Program Manager
Lisa Ka'aihue
907.273.6225
3709 Spenard Rd., Ste. 100
Anchorage, AK 99503
NIS Studies
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NIS Completed Studies
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Ballast Water Treatment Studies
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BWT Studies Underway
The potential for invasion by non-indigenous species into Prince William Sound and other Alaskan waters from oil tanker ballast water discharges has been a priority issue for PWSRCAC since 1996. PWSRCAC, in collaboration with the U.S. Fish & Wildlife Service, NOAA National Sea Grant Program through Oregon State University, and the University of Alaska Fairbanks, funded a series of studies to assess the potential for invasion of Prince William Sound by non-indigenous marine species.
2006
The following report, submitted by Smithsonian researchers, forecasts the northward spread of four invasive species to Alaska waters. The report concluded all four species—an invasive barnacle, the European green crab, the club tunicate, and the Atlantic periwinkle—could find suitable environments in Alaska waters to survive and could be indicative of other invasive species spreading to Alaska.
Northward Spread of Marine Nonindigenous Species along Western North America: Forecasting Risk of Colonization in Alaskan Waters Using Environmental Niche Modeling. By Catherine E. de Rivera, Brian P. Steves, Gregory M. Ruiz, Paul Fofonoff, and Anson H. Hines. 2006 (pdf/2.9MB)
The following report systhesizes the results of biological surveys conducted at several sites including sites in Prince William Sound. The report looks at Alaska in the context of the entire United States. Results indicate that Alaska has a low level of invasions compared to other sites; however, there is no evidence to suggest that Alaska has a low susceptibility to invasions. The authors urge precautionary and proactive management strategies to limit the transfer of organisms by various vectors, including ships.
Biological Invasions in Alaska’s Coastal Marine Ecosystems: Establishing a Baseline. By Gregory M. Ruiz, Smithsonian Environmental Research Center, et. al. 2006. (pdf/2.8MB)
2005
The following 2005 report to the National Fish & Wildlife Foundation found that the number of invasive species decreases at higher latitudes, with Alaska having the lowest numbers of all sampled U.S. west coast sites. This was a collaborative project by Smithsonian Environmental Research Center, the National Estuarine Research Reserve System (NERRS) and the National Marine Sanctuary Program (NMSP).
Final Report Summary: Broad-Scale Non-indigenous Species Monitoring along the West Coast in National Marine Sanctuaries and National Estuarine Research Reserves (pdf/1.3MB)
Site-specific Projects (pdf/6.5MB)
Overall Conclusions (pdf/3.1MB)
2004
Smithsonian Environmental Research Center developed a projection of the potential spread of the European Green Crab in Alaska. The European Green Crab is an invasive species that has successfully colonized many world regions with significant ecological and economic impacts. The temperatures and salinities that the European Green Crab larvae need to survive and thrive were tested in laboratory experiments. Based upon temperature-specific development rates, several sites within Prince William Sound and elsewhere in Alaska appear warm enough to support self-sustaining European Green Crab populations. The researchers conclude that Alaska is at risk of invasion by European Green Crabs.
Projecting Range Expansion of Invasive European Green Crabs (carcinus maenas) to Alaska: Temperature and Salinity Tolerance of Larvae (2004) Anson H. Hines, Ph.D. Gregory M. Ruiz, Ph.D. Natasha Gray Hitchcock, M.S. Catherine deRivera, Ph.D. (pdf/563KB)
2001
This report summarizes research on non-indigenous species in marine ecosystems of Alaska during the year 2000 by the Smithsonian Environmental Research Center. The project is an extension of three years of research on NIS in Prince William Sound and describes the progress in documenting NIS and biodiversity of Southcentral Alaska. Previous surveys of NIS in Southcentral Alaska indicated that Homer Boat Harbor on Kachemak Bay appeared to have a greater number of NIS than other sites in the Prince William Sound region. This elevated concerns of NIS risks because of recently increased shipping activity for wood products at Homer and tankers at Nikiski. Sites of successful invasions could allow NIS to spread readily to neighboring areas. To assess the prevalence of non-indigenous species, a team of about 20 taxonomic and ecological experts conducted intensive field surveys in Kachemak Bay on a low tide series during August 2000. Major findings include:
• Surveys in Kachemak Bay and Cook Inlet found 13 NIS in diverse taxonomic groups, including 3 NIS of hydroids, 1 bryozoans, 2 bivalve mollusks, and 7 species of vascular plants
• Taxonomic experts confirmed 4 "cryptogenic species" (species of unknown but suspicious origins) in Kachemak Bay, including a new species of ascidean, a sea star, and 2 species of hydroid.
• Field and fouling plate surveys in Kachemak Bay provided new documentation of the biodiversity of the region, and helped develop species lists for the National Estuarine Research Reserve
Marine Invasive Species and Biodiversity of South Central Alaska (2001) (pdf/221KB)
2000
This report provided the first synthesis of NIS known to be in Alaska, resulting from an extensive literature review and field-based surveys. The study concluded that several NIS are present in the segregated ballast water released by oil tankers into Prince William Sound. The Smithsonian Environmental Research Center identified a total of 15 NIS in Prince William Sound. These NIS may have been transferred to Prince William Sound in the ballast water of oil tankers, on the bottoms of vessel hulls or sea chests, or by other means.
