Sea Ballast and Zebra Mussels (BALLAST)



  
          CASE NUMBER:        166
          CASE MNEMONIC:      BALLAST 
          CASE NAME:          SEA BALLAST AND ZEBRA MUSSELS 

A.   IDENTIFICATION 
1.   The Issue 

     The introduction of zebra mussels into the Great Lakes
ecosystem  has created a new set of problems for both industry and 
environmentalists as they attempt to combat the rise in population
of  this particular menace. First brought to Lake St. Clair in the
ballast  of cargo ships, zebra mussels have reproduced at a
phenomenol  rate. They currently threaten several indigenous
species and  constantly clog the water intake pipes of water
treatment plants  as well as nuclear power facilities. 
 
2.   Description

       Freighters frequently carry cargoes other than what is in
their holds, and one such example is that of the zebra mussel. In
1986, a ship bound for the Great Lakes emptied its ballast tanks of
sea  water into Lake St. Clair while waiting to load its cargo of
grain.  This seemingly harmless action introduced the microscopic
larvae of the zebra mussel into the ecosystem of the Great Lakes
(Nash, p. 63), which had previously been confined to the water
systems of eastern Europe. The zebra mussel is native to the
Caspian Sea  and has spread throughout the canals, rivers, and
lakes of Europe  over the past 150 years (Nash, p. 63). 
     Generally, ships take on a certain amount of water as ballast 
when they have no cargo in order to better handle the oceans 
while in transit. The water which had been sucked in must then 
be discharged when arriving at the ship's destination to make room 
for the ship's cargo. Whatever else has been sucked in with the 
water is then introduced into a different environment when the 
ship discharges its ballast. This is how the zebra mussel was first 
brought into North America. [This is also true of the sea lamprey, 
the spiney perch, and the alewife (McCosh, p. 63).] 
     Zebra mussels (driessena polymorpha) tend to grow in colonies 
of anywhere from thousands to millions of individuals. They inhabit 
smooth surfaces which are easier to adhere to such as clams, boat 
hulls, pilings, pipes, and bouys (Time, p. 63). This species
receives  its "zebra" name from the alternating dark and light
stripes across its  shell which become darker with age. Each mussel
is roughly two  inches long and lives for a period of five years. 
     The zebra mussel was first detected in the United States in 
1988, but probably reached the US in 1986 on board a freighter  as
mentioned above, based on how large the colonies had become  when
detected. [It is not until its second year of life that a zebra 
mussel is capable of being detected because of its microscopic size 
at younger ages (Stegemann, p. 37).] Female zebra mussels lay 
approximately 30,000 eggs per year which then become microscopic, 
floating larvae. It is while in this stage of life that the mussel
is most  easily spread, whether in bilge water or on the wings of
waterfowl  (Miller, p. 2334). 
     Zebra mussels provide several benefits to the waters in which 
they live. A single mussel can filter up to one liter of water per
day as a method of obtaining its food (Conservationist, p. 39),
which effectively rids the surrounding areas of many pollutants
including cadmium and selenium (Omni, p. 29). Mussels can also
filter out green-brown algaes, which frequently discolor water. The
resulting clear water provides the habitat needed for an increase
in the numbers of snails, crayfish, and amphipods which are then
eaten as food by other species of gamefish (Cohen, p. 16). However,
there seem to be many, more negative aspects of the zebra mussel.
       The same filter-feeding allows the unchecked growth of
bottom-growing seaweed which can then choke water systems. The
mussels also filter out plankton which is a primary foodsource for
fish and waterfowl (Miller, p. 2334). Zebra mussels outgrow native
clam and mussel species by ten to twenty times and attach
themselves to other mollusks' shells which then cannot open to
feed, in effect strangling them. This is an additional problem
because seven of the native Great Lakes clam species are on the
endangered species list (Technology Review, p. 15). 
     The largest problems involve where the mussels attach
themselves for their five year lives. Zebra mussels have submerged
navigational bouys because of the weight of their colonies. More
significantly, the mussels pose a serious economic cost to many
industries in the Great Lakes area. During 1990, the city of
Monroe, Michigan lost power for two days because zebra mussels had
clogged the water intakes for the cooling system of the city's
power plant. Detroit Edison, a Michigan  power company, estimated
that it spent $500,000 to correct this problem (Time, p. 63). 
     There are numerous other examples of similar problems. Ford 
Motor Company was forced to close one of its plants for the same 
reason. Industries and utilities in Michigan estimate that over a
ten  year period, they will spend more than four billion dollars to
get rid  of and control the zebra mussel population (Technology
Review, p. 15).  The mussels cause obstruction of pipes, corrosion
of steel, a loss of efficiency, and the production of large amounts
of methane. 
     There are many proposals concerning how to deal with the zebra 
mussel problem. Divers can physically remove the shells by scraping 
them from the intake pipes. However, this is extremely expensive, 
dangerous, and time-consuming. Certain species eat the zebra
mussels  (which are unfit for human consumption). Black carp could
be imported  from Asia, farmed in the US, and sold to industry.
However, the carp could possibly bring with them diseases which
have never been found In the United States before. In addition,
these fish could behave in a different manner when put into a new
environment and eat other native species such as snails (USA Today:
The Magazine of the American Scene, p. 9). 
     Sea ducks are capable of eating the mussels but not in
significant  numbers. The pumping of extremely hot water through
intake pipes can be an effective killer of zebra mussels and is the
cheapest option for widespread industry use. The last option is the
use of chemicals.  Oxidizing biocides, potassium, chlorine, and
ozone are all effective at killing the zebra mussels. Regardless of
the method used, the problem still remains, to remove the shells of
the dead mussels (Miller, p. 2335). 
     The last problem which then must be solved is the disposal of
the  mussel shells and meat. Landfills will not accept them because
of the intolerable odor they create. In addition, many of the
organisms are considered to be toxic because of the high levels of
contaminants found in their bodies. The most successful plan so far
has been the  idea of composting the mussels. 
     The state of Michigan is attempting to compost mussels in a 
manner similar to the method Wisconsin uses for composting fish 
wastes. Michigan could then use the resulting product for
agriculture and horticulture. The shells of the mussels could also
be crushed and used as a calcium supplement in animal feed (Omni,
p. 29). There are four methods which will be attempted: leaving a
static pile under cover, putting a static pile outside, aerating a
covered pile, and aerating a pile outside. The results can then be
compared to examine which is the superior method (BioCycle, p. 52).

