James Bond Gadget or Scientific Instrument?

Photo by Chris Linder (copyright)

The Woods Hole Team with Middle Caye staff and of course the REMUS

Glovers Reef Marine Research Station was full last week with visiting researchers. And although the work of the Shark Group (see previous post) was excitingly dangerous (!!), the Woods Hole Institute (http://www.whoi.edu) team had the coolest "toys". Hearing Glen Gawarkiewicz and his team from the Oceanography department of the Woods Hole Institute explain what the REMUS autonomous underwater vehicle system can do, it certainly sounds like (and is) a very expensive and rare piece of equipment worthy of the best James Bond gadgets.

In tandem with the Oceanography group, Simon Thorrold was leading the team from the Biology department of the Woods Hole Institute. The objective of both teams was to collect data on the physical oceanography of water around Glovers Reef, in particular the water movements around the passes where Nassau Grouper aggregation are observed and studied.

Methods

Photo by Chris Linder (Copyright)

Deploying the REMUS from Slippery.

The Oceanographic group deployed the REMUS to collect high spatial resolution data on temperature, salinity and current velocity. This torpedo-like instrument has multiple sensors such as side scan sonars, CTD (Conductivity-Temperature-Density) and ADCPs.

They are also planning to create a high resolution bathymetric map of Glovers Reef to help model the water movements near grouper spawning sites. This will be done using the REMUS, which has an extremely precise internal navigational system and sensors measuring depth and vertical distance from the vehicle to the bottom.

In addition to this, two bottom-mounted acoustic Doppler current profilers (ADCPs) were deployed, one near the Northern grouper spawning site, the other at the Southeast Channel. They will be left for 9 months to record depth-specific current velocities.

Photo by Chris Linder (Copyright)

Programming the trajectory of the REMUS before deploying it

What is the link to conservation?

This work will allow to predict where planktonic Nassau Grouper larvae are traveling:

Are they staying in the vicinity of Glovers Reef and larvae are recruiting with the protected area, or are they being exported to areas where there might not be any management or protection?

Finding answers to these questions will give managers the knowledge to efficiently protect Nassau groupers by protecting the site where grouper larvae settle as well as the

spawning site they come from.

Future work at Glovers Reef

Both teams will be coming back to Glovers to complete their work. The oceanographic group will concentrate on the area near the Northeast spawning site to create a detailed map of the area.

The biology group plans to tag larvae to test the model created from the data previously connected and see if it can be applied. This would require chemically tagging female groupers at spawning sites, then catching larvae after spawning and tracking where they come from.

Photo by Chris Linder (Copyright)

Watching the Shark Team come back.