Wednesday, March 16, 2011

Indonesia Expedition: All Eyes on Raja Ampat

This post is written by Dr. Erika Heine Montague, Monteray Bay Aquarium Research Institute (MBARI).

Amongst the many remarkable experiences I've had on our journey, the most gratifying has been the opportunity to connect with coral reef biologists, deep-sea explorers, conservationists, professional photographers, research technologists and Raja Ampat's ecotourism pioneers, all working towards one goal: documentation of the region's magnificent and potentially threatened underwater landscape.

Stunning Acropora corals dominate Raja Ampat underwater, while karst islands rise above. (Photo: R. Rotjan)

The need to work together on this problem was a unifying theme, one which spurred on my continuing enthusiasm to develop feasible autonomous and manned monitoring methods. After some discussion with the researchers, it became immediately clear how limited they are by time underwater. An average SCUBA dive lasts only about 60 minutes, with almost an equal amount of time on the surface (depth-depending) to safely manage blood nitrogen levels. A scientist who dives a reef several times a week can still miss some critical transitions: dynamic reef systems change on the order of minutes to years by daily factors (tidal cycles, sunlight, weather) and long-term trends (climate change, pH levels, fishing pressures).

Elvis Mambraku (CI Monitoring Team) measuring reef health underwater in Raja Ampat. (Photo: M. E. Lazuardi)

Not only are the divers' datasets limited by time but also by how human presence can alter reef behavior. Simply put, the group needs a diver who can breathe, look, and behave like the other reef species to get a unbiased sense of life on the reef. Technology of this manner does not exist, nor is is likely to exist in the near future, but the potential to create some elements of this ideal system are possible and very enticing to the marine monitoring community.

A CI monitoring team staff member on SCUBA, watching fish behavior in Raja Ampat (Photo: M. E. Lazuardi)

Present on our boat are the people who have the experience and foresight to assist in this development. Imaging technology, in the form of digital stills and video, immediately rose to the top of desirable monitoring methods. Often, visual documentation is needed after a dive to confirm or document species identification, however, stopping constantly to photograph each organism of interest is time consuming and uses precious air. To address this dilemma we mounted small and lightweight video cameras mounted to divers as they swam transects. As with many new methods, it was a good idea but still needs work. The professional photographers point out the limitations with our optics, both how sunlight is altered through near-shore water, how light enters through the housing's view port and how the imaging system of the camera interprets that light. After several dives with the test cameras, I now feel we have enough information to go home and make a more effective diver-mounted system. In addition to our small cameras, an autonomous camera was placed on the reef in several locations up to periods of 6 hours (mentioned in this post).

An autonomous underwater camera, rigged on the reef with a float to enable easy retrieval. Photo: R. Rotjan

These images gave us a sense of what reef activity looks like in the absence of diver activity.  Several areas, such as Imbikwan point, delighted us with video of blacktip reef sharks, green sea turtles, and schools of bumphead parrotfish (mentioned in this post).

Data like these are critical to understanding what is present in Raja Ampat and how that diversity changes over time. The fate of Raja Ampat's reef system impacts not only the local Papuan community, who rely on this resource, but also the source of several unique species endemic to this region.

-Dr. Erika Montague

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