Monday, August 29, 2011

Jellyfish Invasion

Jellyfish Invasion

A very good video on Jelly fish.
Jelly fish may be blooming due to increase in Dinoflagellate biomass and decline in Diatoms.

Monday, August 22, 2011

Great Barrier Reef - Algal Blooms

Phytoplankton Bloom in the Great Barrier Reef
acquired August 9, 2011download large image (6 MB, JPEG)
acquired August 9, 2011download GeoTIFF file (64 MB, TIFF)
acquired August 9, 2011download Google Earth file (KML)

The Sea in many places is here cover’d with a kind of a brown scum, such as Sailors generally call spawn; upon our first seeing it, it alarm’d us, thinking we were among Shoals, but we found the same depth of Water were it was as in other places.

Sailing through the Coral Sea outside the Great Barrier Reef, Captain James Cook made those observations on August 28, 1770. His journals contain the first mention of the long brown filaments of cyanobacteria that arecommon along the Australian coast.

On August 9, 2011, the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite captured this view of a similar band of brown between the Great Barrier Reef and the Queensland shore. Though it’s impossible to identify the species from satellite imagery, such red-brown streamers are usually trichodesmium.Sailors have long called these brown streamers “sea sawdust.”

Trichodesmium, a form of cyanobacteria, are small, usually single-celled organisms that grow in the ocean and produce food through photosynthesis like plants. They play an important role in Earth’s oceans because they convert nitrogen gas from the atmosphere to ammonia, a fertilizer that plants can use to grow. At the same time, trichodesmium removes carbon dioxide from the atmosphere. Their blooms often occur in warm, nutrient-poor waters. Charles Darwin observed one such bloom from the HMS Beagle in 1832, marveling that “their numbers must be infinite.”

  1. References

  2. Cook, J. (1771). Captian Cook’s journal during his first voyage round the world made in H.M. Bark 1768-71.University of Adelaide, 2010. Accessed August 16, 2011.
  3. Darwin, C. (1845). Voyage of the Beagle. Published on Accessed August 16, 2011.
  4. Kuring, N. Great Barrier Reef. NASA Ocean Color Web. Accessed August 16, 2011.
  5. University of California Museum of Paleontology. (n.d.). Introduction to the cyanobateria. Accessed August 16, 2011.
  6. Woods Hole Oceanographic Institution. (2002, September). Trichodesmium. Accessed August 16, 2011.

NASA Earth Observatory image created by Jesse Allen, using data obtained from the Land Atmosphere Near-real time Capability for EOS (LANCE). Caption by Holli Riebeek.

Aqua - MODIS

Barents Sea - Algal Bloom

Bloom in the Barents Sea
acquired August 14, 2011download large image (3 MB, JPEG)
acquired August 14, 2011download GeoTIFF file (19 MB, TIFF)
acquired August 14, 2011download Google Earth file (KMZ)

Brilliant shades of blue and green explode across the Barents Sea in this natural-color image taken on August 14, 2011, by the Moderate Resolution Imaging Spectroradiometer (MODIS) on the Aqua satellite. The color was created by a massive bloom of phytoplankton that are common in the area each August. The clear view is a rare treat since the Barents Sea is cloud-covered roughly 80 percent of the time in summer.

Plankton blooms spanning hundreds or even thousands of kilometers occur across the North Atlantic and Arctic Oceans every year. Many species thrive in the cooler ocean waters, which tend to be richer in nutrients and plant life than tropical waters.

In this image, the milky blue color strongly suggests that the bloom contains coccolithophores, microscopic plankton that are plated with white calcium carbonate. When viewed through ocean water, a coccolithophore bloom tends to be bright blue. The species is most likely Emiliana huxleyi, whose blooms tend to be triggered by high light levels during the 24-hour sunlight of Arctic summer. The variations in bloom brightness and color in satellite images is partly related to its depth: E. huxleyi, can grow abundantly as much as 50 meters below the surface.

Other colors in the scene may come from sediment or other species of phytoplankton, particularly diatoms. The Barents Sea usually witnesses two major bloom seasons each year, with diatoms peaking in May and June, then giving way to coccolithophores as certain nutrients run out and waters grow warmer and more layered (stratified).

The area in this image is located immediately north of the Scandinavian peninsula. The region is a junction where several ocean current systems—including the Norwegian Atlantic, the Persey, and east Spitsbergen currents—merge and form a front known as the North Cape Current. The intersecting waters, plus stiff winds, promote mixing of waters and of nutrients from the deep.

Ice-covered for most of the year, the shallow Barents Sea reaches its warmest surface temperatures (6.6 C) in August, when ice cover is at a minimum and the water is freshest (less saline due to ice melt and river runoff) and most nutrient depleted. Those conditions, researchers have found, are perfect for coccolithophores to take over from other species and dominate the surface waters.

In a 2009 paper by Signorini et al, the researchers note:

Coccolithophores, among which E. huxleyi is the most abundant and widespread species, are considered to be the most productive calcifying organism on earth. They are important components of the carbon cycle via their contribution and response to changes in atmospheric CO2 levels...Coccolithophores appear to be advancing into some sub-Arctic Seas and climate change induced warming and freshwater runoff may be causing an increased frequency of coccolithophore blooms within the Barents Sea.

NASA recently sponsored a research cruise—known as ICESCAPE—in Arctic waters north of Alaska and Canada. Researchers were sampling coccolithophores there, among other species and environmental characteristics, to get a better view of the Arctic Ocean ecosystems and how they may be changing. The cruise is over, but you can still read the daily postings from six weeks at sea. Click here.