Biological Invasions of Cold-Water Coastal Ecosystems: Ballast-Mediated Introductions in Port Valdez / Prince William Sound Alaska (2000) Dr. Anson H. Hines, Ph.D. and Dr. Gregory M. Ruiz, Ph.D. (pdf/1.6MB)
1997 Smithsonian Pilot Study
Although non-indigenous species are common in marine environments, and some cause significant environmental and economic impacts throughout the world, prior to this study there was very little information available for the frequency or impact of invasions by non-indigenous species at high latitudes. This pilot study was conducted over a one-year period as an initial step in defining the problem and potential risks in Port Valdez and Prince William Sound. The 1997 pilot study showed that plankton are abundant and diverse in the arriving ballast water and that some are not indigenous to Prince William Sound. The consultants doing the study concluded that the sound is at risk of invasion. The study was extended to provide further investigation into the content and management of ballast water. Aquatic samples were collected and analyzed to see what non-indigenous species have already become established.
The Risk of Nonindigenous Species Invasion in Prince William Sound Associated with Tanker Traffic and Ballast Water Management: Pilot Study (1997) (pdf/5.3MB)
Supplemental Report Data (pdf/3.3MB)
The first comprehensive biological assessment of non-indigenous aquatic species in Prince William Sound was completed in 2000.
Since then, PWSRCAC has provided funding for an array of field studies, laboratory experiments, ballast water analyses, and data management projects to measure the patterns and risk of invasive species in the marine ecosystems of Prince William Sound and other sites of coastal Alaska.
Currently, PWSRCAC is working with University of Washington to evaluate the risk posed by vessel fouling in Prince William Sound. Vessel fouling refers to marine species attaching themselves to the hulls of vessels. In recent years, researchers across the world have been recognizing hull fouling as a significant pathway for invasive species. The research objectives for our hull fouling work include:
This work is being supported through a grant from the US Fish and Wildlife Service, and is scheduled to be completed in December 2008.
Strategies for Shipboard Evaluation of Ballast Water Treatment Systems
A workshop in June 2005 reviewed strategies for shipboard evaluation of ballast water treatment systems. The overall objective of the workshop was to develop consensus recommendations and general guidelines for a standardized approach to shipboard evaluation, including groundwork leading up to full-scale testing. The workshop and report were supported by the Alaska Department of Fish and Game, the Pacific States Marine Fisheries Commission, and Prince William Sound Regional Citizens' Advisory Council.
Workshop Report on Testing of Ballast Water Treatment Systems: General Guidelines and Step-wise Strategy Toward Shipboard Testing. by GM Ruiz, GE Smith, & M Sytsma, Aquatic Bioinvasion Research and Policy Institute. 2006. (pdf/249KB)
Efficacy Rate of Mid-ocean Ballast Water Exchange
The Smithsonian Environmental Research Center performed a series of experiments on board oil tankers to determine the efficacy rate of mid-ocean ballast water exchange in reducing the amount of species transferred in ballast water from port to port. The study found ballast water exchange on oil tankers arriving to Prince William Sound was highly effective and that the technique is a valuable management tool. This management tool is not currently required for the tankers engaged in the Trans Alaska Pipeline oil trade. See more about NIS legislation.
Ballast Water Exchange: Efficacy of treating ships’ ballast water to reduce marine species transfers and invasion success? Smithsonian Environmental Research Center. 2005. (pdf/187KB)
British Petroleum's Ozone System Study
In 1998, BP Alaska conducted a study testing ozone gas as a method of decontaminating ballast water containing non-indigenous aquatic species. A full-scale prototype ozonation system was installed and tested on board the then BP-affiliate ship the Tonsina, operated by Alaska Tanker Company. A final report on this study was issued in May 2002.
The study's objectives were to:
• Determine the disinfection effectiveness of a full-scale ozone system in comparison with ballast water exchange efficiency
• Determine the acceptability of discharging treated ballast water using whole effluent toxicity testing, and to determine the latent toxicity of the subsequent ballast water discharge
• Obtain operational experience with the prototype ozone system in order to implement further system improvements
The study concluded that ozonation has the potential for being an effective and safe technology for removal of non-indigenous species from ballast water. They concluded that:
• Using the prototype system, 5-10 hours of ballast water ozonation resulted in 71-99% removal of most marine phytoplankton, zooplankton, and bacteria depending on the amount of ozone gas delivered to individual ballast water tanks over time. Benthic organisms (e.g. crabs, amphipods) appear to be relatively resistant to ozone treatment. The study noted that the overall system effectiveness may have been underestimated because of the longer-term residual toxicity of bromine.
• The organism removal efficiency was greater than that achieved (64% on average) using empty-refill ballast water exchange on the same vessel.
• Field and laboratory experiments suggest that significant organism mortality can be achieved once concentration of ozone-produced oxidants reach 1-3 mg/l (as chlorine equivalents) or when oxidation-reduction potentials reach levels of 700-800 mV.
• Bromine was the ozone-produced oxidant that was most likely responsible for organism mortality. Bromine may also persist at toxic concentration in ballast waters 1-2 days following ozonation depending on storage conditions and exposure to sunlight. However, bromine may be easily eliminated following ballast water discharge.
There have been a number of studies to examine potential ballast water treatment options that may be effective for use in the Alaska North Slope crude oil tanker trade.
To read more about techniques used to compile studies, please refer to our bibliographic database page.
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