Post-event
materials:
Event
Coverage
Sea Grant
"Results
of Long Island Sound Lobster Research are Presented"
(Coastlines, NYSG, Spring '05)
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PDF
Media
Reporters for numerous newspapers, television,
and radio stations covered the event
|
Click
Here
Research Summaries
General overview of research summaries
Identifying the Driving For Forces Behind the 1999 Lobster
Mortality
Event - Fitting Together the Pieces of the Puzzle
| PDF
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Summary:
A wealth of new information on how American lobsters
interact with their environment, their physiological responses
in the presence of various stressors, and findings on two
new infectious lobster diseases will be of long-term benefit
to researchers and resource managers throughout the range
of this species.
Topical
research summaries
Immune
& Endocrine Compromise in American Lobsters /
Disease in American Lobsters |
PDF
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Synopsis
of summary on immune and endocrine compromise studies: As
cold-blooded animals, the metabolism of lobsters is extremely
sensitive to prevailing environmental conditions. At the
start of this research, research tools needed to explore
issues such as the effects of temperature and hypoxia
(low dissolved oxygen in the waters) on
lobster health were lacking. And so, significant time and
effort was devoted to develop a tool kit of laboratory techniques
that we could use to answer these questions.
Synopsis on findings: Application of these tools,
similar to many medical and veterinary tests, showed that
lobsters are indeed stressed by the environmental conditions
in LIS in late summer. They show reduced immune function,
disrupted hormone systems (including the molting hormone)
and, when temperature and hypoxia combine, can die directly
from environmental stress. These results suggest that environmental
inputs can have a dramatic effect on lobster health and
survival both directly and indirectly, by reducing their
ability to fight infectious pathogens and tolerate chemical
contamination.
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Synopsis
of summary on
lobster disease studies: A subpopulation of lobsters
from the 1999 die-off were infected with paramoebae without
consistent evidence of other disease-causing infectious
agents, and this fact must be accounted for in an understanding
of that mortality event. Lobsters since the die-off lobsters
have been identified as infected with paramoebae, although
at much reduced levels.
Synopsis
on findings: One
possible explanation for the presence of a paramoebae in
1999 lobsters is to postulate that high water temperatures,
combined with record-high population densities of temperature-challenged
lobster under hypoxic conditions, promoted infection of
a subpopulation of lobster that contributed to the die-off.
Long-
Term Population Trends in American Lobster in Long Island Sound
/ The Role
of Physical & Chemical Conditions in Lobster Mortality in
LIS | PDF
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Synopsis
of summary on population
trends studies: Existing long-term monitoring data and studies
initiated in response to the 1998-1999 lobster die-off in Long
Island Sound were examined to determine long-term trends that
may clarify the causes.
Synopsis
on findings: Many factors probably
played a role in the higher than normal mortality recorded in
1999, however, the long-term monitoring data examined here implicate
increased bottom water temperatures as a significant contributing
factor to the dieoff.
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Synopsis
of summary on physical and
chemical conditions studies: The lobster mortality event
of 1999 raised many questions about the environmental conditions
present in western Long Island Sound prior to and during the
die-off. Over the past three years, research scientists sought
ways to understand, in detail, the environmental conditions
present in 1999.
Synopsis
on findings: Results
of these studies can be grouped into three main headings: hypoxia,
temperature, and rainfall. All
three of these appear to have played a potentially important
role in the 1999 mortality event. At a minimum, the environmental
conditions present in the western Sound in 1999 placed those
lobster populations under physiological stress, making them
extremely susceptible to pathogens or chemical stressors. The
probability of this confluence of phenomena occurring again,
based on the variability inferred from existing records, is
high.
Modeling Pesticide Concentrations in Long Island Sound
/ Effects
of Pesticides in American Lobsters |
PDF
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Synopsis
of summary on modeling pesticide
concentration studies: A phased approach was used for applying
numerical models developed previously by HydroQual (an
independent party) to address quantitatively
whether or not application of four pesticides (i.e., methoprene,
malathion, resmethrin, and sumithrin) to combat mosquitos carrying
West Nile Virus could alone have caused the massive die-off
of lobster observed in Long Island Sound during 1999.
Synopsis
on findings: We
cannot fully rule out the possibility that sumithrin may have
been a stressor.
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Synopsis
of summary on pesticides
effects studies: The possible contribution of pesticides
to the 1999 lobster die-off was investigated in several laboratories
to assess (1) the concentrations of pesticides that cause effects
(lethal and sublethal) in lobsters of different age classes
(larvae, juveniles and adults), and (2) whether these concentrations
might have been found in Long Island Sound in 1999.
Synopsis
on findings:
Methoprene bioaccumulated in tissues of lobsters, but its maximum
concentration likely to have reached LIS based upon the pesticide
model was well below the threshold for effects in lobsters.
The maximum malathion concentrations likely found in LIS based
upon the pesticide model in near bottom water were not found
to be within the range of concentrations having effects in lobsters.
Resmethrin had several lethal and sublethal effects in lobsters.
Its maximum concentrations likely calculated in LIS surface
and bottom waters based upon the pesticide model may have had
lethal effect on larvae and immune effect on adults in LIS in
1999, based on the pesticide model results.
More investigation is warranted to rule out sumithrin as a stressor
in limited areas as it was not specifically studied as part
of the research initiative. Related results are from modeling
conducted by HydroQual, an independent party, and are based
on pesticide application data.
Pre-event
materials:
- Press Release
- Driving forces behind lobster die-off revealed |
Click
Here
- Meeting
agenda |
PDF
Background
information -
on the lobster fishery, research initiative and symposia
Researchers and resource managers have gathered a wealth of new knowledge
on the general health status of American lobsters in Long Island Sound
since the 1999  lobster
mass mortality. New diseases have been diagnosed and key factors that
constrain lobster biology and physiology have been identified.
A special Lobster
Research Steering Committee was appointed by the Atlantic States Marine
Fisheries Commission to coordinate the research that was implemented
through funds from the federal government and the State of Connecticut's
Long Island Sound Research Fund.
The 4th Annual
Long Island Sound Lobster Health Symposium, held at Stony Brook University
on Monday, October 4, 2004, was a forum for researchers, resources
mangers, industry, and the general public to exchange information.
At this meeting, the most likely causes of the mass mortality event
in 1999 were identified, and issues necessary to resuscitate Long
Island Sound American lobster fishery were discussed.
The Long Island Sound Lobster Research Initiative is a collaboration
funded by National Oceanic and Atmospheric Administration's (NOAA)
Fisheries Service, Connecticut Department of Environmental Protection,
and the Sea Grant College Programs in New York and Connecticut.
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