and volcanic activity.

The voyages, part of the International Year of the Salmon initiative, began in 2017 and concluded in 2022, though analysis of the collected data continues. These voyages were a collaborative effort involving the North Pacific Anadromous Fish Commission (based in Vancouver, Canada), the North Atlantic Salmon Conservation Organization (based in Edinburgh, Scotland), and various other organizations across multiple countries. Their goal was to raise awareness about the importance of salmon conservation.

This latest research report was published on July 8 in the ICES (International Council for the Exploration of the Sea) Journal of Marine Science.

Researchers concluded that salmon displayed species-specific positive associations with potential prey species and competitors. However, some salmon were negatively associated with specific cnidarians and harmful algae. Cnidaria are a group of aquatic invertebrates found in both freshwater and marine environments, ranging from jellyfish, sea anemones, and corals to some of the smallest marine parasites.

Read the full article at the National Fisherman

Genome sequencing may be key to effective fishery stock management, US research finds

January 2, 2024 — Researchers at U.S. university Texas A&M recently released a study concerning whole genome sequencing used in fish stock research, claiming that the scientific technique could be the key to stronger stock management plans and preventing overfishing.

The study, titled “How Fish Population Genomics Can Promote Sustainable Fisheries: A Road Map” and published in the Annual Review of Animal Biosciences, detailed how fish genomics – a laboratory procedure that determines the DNA sequence of a fish’s genome – reveals critical data, such as spawning conditions and migratory behaviors, to researchers. The additional data allows researchers to better distinguish separate populations within a stock and more precisely define management areas for them.

Read the full article at SeafoodSource

US officials to use eDNA to test for harmful invasive species in Columbia River Basin

December 30, 2024 — The U.S. Fish and Wildlife Service (USFWS) plans to use environmental DNA (eDNA) to detect invasive species that can harm native salmon populations in the Columbia River Basin, according to a solicitation posted by the agency on 16 December.

eDNA is genetic material, such as tissue cells, mucus, or urine, that is shed by an organism in its environment. After collecting water samples, scientists can conduct lab tests to detect eDNA and determine whether a species is present in a given habitat.

Read the full article at SeafoodSource

Japanese studies advance use of eDNA in estimating fish populations

July 17, 2020 — A recent test in Japan using environmental DNA (eDNA) to survey eel populations in rivers achieved similar detection rates to electro-shock fishing – without killing eels – and another test, on jack mackerel, improved estimation accuracy.

Molecular analysis of DNA left in the environment has proven to be an effective tool for detecting the presence of species, and is being applied more frequently in place of traditional survey fishing. It usually uses the polymerase chain reaction (PCR) process – a process also used in the COVID-19 antibody test – to rapidly duplicate genetic material to a quantity that can be effectively detected and identified. It has the advantage that it does not disturb or kill the fish – important for endangered species.

Read the full story at Seafood Source