Tag Archives: marco coolen

The Black Sea is a Goldmine of Ancient Genetic Data

New Study Reconstructs the Past Ocean ‘Paleome’

When Woods Hole Oceanographic Institution (WHOI) marine paleoecologist Marco Coolen was mining through vast amounts of genetic data from the Black Sea sediment record, he was amazed about the variety of past plankton species that left behind their genetic makeup (i.e., the plankton paleome).

The semi-isolated Black Sea is highly sensitive to climate driven environmental changes, and the underlying sediments represent high-resolution archives of past continental climate and concurrent hydrologic changes in the basin. The brackish Black Sea is currently receiving salty Mediterranean waters via the narrow Strait of Bosphorus as well as freshwater from rivers and via precipitation. (more…)

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Human Impact Felt on Black Sea Long Before Industrial Era

When WHOI geologist Liviu Giosan first reconstructed the history of how the Danube River built its delta, he was presented with a puzzle.

In the delta’s early stages of development, the river deposited its sediment within a protected bay. As the delta expanded onto the Black Sea shelf in the late Holocene and was exposed to greater waves and currents, rather than seeing the decline in sediment storage that he expected, Giosan found the opposite. The delta continued to grow. In fact, it has tripled its storage rate.

If an increase in river runoff was responsible for the unusual rapid build up of sediment in the delta, says Giosan, the question is, “Was this extraordinary event in the Danube delta felt in the entire Black Sea basin? And if so, what caused it?” (more…)

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Identical Virus, Host Populations Can Prevail for Centuries, WHOI Researcher Reports

A Woods Hole Oceanographic Institution (WHOI) scientist, analyzing ancient plankton DNA signatures in sediments of the Black Sea, has found for the first time that the same genetic populations of a virus and its algal host can persist and coexist for centuries. The findings have implications for the ecological significance of viruses in shaping algae ecosystems in the ocean, and perhaps fresh water as well.

“The finding that the DNA of viruses and algal host cells can be preserved in the geological records is of great interest to microbial ecologists,” said Marco Coolen of WHOI’s Marine Chemistry and Geochemistry department and author of the study, which appears in the July 22 issue of Science. “This offers unprecedented insights into long-term algal, viral, and host population dynamics between globally important algae and their viral pathogens in the ocean.” (more…)

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