.Croatian Collaboration
 

Dr. Sean Colin from Roger Williams College in Providence, RI, prepares to follow Dr. Monty Graham diving into the water.
  Led by Dr. Monty Graham, a team of US marine scientists from the Dauphin Island Sea Lab, Providence College, Roger Williams College and the National Science Foundation traveled to Croatia this summer to collaborate with colleagues in that war-torn country. Working out of a 12th-century monastary near the medieval walled city of Dubrovnik the scientists
conducted experiments and collected biological data during a research cruise and shore-based experiments.

Only eight years ago, Croatia was embroiled in war with its former Yugoslavian neighbors Serbia and Montenegro. Since then, marine scientific research in Croatia has been limited by economic recovery from the war, but collaborative efforts with US scientists are accelerating the process. The current research program, which was initiated in summer of 2002, is a cooperative effort funded through the National Science Foundation and the United States Department of State that looks to increase scientific collaborations between the United States and Croatia.At the center of the research program of this year’s expedition is the small island of Mljet (pronounced Me-yet). On the northern end of this island is one of Croatia’s five national parks, which contains two salt water lakes‚ connected to the sea by a small, narrow inlet. Within these lakes is a population of jellyfish very similar to those found here in the Gulf of Mexico. Scientists believe that the Mljet population has been isolated for about 7000 years when the lakes were first filled with seawater. The isolation of this small population of jellyfish allows the research team to conduct experiments in a controlled manner unlike anywhere else in the world.
Unlike their Gulf of Mexico counterparts that grow to sizes exceeding large dinner plates, the Mljet jellies only reached the size of a coaster. Yet despite their small size, they are fully reproductive. Interestingly, Mljet seems to be an extreme in food depletion and therefore the jellies have acquired the ability to put almost all of their food energy into making offspring. By working with the Mljet population, the scientists had hoped to ask and answer questions about how changing the amount of food provided to jellies will influence their ecology and reproduction.
 		  
Field work becomes enjoyable on a crystal blue Croatian lake. Left to right, John Higgins, Luciano Chiaverano, Heather Fletcher and a Croatian graduate student.
While researching these lake-bound jellies this summer, the team made a startling discovery: about 40% of the population is infected with an enigmatic parasite that causes severe starvation in highly infected medusae. Although Dr. Graham’s team have not yet been able to identify the parasites of these jellies, they appear to have developed an ecologically stable relationship with the jellyfish population. States Dr. Graham, “The parasites have created an unusual opportunity for studying the relationship between feeding, growth and reproduction in jellyfish because we can now compare, within a single population, starving and non-starving medusae.”

In addition to their own ongoing research, Dr. Graham’s team anticipates returning to Croatia next year as part of a newly established Adriatic Summer Institute. This summer institute will include participation of various research teams and disciplines from several European countries and the United States.

The team members from DISL are Dr. Monty Graham, Heather Fletcher, John Higgins, Luciano Chiaverano, Laura Linn and Mike Fletcher.

-- Dr. Monty Graham