Marine water invaders on Most Wanted
State aims to stop non-native species
By Beth Daley
The Boston Globe Staff
Published January 9, 2006
The sea slime alarm was sounded in 2002. Scientists discovered
small, dense mats of a strange gooey creature on the ocean
floor more than 100 miles offshore. A year later, the
sea squirts had carpeted more than 6 square miles there
and kept going. Soon, the bizarre, stringy squirts were
showing up in enormous colonies in new places along the
shoreline and fishermen began complaining they were smothering
State officials have surrendered any hope of slowing
the sea squirts' goopy spread, which may be making the
seafloor inhospitable to fish eggs. But they are determined
to stop other marine invaders -- many of which hitchhike
accidentally across the ocean on ships -- from establishing
a foothold and harming fishing, tourism, or biodiversity.
Starting this summer, state officials will pay to train
scores of volunteers to scour the state's beaches and
peer at the underside of docks looking for any sign of
invasive species. Armed with a marine Most Wanted list
-- a deck of 20 laminated cards picturing likely invaders
-- the volunteers will collect information for a database
being developed with the Massachusetts Institute of Technology
Sea Grant Program.
Officials hope the early discovery of potentially dangerous
species will help the state mobilize a strike team to
''We know this is really hard and we're just beginning,"
said Beth Suedmeyer, invasive species specialist for the
state Coastal Zone Management office.
Despite hundreds of documented marine invasions in the
United States, officials have been able to contain only
one: a fast-growing Mediterranean seaweed introduced into
two California lagoons in 2000 that was killed with chlorine.
''We're hoping there will be opportunities to [stop]
something . . . from moving up the coast in the future,"
Invasive land species have long been the scourge of gardeners
and landscapers -- ask anyone who has tried to extract
plants from the choking grip of an oriental bittersweet
vine. This month, Massachusetts began banning more than
140 plants from being bought or sold in the state because
they are threatening native species.
The freshwater zebra mussel that arrived in the Great
Lakes in 1988 is the invasive species poster child, spreading
to 20 states and reproducing so densely it clogs drain
One alarming estimate places the economic cost to businesses
from invasive species as high as $100 billion a year,
but scientists say no one has accurately isolated how
much of that is from marine species.
What's hard enough to control on land or in lakes has
been nearly impossible to identify in the sea's murky
depths, where the animals are often out of sight.
Scientists say they believe most of the marine invasive
species are sucked into ships' holds with tons of ballast
water used to keep the vessels steady on voyages, only
to be silently discharged half a world away into an environment
where they may have few predators.
Scientists know of about 50 non-native species off New
England's coast that they probably can't do anything about,
including a European seaweed known as ''dead man's finger"
that arrived in the 1960s and is now being tied to the
destruction of cod and sea urchin habitat.
The US Coast Guard began a mandatory program in 2004
to require all large ships traveling from overseas to
exchange their ballast water with ocean water at least
200 miles from shore, where there will be fewer organisms
to bring to a new port. Last month, the agency prohibited
a Panamanian-flagged ship traveling from the Bahamas to
Boston from entering the city's port until it went back
out to sea and exchanged its ballast water because the
ship could not prove it had done so. The ship did not
have required records of when it took in and discharged
But specialists say the invaders have many other ways
to get here, such as attaching to the hulls of boats,
or contained in deliveries of aquaculture, aquarium supplies,
or live bait.
Scientists say some submerged invaders have probably
been around since Colonial days and people may mistakenly
believe they are native.
But in recent years, a series of invasions have gotten
scientists' full attention. In 1992, a group of schoolchildren
on a science trip in Woods Hole spotted an inch-long crab
scurrying on the rocky beach. It was an Asian shore crab,
and within several years it had spread to Boston. This
summer, it reached Acadia National Park in Maine. Discovered
in New Jersey in 1988, the crab eats almost anything it
can find and scientists say it is forcing out native populations
of mud crabs and might also be competing with lobsters
or larger crabs for food.
The invasion news got worse with the sea squirt, which
fishermen say looks like fast-spreading pancake batter.
There are other kinds of non-native squirts off New England,
but none is as feared as this kind, known as Didemnum.
The animals are a kind of superorganism, able to reproduce
both sexually and asexually so even a tiny fragment can
form new colonies. Nothing eats them, and where they came
from and when is unknown.
In 2000, scientists began assessing exactly what was
in New England marine waters by descending on regions
for a week at a time to count and identify species, but
the program provides only a snapshot of the problem.
To help in the Bay State, Massachusetts gave Salem Sound
Coastwatch, a local nonprofit, a grant of $10,000 in 2004
to develop a pilot program for average citizens to identify
invasive marine species. Officials say they cannot expect
citizens to identify all species -- even taxonomists have
a hard time with that -- but citizens can identify certain
foreign creatures that have caused problems elsewhere.
The Salem program trained more than 50 people, and this
year state officials have about $20,000 to help train
about five more nonprofit groups.
Now, state officials, along with a coalition of other
New England officials and scientists, are trying to develop
a plan in case they find a potentially dangerous invader.
Possibilities include simply pulling the creatures out
of the water or sand by hand and throwing them away, or
using pesticides or parasites that can be targeted to
the invasive species.
''The best approach is get them early because you don't
know what is going to happen, " said David Delaney,
a doctoral student at McGill University who is helping
to create a network of citizen groups in the Northeast
to identify invasive marine species. ''It is roulette."