Tuesday 25th of February 2020

algal bloom...

algal bloom...

More than two weeks ago (8 November 2012) I noticed a small open water drain being covered with what I suspect was green algae... My guess at the time was that I could be wrong. The bloom was not total... It could have been just weeds, but having seen blooms before, I took a picture... Picture above by Gus Leonisky. 

This small drain, coming from Moore Park, flows into the Alexandra Canal which in turn flows into the Cooks River which in turn flows into Botany Bay, Sydney...

Algal blooms tend to develop in stagnant water where a lot of nutrients (phospate from effluents and fertilisers — including golf courses) are found... Usually when it rains enough, the small bloom is washed off and destroyed, but when it rains just a bit, the slow flow of water displaces the bloom into larger body of water...

Then on November 25 we were warned not to eat shellfish from Botany bay because of an "algal bloom".

"Algal bloom tend to produce toxins and when the bloom dies, the green algae often turns to a reddish colour.... 


I could be wrong. Other sources of the bloom could have been the Cook's River itself, though councils tend to pay attention to such problems.. who knows...

red tide at bondi...


Bondi Beach could be closed for up to 36 hours while tests are conducted on the algal bloom that stained the water a red colour this morning.

A spokeswoman for Sydney Water said a maintenance team, including a water quality expert, arrived at Bondi at 11am to carry out extensive tests on site, plus take samples to be tested in laboratories.

''We think it is looking very likely that it is a blue-green algal bloom,'' she said.


Read more: http://www.smh.com.au/environment/blooming-stink-as-bondi-closes-20121127-2a4nl.html#ixzz2DONx62Ds


Algal bloom can straddle fresh water and salt water


An algal bloom is a rapid increase or accumulation in the population of algae (typically microscopic) in an aquatic system. Algal blooms may occur in freshwater as well as marine environments. Typically, only one or a small number of phytoplankton species are involved, and some blooms may be recognized by discoloration of the water resulting from the high density of pigmented cells. Although there is no officially recognized threshold level, algae can be considered to be blooming at concentrations of hundreds to thousands of cells per milliliter, depending on the severity. Algal bloom concentrations may reach millions of cells per milliliter. Algal blooms are often green, but they can also be other colors such as yellow-brown or red, depending on the species of algae.

Bright green blooms are a result of cyanobacteria (colloquially known as blue-green algae) such as Microcystis. Blooms may also consist of macroalgal (non-phytoplanktonic) species. These blooms are recognizable by large blades of algae that may wash up onto the shoreline.

Of particular note are harmful algal blooms (HABs), which are algal bloom events involving toxic or otherwise harmful phytoplankton such as dinoflagellates of the genus Alexandrium and Karenia, or diatoms of the genus Pseudo-nitzschia. Such blooms often take on a red or brown hue and are known colloquially as red tides.


I remember in the early 1990s, thousand of kilometres of inland rivers in Australia being infected by algal blooms after a long drought, discharge of untreated efluents from small towns, fertilisers from cultivated fields and cow poop from cattle after a drink on the river banks.


and below the water...

HANALEI, Hawaii — When compiling a list of places that may be described as paradise, Hanalei Bay on the rugged north shore of the island of Kauai surely qualifies.

The perfect crescent bay, rimmed by palm trees, emerald cliffs and stretches of white sand, has always had a dreamy kind of appeal. It was on these shores that sailors in the movie "South Pacific" sang of the exotic but unattainable "Bali Ha'i."

The problem is what lies below the surface of the area's shimmering blue waters.

Since June, a mysterious milky growth has been spreading rapidly across the coral reefs in Hanalei and the surrounding bays of the north shore — so rapidly that biologist Terry Lilley, who has been documenting the phenomenon, says it now affects 5% of all the coral in Hanalei Bay and up to 40% of the coral in nearby Anini Bay. Other areas are "just as bad, if not worse," he said.

The growth, identified by scientists at the U.S. Geological Survey as both a cyanobacterial pathogen — a bacteria that grows through photosynthesis — and a fungus, is killing all the coral it strikes, and spreading at the rate of 1 to 3 inches a week on every coral it infects.

"There is nowhere we know of in the entire world where an entire reef system for 60 miles has been compromised in one fell swoop. This bacteria has been killing some of these 50- to 100-year-old corals in less than eight weeks," Lilley said. "Something is causing the entire reef system here in Kauai to lose its immune system."


rogue geoengineering....

