Environment

Environment (9)

Humble lichens have been credited as sentinels of air quality.

Lichens are the mosaics of fungi that speckle tree bark and rocks at the ocean. In those precarious perches, lichens absorb their food from the fog the wind and the rain. With no roots but with very absorbent tissue, but no roots lichens are exquisitely vulnerable to gases released from any pollutants carried by the wind and rain. It is this sensitivity that makes lichens powerful sentinels of forest health.

Pollution builds up inside lichen tissues in proportion to its concentration in the wider environment. Anything poisoning lichens also accumulating more broadly in their environment.

Despite their plant-like form, lichens are not plants often called tiny ecosystems, they are actually compound organisms made up of two, or even three, very different partners, none of which is a plant. The dominant partner in a lichen symbiosis is a fungus, a colony of algae, supplying food by photosynthesis. Separated from its partners, the fungus itself would be a shapeless glob.

lichens aghulas

Lichens to dye for

An arsenal of nearly 600 chemicals unique to lichens helps them survive in marginal environments and ward off attacks by bacteria, other fungi and grazing herbivores. Many lichen species contain bitter compounds that may discourage feeding by invertebrates The pigments, toxins and antibiotics have made lichens very useful to people in an array of cultures as a source of dyes and medicines.

lichen Navajo clothThe warm brown rugs made by Navajo Indians. come from boiling the vagrant lichen, Xanthoparmelia chlorochroa. Known as a vagrant lichen because it grows loose on the ground, "ground lichen" is free to wander on the wind. Before weaving a rug or blanket, members of the Ramah Navajo Weavers Association raise and shear their own sheep, spin the yarns, and dye them with vegetal dyes "ground lichen" shown loose in the basket.

The lichens once used to dye Scottish Harris Tweed contain substances that gave the fabric an earthy aroma and reputedly made it moth repellent.

lichen dye groupShrubby grey lichens scraped off coastal rocks and soaked in ammonia-rich stale urine, yielded some of the famous royal purple dyes of antiquity.

The most widely used dye lichen among Native Americans was the eye-catching wolf lichen, Letharia vulpine. A tribe in Alaska traded coastal commodities such as fish oil for wolf lichen from the inland to colour their prized dancing blankets. Though famed as a wolf poison, the wolf lichen often becomes one of the prized medicines in tribal pharmacies. Medicinal tea was made from it or used externally to treat skin problems. The lichen substance usnic acid has been used in some European antibiotic creams.

lichens crustose-lichens-sylvia-sharnoffDesigner rocks

As if painted by a mad hand, a tombstone encrusted with lichens.

The brightly coloured crustose lichens used as medicines such as Pleopsidium oxytonum translates literally as “lizard semen”- alluding the push-ups that lizards do during courtship displays.

Colonizers

lichen_main science newsAlmost any stable surface makes suitable turf for lichens. Under favourable conditions, lichens will find a home on the stained-glass windows of cathedrals, even on the backs of Galapagos tortoises!

Growing imperceptibly for centuries - even millennia- some lichens are amongst the world’s oldest living things; this makes them useful to scientists for dating archaeological artefacts and tracking geological events such as the retreat of glaciers.

There are rich lichen floras in the intertidal zone in many places, and they are accompanied by a correspondingly complex set of invertebrates.

lichens snailLichens are prominent role players in transforming landscapes by slowly chipping away and dissolving rock into soil, adding organic matter when they die. In the Negev Desert, in Israel, two species of snails that eat lichens growing under the surface of limestone rocks ("endolithic lichens") were discovered to be converting rock to soil at the amazing rate of 0.7 to 1.1 metric tonnes per hectare per year! lichens desert

The action was due to the fact that the snails pass significant amounts of rock through their digestive tracts in the process of consuming the lichen. In addition, the snails were taking nitrogen from the lichens and leaving it behind in the new soil; this was found to be a principal component of the nitrogen cycle of this desert.

Environmental watchdogs

lichen -wolf moss Letharia vulpineFar from the rain-drenched forests of the Pacific Northwest, on the grey streets of 1860s Paris, a botanist named William Nylander was one of the first scientists to notice a peculiar pattern. More lichen species grew in the oasis of the Luxembourg Garden than elsewhere in the city. The park was less polluted than the rest of Paris.

Nylander made the connection: Better air quality meant higher lichen diversity. Protect them and everything else is safe.

Because of their extreme sensitivity, lichens are useful indicators of air quality. Thriving in pristine environments lichens are fast disappearing in regions of air pollution and habitat disturbance. Lichens act like sponges, taking up pollutants that come their way. By analysing lichens chemically, scientists can tell what’s in the air.

