What people on the East Coast call productive
vegetation is considered an invasive weed on the West
Coast and China. On the East Coast, Spartina alterniflora
is planted and Phragmites is eradicated, while in Europe
and China they value Phragmites and are concerned about
it dying back. It does make you wonder if a certain amount
of xenophobia is involved in our responses to
nonindigenous species.
Green algae: Caulerpa
A strain of Caulerpa taxifolia developed for use as an
aquarium plant was inadvertently released into the Mediterranean Sea from the Monaco Aquarium in the 1980s.
It initially occupied only a few square feet, but was not
removed and subsequently grew and spread so vigorously
that it practically took over the Mediterranean (Meinesz
et al., 1993). It can regenerate from fragments, so physical
removal can make the problem worse. In areas where it
grows, hardly any fishes and no other algae or invertebrates are found. To make matters worse, it contains toxic
chemicals that keep grazing animals from eating it and
inhibit the growth of sea grasses and other plants
(Piazzi et al., 2001). Caulerpa rapidly overgrew native
macroalgae so species cover, numbers, and diversity
greatly decreased. During a period when cover and biomass of Caulerpa diminished, the macroalgal community
did not return to initial conditions. Instead, the structural
changes increased in the following season, indicating the
importance of the invasion. It grows unchecked and is
considered one of the most harmful marine invasive species (Figure 2).
Its presence was discovered in June 2000 in California
in an eelgrass bed in Agua Hedionda Lagoon. Because of
knowledge about its spread in the Mediterranean Sea, it
was already on the US Federal Noxious Weed list. Alarm
about its potential damage prompted rapid action and
cooperation among governmental agencies, private
groups, and nongovernmental organizations. The San
Diego Regional Water Quality Control Board deemed this
invasion tantamount to an oil spill and provided emergency funding and mobilized crews of divers. California
passed legislation prohibiting the possession and sale of
Caulerpa, and it was successfully eradicated (Anderson,
2005). California’s integrated rapid response and financial
resources resulted in effective containment and eradication of the alga (for the time being), one of the few examples of rapid, successful eradication. But despite the
concerns of ecologists and conservationists, it is still possible to purchase Caulerpa from aquarium supply stores
and through the Internet, so new releases may be inevitable. A similar response will undoubtedly be necessary in
the future to eradicate other invasive species before they
spread and become a big problem.
Red algae: Eucheuma (Kappaphycus)
Eucheuma is cultured throughout the Pacific. It is a major
source of agar and carrageenan, which are used as food
additives for gelling and stabilizing; small amounts are
used by the pharmaceutical and cosmetic industries. It
was imported by the late Maxwell Doty’s research lab in
Kaneohe Bay, Hawaii, from the Philippines in the 1970s,
and this research helped the Philippines and other nations
establish multimillion-dollar industries based on the algae.
Invasive Species, Figure 2 Photo courtesy of NOAA.
366
INVASIVE SPECIES
vegetation is considered an invasive weed on the West
Coast and China. On the East Coast, Spartina alterniflora
is planted and Phragmites is eradicated, while in Europe
and China they value Phragmites and are concerned about
it dying back. It does make you wonder if a certain amount
of xenophobia is involved in our responses to
nonindigenous species.
Green algae: Caulerpa
A strain of Caulerpa taxifolia developed for use as an
aquarium plant was inadvertently released into the Mediterranean Sea from the Monaco Aquarium in the 1980s.
It initially occupied only a few square feet, but was not
removed and subsequently grew and spread so vigorously
that it practically took over the Mediterranean (Meinesz
et al., 1993). It can regenerate from fragments, so physical
removal can make the problem worse. In areas where it
grows, hardly any fishes and no other algae or invertebrates are found. To make matters worse, it contains toxic
chemicals that keep grazing animals from eating it and
inhibit the growth of sea grasses and other plants
(Piazzi et al., 2001). Caulerpa rapidly overgrew native
macroalgae so species cover, numbers, and diversity
greatly decreased. During a period when cover and biomass of Caulerpa diminished, the macroalgal community
did not return to initial conditions. Instead, the structural
changes increased in the following season, indicating the
importance of the invasion. It grows unchecked and is
considered one of the most harmful marine invasive species (Figure 2).
Its presence was discovered in June 2000 in California
in an eelgrass bed in Agua Hedionda Lagoon. Because of
knowledge about its spread in the Mediterranean Sea, it
was already on the US Federal Noxious Weed list. Alarm
about its potential damage prompted rapid action and
cooperation among governmental agencies, private
groups, and nongovernmental organizations. The San
Diego Regional Water Quality Control Board deemed this
invasion tantamount to an oil spill and provided emergency funding and mobilized crews of divers. California
passed legislation prohibiting the possession and sale of
Caulerpa, and it was successfully eradicated (Anderson,
2005). California’s integrated rapid response and financial
resources resulted in effective containment and eradication of the alga (for the time being), one of the few examples of rapid, successful eradication. But despite the
concerns of ecologists and conservationists, it is still possible to purchase Caulerpa from aquarium supply stores
and through the Internet, so new releases may be inevitable. A similar response will undoubtedly be necessary in
the future to eradicate other invasive species before they
spread and become a big problem.
Red algae: Eucheuma (Kappaphycus)
Eucheuma is cultured throughout the Pacific. It is a major
source of agar and carrageenan, which are used as food
additives for gelling and stabilizing; small amounts are
used by the pharmaceutical and cosmetic industries. It
was imported by the late Maxwell Doty’s research lab in
Kaneohe Bay, Hawaii, from the Philippines in the 1970s,
and this research helped the Philippines and other nations
establish multimillion-dollar industries based on the algae.
Invasive Species, Figure 2 Photo courtesy of NOAA.
366
INVASIVE SPECIES