U.S. EPA Office of Research
and Development's Science
To Achieve Results (STAR)
Research in Progress
Vol. 1 Issue 2 Dec. 1997 A product of the National Center for Environmental Research and Quality Assurance
HARMFUL ALGAL BLOOMS
Harmful algal blooms occur when some
species of algae, the universally present, mi-
croscopic plants that form the base of aquatic
food chains, multiply quickly and aggregate in
a given coastal area. Most microscopic algae
are not harmful, but a few species produce
potent toxins that can be transferred through
the food chain, affecting and sometimes kill-
ing zooplankton, shell-
fish, fish, birds, marine
mammals and even hu-
mans. Sometimes the
algae become so abun-
dant that they form
dense, visible patches
near the water's surface.
"Red tide" or "brown
tide" are common
names for such phe-
nomena, because some
algae contain pigments
that make the water ap-
pear colored. However,
these terms are misnomers because the blooms
are not associated with tides, and some algae
never reach densities that discolor the water
but nevertheless have devastating effects on fish
and other living things. Scientists now prefer
Electron micrograph of Pfiesteria (cyst form)
the term "harmful algal blooms" (HAB) to en-
compass all blooms with negative impacts.
HABs that do not involve visible discolora-
tion of the water include outbreaks of the di-
noflagellate Pfiesteria and related species. This
microorganism's attacks on fish tissues create
open sores, and can ultimately lead to massive
fish kills. Pfiesteria and re-
lated species release toxins
believed to cause human
sores and nervous system
(damage due to exposure to
affected waters. The term
HAB also includes blooms of
another type of algae, the
large seaweeds and other
soft-tissued aquatic plants
called "macroalgae", which
are stimulated by excess nu-
trients or other ecological
imbalances. Macroalgae
do not create toxic hazards.
But they create noxious conditions and eco-
system imbalances if stimulation by nutrients
leads to excess growth, decay and oxygen
depletion, overgrowth of habitats, or local ex-
tinctions of other plants and animals.
Most microscopic algae are not harmful, but a few species produce potent toxins
that can be transferred through the food chain, affecting and sometimes killing
zooplankton, shellfish, fish, birds, marine mammals and even humans.
&EPA
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HAB Impacts on
Public Health and
Ecosystems
Common impacts of
HABs are fish kills, mass mor-
talities of wild and farmed
fish and shellfish in bays, es-
tuaries or marine coastal
waters. Human illness and
even deaths can result from
eating seafood contami-
nated by some of the alge
that create blooms, and
deaths of marine mammals,
seabirds and other animals
high in aquatic food chains
are common in some re-
gions. In addition, the
blooms cause alterations of
marine habitats and food
webs, so that plants and ani-
mals normally present be-
come rare, and unusual,
sometimes less valuable or
noxious species can replace
them.
AC*
Coordinated Response:
The ECOHAB National Research Plan
Over the last several decades, the frequency of HABs in the
United States has markedly increased. The causes of this expansion
are still a matter of debate, with possible explanations ranging from
natural changes in species dispersals to a host of human-related
phenomena such as nutrient enrichment, climatic shifts or trans-
port of algal species via ship ballast water. Whatever the reasons,
virtually all coastal regions of the U.S. are now subject to an unprec-
edented variety and frequency of HAB events. The U.S. is not alone
in this respect, as nations throughout the world are faced with in-
creasing incidences of HABs caused by an array of harmful species.
HABs result from physical, chemical, and biological mecha-
nisms and interactions that are for the most part poorly understood.
Focused research into these mechanisms is urgently needed. In the
United States, a coordinated research program called ECOHAB (Ecol-
ogy and Oceanography of Harmful Algal Blooms) has been devel-
oped to meet these research needs. A group of federal agencies,
led by the National Oceanic and Atmospheric Administration
(NOAA), has developed a national ECOHAB research agenda to guide
General Information: The Environmental Protection Agency's STAR Research Program
Grants described in this report are part of EPA's Science to Achieve Results (STAR) program, a major research
initiative designed to improve the quality of scientific information available to support environmental decision
making. The STAR program is managed by EPA's National Center for Environmental Research and Quality Assur-
ance in the Office of Research and Development (ORD). The program funds approximately 200 new grants every
year, with the typical grant lasting three years. Funding levels vary from $50,000 to over $500,000 per year, with
FY1997 funding level at about $80 million for grants to individual principal investigators or groups of investigators.
Additional STAR funds are provided for a number of Research Centers specializing in scientific areas of particular
concern to EPA, and for a fellowship program supporting graduate students conducting environmental research.
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academic and government re-
search. The objective of the
ECOHAB research program is to
investigate fundamental physi-
cal, biological and chemical
oceanographic questions critical
to management of fisheries re-
sources and public and ecosys-
tem health in areas threatened
by toxic and harmful algae. The
Environmental Protection
Agency (EPA) is a partner in the
ECOHAB research effort. This
report highlights ECOHAB re-
search funded through EPA's
The causes ofHABs
expansion are still a
matter of debate,
with possible expla-
nations ranging
from natural
changes in species
dispersal and aggre-
gation to a host of
human-related phe-
nomena such as
nutrient enrichment,
climatic shifts and
transport of algae in
ship ballast water.
extramural research program,
the Science to Achieve Results
(STAR) program. Additional in-
formation about ECOHAB re-
search is available from the
ECOHAB Internet website refer-
enced in the section, "Find Out
More".
RESEARCH SUPPORTED
BY EPA AND OTHER
AGENCIES
Pfiesteria Research
In 1997, an EPA STAR re-
search grant was awarded to
North Carolina State University
to fill critical
gaps in our un-
derstanding of
the causes of
blooms of the
toxic dinoflagel-
late, Pfiesteria
piscicida, as well
as to improve
upon available
techniques for detecting this or-
ganism in the natural environ-
ment. This is the species believed
responsible for recent fish kills in
coastal waters of North Carolina
and the eastern shore of the
Chesapeake Bay, in which some
researchers, fish and wildlife
agency employees and fishermen
experienced skin lesions and ner-
vous system damage, such as
memory loss, that may have been
due to contact with the contami-
nated water.
Specific objectives of the
North Carolina study include the
following: 1) to examine the ef-
fects on Pfiesteria of different types
of nutrients, including nitrogen
and phosphorus-containing com-
pounds from natural and human
sources; 2) to develop species-
specific fluorescent-labeled mo-
lecular probes to allow rapid, rou-
tine detection of Pfiesteria's ma-
jor life stages at sites where fish
lesions or fish kills occur; and 3)
to assess lethal and sublethal ef-
fects of Pfiesteria on commercially
and ecologically valuable shellfish
species. These results will support
more rapid and accurate field test-
ing to determine when a Pfiesteria
problem exists in an area. And
results of the nutrient
testing may provide in-
sights to improve strate-
gies for preventing or re-
ducing Pfiesteria blooms
through pollution pre-
vention approaches for
nutrient sources in
coastal watersheds.
Other Toxic
Dinoflagellates
Toxic chemicals released
by the common dinoflagellate
algae Gymnodinium breve can
kill planktonic animals that feed
on them, or can be retained in
the plankton and passed along
to fish and other organisms
higher in the food chain. An EPA
STAR grant has been awarded
to the Florida State Depart-
ment of Environmental Pro-
tection for research into
G. breve's toxicity and growth
and reproductive impacts on a
key planktonic animal, the cope-
pod Acartia tonsa. This study
will also refine a method for de-
tecting G. breve toxins in wa-
ter, air and sediments. Results
will help establish how long G.
breve toxins remain active in the
environment, and help scientists
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better predict effects of G, breve
blooms on animal abundances
and the contamination of critical
food chain organisms such as
Acartia.
To predict conditions under
which toxic dinoflagellate blooms
may occur, scientists need to un-
derstand how the algae interact
with all parts of the food web.
Blooms may result from reduced
consumption of the algae by ani-
mals that normally eat
them, planktonic ani-
mals and filter-feed-
ing shellfish such as
oysters, mussels and
clams. For example,
perhaps initially mod-
est changes in abun-
dance of toxic algae
could lead to some
consumer animals be-
ing killed by the tox-
ins, setting up a cycle
in which increasingly
fewer consumers and
more harmful algae
survive, with a toxic bloom the
result. A joint study by the Na-
tional Marine Fisheries Service
(NMFS) laboratory in Milford,
Connecticut, the Bigelow Labo-
ratory for Ocean Sciences in
Maine, the University of Con-
necticut and the University of
Pennsylvania is taking advantage
of the NMFS lab's dinoflagellate
cultures to assess grazing and tox-
icity rates of animals exposed to
toxic algae. This will help scien-
tists predict ecological conditions,
such as balances of species
present, that can predispose
wiih dll pdrij
the food
coastal ecosystems to HAB inci-
dents.
Four dinoflagellate ECOHAB
studies are being funded by other
agencies. NOAA is supporting a
study of the ecology in the Gulf
of Maine of the toxic dinoflagel-
late Alexandrium, comprehen-
sively assessing chemical, physi-
cal oceanographic and biological
factors affecting bloom develop-
ment. The National Science
Foundation (NSF) is
supporting a Univer-
sity of Rhode Island
study of the control
of Alexandrium
blooms and food
chain transfers of tox-
ins due to zooplank-
ton grazing. Another
NSF study, by the
Medical University
of South Carolina, is
investigating how
bacteria that can kill
algae may affect
Gymnodinium blooms
in the Gulf of Mexico. This alga
frequently causes fish kills, and
can result in neurotoxic shellfish
poisoning in humans.
Another NSF-supported
project involves research by the
California State University at
Monterey Bay into effects of para-
lytic shellfish poisoning (PSP) on
higher level marine predators.
PSP, caused by Gonyaulax
catenella, can cause serious illness
or death in humans consuming
mussels or other contaminated
shellfish. Researchers will investi-
gate whether certain birds and
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sea otters can detect and avoid
PSP contaminated shellfish, the
extent to which they are harmed
if they consume contaminated
shellfish, and whether there are
significant effects on bird and ot-
ter populations due to PSP.
Toxic Diatoms
While HABs in the United
States usually involve microscopic
algae called dinoflagellates, some-
times diatoms, the other most
common microalgae, are at fault.
Most diatom species are not toxic,
but some are. On the west coast,
diatoms in the Pseudo-nitzschia
group have caused human poi-
sonings from eating clams and
crabs in Oregon and Washington.
They have also caused wildlife
deaths, such as seabird kills in
California. The University of
California at Santa Cruz has re-
ceived a STAR grant to investigate
causes of toxic diatom blooms.
Hypotheses they are testing in-
clude the following: 1) changing
concentrations of the major dia-
tom nutrients, nitrogen and sili-
cate, may trigger a bloom if the
nutrient that limits growth in an
area becomes increasingly avail-
able; 2) increasing concentrations
of iron, a "micronutrient" needed
in trace amounts, might stimulate
the blooms; or 3) not only are
the diatoms' growth and repro-
duction affected by iron, nitrogen
and/or silicate concentrations, but
the amount of toxins produced
and released by each diatom may
be enhanced by specific nutrient
or micronutrient conditions. Re-
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search results are expected to
make a significant contribution to
management strategies for pre-
dicting, monitoring and imple-
menting public health responses
to toxic diatom blooms in the
Pacific and elsewhere.
Other Toxic Algae
Tiny bacteria-like plants
called cyanobacteria, with the
common name "blue-green al-
gae", are a frequent cause of HABs
in stressed tropical waters. They
release a toxin that can be deadly
to coral reef animals, or to hu-
mans that eat fish or invertebrates
from an affected area. The
growth of blue-green algae, like
all algae, may be stimulated by
the nutrients and micronutrients,
principally nitrogen, phosphorus
and iron. However, an additional
mechanism may be involved in
blue-green algae blooms, similar
to that discussed in relation to
toxic dinoflagellates. This is that,
once they are stimulated to in-
crease in abundance, the toxins
they emit, called "secondary me-
tabolites", may kill or keep away
fish and other animals that graze
on algae, resulting in a sudden
HAB as the toxic algae are re-
leased from grazing pressure. The
University of Guam has received
an EPA STAR grant to study each
of these possible causes of blue-
green algae blooms. They will
document bloom patterns in
space and time, and assess the
roles played by various sources of
coastal nutrient pollution as com-
pared to impacts of overfishing of
grazing species, and the impacts
of secondary metabolites in re-
ducing grazing.
During the past decade, the
brown tide organism Aureococcus
very recently discovered, and are
considered an entirely new ma-
jor grouping (an order) of plants.
Many of their basic characteristics
anophagefferens has devastated
the ecology of several bays on
New York's Long Island, destroy-
ing commercial shellfisheries. An-
other, related organism causes
persistent brown tides in some
Texas bays. These microalgae are
have yet to be determined. NSF
is supporting research by the New
York University Medical Center
into the population genetics of
these algae, which may help in
developing strategies for reduc-
ing or controlling the blooms.
Find Out More About the STAR Research Program
Further information on the STAR program is available from the fol-
lowing sources:
Internet Website, managed by the ORD National Center for Environmen-
tal Research and Quality Assurance (NCERQA):
URL: http://www.epa.gov/ncerqa
Mailing Address:
Office of Research and Development
National Center for Environmental Research and Quality Assurance
Office of the Director (8701 R)
401 M Street, SW
Washington, DC 20460
Or, use the Telephone Hotline, 1-800-490-9194, to leave messages and
receive auto faxes of announcements.
Other HAB research information is available at the ECOHAB Website:
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STAR Research Projects Described in this Report and other Partner Awards
£ 1) "ECOHAB-Gulf of Maine:
The ecology and oceanography
of toxic Alexandrium blooms in
the Gulf of Maine."; lead PI in-
stitution: Woods Hole
Oceanographic Institution, Rl
-^ 2) "ECOHAB: Florida."; lead PI
institution: Flordia Dept. of En-
vironmental Protection
^Af 3) "Trophic effects of two di-
noflagellates." lead PI institu-
tion: University of Connecti-
cut (also NMFS Laboratory, 4^
Milford, CT)
A 4) "Population genetics of A5) "Algicidal bacteria and the^6) "Ecophysiology studies of
brown tide blooms."; lead PI in- regulation of Gymnodinium Pseudo-nitzschia species."; lead
stitution: NY University Medi- breve blooms in the Gulf of PI institution: University of Cali-
cal Center, NY Mexico."; lead PI institution: fornia, Santa Cruz
Medical University of South
Carolina
EPA Funded
NOAA Funded
A NSF Funded
"Chemical ecology of
cyanobacterial blooms on the
tropical reefs of Guam."; lead PI
instition: University of Guam
S) "Zooplankton grazing of
toxic Alexandrium spp. as a
mechanism in the control of
bloom formation and toxin trans-
fer."; lead PI institution: Univer-
sity of Rhode Island
9) "Influence of harmful algal
blooms on the distribution and
ecology of high level marine
predators."; lead PI institution:
California State University,
Monterey Bay
"IO) "Toxic Ambush-Predator Di-
noflagellates - Potential Biosenors
of Estuarine Stress", Lead PI In-
stitution: North Carolina State
University, North Carolina
United States
Environmental Protection Agency
Mail Code 8701R
Washington, D.C. 20460
Offical Business
Penalty for Private Use
$300
EPA/600/F-97/025
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