Project Manager: Kim Reisenbichler
Lead Scientist: Bruce Robison
The long-term goal of MBARI’s midwater research program is to develop an
ecological model of the natural communities that occupy the oceanic water
column. In 2001 we began to shift the emphasis of our field work from
mesopelagic animals in the upper 1000 m of the water column, to the bathypelagic
species that live down to 4000 m. These animals have never been studied with the
kind of technology that MBARI can bring to bear on this problem, and they
represent the largest gap in our understanding of carbon flux through the
oceanic water column.
Our preliminary deep dives this year revealed a rich and diverse bathypelagic
fauna that contains a large number of unknown animals. We are learning which species are present, which are most important,
their relative abundances, and which parts of the water column they inhabit. In
years 2002 and 2003 we will make quantitative measurements to elucidate
community structure, function, and dynamics, much as we have done with Ventana
at shallower depths. This will allow us to determine the ecological links
between Chavez’ upper water column studies, our mesopelagic studies, and Barry’s
benthic community work.
Our work on mesopelagic animals is shifting from surveys to process studies.
We will conduct laboratory studies to follow up on recent results, which
indicate the ability of gelatinous animals to take up dissolved organic
compounds from seawater. Laboratory work will also include oxygen consumption
measurements of keystone species in order to determine their metabolic rates,
which will allow us to factor energetics into the community model.
We are working to develop two instruments for deep water applications; both
are off-the-shelf technologies which we will adapt for our research. The first
is a class of very small acoustic transmitters that we will implant in or on
gelatinous animals so that we can track their movements over time. The second is
an electromagnetic field sensor that we believe may provide a revolutionary new
perspective on the midwater habitat. We plan to acquire commercial examples of
these instruments and to test them in shallow water, then adapt them
for use by ROVs and AUVs during years 2002 and 2003.