The Council’s annual report, Year in Review 2022/2023, is now available. This report covers the many programs and projects we’ve been working on over the past year, such as oil spill prevention and response, environmental monitoring, oil spill contingency plans, operations at the Valdez Marine Terminal, invasive species monitoring, our outreach efforts, and much more. Highlights from this year include:
An assessment of risks and safety culture at the Valdez Marine Terminal
Ensuring the adequacy of secondary containment liners for the terminal’s crude oil storage tanks
Supporting solutions for sustainable funding for state spill
prevention and response
Improvements to how the Council monitors weather and sea currents in our region
Monitoring oil spill drills and exercises
Reexamining the Council’s position on use of dispersants in our region
New techniques in the field of genetic analysis are improving our understanding of the effects of oil spills.
The Council collects samples from blue mussels like these to better understand the effects of oil spills. Photo by Lisa Matlock.
Since 1993, the Council has gathered data on the presence of hydrocarbons in sediments and blue mussels in the region. Samples of sediments and mussels are collected and analyzed for the presence of oil or other pollutants that originate from the Valdez Marine Terminal and tankers that ship oil from there.
In 2019, the Council began looking at new methods to measure the impacts of oil on the environment. In April 2020, a spill from the terminal leaked approximately 1,400 gallons of oil into Port Valdez. This unfortunate incident presented a unique opportunity to learn.
The new research analyzes the genes of blue mussels using a technique known as “transcriptomics.” Transcriptomics involves measuring how particular genes are expressed in an organism. This expression can be affected by conditions in the environment.
The research began in 2019 with a pilot study. The early research looked at 14 specific genes. More recent work expanded the study to over 7,000 genes, and is summarized in a new report sponsored by the Council.
The researchers compared samples of mussels taken from sites near the terminal, near the Valdez harbor, and a third control site. They found some interesting results.
Effects of oil on genes lingers
After the April 2020 spill, the levels of oil in the mussels had declined by August, however the mussel’s genes showed evidence of lingering effects.
Different pollutants have different effects
More recently, researchers tried to identify how the effects differed according to different contaminants. The crude oil-contaminated samples were compared to samples from the Valdez harbor, which were contaminated with pollutants such as diesel fuel or vessel exhaust, and the control site.
Genes such as those associated with stress, neurotransmitters, and the immune system were among those that varied between the three sites.
Results expected to have far-reaching implications
The information in these studies will help improve the Council’s monitoring program in the future. The researchers noted in the report that the findings are not just applicable to Alaska but could potentially improve monitoring in marine environments around the world.
The oil spilled in 1989 (pictured above) was “heavier” than the oil flowing through the Trans Alaska Pipeline today.
Crude oil is often referred to as a “fossil fuel” because it is made up of plants and animals that lived millions of years ago. Over time, these remains were exposed to heat and pressure inside the Earth’s crust, forming crude oil.
This process is full of variables. The organic materials that make up one pocket of oil can differ from another, or the deposit could have been exposed to different pressures or temperatures during formation. These variables mean oils have different properties such as density, viscosity (thickness), or tendency to form an emulsion.
The oil pumped through the Trans Alaska Pipeline System is a mixture from different fields. That mixture changes over time. The properties of oil can change as the field ages, and new fields are brought into production.
These variations mean the oil behaves differently. It can flow faster or slower, or evaporate more readily.
These, and other variations, influence the techniques used to clean up a spill.
Approximately every five years, the Council obtains a sample of crude oil from the Trans Alaska Pipeline System for analysis. Researchers look at properties such as weight, evaporation, and emulsification. A new report summarizes the latest findings.
Weight
A “heavy” oil is denser than a “light” oil, which flows more easily. Heavy oils are more useful for asphalt and plastics, while lighter oils are processed into gasoline and jet fuel.
When the pipeline first started transporting oil, the oil was considered “heavy.” In 2010, a sample analyzed by the Council found that the oil had lightened considerably. The trend continued in 2015 and again with this recent sample, although the shift has not been as dramatic since 2010. The most recent analysis categorizes the oil as a “medium” viscosity.
