Effectiveness of Ballast Water Exchange in Protecting Puget Sound from Invasive Species

This report is provided to meet project scope of work requirements for Task 6 (Phase 3 Stakeholder review of draft final report), deliverable 6.1 (Phase 3 final report), which incorporates all stakeholder review comments provided by the Washington Department of Fish and Wildlife’s Ballast Water Work Group¹. This report was made possible by a grant of $139,943 from the Environmental Protection Agency’s Puget Sound Marine and Nearshore Grant Program.

Background

Preventing invasive species from establishing and spreading is the most cost effective and least environmentally damaging method of protecting Puget Sound ecosystems and local economies from the impacts of those species. This project addresses the Puget Sound Partnership’s 2012/2013 Action Agenda priority B5.3 NTA 4 to â€�"complete an assessment of and make recommendations to improve the effectiveness of open sea exchange and treatment in meeting state ballast water standards.” This project addresses the effectiveness of ballast water exchange, as it remains the primary management requirement for ships until operation of treatment systems to meet federal discharge standards is required. It is expected ballast water exchange will remain a significant management option until at least 2021 because at the time of this report, very few ships using treatment systems have been arriving at state ports, no treatment systems have been type-approved by the U.S. Coast Guard resulting in numerous compliance date extension requests, and the implementation timeline for the largest class of existing vessels (>5,000 cubic meter volume ballast water capacity) will likely result in those vessels not installing treatment systems until 2021 (first scheduled drydocking after January 1, 2016 â€" and applying common drydock period of 5 years).

Ballast water is one of the most significant global pathways for movement and spread of invasive non-indigenous species (Ruiz et al., 1997; Molnar et al., 2008; Hulme 2009; Keller et al., 2010; Kolzsch and Blasius 2011). Ships use ballast water taken up in other national or international locations to maintain trim and stability during voyages and then discharge the ballast water when taking on cargo, containers, passengers, or fuel at Washington ports. On average, 1,350 or a third of Washington State total annual vessel arrivals (4,100) discharge over 15 million cubic meters of ballast water, which is equivalent to the volume capacity of 104,550 railroad grain cars. Such a train would stretch from Los Angeles, California, to Seattle. Within Puget Sound, on average 735 vessel arrivals discharge 6.6 million cubic meters of ballast water per year. In 2000, the legislature directed WDFW under Chapter 77.120 of the Revised Code of Washington (RCW) to ensure that the discharge of ballast water by ships poses minimal risk of introducing non-indigenous invasive species into waters of the state.

State ballast water management regulations under chapter 220-150 of the Washington Administrative Code (WAC) require ships to perform an open sea ballast water exchange (or gexchangeh) to minimize discharge of high-risk coastal species which contain varying densities of potentially invasive non-indigenous species. Exchange is required beyond 200 nautical miles from any shore and in waters greater than 2,000 meters deep for voyages from outside the U.S. Exclusive Economic Zone (EEZ) and beyond 50 nautical miles from any shore and in waters greater than 200 meters deep for coastal voyages that do not voyage outside the U.S. EEZ.h Exchange is not required for voyages from a gcommon waterh zone established between the Columbia River (including both Washington and Oregon ports) ports that are south of 50° N latitude in British Columbia.

Ballast Water Exchange Effectiveness History

The purpose of ballast water exchange is to minimize invasive species risks by reducing the densities of all coastal organisms in shipfs ballast. This is accomplished by flushing coastal organisms into open sea waters and then altering the environmental conditions (e.g. salinity and temperature) within the ballast tank to decrease survivorship of any residual coastal organisms that remain following exchange. Coastal zooplankton species are used as a surrogate for efficacy of ballast water exchange for all coastal organisms as identification of coastal from oceanic species is possible. In controlled studies on four ship types, Ruiz et al. (2007) found that three of the four ship types tested (i.e. crude oil tankers, USN refueling ships, bulk carriers) reduced the densities of coastal zooplankton on average by ≥ 90%. The fourth ship type (container) reduced the densities of coastal zooplankton on average by ≥ 80%. Lower efficacy was assumed to be a result of generally smaller ballast tank size and more complex design.

Previous studies using Washington State ballast water exchange data have shown that although compliance with exchange regulations is high, exchange does not necessarily correlate with significant reductions in coastal zooplankton (Cordell et al. 2009; Lawrence and Cordell 2010). One of the primary purposes of this report is to build on these and other studies to assess whether factors such as ship type, ballast origin, ballast water age, and ballast water exchange method can be used to enhance the statefs risk-based management program.

In 2001, the University of Washington (UW) began collecting zooplankton samples from ballast water held in ballast tanks from a subset of ships arriving in Seattle ports. In 2004, WDFW took over this sampling and expanded it to all Washington ports as part of an initial ballast water management and compliance program to determine the effectiveness of state ballast water exchange management requirements. This is a unique program with an unprecedented archive of existing samples. Prior to this project, approximately 380 samples taken between 2001 and 2007 had been analyzed and the results presented in two published papers (Cordell et al. 2009; Lawrence and Cordell 2010). For this project, an additional 436 samples have been collected for a combined data set of 816 samples from 569 individual ships². There is no data on the actual number of ship arrivals that discharged into Puget Sound since 2001, but assuming an average of 735 vessel arrivals that discharged annually, the 816 samples represent up to 8% of those arrivals.

Ballast Water Exchange Sampling as a Management Tool

WDFW has used ballast water exchange sampling in the past primarily to estimate overall non-indigenous zooplankton introduction risks by vessels discharging into Puget Sound and secondarily to demonstrate relative vessel risks due to factors such as frequent routing from ports with high risk non-indigenous zooplankton profiles, suspected ballast tank design limitations, and discharge of non-compliant ballast water. The assumption is that samples from vessels that conducted effective exchanges would have relatively lower percent compositions and densities of coastal zooplankton than those vessels that did not.

A major challenge of using ballast water exchange sampling is determining when higher percent composition and density of coastal species indicates poor exchange effectiveness due to ballast tank design limitations, non-compliance with exchange regulations, or environmental factors.

In 2009, WDFW established provisions for using ballast water exchange sampling as a management tool under Washington Administrative Code (WAC) 220-150-035 �"Vessels carrying high risk ballast water.” This regulation directs the department to �"identify, publish, and maintain a list of vessels that pose an elevated risk of discharging ballast water or sediment containing non-indigenous species into the waters of the state.” The primary listing criteria for using exchange sampling is to provide a non-indigenous species profile of originating waters and evidence of ballast tank design limitations that prevent effective exchanges. Vessels on the list could then be prioritized for further evaluation, which might include additional sampling and completion of temporary compliance plans or alternative strategies under WAC 220-150-037.

One of the objectives of this report is to identify and recommend threshold(s) for determining when there is sufficient evidence for listing (or delisting) a vessel under WAC 220-150-035, and determine if there is a gross exceedance threshold that can establish non-compliance.

¹ Established under WAC 220-150-010(2)

² Total samples can represent different ballast tanks on same ship and same voyage or from same ship and different voyages.