View from space: Toxic algae bloom in Lake Erie

Landsat-5 satellite images acquired in early October, 2011 revealed the worst algae bloom North America’s Lake Erie has experienced in decades. The bloom is primarily microcystis aeruginosa, an algae that is toxic to mammals, according to the Great Lakes Environmental Research Laboratory. The reasons for this year’s giant bloom are complex, say scientists, but might be related to a rainy spring and invasive mussels.

See pictures and more of the story at:

http://earthsky.org/water/view-from-space-toxic-algae-bloom-in-lake-erie
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Source: EarthSky.org Water Blog

Algal Turf Scrubbers

An article published in the June issue of BioScience describes the early scale-up stage of a new biotechnology with environmental benefits and possible commercial potential. Algal turf scrubbers are field-sized, water-treatment systems that can extract excess nutrients from streams, canals, and lakes polluted by agricultural, domestic, and some industrial runoff. They use sunlight as their principal source of energy and simultaneously restore oxygen levels. The devices work by pulsing contaminated water across algae that are allowed to grow on screens. Algal turf scrubbers produce waste suitable for use as a nitrogen- and phosphorus-rich fertilizer. Some algal turf scrubbers can even operate in open water, thus minimizing loss of agricultural land to the systems.

The BioScience article, by Walter H. Adey of the Smithsonian Institution, Patrick C. Kangas of the University of Maryland, and Walter Mulbry of the US Department of Agriculture, notes that the need to clean wastewater and various types of runoff contaminated with nitrogen and phosphorus is immediate in many places where natural waters are polluted.

The article stresses that algal turf scrubbing is not likely to ever be profitable just as a way of making a fuel crop. Algal turf scrubbing could become common if the economic value of nutrient removal can be applied to the cost of building and running the units. That might depend on public policy that imposes a predictable cost on pollution of natural waters.
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Source: NALMS Notes - June 2011
http://www.nalms./org

Newly Discovered Group of Algae Live in Both Fresh Water and Ocean

ScienceDaily (Jan. 21, 2011) — A team of biologists has discovered an entirely new group of algae living in a wide variety of marine and freshwater environments. This group of algae, which the researchers dubbed "rappemonads," have DNA that is distinctly different from that of other known algae. In fact, humans and mushrooms are more closely related to each other than rappemonads are to some other common algae (such as green algae). Based on their DNA analysis, the researchers believe that they have discovered not just a new species or genus, but a potentially large and novel group of microorganisms.

Read the rest at http://www.sciencedaily.com/releases/2011/01/110120151633.htm

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Posted using BlogPress app on my iPhone

Most Abundant Food Source Disappearing

In oceans around the world, there has been a surprisingly large and extensive decline in phytoplankton -- the tiny algae that keep marine food webs afloat.

The drifting green flecks have been dying off for at least a century, with a staggering 40 percent decline since 1950, according to a new study.

Phytoplankton make up half of all plant matter around the globe, said marine ecologist Daniel Boyce, whose study appears this week in the journal

Nature. Its disappearance threatens the stability of climate, the well-being of fisheries and the overall health of the oceans.

"It's hard to really imagine phytoplankton could be so important because most people don't see them in their daily lives. They're microscopic and they live out at sea," said Boyce, of Dalhousie University in Halifax, Canada. "But everything that happens to them affects the entire marine food chain, including us."

Some recent satellite images have shown the ocean turning from green to blue as a result of phytoplankton declines, but those data stretch back only 13 years. Other studies have offered mixed results.

To get a more accurate picture and to look further into the past, Boyce and colleagues collected a half-million measurements of ocean clarity from a public data set that dated back to 1899.

Over the last century-plus, analyses showed, phytoplankton levels have dropped by one percent each year in eight out of 10 large ocean regions. The greatest decline occurred in areas around the poles, near the equator and in the open oceans. The rate of disappearance picked up after 1950, totaling a 40 percent drop-off since then.

"It's really big," said David Siegel, a marine scientist at the University of California, Santa Barbara. "I'm a little leery about how big that number is."

The scientists can't yet say what's causing the mass die-off of phytoplankton, but temperature data offer a clue. The declines were worst in places where the surface of the sea has warmed the most. Warmer ocean water limits the amount of nutrients that can get from the depths to the surface. Phytoplankton need those nutrients to live.

With less phytoplankton around, fish have less to eat. As the decline works its way up the food chain, fishermen will have less to catch and fish-eaters less to eat. Phytoplankton even affect climate by taking up carbon dioxide and absorbing heat.

"Everyone looks at blue oceans and goes: 'Isn't that beautiful?'" Siegel said. "But a blue ocean is full of nothing. You really want something, and we're only making more of the blue ocean."

Source: Discovery News
http://news.discovery.com/earth/phytoplankton-oceans-food-web.htmlOcean's

Harmful algal blooms, or HABs

Harmful algal blooms, or HABs, in the new limno-lingo, represent a serious issue. When I was in lake school many years ago, we knew that certain algae could be hazardous. But these were marine algae that caused red tides or were rare events in freshwater, and then usually in cow ponds. Now HABs are front and center at many lakes.

The EPA report, Scientific Assessment of Freshwater Harmful Algal Blooms (available from EPA as a PDF) is the latest compendium of HAB science and is the techno-tell-all of what we know and what we no not know about HABs. We know for example that:

“Freshwater HAB toxins can have a broad range of negative impacts on humans, animals, and aquatic ecosystems. Many cyanobacteria can produce neurotoxic, hepatotoxic, dermatotoxic, or other bioactive compounds, and blooms of toxigenic cyanobacteria pose a particular threat if they occur in drinking water sources.”

A lot of new words and jargon that say in essence that these blooms can’t be good.

Seriously, as lake managers, we cannot ignore HABs. HABs pose threats beyond what we have traditionally dealt with as lake managers. HABs threaten water supplies, human health, and fish and wildlife.

What we don’t know or at least don’t know well includes risk assessment, analytical methods, toxicity pathways, or the appropriate response framework. The report provides an assessment and roadmap to better attend to these needs.

Of course, if we confront lakes experiencing HABs, we cannot wait for the answers to all the unknowns. We can fall back on our tried-and-true approaches to lake management - lake management basics – which ought to be relied upon to minimize and manage the impacts of HABs.

This means priority ought to be given to nutrient management. Specifically,

• Top priority for watershed protection for those lakes not yet affected by HABs
• For lakes already experiencing HABs, watershed rehabilitation may be too slow, so in addition, we should initiate in-lake nutrient reduction methods.
• In cases where nutrient reduction may not be timely or sufficient, other in-lake techniques should be used.
  

These strategies and techniques are explained fully in the textbook, Restoration and Management of Lakes and Reservoirs or the manual, Managing Lakes and Reservoirs – both available in the NALMS Bookstore (currently off-line). You may also purchase Managing Lakes and Reservoirs through Amazon.com using the Lake Stewardship Store.

Article by Dick Osgood, President of the North American Lake Management Society (NALMS), used by permission. Read the latest NALMS' newsletter online.