The first week in August, a team of scuba divers completed their annual survey of rockfish, lingcod, and other kelp forest species along the outer coast of Washington. This is the 10th anniversary of this long-term sampling program.
The team included divers from the Northwest Fisheries Science Center, with partners from:
- Olympic Coast National Marine Sanctuary
- University of Washington
- Monterey Bay National Marine Sanctuary
The 2025 survey produced two standout observations reflecting the resilience of the Northwest coastal ecosystem.
Rockfish in Abundance
First, the abundance of young-of-the-year rockfishes was the highest since the banner year of 2016. The dive team often sees a few of the newly settled fish from time to time over the course of their dives. This year, however, they saw schools of young black, yellowtail, canary, and deacon rockfish in the thousands. Rockfish support productive and valuable commercial and recreational fisheries that boost coastal economies. Commercial landings averaged close to $70 million each of the last 5 years, and recreational catch was in the hundreds of thousands of fish annually since the 1980s.
These observations are important because large numbers of juvenile rockfish may lead to higher catches of adults in the future. That will depend in part on how well ocean conditions support their growth and survival, since rockfish may take several years to reach reproductive age. Predation also tempers the population-level impact of recruitment, with predators from birds to salmon taking advantage of readily available and abundant prey. Researchers have also reported an abundance of young rockfish off the California coast, indicating their strong reproduction may extend to other parts of the West Coast.
“The Olympic coast sustains complex, diverse, and immensely productive marine ecosystems,” said Ole Shelton, a research scientist at the Northwest Fisheries Science Center who helped lead the surveys. “We do the surveys to learn how key species are doing and how they will support fisheries and the marine food web in coming years. This is a very good year for young rockfish.”
Shocking Sea Stars
The second surprise of the dive surveys was an increase in large, healthy sunflower sea stars. This key coastal species suffered severe die-offs over the last decade. NOAA Fisheries proposed listing them as threatened under the Endangered Species Act in 2023.
Divers observed sunflower seastars across multiple survey sites and depths. Some were the size of large pizzas, which may be close to 5 years old. Such large sea stars have been nearly absent over the last decade due to a pandemic of wasting disease. The disease wiped out billions of seastars over much of their range between 2013 and 2017.
The 2025 survey found more sunflower seastars than the previous 10 years combined! The dive surveys had observed fewer than five sunflower sea stars over the previous decade of monitoring dives. This year, the team observed 13 sunflower seastars, which appeared to be thriving—with no sign of disease. This may offer a glimmer of hope for recovery of the species, especially in light of recent identification of the pathogen that causes sea star wasting disease.
A Decade of Diving
The annual dive survey began in 2015 and collects information about the size and abundance of fisheries resources and species of conservation concern. It also captures comprehensive details on ecosystem conditions. It helps track and understand the dynamics of highly productive nearshore kelp forest habitats in the Pacific Northwest that expanded after the reintroduction of sea otters in the 1960s. The data from these surveys have contributed to:
- Groundfish stock assessments (black rockfish, yellowtail rockfish)
- Population viability analysis for the sunflower seastar listing
- Multiple peer-reviewed manuscripts (Shelton et al. 2018, Tolimieri et al. 2023, Johnson et al. 2023) tracking the health of such habitat
The information gathered from this unique, long-term survey helps NOAA Fisheries, tribes, and other partners manage commercial and recreational fisheries to benefit the economy, ecosystem, and others who rely on marine resources.
Expanding the View with Environmental DNA
Since 2022, the dive survey has collected water samples alongside diver transects to capture environmental DNA. eDNA consists of genetic traces organisms such as fish constantly shed into their environment. Processing eDNA samples can help detect and quantify fish and invertebrate species, including those rarely seen. It works similarly to how detectives might seek traces of DNA at a crime scene to identify a suspect. Survey scientists are developing methods for integrating diver and eDNA data to provide a more complete description of the nearshore marine community.
From Data to Decisions
The scientists who joined the dive are confident that the long-term monitoring data will provide early warnings of changes in the abundance of species. They will notify us of changes months or years before the focal species will be available to or affected by recreational and commercial fisheries. They also hope to gain insight into the recovery of sunflower sea stars and other species of conservation concern, such as pinto abalone. Washington state listed pinto abalone as an endangered species in 2019 following their decline.
The dive survey program is the only one of its kind on the outer coast of Washington. Researchers said its value increases each year that they add data to the long-term record. They hope to integrate the data with the results of other NOAA Fisheries sampling efforts, such as a trawl survey for groundfish, including rockfish. These surveys more clearly record changes in abundance of adult fish. Combining the results of surveys spanning habitats across the life cycle of species provides more insight into their abundance, helping determine sustainable harvest levels.