  1. Related Reading

  2. Signorini, S. R., and C. R. McClain (2009), Environmental factors controlling the Barents Sea spring-summer phytoplankton blooms. Geophysical Research Letters, 36, L10604, doi:10.1029/2009GL037695.
  3. NASA Earth Observatory (1999) What is a Coccolithophore?" Accessed August 17, 2011.
  4. NASA (2011) ICESCAPE Blog. Accessed August 17, 2011.

NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team at NASA GSFC. Caption by Mike Carlowicz and Holli Riebeek, with interpretation from Barney Balch (Bigelow Laboratory) and Norman Kuring and Sergio Signorini of NASA's Goddard Space Flight Center.

Aqua - MODIS

Saturday, August 20, 2011

Algal Bloom in NY/NJ Bight: Help Needed!

Friday, August 19, 2011

Algal Bloom in NY/NJ Bight: Help Needed!

A huge algal bloom, indicated by the green color in the ocean water, was observed on August 17, 2011 in this True Color Satellite Image. The Mid-Atlantic Regional Association Coastal Ocean Observing System, MARACOOS, has posted this image and additional information and data on its website, click here. The bloom covered much of the New York/New Jersey Bight which extends from Montauk, NY (the tip of Long Island) to Cape May, NJ.

The bloom consists of tiny algae, called phytoplankton, that contain the pigment, chlorophyll-a, which is measured in the satellite images. MARACOOS webpage shows an image of the Bight area on July 1 under more normal conditions for this time of year. The bloom initially began in mid-July along the middle to southern part of the Jersey Shore. Winds from the southwest blowing northeast became dominant from July 23-30 driving surface waters toward the ocean and causing water to upwell along the NJ coast. Nutrient-rich, cold waters from the ocean bottom rises during upwelling, fueling algal growth and blooms. These waters combine with coastal surface waters that are also nutrient rich due to the Hudson River outflow and coastal runoff.

In the summer, southwesterly winds and the associated occasional coastal upwelling is normal along certain specific areas of the Jersey shore. However, these blooms usually affect an area within about 9 - 12 miles (15-20 km) from shore, whereas the algal bloom this August extends to over 62 miles (100 km) into the ocean.

As the algae in the bloom die, they settle to the seafloor and decay using up oxygen. Reductions in dissolved oxygen to 4-5 mg/L have been observed by one of the autonomous underwater vehicles (Gliders) that have been deployed by Rutgers University to sample and monitor the Bight. Updates on glider data can be found here. Levels below the water quality of standard of 5 mg/L can stress and harm fish and other aquatic organisms. Clean Ocean Action (COA) has previously advocated for a glider to be used along the NJ coast by NJDEP and EPA and it is great to see that this effort has been funded, especially given this massive bloom event.

In addition to the upwelling process, another coastal oceanographic process off the northern part of the Jersey Shore has developed over the last week apparently in response to the extensive rain over the weekend in the New York/New Jersey region that resulted in high volumes of runoff and combined sewer overflows in the metropolitan area that discharge into the Hudson River Estuary. The bloom activity in the northern part of the Jersey Shore appears to be related to coastal runoff and the plume, the outflow, of the Hudson River.

COA is requesting the help of divers, fishermen, and boaters in the area to look for tell-tale signs of low dissolved oxygen and document their locations. Fishermen and boaters should be looking for fish floating on the surface or in their nets. Divers should look for lobsters, crabs and fish that usually hide in crevices, but are now in the open and lethargic. Also, divers should look for fish that are located higher on the wrecks and/or breathing with difficulty. If divers know how to use dissolved oxygen kits, they should take samples. COA is also asking government agencies to sample and monitor the bloom and its impacts.

Tuesday, August 2, 2011

Omega-3 taken in pregnancy could protect infants' health: study

Omega-3 taken in pregnancy could protect infants' health: study

Click on the flag for more information about United StatesUNITED STATES
Wednesday, August 03, 2011, 04:20 (GMT + 9)

A new study by Emory University suggests that babies will be protected against illness during early infancy if their mothers consume omega-3 fatty acids from supplements or fish during pregnancy.

The findings of the randomized, placebo-controlled trial were published online in the journal Pediatrics.

Scientists followed about 1,100 pregnant women and 900 infants in Mexico. The women were given daily supplements of 400 mg of Docosahexaenoic Acid (DHA) in
the algal form or placebo from 18 to 22 weeks gestation through childbirth.

The researchers said no fear should exist of mercury contamination in DHA from algae, HealthDay reports.

Children whose mothers took DHA supplements were found to suffer from fewer colds and shorter illnesses at one, three and six months of age.

"This is a large scale, robust study that underscores the importance of good nutrition during pregnancy," said Usha Ramakrishnan, PhD, associate professor, Hubert Department of Global Health at Emory’s Rollins School of Public Health.

Ramakrishnan noted that, according to the study, pregnant women who take 400 mg of DHA are more likely to deliver healthier babies.

“There is research to suggest that the fatty acid composition of many of our cells—particularly the immune cells—affect their function,” Ramakrishnan commented, reports.

At one month of age, the infants in the DHA group had a reduced incidence of cold symptoms by 25 per cent, such a shorter duration of cough, phlegm and wheezing.

At three months of age, those infants spent 14 per cent less time sick.

At six months of age, those infants experienced shorter duration of fever, nasal secretion, difficulty breathing and rash, even though they had a longer duration of vomiting.

Ramakrishnan and her colleagues previously reported findings that babies of women pregnant with their first child who consumed 400 mg DHA during pregnancy delivered babies 100 g heavier at birth and 3/4 cm longer at 18 months of age.

The researchers also detected increased DHA levels in breast milk, and all of the infants in the study were breastfed.

“Recommending women to take a dose of up to 400 milligrams of DHA during pregnancy would be safe, [but] how much of a benefit there is we don’t know yet,” Ramakrishnan concluded.

The study was funded by the NIH and the March of Dimes Foundation.