02 February 2010


I write fairly extensively about phytoplankton in DEEP BLUE HOME. I feel indebted to them for the multiple ecological services they perform, helping to make and keep Earth habitable... helping to make Earth lovely when seen from afar... potentially informing distant intelligences that there is life on this planet.

The ethereal image of a spring phytoplankton bloom off New Zealand was posted by NASA'S Earth Observatory back in October 2009:

"Cold rivers of water that have branched off from the Antarctic Circumpolar Current flow north past the South Island and converge with warmer waters flowing south past the North Island. The surface waters of this meeting place are New Zealand's most biologically productive. This image of the area on October 25, 2009, from the MODIS sensor on NASA’s Aqua satellite shows the basis for that productivity: large blooms of plantlike organisms called phytoplankton."

We've come a long way since this 1927 plankton article (below, click for larger view) "Remarks on the need for life history studies of marine plankton animals," by W.E. Allen at the Scripps Institution of Oceanography:

W.E. Allen: "In the matter of food relationships alone, it is apparent that every plankton animal is important, and if we are to properly understand marine life, the degree and manner of its influence needs to be traced."

Four years after Allen's call to scientific arms, the Continuous Plankton Recorder (CPR) was launched, using plankton tows attached to merchant ships and ships of opportunity crossing the North Atlantic and the North Sea. In the years since, nearly 300 vessels have been involved in collecting these data, including Greepeace ships, research vessels, passenger ferries, and cargo ships.

The CPR has provided nearly 80 years of data, among the longest running of biological monitoring programs, painting an evolving picture of the spatiotemporal dynamics of plankton. Today the survey is based at the Sir Alister Hardy Foundation for Ocean Science in Plymouth, UK. Here's a map of their network of monitoring routes:

The CPR helps us understand complex issues including climate change, biodiversity, biological invasions, dead zones, fisheries, and regime shifts. 

What's a regime shift? Terry Hughes from the Australian Research Council Centre of Excellence for Coral Reef Studies explains:

For an excellent overview of the history and results from more than 900 scientific papers published with CPR plankton-tow data, download the pdf of "The Continuous Plankton Recorder: Concepts and history, from Plankton Indicator to undulating recorders," published in Progress in Oceanography in 2003. It details the evolving scientific lineage of people, technologies, and thought that has steered the interface between marine biology and oceanography in the 20th century. 

Other continuous plankton recorders are now up in running, including one in the Southern Ocean, not far from the curlicue blooms seen in the satellite image off New Zealand.

Diatoms (phytoplankton) through the microscope by Gordon T. Taylor, Stony Brook University, for NOAA
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