Oil Spill Response

Analysis of genes increases understanding of oil’s effects

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New techniques in the field of genetic analysis are improving our understanding of the effects of oil spills.

Image of a colony of blue mussels on a shore in Larsen Bay, Prince William Sound. The waters and mountains of Prince William Sound can be seen in the distance.
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.

Alaska North Slope oil trending lighter since 2010

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Photo take after the Exxon Valdez oil spill of a rocky beach in Prince William Sound. The rocks are coated in black crude oil.
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:

Drills and exercises getting back to normal

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Photo shows responders practicing an oil spill response during low-light conditions. The area is lit using multiple bright lights to be able to see the equipment.
The Council would like to see more exercises performed during low-visibility conditions. If a spill were to occur during winter or a foggy summer day, crews don’t have as much practice in how to adjust tactics for these conditions. Photo by Jeremy Robida.

For the past few years, the COVID-19 pandemic affected many aspects of daily life. Oil spill drills and exercises were not exempt. Restrictions to protect the health and safety of responders limited these activities.

Not only were there fewer drills and exercises, they were harder to observe. Social distancing meant that Council staff could not board tugs and barges to see response operations up close. Council staff members Roy Robertson and Jeremy Robida, who have monitored drills and exercises in Prince William Sound for the past 18 and 13 years respectively, conducted some observations from a separate chartered vessel.

Fortunately, this year many of the restrictions were lifted.

New report summarizes 2022 drills

The Council’s annual report on drills and exercises conducted in Prince William Sound in 2022 has been released. The report highlights some of the continuing effects from the pandemic, along with a few changes that are here to stay.

Conducting business online

Virtual conferencing has changed many workplaces, including oil spill response. These technologies have shown up in several ways.

Coordinating online: Many drills are now hybrid (in person with online participants). Meetings are broadcast on videoconferencing platforms. Documents and other data are shared through online collaboration tools. Robertson says there are still some glitches, but these are improving.

Live video streaming: During a drill in May, the Alaska Department of Environmental Conservation deployed a drone over some activities out on the water. They were able to stream live video to the Valdez command center and participants in Jacksonville, Florida. The video was also recorded and available for later review.

Online training options: Alyeska’s Ship Escort Response Vessel System conducts annual trainings for crews of local fishing vessels, who are contracted to respond in case of a spill. Before the pandemic, part of the training sessions were held in a classroom, part were hands-on experience with equipment on dry land, and finally, crews would practice deploying equipment on the water.

Since the pandemic, the classroom sessions have been held online. The dry-land portion that required closer physical interaction between participants had not been held since 2020, but returned in 2023. The on-water portion remains the same.

Improvements at Valdez Duck Flats

Pandemic restrictions particularly affected exercises to practice either diverting oil from shorelines or protecting locations that are particularly sensitive to oil contamination, such as hatcheries. These tactics are performed by fishing vessels which have little room for social distancing. The return to in-person exercises is important for these activities.
Robertson noted in the report that responders spent more time this year practicing tactics to protect the Valdez Duck Flats, a highly productive biological area that provides critical habitat for a variety of waterfowl, small mammals, and marine mammals. This area is particularly sensitive to oil contamination. This was time well spent, he says. Robertson said that the responders have become more proficient at these tactics.

More details in the report: Drill Monitoring Annual Report for 2022

 

Cleaning up a big oil spill

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A large spill would require equipment brought in from other regions. The Council recently sponsored a study on the availability of equipment on short notice.

The oil industry in Prince William Sound has one of the best-equipped spill prevention and response systems in the world. However, if a big spill were to occur, more equipment would still be needed.

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