August 1, 2009

Onward to the Middle Eastern Corals

Assistant Professor of Biology and Environmental Science at CUNY, Baruch College and Reseach Associate, American Museum of Natural History

EILAT, Israel | After a flight to Tel Aviv and then a hop aboard an Arkia flight to Eilat, I arrived at the Interuniversity Institute for Marine Sciences. It was founded in 1968 and has produced over 1,600 scientific papers. A unique aspect of the location (on the border of Saudi Arabia, Jordan and Egypt) is that it has excellent diving conditions virtually year-round. From this location divers embark on 3,500 scientific dives a year, with about 140 being trimix dives.

I was met by the institute director, Dr. Dan Tchernov, and Dr. Tom Bibby of the National Oceanography Centre, Southampton. We will be using a Tri-Mix (Oxygen, Helium, Nitrogen) closed SCUBA diving system technology, known as rebreathers. The institute has 4 rebreather systems and 4 technical diving gear modified for TriMix diving (similar to diving on Little Cayman). With a very small volume of gas, we will be able to stay under water for 5 hours. Though rebreathers have been around 15-20 years, they are only recently becoming more widely used by scientists.

We awake before dawn to take advantage of the cool weather (only 92F) and head to the Institute to begin assembling rebreather equipment. It takes an hour or so to go through all the pre-dive safety checks to make sure the Megalodon Closed Circuit Rebreather trimix system is functioning properly. We are told a harrowing statistic: that there is a 1 percent fatality rate of all re-breather owners. Oded Ben-Shaprut, 56, is the dive safety officer at the IUI . He is touted as the second most qualified diver in the state of Israel. He began diving in 1971 and has logged over 20,000 dives with 2,000 being technical dives. He started diving in the special operations diving unit of the Israeli army before working his way into scientific diving.

We begin our descent to 100 meters. The first observation is the deafening silence of re-breathers. Unlike the cacophony of open-circuit diving, re-breathers are eerily quiet. The fish certainly don’t see us coming and it is possible to almost reach out and touch them before they notice.

The aim of this diving is to understand the governing principles that dictate the modification of the reef’s calcifying activities, biogeochemistry and physiology under climatic change. The ultimate goal is to determine weather or not current climatic conditions are an anomalous event that might lead to mass extinction, or a part of the normal glacial/interglacial cycles.

As we descend, we collect fragments of four main coral species (Alveopora allingi, Favia favus, Stylophora pistillata, and Seriatopora hystrix) will be collected, every 10 m along the reef slope (depths of 0.1, 10, 20, 30, 40, 50, 60,70, 80, 90 and 100m). We also collect small pieces of shallow S. pistillata and fragments of S. hystrix and the same amount of deeper fragments from the same species for the transplant experiment. In order to achieve uniform light conditions for all fragments collected, only the colonies facing-up and exposed to the maximum light intensity in their depth are picked. Back in the seaside laboratory, fragments will be used for the determination photosynthetic and phylogenetic responses to the changing depth and light regime.