I am writing to the listserv with an inquiry and general request.
I would like to find out if any list members are aware of projects
underway to examine the effects of the Deepwater Horizon spill on
benthic invertebrate communities in the Gulf of Mexico. If so, I want to
encourage researchers to "save the dead" as well as live
macroinvertebrates found in their samples.
Benthic surveys of living communities in the Gulf are critical for
establishing a baseline against which post-spill communities can be
compared. However, such surveys are often challenged by the relative
scarcity of live individuals on the seafloor and the resulting
volatility in various measures of biological diversity (e.g., species
richness, taxonomic composition) that results from patchy distributions
and small sample sizes. Recent research (select references below) has
shown that benthic death assemblages (i.e., marine macroinvertebrate
skeletal remains entombed in surficial soft sediments) can be used to
establish biological baselines for pre-impact marine communities. Yet,
most often death assemblages are discarded during the process of benthic
sampling. Samples of death assemblages are rich sources of biological
data and can be costly to collect, so I am writing with the hope that
these valuable data can be retained and archived as a part of any
post-spill benthic sampling in the GoM. Such data would not allow us to
identify the impacts of the Deepwater Horizon oil spill specifically,
because death assemblages form over decadal to centennial time scales,
but when analyzed in tandem with syn-spill surveys of living benthic
communities would provide an integrated picture of present-day and
historical human impacts in the Gulf.
Please email me ([email protected]) if you are aware of relevant
projects that may be able to broaden their sampling strategy to include
the retention of associated "death assemblages".
Sincerely,
Paul Harnik
Select references
Flessa, K. W. et al. 2005. The geological record of ecological dynamics:
understanding the biotic effects of future environmental change. The
National Academies Press, Washington, D.C.
Kidwell, S. M. 2007. Discordance between living and death assemblages as
evidence for anthropogenic ecological change. Proceedings of the
National Academy of Sciences of the United States of America 104:17701.
Kidwell, S.M. 2008. Ecological fidelity of open marine molluscan death
assemblages: effects of post-mortem transportation, shelf health, and
taphonomic inertia. Lethaia 41: 199.
--
Paul Harnik
Department of Geological and Environmental Sciences
Stanford University
450 Serra Mall, Building 320
Stanford, CA 94305
Phone: (773)241-1284
E-mail: [email protected]
Web: http://stanford.edu/~pharnik
