NEWS AND NOTES (Part-1)
Australian city taps drain water, supplies to households
On April 23, Orange city in Australia crossed a major milestone. The city, 260 km west of Sydney, became the first in the country to commission a storm water harvesting system that uses rainwater runoff to augment its drinking water supply.
“Tests on the initial batch of storm water have shown the water to be as clean, if not cleaner, as the water that currently flows into the Suma Park reservoir, the city’s primary drinking water source,” Mayor Ref Kidd said.
The water would be enough to take care of 40 percent of the water needs of the 40,000 residents of Orange. As of now, 1,300 ML rainwater is harvested.
Atlantic horseshoe crab
Anyone who’s ever walked Florida’s beaches has surely seen the Atlantic horseshoe crab (Limulus polyphemus). This crab lives along the Atlantic and Gulf coast of North America from New York to Mexico.
Like other animals with an exoskeleton, the horseshoe crab outgrows its shell. It’s usually the discarded shell, and not the actual animal, that washes ashore. The crab’s new shell is soft and pleated at first, but soon swells and hardens. Molting happens several times during the first year, but tapers off to once a year after three to four years. Each new shell is about 25 percent larger than the previous one.
Horseshoe crabs belong to a large group called Arthropoda, which includes lobsters, insects, crabs spiders and scorpions. They’re more closely related to spiders and scorpions than to crabs like insects, horseshoe crabs have compound eyes, allowing them to see in all directions. They have gills remain moist; they can also use oxygen from the air.
Their tail is not poisonous, nor does it have a stinger. The animal uses its tail to turn over when it finds itself upside down.
All horseshoe crabs eat marine worms, mollusks and dead fish. Because they don’t have jaws, they use their legs to crush food and therefore can eat only while walking.
They must be doing something right, as they date back 300 million years, long before the dinosaurs. At one time there were hundreds of different species, but today there are only four worldwide, and only one on the North American coast. Because their shape hasn’t changed for millions of years, they are true living fossils.
Although Native Americans ate both the eggs and the muscle in the abdomen that moves the tail, horseshoe crabs are generally not consumed by people anymore. At least a dozen species of migratory birds do eat the horseshoe crabs’ eggs, however. As they migrate north in the spring, ruddy turnstones, sander lings and black-bellied plovers eat large quantities of the eggs, most of which come from nests disturbed by storms in the Delaware Estuary. The estuary is the largest feeding area for shore birds in Atlantic Flyway. It’s where the birds can double or even triple, their weight, replenishing their fat supply for their trip to Arctic breeding grounds.
Horseshoe crab eggs are also an important food for loggerhead sea turtles. Fortunately for horseshoe crab, each female lays up to 20000 eggs at a time.
Horseshoe crab shells contain a substance called chitin that, when refined into chitosan, is used in making contact lenses, skin creams and hair sprays. Chitosan is also a source for removing lead and other metals dissolved in drinking water.
Humans benefit directly from research done on horseshoe crabs eyes that led to a better understanding of the human optic nerve. And recently, scientists have begun using horseshoe crab blood for medicinal purposes. The blood contains special cells that kill some bacteria that area harmful to man. The blood can be collected and the crabs released unharmed.
Perhaps no other animal so illustrates the interdependence of all animals, including man. The horseshoe crab’s future depends on man’s understanding of their importance of both wildlife and human. To see these and other astonishing marine animals, visit, any of Florida’s spectacular beaches. And enjoy a refreshing swim while you’re at it.
(Extract from Fort Myers Florida weekly by Sharad Varadkar) (Contd…2)