Environmental Monitoring News

With support from the council, a network of citizens monitor our region for invasive species, particularly European green crab and tunicates. This program was initiated by the council in 2000, and has evolved into a self-sustaining grassroots system. Many communities such as Homer and Seward now run their own operations through local science centers. The council supports participation in some of the smaller communities.

The council is particularly concerned about the European green crab. This crab, known to travel in the ballast water of ships at seas, is an efficient and voracious predator that has invaded the West Coast from San Francisco to Vancouver Island. It is feared that the green crab will find its way to Alaska waters. Fortunately, no green crabs were captured in the communities of Chenega, Seward, Homer, Kodiak or Valdez in 2012.

All photos by Janice Banta.

Temperature and salinity of water can have an effect on how toxic dispersed oil is to organisms in the environment, a council study has found.

The Canadian Centre for Offshore Oil, the Bedford Institute of Oceanography and Department of Fisheries and Oceans conducted a council-sponsored study to look at the absorption of dispersed crude oil during the early life stages of herring, salmon and cod when the fish are most sensitive to toxins.

For example, the study found two main causes of higher toxic effects on herring:

1. Herring in cold waters develop at a slower rate than their warm water counterparts.
2. The breakdown of chemicals in cold water is significantly slower than in warm water.

These two factors mean the herring are exposed to toxins for a longer period during their early, more sensitive, life stages.
The study also found that herring were 200 times more sensitive to chemically dispersed crude oil than previously reported.

The council has long endorsed mechanical recovery as the primary tool to combat an oil spill. Unlike dispersant use, which spreads the oil through the water, mechanical recovery with booms and skimmers removes oil from the water.

For more on the council’s research on oil spill dispersants, visit our Dispersants project page.

The long and short term effects of low level exposure to chemically dispersed crude oil on zooplankton needs more research, according to the council’s science committee.

Studies have been conducted on the effects of high-level exposure to crude oil on large animals, such as sea otters and birds. However, not as much is known about the effects of oil on smaller species, such as zooplankton.

Zooplankton and other small species are important to the health of any marine ecosystem. They are the building blocks of the food chain, providing food for larger animals.

One of the first steps in beginning such research is finding out what information already exists. This step helps identify gaps where more research is needed.

A recent council report put together information about research on the effects of chemically dispersed oil on zooplankton and fish larvae.

Chemical dispersants are substances applied to spilled oil with the goal of dispersing oil into the water column rather than leaving it floating on the surface in a slick to be removed or to disperse naturally. Oil slicks treated with dispersants can create underwater plumes of tiny droplets of dispersed oil.

The report indicated that an application of dispersants after an oil spill in Alaska and Prince William Sound could lead to the formation of dispersed oil droplets which could be ingested by zooplankton and other small species.

The researchers looked at the results of studies conducted after large spills such as the Exxon Valdez spill and BP’s Deepwater Horizon explosion in 2010.

The previous research showed three main points that need to be considered in future council studies:

1. An underwater plume of dispersed oil can form after application of dispersant to a large oil spill.
2. Zooplankton have been shown to ingest dispersed oil both in the field and laboratory.
3. Studies carried out after oil spills treated with dispersants have shown effects on the growth and reproduction of zooplankton.

The study also identified priority areas for future research on effects of dispersed oil on zooplankton, including effects on growth and reproduction and whether the cold water zooplankton found in Prince William Sound would respond differently to exposure than warmer water zooplankton.

The council is interested because dispersed oil can impact important subsistence, sport and commercial fisheries species such as herring and salmon.

To read more about the council’s studies on the effects of crude oil, visit our Hydrocarbon Toxicity project page.