Having just completed my first year as a graduate student in marine biology at the University of Hawaii at Manoa, I was humbled to have made the cut to join the 2014 Seaver Institute Pohnpei Expedition. Some of the team members are the very individuals who initially inspired me to pursue marine science and rebreather diving.

My own expedition objectives, like those of the entire team, were extensive. Richard Coleman and I were on the ‘transect crew’; my job was to run a video camera (for post-dive species identification) and to assist Richard in any way he deemed necessary. We would generally lay 7-10 transects between depths of 30 and 220 feet (10-66 meters), drop off our camera gear and transect tapes, and grab spears and collection bags to collect specimens for Toonen-Bowen lab members back home, among others.

A larval trap desgned by Garrett Johnson for his research project on larval fish recruitment on mesophotic reefs.  This one was set overnight at a depth of 300 feet (90 meters).  Photo by Sonia Rowley.

A larval trap desgned by Garrett Johnson for his research project on larval fish recruitment on mesophotic reefs. This one was set overnight at a depth of 300 feet (90 meters). Photo by Sonia Rowley.

My research focuses on the connectivity of larval fish populations between mesophotic and shallow reefs of the western Pacific. Some researchers have long hypothesized that mesophotic reefs may provide a critical refuge for shallow water species affected by human-induced and natural disturbances. With the objective in mind to collect post-settlement larval fishes, for the past 2.5 years I have been working on fish traps designed specifically for placement on mesophotic reefs. The Fish trap with Automated Recovery Timer (“FART”) is fitted with electronics combining a small circuit board, solenoid (one-way gas valve), and an on-board ‘clock’ to activate a small CO2-filled disposable paintball cartridge designed to fill a lift bag; this allows retrieval by boat, removing the need for a repetitive dive to the same site for recovery.

The electronics console designed by Garret Johnson to automatically release a larval trap by inflating a lift-back and bringing it to the surface. Photo by Garrett Johnson.

The electronics console designed by Garret Johnson to automatically release a larval trap by inflating a lift-back and bringing it to the surface. Photo by Garrett Johnson.

One of the many goals of this expedition was to complete a ‘shakedown’ dive to deploy the “FARTs” and test their efficacy. After a long day attempting to finalize programming on the electronics, several software bugs were found in the code and deemed irreparable until I have time to troubleshoot upon my return home. I must admit, it was quite a disappointment. Later that evening, the team informed me that they had decided to sacrifice one day of diving ‘virgin ground’ at one area to complete a repetitive dive at another site. This was a go-ahead for the test run of my traps; we planned to deploy them one day and manually retrieve them 24 hours later. It was a huge sacrifice for the team, and I’ll remember that one for a long time to come.

Sonia Rowley prepares to send one of Garrett Johnson's larval fish trap to the surface, after the trap had spent the night on the reef at a depth of 300 feet (90 meters). Photo by Richard Pyle.

Sonia Rowley prepares to send one of Garrett Johnson’s larval fish trap to the surface, after the trap had spent the night on the reef at a depth of 300 feet (90 meters). Photo by Richard Pyle.

After an all-nigher assembling the six traps I brought with me, we headed to the north end of Pohnpei. I was on the ‘shallow team’ (<210 ft/63 m) completing transects with Richard Coleman, so Richard Pyle and Sonia Rowley graciously offered to place two deep traps at 300 ft (90 m). Dave Pence, Josh Copus, Richard Coleman, and I then placed the two most shallow traps on the reef crest at 60 ft. (18 m) before Dave and Josh parted from us to complete their deep dive. Richard and I then dropped off the wall and descended to 200 ft. (60 m) to place the final two traps. The traps had been fitted with more glow-sticks than a European rave. They were left on the reef overnight to collect fish larvae as well as other photoactic plankton.

 juvenile damselfish (Chrysiptera traceyi) that Garrett found inside one of his larval traps, It was placed there as a prank by Brian Greene.  Note the parasitic isopod attached to its lower side. Photo by Garrett Johnson.

juvenile damselfish (Chrysiptera traceyi) that Garrett found inside one of his larval traps, It was placed there as a prank by Brian Greene. Note the parasitic isopod attached to its lower side. Photo by Garrett Johnson.

The following day, we headed back to the site to retrieve the traps. Richard Coleman and I remained in the boat to retrieve the traps from the surface before commencing our dive. I was relieved to find larvae in all six traps, though their exact identities will remain unknown until I return to Hawaii and examine them in the lab. To my surprise, there were two juvenile damselfish in one of the shallow traps. They were larger than the acrylic access holes! It was not until later that I found out that Brian Greene had decided to prank me and put two he had caught in there while on decompression. I won’t forget that one, Brian!