But research by Sydney University and the Sydney Institute of Marine Science found large-scale iron fertilisation would be a waste of time and money in almost all conditions.
''It blows iron fertilisation out of the water,'' said Daniel Harrison, whose paper on the subject is published in the International Journal of Global Warming. ''It is possible to do iron fertilisation efficiently but the perfect conditions you would need are so rare that it would be a very limited contribution to the problem.''
By analysing all known iron fertilisation experiments, and calibrating them with computer models estimating the ebb and flow of the oceans, he established storing carbon dioxide in the ocean would cost about $433 per tonne. This compares unfavourably with the $23 per tonne Australian carbon price.
The process works because iron is a nutrient plankton needs in order to grow. When they die, some sink so deep the carbon dioxide they harvest from the atmosphere is removed from the Earth's carbon cycle for over 100 years.
But Mr Harrison's work shows fertilising a square kilometre of the Southern Ocean would only store about 10 kilograms of carbon dioxide - about as much as a car would emit from burning four litres of petrol.

Read more: http://www.smh.com.au/environment/climate-change/tiny-solution-for-climate-change-shown-to-be-a-big-waste-of-money-20121216-2bhkw.html#ixzz2FFVQpkkh

the bloom of death...


Florida Algae Bloom Leads to Record Manatee Deaths


Florida’s endangered manatees, already reeling from an unexplained string of deaths in the state’s east coast rivers, have died in record numbers from a toxic red algae bloom that appears each year off the state’s west coast, state officials and wildlife experts say.

The tide has killed 241 of Florida’s roughly 5,000 manatees, according to the state Fish and Wildlife Research Institute, and the toll appears certain to rise.

The number of deaths from the tide far exceeds the previous annual record of 151. Most occurred along the lower west coast of Florida near Fort Myers, where an algae bloom that began last fall was especially severe and long-lasting.

“Southwest Florida is an area where a lot of manatees are during the winter months,” Kevin Baxter, a spokesman for the research institute, said Friday. “It’s a warm-water area. The bloom has persisted there for quite a while.”

Although the algae had largely dissipated by mid-March, he said, the manatee deaths are likely to continue for a few months because remnants of the toxin still cling to sea grasses. Manatees can eat 100 pounds of sea grass daily, said Pat Rose, an aquatic biologist and the executive director of the Save the Manatee Club in Maitland, Fla.





From the NCCOS...


What is the relationship between Climate Change and HABs?

Climate is always changing, whether from longer time-scale (such as glacial cycles) or shorter time-scale (such as El Niño-Southern Oscillation) events. However, in addition to these natural changes, increased carbon dioxide (CO2) in the atmosphere as a result of human activities, like the burning of fossil fuels, introduces another layer of climate variability that will likely impact HABs.

Climate change has the potential to affect the occurrence and severity of HABs because the growth, toxicity, and geographic distributions of HAB species (like all phytoplankton) are impacted by environmental variability. Additionally, the susceptibility of shellfish, fish, and marine animals to the impacts of HABs can be exacerbated by other stressors that are also caused by climate changes.

How is Climate Change Affecting HABs Today?

Recent data shows that unusual or unprecedented algal blooms have been linked to climate anomalies (e.g., Belgrano et al. 1999, Skjodal and Dundas 1991, Cloern et al. 2006, Moore et al. 2009). Further, rising sea surface temperatures have been associated with increases in dinoflagellates (many HAB species are dinoflagellates) in the North Atlantic, North Sea, and Baltic Sea and with an earlier appearance of dinoflagellates in the seasonal cycle (reviewed by Dale et al. 2006). Evidence also indicates that climate warming may benefit some species of harmful cyanobacteria (both freshwater and marine) by providing more optimal conditions for their growth (reviewed by Paerl and Huisman 2008 and 2009). Increasing temperature and CO2 either alone or in combination with nutrient availability may determine the growth and relative abundance of HAB species (Fu et al. 2008). Historical evidence from long term phytoplankton monitoring data and fossil records suggests that future climate warming could impact HABs through the alteration of their geographic range and shifts toward relatively more and earlier blooms (reviewed by Dale et al. 2006).



In some scientific scenarios of extinction of species through warmer climate, acidification of the seas and other unpleasant factors, algae (or algal) blooms are like the end processors of change, in which the toxins from the bloom kill most of life — already struggling to survive due to environmental changes brought in by the warming. The bloom eventually dies off. The dead bloom takes a lot of the carbon to the sea floor... The complex process is theorise as simply followed by a cooling event, in which the species that have managed to survive the mass extinction, have to adapt to new conditions.


