Red algae closes beaches in Sydney

Dinoflagellates in at Clovelly beach in Sydney Australia

From the Herald Sun:

Red tide of algae strikes 10 more Sydney beaches

The Metropolitan Sydney, South Coast and Hunter Regional Algal Co-ordinating Committees yesterday said they had warned "communities along coastal beaches between Sydney and the Central Coast about algal blooms.

"This bloom has likely occurred as a result of the upwelling of nutrient-rich deep ocean water on to the continental shelf," they said.

"Testing of samples taken from Bondi beach have been identified as noctiluca scintillans, which appears as a pinkish to reddish discolouration in water."

"Upwellings create food sources for the predatory noctiluca scintillans - there's more bacteria and phytoplankton for them to eat," Dr Murray said.

...

"They live on the surface off the coast and are very buoyant, so they are at the mercy of wind and ocean currents. If you have the right mix they can be concentrated in dense groups and pushed on to the beaches.

"These two algal concentrations - on the northern and eastern beaches - would have come from the same offshore source.

"They aren't toxic but accumulate ammonia because of what they eat, which can be irritating to some people."

"Hawaii's famed white sandy beaches are shrinking"

This article refers to a geologist saying the causes include "a steady historical climb in sea levels that likely dates back to the 19th century" (and not global warming). Maybe he doesn't know that global warming started accelerating with the industrial age - that easily goes back to the 19th century.

AP:

KAILUA, Hawaii – Jenn Boneza remembers when the white sandy beach near the boat ramp in her hometown was wide enough for people to build sand castles.

"It really used to be a beautiful beach," said the 35-year-old mother of two. "And now when you look at it, it's gone."

What's happening to portions of the beach in Kailua — a sunny coastal suburb of Honolulu where President Barack Obama spent his last two family vacations in the islands — is being repeated around the Hawaiian Islands.

Geologists say more than 70 percent of Kauai's beaches are eroding while Oahu has lost a quarter of its sandy shoreline. They warn the problem is only likely to get significantly worse in coming decades as global warming causes sea levels to rise more rapidly.

"It will probably have occurred to a scale that we will have only been able to save a few places and maintain beaches, and the rest are kind of a write-off," said Dolan Eversole, a coastal geologist with the University of Hawaii's Sea Grant program.
The loss of so many beaches is an alarming prospect for Hawaii on many levels. Many tourists come to Hawaii precisely because they want to lounge on and walk along its soft sandy shoreline. These visitors spend some $11.4 billion each year, making tourism the state's largest employer.

Disappearing sands would also wreak havoc on the environment as many animals and plants would lose important habitats. The Hawaiian monk seal, an endangered species, gives birth and nurses pups on beaches. The green sea turtle, a threatened species, lays eggs in the sand.

Chip Fletcher, a University of Hawaii geology professor, says scientists in Hawaii haven't yet observed an accelerated rate of sea level rise due to global warming.

Instead, the erosion the islands are experiencing now is caused by several factors including a steady historical climb in sea levels that likely dates back to the 19th century.

Other causes include storms and human actions like the construction of seawalls, jetties, and the dredging of stream mouths. Each of these human actions disrupts the natural flow of sand.

But a more rapid rise in sea levels, caused by global warming, is expected to contribute to erosion in Hawaii within decades. In 100 years, sea levels are likely to be at least 1 meter, or 3.3 feet, higher than they are now, pushing the ocean inland along coastal areas.

Fletcher says between 60 to 80 percent of the nation's shoreline is chronically eroding. But the problem is felt particularly acutely in Hawaii because the economy and lifestyle are so dependent on healthy beaches.

The state is doing everything it can to keep the sand in Waikiki, for example, joining with hotels in the state's tourist hub on a plan to spend between $2 million and $3 million pumping in sand from offshore...

For undeveloped shoreline, the state wants to make sure these areas stay pristine. This happened recently when a Florida-based developer announced plans to build luxury homes on sand dunes in Kahuku on Oahu's North Shore.

"We just kind of went nuts, pulled out all the guns on that one, basically got them to back off," Lemmo said. "We're working pretty hard to keep any new development away from these areas."

The University of Hawaii's Sea Grant program is working with a consultant to develop a beach management plan for Kailua that would address how to deal with a 1 meter rise in sea level. The state hopes this will be the first of many site-specific management plans for Hawaii's beaches...

Ultimately the beach will disappear. Or we could have an alternative to that, to identify now some portions of Kailua shoreline where we want the beach to live."

"Crushed glass to be spread on beaches"

APPicture a beautiful beach spanning miles of coastline, gently lapped by aqua-colored water — and sprinkled with glass.

Ouch? Think again. It feels just like sand, but with granules that sparkle in the sunlight.

Faced with the constant erosion of Florida's beaches, Broward County officials are exploring using recycled glass — crushed into tiny grains and mixed with regular sand — to help fill gaps.

It's only natural, backers of the idea say, since sand is the main ingredient in glass.

"Basically, what we're doing is taking the material and returning it back to its natural state," said Phil Bresee, Broward's recycling manager.

The county would become the first in the nation to combine disposal of recycled glass with bolstering beach sand reserves, Bresee said.

"You reduce waste stream that goes to our landfills and you generate materials that could be available for our beaches," said Paden Woodruff of the state Department of Environmental Protection.

Sand is a valuable commodity in South Florida, where beach-related business generates more than $1 billion a year for Broward alone.

Sand to replenish eroded beaches is typically dredged from the ocean floor and piped to shore — about 13 million tons of it since 1970 in Broward. That's enough sand to fill the Empire State Building more than 12 times over.

But with reef preservation restricting future dredge sites, sand is becoming scarce. And the price is rising as construction and fuel costs rise and dredge operations are pushed farther offshore.

In 2005, dredging brought in about 2.6 million tons of sand at a cost of $45 million. A similar operation in 1991 brought in about 1.3 million tons of sand for just $9 million.

The county would create only 15,600 tons of the glass material each year, not enough to solve its sand shortage, but enough to create a reserve for filling eroded spots before they can worsen, Bresee said.

Most of Broward County's 24 miles of beaches are considered critically eroded, and more than a quarter of Florida's 1,350-mile coastline falls into the same category. About $80 million is spent annually restoring Florida's beaches...

Recycled glass also has been used for beaches along Lake Hood in New Zealand and on the Dutch Caribbean island of Curacao.

It's unclear how much the project would cost Broward County, or if the project is even feasible. The state and county have so far spent about $600,000 just on tests and engineering.

The county tested a small patch of glass sand on a dry patch of beach last year, using sensors to measure effects of heat and moisture. Scientists have also conducted laboratory tests that show organisms and wildlife can thrive in the material just like natural sand, they said. The county is awaiting a permit to test glass sand in the surf zone.

Some people are raising caution flags.

"There's no way that you can predict all the environmental consequences of an action like this," said Dennis Heinemann, a senior scientist with the Ocean Conservancy. "There always will be unforeseen consequences."

One example sits just off shore.

The state and Broward County are spending millions to remove some 700,000 old tires that were placed on the ocean floor off Fort Lauderdale in the 1970s and fastened together to create an artificial reef. The tires came loose, moving around and scouring the ocean floor and wedging against natural reefs, killing coral.