These properties may affect response tactics. For instance, if spilled, lighter oils may be easier to pump, however lighter oils could spread more rapidly, covering a larger area.
Evaporation
Lighter weight oils are made up of substances that evaporate more easily. A fuel such as gasoline can evaporate completely at temperatures above freezing. In crude oil, however, evaporation of lighter molecules leaves behind heavier components of the oil. The heavier oil components emulsify more readily.
Emulsification
Emulsification is the process by which one liquid is dispersed into another one in the form of small droplets. Mayonnaise is an example of an emulsion: oil, water, and egg yolks are whisked together to form a thick paste, with the egg serving as the emulsifier to keep the oil and water from separating. In a similar fashion, ocean waves and wind can mix water droplets into spilled oil.
Some emulsified oils break down and separate back into oil and water over time, however in heavier oils, this mixture can stabilize, becoming permanently emulsified.
Emulsified oil is much more difficult to clean up. The volume can triple in size and become almost solid. If the emulsion stabilizes, it is difficult or impossible to recover with a skimmer.
Oil samples analyzed by the Council prior to 2001 formed stable emulsions when weathered. Tests performed on the recent sample found that the newer oil will emulsify, but does not stabilize into a permanent emulsion.
Report available online
The tests on the sample were conducted by Environment and Climate Change Canada. Dr. Merv Fingas interpreted the lab results, which are summarized in the new report:
A new study hints that the herring population in Prince William Sound could be on the rise.
In the early 1990s, the numbers of herring declined drastically, destroying a healthy fishery. The reason for that crash has never been confirmed, though the Exxon Valdez oil spill is considered a contributing factor.
Since then, the herring population has never recovered to the point that fisheries could permanently reopen. Then in 2015, the population crashed again, possibly due to a disease outbreak.
Researchers at the Prince William Sound Science Center have been studying herring for several decades to find out why the population is struggling to recover. The author of the report, Dr. Scott Pegau, coordinates the center’s herring research and monitoring programs. Part of his work includes surveying the coastline of Prince William Sound from a small plane to count the size, numbers, and age of schools of juvenile herring.
The Council sponsored the last four years of these surveys. Forage fish species, such as herring, are often found in shallow coastal waters, so they are particularly susceptible to the effects of an oil spill. The data on where schools of herring and other “forage fish” tend to congregate could be used to help protect those areas in case of a spill.
Second year of increased numbers of herring
Shape and behavior tell the story The different species have different characteristics, for instance, herring form circular or oval-shaped schools, while sand lance schools are irregular. The age of the fish can be identified from the air too. Schools of young herring sparkle as light reflects from the fish as they roll. Older herring have larger, more distinct flashes.
The populations of forage fish can fluctuate, so it’s important to be able to compare the numbers and sizes of schools to past years. Similar surveys have been conducted as far back as the 1990s.
The number of schools of 1-year-old herring is used to estimate future population growth. Surveys conducted in 2022 found an increase in these young herring for the second year in a row. The researchers are hopeful that this means an increase in the number of herring that will return to spawn in the next two years.
“If this is true, we can expect that the herring population will have robust growth in the near future,” Dr. Pegau notes in the report.
Dr. Pegau also advises caution. He notes that these surveys were conducted during a period of unusually warm and sunny weather, and that this could have inflated the count. Future surveys will confirm whether this increase will be permanent.
Read more about the Prince William Sound Science Center’s herring research on their website: Prince William Sound Science Center’s Herring Research and Monitoring Program
The Council’s annual report, Year in Review 2022/2023, is now available. This report covers the many programs and projects we’ve been working on over the past year, such as oil spill prevention and response, environmental monitoring, oil spill contingency plans, operations at the Valdez Marine Terminal, invasive species monitoring, our outreach efforts, and much more. Highlights from this year include:
