Development of Biomarkers of Contaminant-induced Effects
Many biological effects (e.g. liver neoplasms in
fish) generally are measurable only in the most highly contaminated
environments and thus are not useful in assessing environmental quality in
areas of low to moderate contamination. Biomarkers of alterations in
marine organisms induced by low to moderate levels of contaminants in
coastal areas are being developed as part of an early warning system for
predicting biological effects in fish and shellfish that may lead to
decreased survival and reproductive capacity. A suite of biochemical,
physiological, and pathological indices in fish and mollusks is currently
being evaluated. The evaluation includes investigations to better
understand both the dose-response relationships between contaminants and
the induction of various biomarkers to effects at the individual and
population levels. Biomarkers that are shown to be linked to contaminant
exposure are further validated in field studies using selected
well-understood species. The concurrent use of several relatively
inexpensive biomarkers provides a better assessment of bioeffects from
exposure to complex mixtures of compounds present in contaminated
environments than measurement of a single indicator. Furthermore, the ECD
has pioneered the application of a number of state-of-the-art biomarker
methods for emerging environmental and resource issues. Data from their
research and monitoring programs are being used to identify levels of
pollution that can serve as indicators of altered ecosystem health. Such
"action levels" are needed by NOAA and other federal and state agencies to
assist in making environmental and resource management decisions.
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Research on Chemical Contaminants in Seafood
The ECD leads the Chemical Contaminants component
of the NMFS's Seafood Product Quality and Safety (PQ&S) Program.
Through a program consisting of research, method comparison and testing,
and performance-based quality assurance, the ECD assures the
cost-effective and reliable analyses of seafood products for important
toxic contaminants. The research conducted under the program focuses on
increasing sensitivity and speed in testing for toxic contaminants in
seafood. Contaminants found in the tissue of fish and shellfish that
require updated methods include PCBs, polycyclic aromatic hydrocarbons
(PAHs) and their metabolites, and organometals (e.g., methyl mercury). In
addition, a hepatoma cell culture bioassay will be used to assess the
effectiveness of the PCB screening method in estimating potential toxicity
of chlorinated hydrocarbons in seafood products. Furthermore, the method
comparison component of the program focuses on comparing results of newly
developed methods to those obtained with standard methods (e.g., FDA,
USDA) before adoption of the new methods. A screening method that has
recently been developed is sensitive enough to detect not only the total
PCB concentrations found with standard FDA/USDA methods, but also the
specific dioxin-like PCBs (planar PCBs) that account for much of the
PCB-related toxicity. The PQ&S Program also includes a quality
assurance component designed to develop control materials and laboratory
standards to assure the accuracy of methods and consistency of data
quality. The result of the PQ&S Program will be used to create a
database for use in risk assessment/management.
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Understanding The Effects of Contaminants on Marine Ecosystems
The ECD scientists conduct a combination of laboratory and field
research to assess damage to living marine resources from contaminants
associated with coastal pollution. Interrelationships among
contaminant-induced physiological changes, and structural changes in key
organ systems are investigated. Recently the ECD scientists have
demonstrated reduced reproductive success in bottomfish living in
contaminated areas of the U.S. One of the goals of this program is to link
effects observed in individual fish to potential changes at the population
level. Preliminary results from predictive population models suggest that
the decline in reproductive potential in certain marine fish species may
be sufficient to significantly reduce populations in contaminated areas.
The ECD scientists are now working to improve the precision of the model
by modifying it to take into account fishing pressure, natural and
contaminantassociated mortality, as well as effects of migration and
density-dependent survival. Cause-and-effect relationships between
reproductive abnormalities and exposure to certain classes of contaminants
are also being evaluated in both field and laboratory studies.
In addition, the ECD scientists have developed assays for testing the
sublethal effects on invertebrates and fish of sediments from coastal
environments exhibiting low to moderate levels of contamination. These
data are used for assessing long-term or chronic effects of contaminant
exposure, and for evaluating ecosystem changes due to contaminant-related
bioeffects. Also, data from sediment toxicity studies combined with data
on the uptake, metabolism, and tissue distribution of contaminants are
valuable in linking cause-and-effect relationships between tissue
concentrations of chemicals and biological effects in animals sampled from
urban estuaries containing a complex mixture of chemicals. The results of
studies with both fish and invertebrates will provide important
information in determining the consequences of contaminant exposure on
marine ecosystems and living marine resources.
