Friday, January 27, 2012

Vero Beach - Algal bloom

ORCA maps pollution in lagoon between Vero bridge spans
By J.G. Wallace
Posted January 26, 2012 at 5:34 p.m.

VERO BEACH — A Fort Pierce-based environmental research group is shining light — bioluminescence, to be precise — on the problem of pollution in the Indian River Lagoon.

Scientists at Ocean Research and Conservation Association, aka ORCA, have started with a pilot program to map pollution in a 1-square-mile area of the lagoon between the 17th Street Bridge and the Barber Bridge in Vero Beach, thanks to a grant from Impact 100 of Indian River County, a women's philanthropic organization.

To find the pollution, scoop up muck from the bottom of the lagoon.

"A lot of people don't realize how much pollution is in sediment," said Edith "Edie" Widder, ORCA's president and senior scientist. "Water moves, and so do the pollutants in it, but sediment stays put, and so do the pollutants in it."

Using a process known as Fast Assessment of Sediment Toxicity technology, Widder mixes the muck with bioluminescent bacteria, marine organisms that emit natural light. She then uses a photometer to see how much and how quickly the light dims as the chemicals kill the bacteria.

The quicker and dimmer, the more pollution.

Widder also looks for nutrients including nitrogen and phosphorus, which she said "aren't technically toxins, but they do plenty of damage" because they stimulate algae growth. Too much algae in the water can lower oxygen levels and kill a wide range of marine creatures. Treasure Coast residents don't have to think back very far to remember the green slime of algal blooms in 2005.

In the Vero Beach study area, Widder's team found the highest levels of nitrogen and phosphates in densely populated residential areas, indicating the pollutants found their way into the lagoon as runoff from overfertilized lawns.

The association found the lowest levels of nitrogen and phosphates directly adjacent to the Vero Beach Country Club, which Widder said correlates to the club's recent transition to using an organic fertilizer in smaller and more controlled applications.

"Golf courses usually get vilified for damaging the environment," Widder said, "but in this case they're the good guys."

Shane Wright, course superintendent at the country club, said his staff is "pretty judicious about what we do. Our course looks good and plays good, and I feel like we have it dialed in now in terms of the environmental practices."

Widder said Treasure Coast homeowners should follow the country club's example. Noting that her teams found grass clippings floating throughout the entire sample area, she said residents who live on the water and even blocks away should be aware that if they wash or blow clippings into storm sewers, fertilizers and chemicals will make their way into the marine ecosystem.

She said bagging, mulching or composting clippings is a better choice for the environment.

"A lot of the solutions are pretty simple," Widder said.

Widder said local ordinances limiting the use of fertilizers, especially during the rainy season, also help keep pollutants out of the lagoon.

"Those laws need to be in place all along the Indian River Lagoon," she said.

Widder also hopes ORCA's pollution mapping project can be in place throughout the lagoon and that one day the maps can be included on Google Earth.

"People need to know how unique the lagoon is," Widder said, "how the water used to run gin-clear and how there used to be massive amounts of fish in the water. With the murky water we have now, it's not the ecosystem it used to be."

Tuesday, January 17, 2012

Great Lakes: Quagga mussels -spit out Microcystis

Invasion of the Great Lakes: Quagga mussels least known, most dangerous invader

Algal blooms return

Many areas of the Great Lakes have seen a return of blooms of the toxic blue-green alga Microcystis.

"The quagga mussels are filtering out particles in the water, but not Microcystis, which they spit out," said Nalepa. "That leaves Microcystis with fewer competitors for nutrients."

Without the brake of competition, the Microcystis algae proliferate.

Wednesday, January 11, 2012

Lake Erie Algae, Ice, Make a Nice Mix in Winter

Lake Erie Algae, Ice, Make a Nice Mix in Winter

Results of the study, "Diatoms abound in ice-covered Lake Erie: An investigation of offshore winter limnology in Lake Erie over the period 2007 to 2010," are reported by Michael Twiss, Mike McKay, Rick Bourbonniere, George Bullerjahn, Hunter Carrick, Ralph Smith, Jennifer Winter, Nigel D’souza, Paula Furey, Aubrey Lashaway, Matt Saxton and Steve Wilhelm in Volume 38, No. 1, of the Journal of Great Lakes Research, published by Elsevier, 2011.


Thursday, January 5, 2012


Diatom facts:

Diatoms photosynthesize. They are categorized as either protists or chromists.
They provide a significant amount of the world's oxygen supply (some say 35%).
There are over a hundred thousand species identified.
Diatoms live anywhere there is water and light, including lakes, streams, estuaries, oceans, puddles and wet rocks or soil.
That brown scum you see on the rocks in the stream is probably diatoms.
Diatomaceous earth is sometimes used in gardening as a pest control.
For more diatom info, check out the Diatom Home Page.

Diatoms are the most important group of photosynthetic eukaryotes,463.html

Diatoms are the most important group of photosynthetic eukaryotes

The oceans of our planet are Earth’s largest ecosystem. About 50% of the primary productivity is attributable to them. The most important photosynthetic eukaryotes are the diatoms; they contribute about 40% of the primary marine production, and thus produce almost 1/4 of the oxygen we breathe. Although they form only a small part of the photosynthetic biomass, in some regions of the ocean, they can fix the same amount of carbon per day as a forest of terrestrial plants.

