The Pelagic-Benthic Coupling lab uses a
suite of instruments to perform long time-series
monitoring of the sea floor at Station M, off shore of
the California Coast (34.5°N, 123° W). Most of the
instruments used at Sta. M are autonomous, working
independently at depth (4000m) without outside control
for nearly a year at a time. The lab has increasingly
worked toward developing instruments that collect data
during extended deployments lasting up to a year.
For an update on the results of long-term monitoring at Station M, see the open access paper:
2013 K.L. Smith, Jr., H.A. Ruhl, M. Kahru, C.L. Huffard and A.D. Sherman. Deep ocean communities impacted by changing climate over 24 y in the abyssal northeast Pacific. Proc. Nat. Acad. Sci. 110(49): 19838-19841
||Sediment traps collect
the samples needed for the lab's measure of
particulate organic carbon. 21-cup sequencing
sediment traps (McLane Research Labs) are
deployed 600 meters above bottom (mab) and 50
mab, above the camera tripod mooring. The cups
are set to a ten-day collect time. The top of
the trap has a plastic baffle, which prevents
large objects from entering the trap and
potentially clogging the funnel.
Upon bringing the traps to the surface, animals that might have swum into the trap are counted and removed. The remaining sample is split into portions for microscopy, pigment analysis and carbon analysis. The latter sample is freeze-dried, weighed, and analyzed for salt-corrected inorganic carbon content and total carbon content, from which organic carbon content can be calculated.
|The Sedimentation Event Sensor (SES) was first deployed at Sta. M in 2012. The SES is a sediment trap that images the sample rather than collecting it, allowing for a temporal resolution of hours rather than days, and more detailed analysis of sediment components. In the image on the left, individual fecal pellets can be identified and counted. The SES also records fluorescence allowing for relative estimates of chlorophyll content in samples|
|The Camera tripod is
moored at 4000m, and takes a picture of the sea
floor every hour. These images show how sea
floor communities change over time in response
to food inputs recorded by the sediment traps,
and as seen as detrital aggregates in the
pictures. Detrital aggregate percent cover,
megafauna density, and some behaviors are
measured using camera tripod images.
When viewed as a time-lapse movie, these images show how deep-sea animals move around, eating food on the sea floor.
|The Benthic Rover
autonomously transits the sea
floor taking measurements of sediment community oxygen consumption, which the lab uses to calculate organic carbon demand at Station M. The Benthic Rover also takes photographs of the sea floor as it transits, both in color and filtered to the fluorescence of chlorophyll excitation.
Watch the Benthic Rover move on the sea floor.
|When working in Antarctica, the
lab uses Lagrangian
Sediment traps to collect organic
matter sinking from below free-drifting