     These solution may solve the current problem. However, it is
still  extremely difficult to prevent the spread of the zebra
mussel's microscopic larvae. The U.S. Coast Guard now has a
regulation requiring vessels to dump their ballast before entering
the St. Lawrence  Seaway. The problem will hopefully end with the
states already affected (Alabama, Arkansas, Illinois, Indiana,
Kentucky, Michigan, Minnesota, Missouri, New York, Pennsylvania,
Wisconsin, Ontario, and Quebec). However, there is currently a new
species of zebra mussel on the horizon which is a larger and
hardier cousin of the zebra. It has yet to be determined whether
these methods will also work on the larger Quagga mussel (Ward, p.
34). 
 
3.   Related Cases 

	1. Hawaii Case

     Keyword Clusters 

     (1):Region                    = NAMER (North America) 
     (2):Bio-geography             = OCEAN (Great Lakes) 
     (3):Environmental Problem     = POLS (water pollution) 
 
4.   Draft Author:  William Macon 
 
B.   LEGAL clusters 
 
5.   Discourse and Status:    AGRee and INPROGress 
          There is general agreement by the states surrounding the 
Great Lakes that the zebra mussel represents a serious problem 
to be dealt with. The exact solution is still being discussed and 
experimented with. 
 
6.   Forum and Scope:    USA and UNILATeral 
 
7.   Decision Breadth:   1 (USA) 
          The United States is the only country which must deal 
with the problem of the zebra mussel because eastern Europe 
already coexists with it and does not see it as a major dilemma. 
The U.S. must deal with the mussel on a unilateral basis. 
 
8.   Legal Standing:     NA 
          The only law applicable is the result of the zebra mussel 

infestation. The U.S. Coast Guard now requires all ships to dump 
their water ballast before entering the St. Lawrence Seaway. 
 
C.   GEOGRAPHIC Clusters 
9.   Geographic Locations 
     a.   Geographic Domain:  NAMER 
     b.   Geographic Site:    NNAMER 
     c.   Geographic Impact:  USA 
          The problem is confined to the continent of North America

and more specifically, the United States. 
 
