2A Marine Biology

61 Route 9W - PO Box 1000

Palisades

NY

10964-8000

US

Phone: 

(845) 365-8837

andyjuhl@ldeo.columbia.edu

View Website

Phytoplankton - single-celled, planktonic algae - are the base of marine food webs. Nearly all other marine organisms are directly or indirectly dependent upon phytoplankton for nutrition. Although individually small, phytoplankton are so numerous in the ocean that their cycles of growth and decay influence global geochemical processes and the earth's climate. On local scales, excessive phytoplankton growth, or accumulations of certain phytoplankton species, can be harmful to other organisms, including humans. For these reasons, I am interested in how environmental factors influence phytoplankton growth and physiology, and the interactions between phytoplankton and other planktonic organisms. From a less utilitarian perspective, planktonic organisms are remarkable, and often beautiful creatures. Observing and studying them can be inspiring and amusing. Because plankton experience a world so different from our own, they provide us with fascinating examples of how unusual life forms can be. Nevertheless, they share many similarities with other creatures and thereby provide us with insight into the general rules of life.

I use a hypothesis-driven approach to address specific questions related to the general fields of interest listed above. I typically combine field sampling with controlled laboratory experiments and analyses.

Current projects include: 1) phytoplankton nutrient limitation in Pensacola Bay (with M.C. Murrell of the US EPA Gulf Ecology Division), 2) predation-deterring substances produced by toxic dinoflagellates of the genus, Alexandrium (with P. J. S. Franks of Scripps Institution of Oceanography and C., Martins of Woods Hole Oceanographic Institution), 3) development of a PCR-based method to measure copepod grazing rates on specific phytoplankton prey species (with S. Dyhrman of Woods Hole Oceanographic Institution), 4) the effect of shear forces on cellular integrity of the toxic , dinoflagellate, Karenia brevis, and 5) attachment and detachment mechanisms of algae to/from sea ice (with C. Krembs of University of Washington, Applied Physics Lab).