The world maritime community recognizes Great Lakes shipping as the originator of many technological and operational advancements. Jones Act carriers invented and then perfected the self-unloading vessel. Lake Carriers’ Association implemented separated traffic lanes, a boon to safety that was eventually adopted in busy waterways throughout the world.
In the years ahead, the Great Lakes governors and maritime and scientific communities will also be remembered as groundbreakers in the efforts to manage ballast water. LCA and the Northeast Midwest Institute, working side-by-side with Canadian carriers and governmental agencies on both sides of the border, will in 1997 begin the most extensive shipboard test of a ballast water management technique ever undertaken in the world. A ballast water filtration system installed on the Canadian-Flag laker ALGONORTH may just prove to be the stepping stone to the first practical system(s) to stop the introduction of non-indigenous species in waterways and harbors throughout the world.
Actually, the Lakes are already recognized as a leader in ballast water management. Sometime in the 1980s, a saltwater vessel introduced the ruffe to Duluth/Superior harbor. When it became apparent that the ruffe posed a threat to other aquatic species, the Great Lakes shipping industry implemented the Voluntary Ballast Water Management Program (VBWMP) for vessels calling on Duluth/Superior. [ Since its introduction, the ruffe has become the most populous fish in Duluth/Superior harbor.] This program has been in effect since 1993 and to date has largely met its goal of slowing the ruffe’s spread. [ Long-term confinement of the ruffe is unlikely unless shorebased measures are implemented. The fish is migrating along Superior’s southern shore at the rate of roughly 25 miles a year. Treatment of streams and inlets with piscicides is probably the only option that might stop the ruffe from reaching the St. Marys River. Once the ruffe enters the St. Marys, it’s only a matter of time before it spreads to the lower Lakes.] Although Duluth/Superior handles roughly 1,000 ship calls each season, the ruffe remains confined to Lake Superior with just one exception. A fledgling population has been discovered in Alpena harbor on Lake Huron, but, biologists cannot state with any certainty that the ruffe arrived in Alpena after implementation of the VBWMP. It is possible the ruffe arrived in Alpena prior to the VBWMP. In any event, the Great Lakes shipping industry responded quickly and has developed a ballast regime for vessels calling on Alpena.
The problem of ballast water transport of non-indigenous species is not unique to the Great Lakes. On the East Coast, ships have introduced the Japanese Shore Crab; in the Gulf, the Brown Mussel; on the West Coast, the Chinese Mitten Crab.
The Great Lakes region has undertaken two steps to reduce the introduction of non-indigenous species. Since 1993, the U.S. Coast Guard has required vessels entering from the sea to either exchange ballast during their ocean voyage or seal ballast tanks for the duration of their Lakes stay.
Neither option is foolproof. First of all, many saltwater vessels enter the Lakes fully loaded and thus have no ballast on board ("NOBOB" vessels). However, there is always a small amount of ballast water that can’t be pumped out and it’s enough to support fishlife. Also, over time, bottom sediment collects in ballast tanks and that "mud" can likewise support fish and plant life.
What happens then is that when the saltie discharges its cargo, it must take on ballast so the ship will ride low enough in the water to maintain safe hull stress, stability and steerage. When the ship arrives at its loading port, it discharges that ballast as it takes on cargo and conceivably introduces a non-indigenous species to the harbor.
The problem with sealing ballast tanks is that it deprives the ship operator of the use of ballast tanks for safety reasons. There is also a remote chance the spaces could be breached during a grounding or collision.
Recognizing the drawbacks to current measures, The Great Lakes Protection Fund awarded LCA and the Northeast Midwest Institute a $1.3 million grant in 1996 to develop and test technology that can be used to treat ballast water aboard a working vessel. (The Great Lakes Protection Fund is a cooperative effort of seven of the eight Great Lakes states to underwrite programs to restore or protect the Great Lakes environment.) After consultation with experts in many fields throughout the United States and Canada, filtration was selected as the most promising technology for further study and evaluation.
The filter installed on the ALGONORTH was designed by Ontario Hydro Technologies. The Canadian utility has extensive experience in filtration as a means of keeping zebra mussels out of its power generating equipment. The filter is capable of trapping particles as small as 25 microns and designed to operate at 1,500 gallons per minute.
The filtration system was installed on the ALGONORTH toward the end of the 1996 shipping season and tested a few times. During the winter lay-up, some refinements were made and installation of other equipment completed. The ship returned to service in April of this year and the system will be run each time the vessel loads and discharges cargo. (The ALGONORTH brings in Canadian iron ore and exits with grain from Lake Superior ports. One of the reasons the vessel was chosen is that it operates in both fresh and salt water environments.)
It is important to understand the scope of these tests. Only a portion of the ballast water the ship takes on will be filtered. The purpose of these tests is to determine if filtration works on a small (but not insignificant) scale. If the tests are successful, then the next step will be design of a filter system that can work on a larger scale.
If filtration of ballast water proves effective against aquatic invaders, another problem — that of pathogens — will be a step closer to a solution. If filtration can sufficiently clear ballast water, then a secondary treatment such as chemicals, heat or ultraviolet can be considered. Pathogens have not been a great problem on the Lakes because few saltwater vessels trade here from the developing world, but the problem is a serious concern elsewhere.
At the July 23, 1996, news conference announcing the grant to LCA and the Northeast Midwest Institute, Wisconsin Governor Tommy Thompson declared, "We are resolved to keep the Great Lakes open to world commerce, but closed to biological invaders." That statement sums up the challenge facing the Great Lakes and waterways throughout the world. Without ships there is virtually no commerce, but without ballasting and deballasting, ships can’t operate. A long-term solution must be found so that commerce can thrive without impacting the environment.
It is important to recognize that the problem of ballast transport of non-indigenous species does not lend itself to a universal approach. The filtration system on the ALGONORTH is but one of several options. Other organizations in other parts of the world are studying heat treatment of ballast water, ultraviolet treatments and even chemical treatment of ballast water. What eventually will evolve will be a toolbox from which ship operators can select the option(s) which best suit their vessels and trades.
There must also be a recognition of what can be remedied. Once a fish or plant has established itself in an environment, eradication is virtually impossible. The ruffe, the zebra mussel, the round goby... are here to stay. The Voluntary Ballast Water Management Program has and will continue to slow the spread of the ruffe, but barring a major development, the fish will eventually reach the other Lakes.
Another reason the emphasis must be on stopping the introduction of new non-indigenous species into the Lakes is that the design of U.S.-Flag Great Lakes vessels poses insurmountable problems concerning management of ballast water. U.S.-Flag lakers carry tremendous amounts of cargo (as much as 70,000 tons each trip), but this means that when empty, they must carry a near like amount of ballast. The 1,000-footers need 14,000,000 gallons of water when in a "light" condition. Even the 500-foot-long ships in the cement trade take on 2.5 million gallons of water when returning to their loading ports. At this point in time, there is no technology even imaginable that could economically filter or treat such volumes of water at the pumping rates on U.S.-Flag lakers (as much as 18,000 gallons per minute).
Next year’s ANNUAL REPORT will highlight the results of the tests aboard the ALGONORTH and detail the next steps. Ballast water transport of non-indigenous species will not be solved quickly, but the efforts begun here on the Great Lakes in 1996 will no doubt be the genesis for procedures and systems that will someday solve the problem.