MARCH 12, 2026 — In 2026, the University of California, Riverside; University of North Texas, NOAA’s Office of Response and Restoration Assessment and Restoration Division, and partners, published a follow-up to a 2025 study examining how developing zebrafish are impacted by exposure to Aroclor 1254, a mixture of industrial chemicals, known as polychlorinated biphenyls (PCBs), which can harm living organisms in multiple ways. The initial 2025 research linked exposure to Aroclor 1254 to impaired neurological and heart rate in early life stage zebrafish. The newer publication, titled "Aroclor 1254 impairs visual and neurosensory signaling pathways independent of the aryl hydrocarbon receptor in larval zebrafish," reports results that lead to a better understanding of how PCBs interact with biological processes.

Zebrafish are commonly used in laboratory studies because they help scientists understand how contaminants affect fish and, in some cases, human health. Chemicals like PCBs are known as “legacy contaminants” because they persist in the environment for decades. They build up in the food chain, moving from small organisms to fish and wildlife, and to consumers of contaminated food. These pollutants can interfere with growth, development, reproduction, and survival, and cause cancer.

Using a technique called RNA sequencing, the team examined which genes were turned on or off in exposed early life stage zebrafish to understand how Aroclor 1254 causes harm. Bioassays were also conducted to assess the toxicity of Aroclor 1254 to larvae exposed as embryos. Findings of this study include:

• Information about how this chemical mixture impairs pathways involved in vision and nervous system development.
• Eye diameter decreased and eye tremor and tremor response behavior increased.
• The resulting visual impairment in PCB-exposed fish may reduce the ability of young fish to survive in the wild.

These research findings underscore the importance of understanding how legacy contaminants like PCBs continue to affect aquatic life at critical stages of fish development as scientists work to protect and restore ecosystems impacted by hazardous waste and oil spills.

The full research dataset is forthcoming and will be published for public access on the National Centers for Environmental Information website. Meanwhile, the sequencing data is available now at The National Center for Biotechnology, and the bioassay data will follow soon.

JAN. 12, 2026 — NOAA’s Office of Response and Restoration (OR&R) is now accepting applications for its 2026 training classes for spill response professionals.

Spill responders and planners are encouraged to apply for the following courses.

Oil Spill Response Training

The Science of Oil Spills (SOS) class addresses the scientific considerations necessary for informed decision-making during oil spill responses.

Applicants may review course details on the SOS Classes page and submit applications via the SOS Application Form.

Chemical Spill Response Training

The Science of Chemical Releases (SOCR) class equips responders with a science-based framework for analyzing chemical and hazardous materials spills and making risk-based decisions to protect public health and the environment.

Applicants may review course details on the SOCR Classes page and submit applications via the SOCR Application Form.

Incident Command System-300 Training – Internal to NOAA only

OR&R will also offer one or two Incident Command System-300 (ICS-300) classes for candidates internal to NOAA. Information is available on the ICS-300 Classes page or through the OR&R Training Team.

General Information about OR&R Training Offerings

There is no tuition cost to attend OR&R classes, but participants must cover their own travel expenses for in-person training. OR&R’s classes experience high demand and are not filled on a first-come, first-served basis.

Responders and planners unable to attend an in-person training may access self-study resources, such as job aids and on-demand training, through the OR&R website. For further information, contact orr.training@noaa.gov or view the OR&R Training Calendar.

NOV. 25, 2025 — A new dataset and updated Environmental Sensitivity Index (ESI) maps are now available for Lake Michigan, providing a critical tool for oil spill preparedness and response in the Great Lakes region. This new Lake Michigan ESI data, which replaces the previous 1993-1994 data, can be downloaded and viewed in Great Lakes ERMA®.

The NOAA Office of Response and Restoration (OR&R)’s ESI program maps sensitive biological and human-use resources, classifies shorelines, and assigns vulnerability rankings based on a shoreline’s sensitivity to oil and chemical spills. These products, in addition to other efforts OR&R is advancing, improve planning and decision-making for environmental response agencies, helping to protect sensitive and rare habitats and inform restoration investments in the Great Lakes.