Sunday, January 1, 2012

Lakes and Green House Gases

Greenhouse Gases
By Kevin Rose | Miami University

Figure 1: Greenhouse gases, especially CO2, are increasing in the atmosphere due to human activities. Natural sources of greenhouse gases include lakes and other freshwater resources.
Gases that trap heat in the atmosphere are known as greenhouse gases. The major greenhouse gases are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O)1. At present, atmospheric CO2 is nearly 35% higher than preindustrial levels and is increasing1. Although these gases are released from natural activity, human activity is responsible for the increase of greenhouse gases in the atmosphere. According to both the European Environment Agency and the United States Environmental Protection Agency, CO2 emissions account for the largest share of total greenhouse gas emissions, equivalent to 80-85% of total emissions. Fossil fuel combustion used for transportation and electricity generation are the main source of CO2 emissions, contributing to more than 50% of total emissions.

Natural sources of greenhouse gases include lakes and other freshwaters such as rivers, streams, ponds, and wetlands as well as terrestrial landscapes such as forests and fields. Lakes are active, changing, and important regulators of (CO2), methane (CH4), and nitrous oxide (N2O).

Carbon Dioxide

Figure 2: Carbon Dioxide (CO2) is an important greenhouse gas, and most lakes act as net sources of CO2, releasing it into the atmosphere. Lakes also bury large amounts of carbon in their sediments, over three times more than the world’s oceans.
Lakes play a much greater role in global carbon cycling than their area would otherwise predict. While lakes make up less than 2% of Earth’s surface area, they bury over three times more carbon in their sediments than all of the world’s oceans combined2. This means on a per area basis lakes bury over 100 times more carbon than the oceans. Small lakes that contain large amounts of algae tend to bury the most carbon; thus, the small drainage ponds, farm ponds, and recreational lakes around the world are important sites for carbon cycling and understanding global climate change3.

Despite the fact lakes bury huge amounts of carbon, they also tend to release more carbon dioxide to the atmosphere than they absorb, making them net sources of greenhouse gases. Most of the world’s lakes are supersaturated in CO2 and consequently release some of it to the atmosphere4. In fact, lakes and other freshwaters release almost as much CO2 as all the world’s oceans. This occurs because lakes generally drain large landscapes and the carbon from forests, fields, and lawns becomes concentrated in lakes where it can be buried or released into the atmosphere. Research studies show that the CO2 released from lakes comes from organism respiration — the breathing of bacteria, algae, zooplankton, fish, and other species5.

While methane is less common than CO2, it is a highly potent greenhouse gas. It has about 20 times more warming potential than CO2. Lakes contribute about 10% of total natural methane emissions, and they produce more methane than the oceans6. Many lakes and other freshwaters produce methane during warm summer conditions or when oxygen levels underwater drop. Most methane is produced in lake sediments when oxygen is no longer present due to different communities of bacteria that grow in environments without oxygen. In some lakes, bubbles can be seen rising from sediments; these bubbles are often methane produced by bacteria in oxygen deprived sediments6. Shallow areas around the shores of warm lakes are hot spots for methane production. Overall, lakes are important sites for carbon dioxide and methane production and release.

Nitrous Oxide
Lakes and other freshwater resources are also sources of nitrous oxide (N2O) cycling, another potent greenhouse gas that is produced in warm lakes by bacteria and other microbes. Within lakes, shallow sediments contribute most to N2O emissions7, while organisms in deep open waters may consume more N2O than they release. Lake shape may be an important predictor of N2O release, as shallow lakes with expansive shorelines may release more N2O than they produce compared with round deep lakes.

Is Hydroelectric Power a “Green” Energy Source?
Lakes and reservoirs are often built or used to generate power. In fact, so much water is retained behind dams that global sea level rise has been reduced by about 0.02 inches (0.55 mm) per year over the past 50 years8. Because fossil fuels are not used to produce hydroelectric power, lakes and reservoirs are often thought of as “green” energy sources. But lakes and reservoirs release potent greenhouse gases — particularly carbon dioxide and methane — into the atmosphere. If a hydroelectric dam releases enormous volumes of greenhouse gases, is it a “green” energy source?

Figure 5: The Three Gorges Dam in China is the world’s largest producer of hydroelectric power. Lakes and reservoirs emit greenhouse gases, and studies have questioned whether hydroelectric is truly a “green” energy source.
Greenhouse gas emissions from freshwater lakes and reservoirs and their contribution to the increase of greenhouse gases in the atmosphere are at the heart of a worldwide debate concerning the electricity generating sector9. Hydropower represents about 20% of the world’s electricity generation capacity and on average emits 35 to 70 times less greenhouse gases per unit power generated than thermal power plants10. When reservoirs are first built for power generation, soils, plants, and trees are flooded. The decay of this plant and soil material can contribute to large emissions of CO2 and CH4 during the first few years after reservoir construction11. Studies show that 3-10 times more greenhouse gases are produced by newly formed reservoirs than from natural lakes of the same size in the first 2-5 years after a reservoir is constructed12.

Beyond the initial release of greenhouse gases, lakes and reservoirs also continue to release carbon dioxide and methane as they produce power. As methane and carbon dioxide enriched water passes through turbines, hydrostatic pressure drops and a large portion of the gas rapidly escapes to the atmosphere. In some regions, such as tropical reservoirs where methane production can be high, reservoirs can release more greenhouse gases than fossil fuel alternatives13.

While lakes and reservoirs used to generate hydroelectric power can release greenhouse gases, they typically release far smaller amounts than traditional fossil fuel based power plants. Hydroelectric is not a perfectly “green” energy source, but it is often much more environmentally friendly than alternative choices and can be part of an alternative energy solutions plan.