Small Boat, Little Room, Big Water: Deploying BRUV’s on an AVON on the Outside Reef at French Frigate Shoals

The team and their BRUVs

The team and their BRUVs

From May 19 to May 31, 2014 the non-profit research vessel Searcher brought small boat coxswain Jamie Barlow, cruise lead Jake Asher and PIRO employee Emily Crigler to French Frigate Shoals in the Northwestern Hawaiian Islands.

French Frigate Shoals map. Source: Wikipedia

French Frigate Shoals map. Source: Wikipedia

They worked as if their individual efforts were like one, they were the “BRUV team” On a small 5 meter AVON rigid inflatable boat on the outside of the atoll reef in sometimes 15-20 knots of wind. Each person was close enough to the other so that everyone could grab a handle, pass a float or flip a 4 ft wide baited remote underwater video station (BRUV) unit onto its “table” without moving more than a foot from “their spot” on the cramped tiny boat. Each set of hands moved to support the others as they deployed and recovered these units. Exercises included: pull out line-bin from under the table, lift top bin and place it on deck, put bottom bin under the table, grab camera case resting on fuel tank and move camera case on bin so that Jake and Emily could swap the memory cards and change batteries. (This was a necessary repetition for the cameras prior to every BRUV deployment). It was a standard motion that the team did so routinely, that everybody knew what to do and 6 hands did everything like one.

“The deck” organized after a BRUV and its line just came on deck

“The deck” organized after a BRUV and its line just came on deck

Jake and Emily watch closely as they fit the cameras into their underwater housings & double check the “seal” before deploying the BRUV over the side

Jake and Emily watch closely as they fit the cameras into their underwater housings & double check the “seal” before deploying the BRUV over the side

A BRUV is a rudimentary frame (station) that holds two stereo video cameras that film fish as they swim in front of the lens. The soak time is for one hour and that is to maximize the species comprehension. Some stations were baited but most were un-baited; the primary study was looking at un-baited.

The footage will be processed back at the lab to show fish species, size and abundance. This information will be used later to complement the surveys The Coral Reef Ecosystem Division (CRED) uses in their reef fish monitoring studies. There are several advantages to using BRUVs as a survey method: 1) they don’t spook fish or attract fish unlike the presence of divers 2) they can be sent to depths past the comfort for safe diving ~100 feet and 3) the team can cover more sites in a day per dive team.

Jamie takes a break in the lee of Round Island

Jamie takes a break in the lee of Round Island

Jake reviews the site selection and decides where to move to next

Jake reviews the site selection and decides where to move to next

The BRUV team often worked outside of the atoll at French Frigate Shoals and would work in 5-6 swells with 4 ft seas. Although that does not sound like much, the game of fitting all the gear in a boat was like a game of Tetris on a moving platform. Three frames, many different lengths of coiled lines, fuel cans, floats, camera case, safety equipment, base bars, and of course, lunch and water. By the end of the trip the team did an average 10 drops (deployments of the BRUV unit) a day, and came away with a lot of footage of fish! By using cameras and technology as a survey method, it is becoming a very viable option to study our reef fish abundance.

Emily stands ready to move a BRUV “to the rail”, she proved to have the reflexes like a cat and the balance of bird on a moving telephone wire.  Emily would lift or move a BRUV with both hands and by only hanging on to the pitching and rolling boat with her toes tucked under the table. Impressive.

Emily stands ready to move a BRUV “to the rail”, she proved to have the reflexes like a cat and the balance of bird on a moving telephone wire. Emily would lift or move a BRUV with both hands and by only hanging on to the pitching and rolling boat with her toes tucked under the table. Impressive.

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