Spring/Summer 2023
Mud and migration
Sediment cores provide clues about early human settlement
How did the first humans get to the Americas? One popular theory is that they came from Asia between 26,000 and 14,000 years ago via a land bridge to Alaska, now covered by the Bering Sea. But then what? Their next steps are still subject to some debate. Evidence is bending towards the idea that early peoples dispersed down the North American coast rather than along an inland route. But there was a major obstacle, regardless of their route: massive ice sheets that covered part of the continent during the last ice age.
A research team led by then-graduate student Summer Praetorius, and including CEOAS’ Alan Mix and Mo Walczak, has provided insight into the possible timing of this migration by pinpointing two intervals when ice and ocean conditions would have been favorable for migration by foot late in the last ice age. While ice sheets on land can block the way for walkers, sea ice could help pave the way, as it is a flat and stable substrate to traverse. Using ocean modeling and data from sediment cores collected in the Gulf of Alaska, the researchers found two distinct climate periods where a combination of winter sea ice and ice free summer conditions likely would have facilitated migration further south. The main clue to the existence of ancient sea ice in these sediment cores was molecular traces of algae known to have grown around shoreline sea ice. In two intervals, from 22,000 to 24,500 years ago and again from 14,800 to 16,400 years ago, sea ice was present in the winter even as summer warmed, plausibly giving early Americans the opportunity to travel along the coast, the researchers say.
Photo: Chris Peterson, Action Works Photography, for Oregon Sea Grant
Stress test
Evaluation impacts of climate change on marine life
Dungeness crab and other marine life have good reason to be stressed. A warming world has introduced overlapping threats to their survival, including ocean acidification, low-oxygen conditions, marine heat waves, rising ocean temperatures and harmful algal blooms. Often, multiple problems such as these require multiple perspectives.
A new Oregon State University effort will combine Indigenous and Western approaches to understand how stressors are impacting marine ecosystems, with a focus on commercially important Dungeness crab and tiny crustaceans called krill. Funded by the National Oceanic and Atmospheric Administration, the research aims to help commercial fisheries and state and Tribal resource managers prepare for the changes ahead.
Researchers will use existing and new ocean data, ocean and climate models, laboratory experiments and fisheries management evaluation techniques to learn more about the relationships between the different stressors and the potential cascading impacts that may result.
In addition, the project will integrate Traditional Ecological Knowledge, which is the accumulation of Indigenous science, including information, practices and beliefs about the relationships and functions of all species and processes within ecosystems. Siletz Tribal member and Oregon State TEK specialist, Samantha Chisholm Hatfield, will lead that aspect of the project.
The work will include interviews with Tribal members to better understand changes to shellfish populations and ocean patterns that Tribal members have orally documented over multiple generations.
“We want to provide context around what changing ocean conditions might mean for the future, not just for the commercial industry, but also the cultural impacts for Tribal communities on the West Coast,” Hatfield says.
Almost ready
To float our boat
R/V Taani, the state-of-the-art Regional Class Research Vessel being built for operation by Oregon State, is coming together … literally. In recent months, the superstructure (the “top part”), constructed at one shipyard in Louisiana, was placed on a barge to be united with the hull, constructed at another facility. Now Taani truly looks like a ship, paint job and all, and has just been launched to undergo sea trials. Check out the great video showing the process of uniting the major ship modules, and keep an eye on our RCRV web cams 6 and 7 for up-to-the-minute views.
Photo: Dean Major
Fruh in new role at NOAA
Alum, Board of Advisors member working with uncrewed vessel program
One of the greatest revolutions in ocean data collection has been the advent of small uncrewed vessels — autonomous underwater vehicles (AUVs) that travel under the surface, or uncrewed surface vehicles (USVs) — that can be deployed from shore or collect data alongside ships at sea. But even uncrewed vessels need humans for everything from programming to data processing.
The National Oceanic and Atmospheric Administration recently created an Uncrewed Systems Operation Center to manage their growing fleet of these robots, and their first hire in the center’s new marine division was CEOAS alum and Board of Advisors member Erica Fruh (MRM ’99) of Newport, Oregon.
In her new role, she has been helping to test one of the agency’s newest hightech USVs, the DriX, built by French company Exail and delivered in 2022.
“The DriX can go up to 12 knots, and you can put any kind of sonar on it,” Fruh explains. “It’s super fast, and it can be deployed for up to 36 hours. The idea is to use it as a force multiplier for ocean mapping and, eventually, fishery surveys.”
NOAA’s DriX was tested for the first time last summer in the Great Lakes, where Fruh helped put it through its paces in taking bathymetric data that can help build charts of the ocean’s bottom. The NOAA crew was pleased with the test runs — “Everything went amazingly well,” Fruh says — and the agency plans to deploy the USV in Alaskan waters this coming summer to test its capability in surveying for fish.
While the DriX is undertaking this new challenge, Fruh will be challenging herself, too, as she will be training to “drive” it, possibly even remotely from Newport.
“As new technologies come on the market and NOAA develops uses for them, I’m excited to learn how to best apply them to science,” Fruh says.
