Thursday, April 25, 2013

We are seeing a global increase in the frequency and severity of Algal blooms

Pea Soup

Photograph from China Daily/Reuters
A boy swims in algae-covered waters off the coast of Qingdao, China (map) in 2011—just one of the places around the world where algae blooms are a growing problem. (Related pictures: "Photos: Thick Green Algae Chokes Beach—Swimmers Dive In.")
With an estimated seven billion people and counting, the world's population will only get hungrier. The advent of fertilizers and high-yield crops have helped growers keep pace with the demand for food.
But there's an unintended crop flourishing around the world that is not always so beneficial. Microscopic, plantlike organisms called algae thrive on the excess nutrients—like nitrogen and phosphorus—found in fertilizers that make their way from backyards and fields, producing blooms that can sometimes be seen from space.
Combined with warming temperatures and water circulation patterns, coastal areas such as Qingdao, the Gulf of Mexico, and the U.S. West Coast—as well as freshwater systems like the Great Lakes—are no strangers to enormous algae blooms that can turn the water green or red. (Related: "Harmful Algae Blooms Plague Lake Erie Again.")
Some of these blooms can create dead zones, or areas that are deprived of oxygen, in the water. And some algal species can also produce toxins that wreak havoc on human livers and neurological functions and cause seizures in marine mammals. (Related: "Sea Lion Seizures May Result From Toxic Algae.")
"There's no question in my mind that we are seeing a global increase in the frequency and severity of these [blooms]," said David Caron, a researcher at the University of Southern California (USC) in Los Angeles who studies harmful algal blooms.
Jane J. Lee
Published April 23, 2013

Monday, April 22, 2013

Algae and fish farm link prospects on global science agenda
Algae and fish farm link prospects on global science agenda


Some of the best scientific minds in the world will this week focus on exploring any potential link between harmful algal blooms and fish farms.

The issue has been put on the agenda of an international algal bloom conference in Paris by senior scientist Lincoln MacKenzie, from Nelson research organisation Cawthron, who described it as a high priority.
His call comes as a toxic algal bloom has frozen the shellfish industry in Queen Charlotte Sound and in Tory Channel, where New Zealand King Salmon operates its Clay Point and Te Pangu Bay fish farms.
The scientists attending the Paris conference are part of the Geohab programme supported by the United Nations Educational, Scientific and Cultural Organisation (Unesco).
On March 23, the Nelson Marlborough District Health Board warned against eating kina, mussels, pipi, tuatua, oysters and cockles harvested from Queen Charlotte Sound and Tory Channel.
Mussel companies voluntarily stopped harvesting in these areas from March 11.
The blooms have no effect on fish, including farmed salmon.
The Alexandrium catenella algae causing the problem was first found at the head of Opua Bay two or three years ago. However, Mr MacKenzie confirmed cysts had been present in sediment on the sea floor for at least 10 years and possibly a lot longer.
Opponents of New Zealand King Salmon's plans to build new fish farms in the Marlborough Sounds argued at an EPA hearing in Blenheim last year that waste from fish farms could increase the frequency and extent of algal blooms.
However, Mr MacKenzie said nothing he had seen suggested a connection between salmon farms and the the algal bloom in Tory Channel. The major source of nutrition for algae was natural oceanic nitrogen.
He went on to say nitrogen levels in the sea were similar from year to year but this toxic bloom was new.People tended to link harmful blooms and fish farming but in most cases he knew of, good evidence did not exist, Mr MacKenzie said.
Cawthron was asking for scientists around the world to work together on the issue because a better understanding of fish farm impacts on water quality and biology would help minimise effects on the environment.

Saturday, April 13, 2013

Lake Okeechobee Performance Measure Diatom / Cyanobacteria Ratio

Lake Okeechobee Performance Measure Diatom/Cyanobacteria Ratio

1.0 Desired Restoration Condition

The target is to substantially reduce the dominance of cyanobacteria relative to diatoms. This can be expressed as a numeric target of having a long-term pelagic ratio of biovolume (diatoms: cyanobacteria) greater than 1.5:1.

2.0 Justification
Studies of phytoplankton taxonomic structure of Lake Okeechobee in the 1970s indicated that the community was dominated by diatoms; today the community is dominated by pollution-tolerant bloom-forming cyanobacteria (Havens et al. 1996). The five-year mean diatom to cyanobacteria ratio for 2000-2005 was 0.63 (SFER, 2006).

This is one of the few projects that identify diatoms as the solution to improving water quality of a lake.

Monday, April 8, 2013

Dead Zone map of the world - 1969, 1989 and 2009

Global Hypoxia 1969: Global pattern of coastal hypoxia in 1989. Each red dot represents a documented case related to human activities. Use scroll arrows to compare with similar data from 2009 and 1969.

Diaz contributes to White House "dead zone" report

Research by Professor Bob Diaz of the Virginia Institute of Marine Science lies at the heart of a new White House report on the growing problem of low-oxygen marine "dead zones." The report, released today to Congress and the public by the President's Office of Science and Technology Policy, notes that low oxygen dead zones now affect nearly half of the 647 U.S. waterways assessed for the report, up from 38 percent reported in the 1980s.
 Diaz was lead author for the report's chapters on the science, economics, and societal impacts of marine dead zones.  He was one of  only 3 academic researchers involved in the report's development.
The report is the final of 5 reports mandated by Congress in the Harmful Algal Bloom and Hypoxia Amendments Act of 2004 and isavailable online through the White House Office of Ocean Science & Technology.