By Ashley Cohen
Halloween in New York is always bittersweet. The autumn is a beautiful, festive time of year. The leaves are changing colors, it is cool enough to go on long hikes, and all the local farms have apple and pumpkin picking. Halloween always marks the beginning of the holiday season and the cold, wet weather, when I usually pass the time indoors hanging out with my fellow grad students from the School of Marine and Atmospheric Sciences, Stony Brook University, NY until March. But this Halloween, I found myself in John F. Kennedy international airport with two suitcases (mostly filled with science gear) being checked in by a United Airlines clerk who was very excited to be dressed like Aladdin down to the last detail (“Do you like my lamp?!” he asked and excitedly showed me that it contained Halloween candy). I was beginning a long two days of travel from New York to Frankfurt, from Frankfurt to Tel Aviv, and finally to my destination- Eilat, Israel- where I would live for two months to do an original research project at the interuniversity institute (IUI) for marine science as a recipient of the ASLO Limnology and Oceanography Research Exchange (LOREX) scholarship.
After linking up with another LOREX fellow bound for the IUI in Frankfurt, we travelled together by train from Tel Aviv to Ben Gurion University of the Negev in Be’er Sheva, where we would catch a ride with my host, Dr. Gilad Antler, to Eilat. It was amazing how quickly the landscape changed during our three hour drive down highway 40. Be’er Sheva is part of the Negev desert, but is higher in altitude and still has a partially Mediterranean climate like northern Israel. Suddenly I found the landscape opening up into breath taking craters, mountains, and dunes. The road would twist and wrap through the canyon walls made of red sandstones and ancient chalk deposits, then emerge high enough so that you could see the colorful green and red Solomon mountains plunging towards the Gulf of Aqaba.
Traveling down highway 40 from Be’er Sheva to Eilat: Ramon Crater, Negev Desert (left) and the Gulf of Aqaba seen below Solomon mountains (right)
I had a busy first two weeks preparing to set up my experiments immediately after we would retrieve sediment cores from 420m deep water in the Gulf. I was interested in this sediment because I thought, based on the published geochemistry, that it could support an interesting but uncommon type of microbially mediated sulfur reaction called disproportionation. In environments that have very small amounts of or no dissolved oxygen, the most common type of microbially mediated sulfur reaction is sulfate reduction. By this reaction, microbes reduce the sulfate in seawater to sulfide (if you have ever smelled that rotten egg smell after it rains, that is sulfide!) to break down organic matter for energy. Some of the sulfide can partially re-oxidize into compounds that have an oxidation state in between sulfate and sulfide, called sulfur intermediate species. These species can sometimes be disproportionated- or split into sulfate and sulfide without any terminal electron acceptor. Most of the time, this doesn’t happen, because if sulfide is present it is energetically easier for microbes to oxidize sulfide. The Gulf of Aqaba, however, receives a lot of reactive iron (non-crystalline iron) by wind deposition. The iron is like a giant sponge that locks up all the sulfide to form iron-sulfide minerals. The gulf also does not receive a lot of organic matter, without which there cannot be very high rates of sulfate reduction. If it could happen in any open marine sediment, this was it!
Despite being too busy to travel right away, I did get to experience some amazing things in the IUI. The views of the Gulf of Aqaba and the mountains in Jordan were stunning. The sunsets were especially colorful due to all the dust. In just a few steps offshore from the beach you are in a vast coral reef and can see every last detail through the crystal-clear water. Where else can you snorkel in a coral reef during your coffee break?!
Sampling day: The IUI research ship coming to shore to take us sampling (left). We brought buckets and core liners (middle) to retrieve sediment from 420m deep in the Gulf of Aqaba for my experiments; The view of the shoreline as we left for sea (right).
Experiment set-up: After getting the cores back to the lab (left), I set up my sediment incubation experiments. I subsample every 4-5 days for a variety of chemical and biological measurements
I did eventually get to travel with my host, who was giving a talk at the Hebrew University of Jerusalem. Along the way we explored scenic viewpoints including a large solidified ancient magma chamber and stopped for a cappuccino in a small quaint town with cafes, fruit stands, and sweet shops. As we drove along, leaving the ostriches, ibex, and sand dunes behind, the landscape transformed and greened into what looked like Italy. We eventually approached the Dead Sea, 430m below sea level, and almost immediately after were soaring into Jerusalem- a city in the mountains. The old city, or historical Jerusalem, is a labyrinth of alleys and roads connected by stairs winding through the hills bustling with merchants, religious pilgrims, tourists, and locals. We made our way to Jaffa Gate (“David’s Gate”), one of the seven historical gates that open into Jerusalem’s historic city walls and within the gate went into Christ church- the oldest Protestant church in the Middle East. Along the way we caught a glimpse of the Citadel, also known as the Tower of David, thought to be built in 2 BCE by King Herod himself. After a stop along the Wall of Jerusalem for sunset we headed to the Mahane Yehuda Market- a cornucopia of every fragrant herb, savory dish, and delicious dessert you could want mingling together in the air over several streets.
My trip to Jerusalem: On the way to Jerusalem we saw an ancient solidified magma chamber (left). The hexagonal pillar pattern forms as the magma contracts and cools. In Jerusalem, after my host’s talk (center) I saw the old city- including Christ Church (right).
Back in Eilat I am still hard at work trying to chase strange sulfur microbes, but lucky just a ten minute drive is all it takes to find lots of hiking and camping. After a hard day in the lab today I decided to go camping. As I sit in the mountains, baking flat bread to eat with cheese and humus over an open flame and watching Venus in the clear night sky, I think about how lucky I am to have this opportunity to explore this sometimes harsh but beautiful land.
Camping! After making flatbread on the fire for dinner (top), I caught a beautiful sunset (bottom left) before turning in early so I could wake up early the next day to catch the sunrise in the mountains (bottom right)