Satellite Images of Emiliania huxleyi Blooms

[click on the small pictures on this page to view them at full size]

[Story of the discovery of Ehux blooms by satellite]

Shown below are some satellite pictures of blooms of Emiliania huxleyi. The coccolith platelets carried by the cells cause reflection of light, making the sea look brighter and hence distinctive in satellite images. Thus satellites enable us, for this species, to delimit the precise extent of its blooms in the sea. Satellites can also detect the presence of chlorophyll in the water, but as a rule cannot distinguish which species are responsible.

The ability to delineate the extent of single-species blooms is an important tool for ecology. For instance, satellites show us that blooms develop simultaneously over a wide area. Their onset is much faster than would be possible if blooms were caused by a "seeding effect", with the initial cells of the bloom being physically transported from elsewhere to start the bloom off. Therefore we can estimate that seeding effects are not very important in phytoplankton ecology. Remote sensing of this single species also allows us to estimate its individual biogeochemical importance.

Two beautiful SeaWiFS satellite images of blooms off Newfoundland in the western Atlantic, the left-hand on 21st July 1999, the right-hand one on 16th July 2000. Humanity has invested billions of dollars putting satellites into space; these images are part of the reward.

Blooms are not often seen close to the coast of Greenland. However, this image shows a bloom at about 65 degrees N, to the east of the icesheet covering Greenland. it was taken on July 27, 2003. MODIS images are courtesy of Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.

Two more stunning SeaWiFS satellite images of a coccolithophore bloom cradling the Falkland Islands (Patagonian Shelf), the left-hand one on 29th November 1999, the right-hand one two weeks later on 13th December. Water sampling has confirmed bright waters in the area to be due to abundant coccolithophores.

Oct 10th 2000 (left) and Sep 12th 2000 (middle) in the Bering Straits / Bering Sea, and late summer 1997 (right) in the eastern Bering Sea. Water samples taken near St. Paul Island in early October 1997 contained abundant Ehux coccoliths.

Ehux bloom in the Barents Sea (north of northern Norway) on July 27th 2004 (left) and a wide-angle picture on July 30th 2004 (right). First picture from MODIS, second from SeaWiFs. MODIS images courtesy of Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.

Satellite picture of a bloom in the Skagerrak and along the Norwegian coast, May 31st 2000. Ehux is well known to produce white waters in this area.

Satellite pictures blooms in the North Sea, Jun 5th 2003 (left) and June 10th 2000 (right).

SeaWiFS satellite images of (a) a bloom to the SW of Ireland, 10th May 2000, (b) small bright patches in the western approaches to the English Channel, 26th June 2000, (c) larger bloom in the same area, 12th june 2003, (d) both areas together with the Bay of Biscay, 21st May 2001, and (e) bloom in the Bay of Biscay, May 16, 2004 (this image from MODIS, courtesy of Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC). Previous bright summer waters have been positively identified as Ehux in these areas.

LANDSAT satellite image of a bloom in the English Channel off the coast of Cornwall, 24 July 1999. The bloom was sampled six days later by scientists at Plymouth Marine Laboratory and positively identified as Ehux. Image courtesy of Andrew Wilson and Steve Groom.

SeaWiFS images of Ehux blooms (as verified by water sample analyses using an SEM) in the Black Sea: (left) June 13 2000 and (right) June 12 2000. Note the colour contrast between the deep blue of the eastern Mediterranean and the paler colour of the Black Sea.

Probable Ehux bloom (bright waters have not been previously sampled here) between Tasmania and New Zealand, 17th Jan 1999.

Three further satellite images (SeaWiFS) of a bloom south of Iceland, this time June 15th, 1998.

Additional pictures from the Bering Sea, Barents Sea, Black Sea, northern North Atlantic, western North Atlantic, Patagonian Shelf.

Pictures from older satellites

What do the satellite sensors actually look like? They are surprisingly small. Many of the images above were obtained with the SeaWiFS sensor. The global bloom distribution was produced using the CZCS sensor.

Temporal development of a bloom along the Norwegian Coast

Ocean in Motion: a video clip prepared from successive satellite images of the extensive 1991 Ehux bloom south of Iceland, with the coccoliths act as visual tracers highlighting, literally, ocean currents moving across the bloom area (produced by Steve Groom).

[Unless otherwise stated, all images on this page were provided by the SeaWiFS Project, NASA/Goddard Space Flight Center and ORBIMAGE. Many thanks to Norman Kuring (NASA/GSFC) for help with images]

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