As a marine biologist retired from the Virginia Institute of Marine Science, College of

William and Mary, I strongly voice my support of this petition to the Virginia Water Control Board. I am keenly aware of the serious environmental threat that large cruise ships pose to the Chesapeake Bay and global ecosystems. These ships are floating cities with the attendant waste stream components which have consequential negative effects on aquatic environments.

The option for using open loop scrubbers for reducing sulfur oxides in exhaust emissions to comply with 2020 International Maritime Organization regulations was a loophole embraced by the cruise industry to avoid the more costly option of burning low sulfur fuels. Presently, approximately 80% of cruise ships use open loop scrubbers to “clean” the toxic exhaust that results from burning the least expensive grade of dirty fuel available (heavy fuel oil with a high sulfur content). This cost-saving loophole for the cruise ship industry was implemented in part because of the scarcity of low sulfur fuels at the time. This is no longer the case. Navy and

Coast Guard vessels use lower sulfur fuels and therefore do not require open loop scrubbers. Other large commercial vessels such as cargo ships require a fraction of the energy for operations when compared to cruise ships which require constant power on a far greater scale to provide passenger amenities.

Open loop scrubbers work by spraying ambient seawater into the ship’s smoke stacks to intercept sulfur oxides and soot. The washwater, which is highly acidic and laden with heavy metals, is then shunted back into the aquatic environment. The efficiency of these systems is directly linked to the alkalinity (and salinity) of the washwater with maximum efficiency at oceanic salinities. In estuaries like the Chesapeake Bay and fresh water bodies, the efficiency in accomplishing sulfur oxide reduction is highly compromised while water pollution from scrubber discharges remains at a high level.

Current federal regulations on the cruise ship industry are outdated and inadequately enforced. Globally, one hundred and twenty ports have banned open loop scrubbers because of their water pollution impacts.  Requiring low sulfur fuels on cruise ships precludes the use of open loop scrubbers and thus impacts on the surrounding environment, and using shore power while in port eliminates engine use altogether.  Additionally, creating no discharge zones for grey and black water effluents reduces the input of phosphates and nitrates to the Bay thereby lowering triggers for phytoplankton blooms. Monitoring onboard compliance of a multibillion-dollar enterprise that is largely self-regulating will enhance enforcement. For these reasons, I fully support the petition calling for stronger, more effective regulations on the cruise industry and encourage the Virginia Water Control Board to implement measures that will protect the important commercial and recreational fisheries resources and Chesapeake Bay ecosystems in general.