In addition to the recently published data for Lake Michigan, OR&R has begun updating the ESI datasets for Lakes Superior and Huron, which were last updated in 1994. The updates will also include the Straits of Mackinac and the St. Clair-Detroit River system, last updated in 2019. These areas are high-traffic shipping routes and are home to infrastructure like the 645-mile-long Enbridge Line 5 oil pipeline, which crosses both the Straits of Mackinac and the St. Clair River. Refineries are also located along the St. Clair-Detroit River corridor.

Since 2019, OR&R has released updated ESI data for Lake Erie, the St. Marys River, the St. Lawrence River, the Straits of Mackinac, the St. Clair-Detroit River System, and Lake Ontario. Once all updates are complete, the Great Lakes ESI data will cover over 2,000 miles of shoreline and produce more than 200 maps, improving coastal resilience in the Great Lakes, where busy shipping routes and pipelines support a massive economy. This vital commerce generates $50 billion in annual economic activity, supports between 35 and 40 million tons of cargo, and provides more than 356,000 jobs in the U.S. and Canada.

The modernization of outdated ESI datasets across the Great Lakes has been a collaborative effort supported by significant federal funding. The 2025 update to Lake Michigan data is supported by funding from the Great Lakes Restoration Initiative, in partnership with the Coastal Response Research Center at the University of New Hampshire. Lake Ontario (2023) and the St. Clair/Detroit River System/Straits of Mackinac (2019) updates were funded by the Great Lakes Restoration Initiative, sponsored by the Environmental Protection Agency. The U.S. Coast Guard separately provided funding for the updates to Lake Erie (2022) and the St. Marys and St. Lawrence Rivers (2021).

JUNE 9, 2025 — A 2025 publication, “Exposure to the Polychlorinated biphenyl mixture Aroclor 1254 elicits neurological and cardiac developmental effects in early life stage zebrafish (Danio rerio),” reports on research carried out by the University of North Texas, NOAA’s Office of Response and Restoration Assessment and Restoration Division, and other partners. The paper evaluates the effects of the PCB mixture Aroclor 1254 on the early life stages of zebrafish. This research builds on existing studies examining how PCBs affect fish.

“This work is a great example of how a university works with a federal agency in a research partnership,” says Aaron P. Roberts, Ph.D., a professor within the Department of Biological Sciences at the University of North Texas and senior author of the publication. “The results of the work are important for assessment of chemicals in the environment, and interactions with federal scientists provide university students real-world experience needed for the job market.”

Legacy contaminants, such as PCBs, bioaccumulate through the food chain from invertebrates to fish and wildlife, causing harm to both wildlife and humans who consume a contaminated organism. These contaminants can negatively affect development, growth, and reproduction of organisms in the ecosystem. Zebrafish (Danio rerio) are a common environmental toxicological model species, making them ideal for comparisons across multiple studies.

The goal of this study was to compare the bioaccumulation of different doses of Aroclor 1254 in zebrafish embryos to associated cardiac and neurologic outcomes under different test conditions. Establishing effect concentrations for cardiac and neurotoxic effects of PCBs in early life stage fish is challenging due to the non-reporting of measured concentrations in fish eggs for lab experiments, the lack of standard exposure methods, and the difficulty conducting experiments with PCBs. By reporting tissue concentrations in fish embryos, this research will support standardization across different tests and may improve the accuracy of effect threshold estimates.

The results of this study showed:

• novel neurologic effects (eye tremors) in zebrafish exposed to PCBs,
• cardiac effects (brachycardia, pericardial edema) from exposure to Aroclor 1254 are much less than elicited by PCB 126, confirming results from other studies,
• and the importance of measuring PCB concentrations in water (exposure medium) and receptors (fish tissue).

These findings underscore the importance of understanding how legacy contaminants like PCBs continue to affect aquatic life at critical stages of fish development as scientists work to protect and restore ecosystems impacted by hazardous waste and oil spills.