2016 Participants

Dan Killam

Conservation Paleobiology of Giant Clams on the Israeli Red Sea Coast

Collaborator: Dr. Jonathan Erez

During my time in Eilat, I will be researching the natural history of giant clams in the Gulf of Aqaba. This population, composed of three species, is the northernmost population of the genus Tridacna in the world. Previous workers have observed that T. squamosina, a recently uncovered cryptic species, was the most common member of pre-human assemblages but is now a remnant population, having largely been replaced by the other species, T. maxima and T. squamosa. I intend to determine whether the giant clams of the Red Sea, particularly T. squamosina, are under increased stress from human predation and pollution in modern times compared to their fossil counterparts. To do so I will collect modern and ancient representatives of Tridacna, from buried fossil reefs on land and modern living reefs directly offshore. Each shell contains a record of the organism's growth during life encased in its regular growth bands, similar to the study of tree rings. I will isolate the organic material from these growth bands and use carbon and oxygen isotopes to determine whether the organisms' growth rate and food sources have changed through time, and whether those changes align with the arrival of humans in the area (and the resulting influx of agricultural and erosion-sourced pollution). Doing so will shed light on whether current efforts to reduce overfishing will be enough to allow these species to recover, or whether additional intervention will be needed to protect the water quality of the reef environments which they require to thrive.

Michele Markowitz

The impact of mineral particles on zooplankton carbon assimilation and implications for the efficiency of the biological pump

Collaborator: Eyal Rahav, Adi Torfstein

Dust deposition is a source of limiting nutrients and other minerals to the ocean, affecting phytoplankton productivity as well as community structure. It has been suggested to facilitate the flux of carbon to the deep ocean; however, these effects are not well constrained. Our experiments suggest a possible feedback mechanism that has been completely overlooked: the presence of dust can significantly reduce the carbon assimilation of marine grazers, resulting in enhanced carbon transport to the deep ocean via fast-sinking, carbon-rich fecal pellets.

Preliminary work suggests that zooplankton ingestion of mineral material increases organic carbon content in fecal pellets, as well as size and density. Based on these observations, I hypothesize that the sinking rates of fecal pellets and associated carbon transport to depth via fecal pellet export will increase with increasing dust deposition. To test this, I will conduct controlled laboratory experiments, mesocosm incubations, as well as collect data from field observations. During the summer of 2016, I will set mesocosm experiments in both the Gulf of Aqaba and the Mediterranean Sea with dust additions and collect the fecal pellets. At IUI in Eilat, I will also analyze fecal pellets collected from sediment trap samples that were deployed during different dust deposition conditions. Results will be contextualized with similar work conducted in Monterey Bay, as well as data collected from fecal pellets taken from sediment trap archives across the world. Investigation of this interaction will offer significant contribution to the understanding of carbon sequestration via the biological pump. 

Karen Lykkebo Petersen

Title: Impacts of Desalination Brine on Phytoplankton and Coral Growth and Health

Collaborator: Miguel Frada, Eyal Rahav, Nurit Kress & Edo Bar-Zeev

Desalination of seawater is a very reliable water resource. It is widely used in countries around the Persian Gulf, the Middle-East and Mediterranean as a primary source of drinking water and it is slowly increasing popularity in other parts of the world too. In the process of desalination a byproduct of high-salinity brine is created and this, mixed with chemicals used in the treatment, is often discharged back out into the coastal environment. The effects of the discharge on the coastal ecology, biology and chemistry are not well understood. In Eilat I will construct two experiments looking at the effects of the brine on local species: 

1)         I will collect phytoplankton in the Gulf of Aqabar, and grow them under different concentrations of brine. I will be investigating their overall growth by looking at the amount of chlorophyll production and I will look at the species diversity and composition. Phytoplankton forms the very base of the trophic levels, and a change in their growth and composition could potentially cause great changes in higher trophic levels.

2)         Specimens of three coral species will be collected from IUI’s coral nursery and grown in different brine concentration. Their overall growth will be measured by weight and their symbiotic algae will be collected from the coral tissue and an array of parameters analyzed to test for their growth, abundance and health. 

I hope to be able to increase our understanding of the desalinations impact of coastal areas, and with this eventually provide tools to increase the sustainability of desalination of seawater.

Noam Baharav
Undergraduate research volunteer

As an undergraduate research volunteer I am excited and eager to be assisting Karen, Dan, and Michele in their projects. I will be aiding in sample collection,  experiment maintenance (cleaning, monitoring etc. ) and in whatever other capacities I may be needed.
As a marine biology undergraduate student I am specifically interested in marine animals, ecology, and conservation. As a certified scuba diver, I am thrilled to be able to experience research-oriented dives, and learn about the research process hands-on. I have had previous exposure to sea turtle rescue facilities and research programs in Costa Rica, as well as Hainan China, and am amazed to now be on the "other side"– that of the researchers and students, and intrigued to see what the work entails, and the variety of projects and research fields at IUI.
I will be joining the research team for the month of July, and then continuing on to a gap year in Israel, during which I will be volunteering full-time in a Pnimia– a home and education village for underprivileged/endangered youth. Luckily, my new home next year will also be on the beach :) .