There has been at least five major mass extinction of species that we know of.



too much nitrogen...


RIVERHEAD, N.Y. — The dead turtles, about 100 of them, started washing ashore near here in late April. Then came the dead fish, in numbers no one had seen before. By this week, tens of thousands of fish carcasses had bobbed to the surface of the Peconic River, which runs along the southern border of this town, and in adjoining Flanders Bay, washing ashore in putrid drifts.

The waters of the Peconic Estuary, on the East End of Long Island, were coughing up their fauna.

There is little debate about what caused the die-offs. Scientists trace the fish carnage to algal blooms fed by elevated levels of nitrogen, which can be attributed in large part to the region’s outdated septic tanks and cesspools. Evidence suggests that a similar sequence killed the turtles in what scientists said was a highly unusual die-off.

Nitrogen loading in the ground and surface waters of Suffolk County is a longstanding problem that threatens the area’s natural ecosystem and, by extension, its economy.

“It really is a crisis,” said Anna Throne-Holst, supervisor of the Town of Southampton, on the southern flank of the Peconic Estuary. “It needs all the attention it can get.”

The pollution problem stems in part from the fact that the population of Suffolk County, now about 1.5 million, grew sharply over the past several decades despite the absence of proper infrastructure. About 74 percent of the county’s residents rely on septic tanks and cesspools rather than municipal treatment plants. Most of those systems were built before 1972.

The nitrogen-rich sewage leaches into the aquifers, which connect to the region’s surface water, its rivers and bays and the Long Island Sound. Nitrogen can also be traced to discharges from wastewater treatment plants and to fertilizer used on lawns, golf courses and agricultural lands, including the area’s well-known vineyards.

The recent nitrogen-fed algal blooms endangered both the turtles and the fish, though for different reasons.



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killer hydrogen sulphide from seaweeds...

Six beaches in France’s Brittany were closed because of hazardous decomposing seaweed amassed in shallow bays, which has come to be known as France’s coastal “killer slime.”

For decades, potentially lethal green algae have amassed in bays on Brittany’s north-western coast, the Guardian reported. Environmentalists say the blossoming of unusually large amounts of green algae is linked to nitrates in fertilisers and waste from the region’s intensive pig, poultry and dairy farming flowing into the river system and entering the sea, providing a great fertilizer for the seaweed.

Moreover, when the algae decompose, pockets of poisonous hydrogen sulfide gases get trapped under its crust, making the slimy seaweed potentially fatal to humans if they step on it. According to Andre Ollivro, former gas technician and environmentalist, the gas “could kill you in seconds.”

The toxic sludge that can lead to loss of consciousness and cardiac arrest has washed up on the shores for decades, but environmentalists say that the problem has worsened this summer due to “exceptional” weather, according to France 24.

“The influx of green algae began very early, there were few storms and June was a relatively wet month, which caused more water to flow from agricultural areas and thus more green algae,” a spokesperson for the Saint-Brieuc town hall told the outlet.

At least two people and dozens of animals have died from inhaling the toxic fumes in the area, though some warn the cases don’t reveal the full scope.

“Around 20 people die on the coast each year, often swept away with tides or currents, but the question is: could some of those people have fainted from toxic gas from seaweed before being swept out? The state has not shed full light on all these issues,” Inès Léraud, who penned an investigative comic book on the scandal, told the Guardian.

Thierry Burlot, a deputy head of environment for the Brittany region who also runs the only refuse centre processing seaweed collected on beaches, said that the situation has become less dramatic as a result of state initiatives that have considerably reduced nitrates in the water system in recent years. 

“Brittany has around 2,700km of coastline, and less than 5% of it is affected by this algae phenomenon,” he added. “Fifteen years ago, at the worst point, we would collect 30,000 tonnes of algae a year from certain beaches in the Côtes d’Armor. Now it’s 10,000 a year […] We’re mobilised to do more.”


Read more:



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Our sense of smell detects H2S at very low concentrations, on the order of one part per million (ppm, 0.0001%). We smell rotten eggs.


At 10 ppm (0.001%), it irritates the eyes and gives a burning sensation to the lungs.


at 100 ppm, we lose the sense of smell. At 200 ppm the olfactory nerve is paralyzed, hence the loss of the sense of smell adds to the danger.


Loss of consciousness and respiratory arrest occur at 0.1%, resulting in death by asphyxiation and cardiac arrest.