10.  Sub-National Factors:    YES 
      The zebra mussel problem is not one for the entire United 
States. Only the eleven states which have detected the zebra 
mussel or its larvae are affected by its presence. 
 
11.  Type of Habitat:    OCEAN 
      Technically, the zebra mussel is a freshwater mollusk which
cannot exist in saltwater oceans. However, this is the only 
category under which the subject can be placed. 
 
D.   TRADE Clusters 
 
12.  Type of Measure:    REGBAN 
          The Coast Guard has now banned all ships from entering 
the St. Lawrence Seaway without first dumping their ballast. 
 
13.  Direct vs. Indirect Impacts:  INDirect 
          The trade in grain or iron ore on the Great Lakes did not
directly result in the introduction of the zebra mussel. Trade 
indirectly introduced the mussel into the ecosystem through the 
shipping process. 
 
14.  Relation of Measure to Environmental Impact 
     a.   Directly Related:   NO 
     b.   Indirectly Related: YES (shipping) 
     c.   Not Related:        NO    
     d.   Process Related:    YES (habitat loss) 
 
15.  Trade Product Identification: TRANSport 
 
16.  Economic Data 
          The major economic problem associated with the spread 
of the zebra mussel is cost of removal. As stated above, in a
single year, the Detroit Edison power company spent $500,000 to
keep the water intake pipes clear in Monroe, Michigan. The mussel
forced Ford Motor Company to temporarily close one of its plants
resulting in a loss of productivity. Over a ten year period,
industries in the Great Lakes region estimate that they will spend
four billion dollars to clean mussels away from water pipes. 
 
17.  Impact of Measure on Trade Competitiveness:  NA 
 
18.  Industry Sector:    SERVices
 
19.  Exporter and Importer:   EUROPE and USA 
          The original source of the zebra mussel was in the
Caspian Sea of eastern Europe. Although not intentionally exported,
Europe must be considered the exporter. The same holds for listing
the United States as the importer, although unintentional as well. 
 
E.   ENVIRONMENT Clusters 
 
20.  Environmental Problem Type:   POLS 

     The zebra mussel is considered to be sea pollution because: 1)
it lives in the ocean, and 2) it is released into an environment in
an uncontrolled manner similar to waste disposal. In addition, the
species has negative effects within the Great Lakes ecosystem. 
 
21.  Name, Type, and Diversity of Species 

          Name:     Zebra Mussel (driessena polymorpha) 
          Type:     Mollusk 
          Diversity:     NA 
 
22.  Impact and Effect:  MEDIUM and PROD 

     Impact of the mussel is medium based on its threat to native
species in the Great Lakes and economic costs. It is the zebra
mussel itself (the product) which is the threat to the environment.

 
23.  Urgency and Lifetime:    LOW and 5 years 
          The zebra mussel has a lifespan of approximately five
years.  It is considered to have little urgency because it does not
pose a direct threat to the earth or the human race. 
 
24.  Substitutes:   NA 
VI.  OTHER Factors 
25.  Culture:  NO 
26.  Trans-Border:  NO 
27.  Rights:   NO 

          The zebra mussel problem does not affect culture or 
human rights. In addition, zebra mussels are not a trans-boundary 
problem which are the fault of one nation and the problem for
another. 
 
28.  Relevant Literature 
 
     Baker, Sherry. "The Redeeming Qualities of Zebra Mussels." 
Omni, 16 (1994), 28-29. 
 
     "Chinese Black Carp vs. Zebra Mussel." USA Today: The Magazine
of the American Scene, 122 (1993), 9. 
 
     Cohen, Tracey. "Pests with Redeeming Values." Technology 
Review, 95 (1992), 15-16. 
 
     McCosh, Dan. "Aliens Among Us." Popular Science, 246 (1995),
94. 
 
     Miller, S. in Environmental Science and Technology, 26 (1992),
2334-2335. 
 
     Nash, J. Madeleine. "Invasion of the Zebra Mussels." Time, 137
(January 21, 1991), 63. 
 
     Stegemann, Eileen C. "The Zebra Mussel- New York's
Carpetbagger." Conservationist, 47 (1992), 37-41. 
 
     Ward, Janet. "Attack of the Zebra Mussel." American City and 
County, 107 (1992), 30-36. 
 
     "Zebra Mussels Enter the Compost Pile." BioCycle: Journal of
Waste Recycling, 33 (1992), 52. 
  

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