Monterey Bay Aquarium Research Institute
Pelagic-Benthic Coupling

Monitoring instrumentation suite

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.


Station M instrumentation suite. Not drawn to scale.
While at sea at Staion M, the deck is full of instruments awaiting redeployment after their brief servicing period.

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 icebergs.
Last updated: Feb. 14, 2014