FloridaRed Tide

This is a guest post form the folks at Nugali.  They propose a Red Tide mitigation method.  Read on:

Red Tides, Diatom Algae and Nualgi

Fish kills, Dead Zones and Red Tides are some of the problems being seen in waters the world over.

A large number of fish kills have been reported all over the US this year, there are about 400 dead zones in oceans all over the world and red tides are reported along the coasts of Florida, Texas, Maine, etc.

All these problems have a common cause and therefore a common solution.

There are various groups of algae –

Cyanobacteria or Blue Green Algae,

Dinoflagalletes or Red Tides,

Green Algae and

Diatom Algae.

Are all algae equally bad or are they harmful only when they bloom or only under specific circumstances?

Red tides are the most harmful since they are toxic to fish and cause health problems in humans.

Cyanobacteria are not generally toxic but they cause mass fish kills when the blooms crash.

Green Algae are benign and are not know to cause any harm, no large blooms of these algae have in fact been reported.

Diatoms are perhaps the most useful of all algae only a few blooms of these have been reported – Didymo Germinata blooms in rivers and a large bloom off Florida coast

http://www.naplesnews.com/news/2009/sep/25/brown-water-dead-fish-wash-naples-beaches/ but this was due to a freak accident resulting in the leak of half a million gallons of flourosilicic acid from a factory in Louisiana.

Diatom Algal Bloom

http://www.tcpalm.com/news/2009/may/19/algae-in-atlantic-could-move-southward-from/

“The algae floating in the Atlantic off Brevard, Flagler and Volusia counties isn’t dangerous; but it deserves monitoring, say scientists.”

http://bayviewcompass.com/archives/960

“Compared to other phytoplankton, diatoms are like juicy steaks,”

Carmen Aguilar, a scientist at the Great Lakes WATER Institute

Algal blooms occur when all the conditions suit their bloom. This would be the availability of all the nutrients, micro nutrients, sunlight and in the case of Diatoms, Silica.

When nutrient (Nitrogen and Phosphorus) level of lakes and rives increases it results in Cyanobacteria blooms and Red Tides in lakes, rivers, estuaries and coastal waters. The crash of Cyanobacteria causes the Dissolved Oxygen level to drop and this causes mass fish kills and dead zones. Red tides are often toxic and detrimental to human health.

Human action has resulted in increase in the inflow of nutrients into lakes, rivers and oceans and a fall in the flow of Silica. Dams across rivers reduce the flow of silt (this contains silica and micro nutrients such as Iron, Manganese, etc.) and increase water availability to the farms in the water shed, farmers use more Nitrogenous and Phosphate fertilizers.

The Silica : Nitrogen ratio in the Mississippi River has changed drastically over the years from about 3 : 1 fifty years ago to <1 : 1 now.

http://www.pubmedcentral.nih.gov/articlerender.fcgi?&artid=23704

Fluctuating silicate:nitrate ratios and coastal plankton food webs

R. Eugene Turner, Naureen Qureshi, Nancy N. Rabalais, Quay Dortch, Dubravko Justic, Richard F. Shaw, and Joseph Cope

“Marine diatoms require dissolved silicate to form an external shell, and their growth becomes Si-limited when the atomic ratio of silicate to dissolved inorganic nitrogen (Si:DIN) approaches 1:1, also known as the “Redfield ratio.” Fundamental changes in the diatom-to-zooplankton-to-higher trophic level food web should occur when this ratio falls below 1:1 and the proportion of diatoms in the phytoplankton community is reduced. We quantitatively substantiate these predictions by using a variety of data from the Mississippi River continental shelf, a system in which the Si:DIN loading ratio has declined from around 3:1 to 1:1 during this century because of land-use practices in the watershed. We suggest that, on this shelf, when the Si:DIN ratio in the river decreases to less than 1:1, then (i) copepod abundance changes from >75% to <30% of the total mesozooplankton, (ii) zooplankton fecal pellets become a minor component of the in situ primary production consumed, and (iii) bottom-water oxygen consumption rates become less dependent on relatively fast-sinking (diatom-rich) organic matter packaged mostly as zooplankton fecal pellets. This coastal ecosystem appears to be a pelagic food web dynamically poised to be either a food web composed of diatoms and copepods or one with potentially disruptive harmful algal blooms. The system is directed between these two ecosystem states by Mississippi River water quality, which is determined by land-use practices far inland.”

http://www.nature.com/nature/journal/v368/n6472/abs/368619a0.html

Coastal eutrophication near the Mississippi river delta

R. EUGENE TURNER & NANCY N. RABALAIS

“CHANGES in delivery of river-borne nutrients such as dissolved phosphate, nitrate and silicate, owing to land-use changes and anthropogenic emissions, are known to result in eutrophication¹— enhanced phytoplankton blooms—and more severe hypoxic events^2–1 in many enclosed bays and seas. Although similar ecological effects might be expected on continental shelves, the occurrence of such eutrophication has remained unresolved⁵. Here we present evidence of eutrophication of the continental shelf near the outflow of the Mississippi river, obtained by quantifying biologically bound silica (BSi) in diatom remnants within dated sediment cores. BSi accumulation rates are greatest in water depths of 20 to 50 m within 100 km of the river mouth, and have increased by as much as 100% this century. The increases were substantial by 1980, by which time riverine nitrogen loading had doubled relative to the beginning of the century, even though the silica loading had declined by 50% over the same period. Thus changes in river-borne nutrient loadings can modify coastal food webs and affect the amount and distribution of oxygen in bottom waters on the scale of continental shelves.”

Thus decline in Diatom population could well be the reason for the increasing incidents of bloom of other phytoplankton.

An increase in Diatoms will control the bloom of harmful algae, this is also corroborated by a research paper from University of Georgia.

“In one experiment, detailed in the journal Harmful Algae, Kubanek’s students grew the red tide algae along with the S. costatum diatom to test her group’s hypothesis and found that the samples with both organisms had a smaller concentration of brevetoxin B than samples without the diatom. They also tested the algae with four different S. costatum diatom strains from around the world and came up with largely the same results. That suggests that evolutionary experience with the red tide algae was not necessary for the diatom to resist the toxins.

In another experiment, covered in Proceedings of the Royal Society B, they found that the red tide algae was able to reduce the growth of the S. costatum diatom, but that exposure of the red tide organism to S. costatum makes the red tide less toxic to microscopic algae. That suggests that the diatom is somehow able to reduce the potency of red tide’s toxins.”

http://www.sciencedaily.com/releases/2008/08/080820163241.htm

We prospose the use of Diatoms for bioremediation of lakes, rivers, estuaries and coastal water. We cause a bloom of Diatoms very easily by using a nano technology micro nutrient powder that contains nano particles of Silica and Iron and 10 other micro nutrients. Since only Diatoms require silica only they bloom when this powder is mixed into water and the resulting bloom increases dissolved oxygen level rapidly and prevents fish kills and its been observed that Cyanobacteria / Blue Green Algae crashes within hours of use of this powder.

This is patented in US – ‘Composition of grow Diatom Algae’, US Patent Application # 20070275856 and is available commercially under the name Nualgi. The company’s website is www.kadambari.net and www.nualgi.com/new .

M V Bhaskar

Kadambari Consultants Pvt Ltd

Hyderabad. India.