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Damage Assessment, Restoration and Monitoring
As part of the Division's interactions with other
NOAA elements, and with agencies outside of NOAA, the ECD provides
emergency response following environmental catastrophes which impact
living marine resources and their critical habitats, and conducts
long-term monitoring and assessment investigations. The ECD was very
active in assessing the damage of the EXXON Valdez oil spill in Prince
William Sound to marine fish species, and participated in studies
conducted to assess the human-health implications of consuming subsistence
seafood by native Alaskans from sites in the path of the spill. In
addition, the ECD conducts damage assessment and participates in
restoration projects as part of the NRDA processes. These projects are
designed to assess the severity and extent of injuries to living marine
resources associated with polluted sites, and to evaluate changes in these
parameters resulting from restoration and mitigation efforts. Damage
assessment projects have included multiyear studies in Seattle's Elliott
Bay that resulted in a Consent Decree between NOAA and the City of Seattle
and Metro for restoration of resource damages in the bay.
Restoration/remediation projects also include a cooperative study with EPA
to evaluate the effectiveness of a sediment capping project in Eagle
Harbor, a Superfund Site heavily contaminated with creosote. The Division
is in a unique position of being able to deploy trained, motivated and
highly capable specialists who are able to rapidly analyze samples either
in the field or in Division laboratories, and are able to rapidly
interpret and disseminate the results to concerned parties. The ECD also
conducts two monitoring and assessment programs (the National Benthic
Surveillance Project and the Bioeffects Survey component of the Coastal
Ocean Program) to document the status of, and changes in, concentrations
of chemical contaminants in sediment and bottomfish and associated
pathological conditions and other bioeffects over time in over 120 sites
nation-wide to allow assessment of the status and trends of environmental
quality in our nation,s coastal and estuarine waters.
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Research on Protected Species
The ECD is involved in long term studies of the effects of
environmental contaminants on the survival and fecundity of several
protected or endangered species. The ECD scientists have initiated a
program to assess exposure to and effects of estuarine contamination on
outmigrant juvenile salmon. Several runs of Pacific salmon are endangered
or threatened. Studies of juvenile Chinook salmon from urban estuaries in
Seattle and Tacoma showed elevated contaminant exposure and biochemical
effects. Salmon from one of these estuaries showed evidence of an altered
immune response, and additional laboratory studies suggested that the
immunosuppression was due to chemical contaminant exposure. Initial
results suggest that fish from one of these estuaries are showing
inhibited growth compared to juvenile salmon from a minimally contaminated
estuary.
The ECD scientists are also continuing to do research on many protected
marine mammals in conjunction with NMFS's Marine Mammal Health and
Stranding Response (MMH&SR) Program. As part of the MMH&SR
Program, they have initiated a project to develop a national database on
chemical contaminants in marine mammals. Since the establishment of a
comprehensive quality assurance program, as part of the MMH&SR
Program, more than 10 marine mammal species from sites nationwide have
been analyzed for chlorinated hydrocarbons as well as for toxic metals
(e.g., cadmium, mercury). The specimens are from both the east, gulf and
west coasts of the U.S., as well as from the Alaskan Arctic.
The ECD scientists are evaluating the extent and magnitude of
contaminant-related bioeffects in protected and endangered species and
associated ecosystems so these influences on their health and survival can
be assessed and factored into management strategies.
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Watershed Program
The Watershed Program conducts research on the
structure and function of Pacific Northwest watersheds to assist in the
management and recovery of anadromous fishes and their habitats. Our
research focuses on natural processes that form and maintain aquatic
ecosystems, and on land uses and restoration actions that can alter these
ecosystems and affect fish populations. Watershed Program scientists have
expertise in fish biology, aquatic and riparian ecology, geomorphology,
hydrology, chemistry, and statistics. Results of our research guide NMFS
regulatory staff and other natural resource managers in the Pacific
Northwest toward actions and policies that protect and restore aquatic
ecosystems, thereby assisting in the recovery of fish
populations. Click here for more information on the Watershed Program.
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