Lichen_encrusted_rocks

After winter rain, leafless forest trees come alive with lichens, including oakmoss lichen, an important ingredient in many fine perfumes. Virtually dormant when dry, lichens become bright, plump and metabolically active when damp.

Everything notwithstanding, lichens will keep growing and changing in step with the changing planet. They’ll breathe in the mountain air, soak up water as it drips down the trees and swell out from the mist rolling in from the sea.

Lichens will forever stand as a beacon of the air we breathe.

Sources:

Science News

National Geographic

Various online

 

The East London aquarium is an interesting little aquarium with daily fish feeding, fun and informative thanks to a number of unique displays and features including a whale-watching deck, a breeding colony of African penguins and an exciting seal shows.

Penguins at the east London Aquarium

The aquarium has some beautiful large fish tank displays that feature most of the local fish population. The lighting of these tanks add to the experience of visiting this small but well planned and maintained establishment.

East London aquarium Tanks

All around this Aquarium is boards with well researched information about South African marine life.

Information Boards East London aquarium

There is a colony of African penguins, sea-turtles, seals, a variety of marine fish and seabirds. Unique to this Eastern Cape aquarium is the display housing three Cape pygmy clawed lobsters.

Sea-turtle

This aquarium also serves as a haven for injured, oiled and distressed marine creatures washed up on East London’s beaches, which total a few hundred seabirds, turtles and dolphins that are treated, rehabilitated and released every year.

Oil birds East London aquarium

The Southern Right whales migrate annually down the coast of South Africa to their arctic feeding grounds and come close inshore at East London and with this in the mind the aquarium built an eleven meter high platform that sits right above the surf and provides an excellent opportunity to watch these magnificent animals breaching in the bay. This is build just above the pool where a couple of seals are staying.

Cape Fur Seals - East London

The East London Aquarium is South Africa’s oldest aquarium, and opened it’s doors in 1931, a must-see for visitors to this charming coastal city, now called Buffalo City in the Eastern Cape.

The Aquarium is open daily from 09:00 in the morning till 17:00 in the afternoon The Seals show and Penguin feeding run daily at 11:30 in the morning and 15:30 in the afternoon Entrance fee is R28 for adults, R17 for children (3 to 18 years) R11 per child in school group and R17 for pensioners.

 

edible beer topsA brewery created by fishermen, surfers and lovers of the sea have come up with a genius solution to end plastic 6-pack rings ending up in the ocean.

Their solution? Edible rings. (For the fish, of course)

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It is estimated that by 2050, there will be more plastic in the ocean than fish. (that's insane.) These brilliant thinkers decided they would help put an end to this by creating edible rings instead of plastic, the fish can therefore eat them instead of getting stuck in them.

This material is made entirely of barley and wheat remains from the brewing process, all of which is 100 percent biodegradable and safe for fish, turtles, birds and other marine life to eat, unlike the plastic ring-holders that are now killing them by the millions.

Article originally appeared in Niume
Friday, 01 March 2019 08:10

Algal blooms dump toxins on the ocean floor

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Toxic algal bloom off Washington, US. Left is the natural colour, right has been enhanced to reveal chlorophyll concentrations (Image: SeaWiFS Project, NASA/Goddard Space Flight Center/ORBIMAGE) Toxic algal bloom off Washington, US. Left is the natural colour, right has been enhanced to reveal chlorophyll concentrations (Image: SeaWiFS Project, NASA/Goddard Space Flight Center/ORBIMAGE)

Toxic algal blooms are bad enough on the ocean surface, but now it turns out that the toxin in them sinks to the ocean floor – where it persists for weeks.

Far from degrading soon after the bloom, as previously assumed, new research suggests that the neurotoxin that causes shellfish poisoning, domoic acid, sinks to the ocean floor and could poison marine mammals, birds and humans.

"The first signs of an algal bloom are often birds washing up on the shore or seals acting funny, aggressive and twitching, looking as if they were drunk," says Claudia Benitez-Nelson of the University of South Carolina.

"We used to think that once the bloom died, the danger was over, but now it turns out that domoic acid is a 'gift' that just keeps on giving."

Benitez-Nelson's team are the first to look for the chemical in algae particles sinking through the ocean, as well as in sediment samples on the ocean floor, up to 800 metres down. They found copious amounts of the neurotoxin, reaching concentrations eight times the US federal limit for the substance in shellfish.

Toxic shock

The team also compared the peak of domoic acid levels from the sediment with those of algae blooms at the surfaces. Their findings indicate that the toxin reaches the bottom of the ocean in only three days but stays there for much longer – at least several weeks.

The speedy trip to the bottom is probably driven by dead algae clumping together at the surface to form heavier aggregates, says the team, a process that also protects the toxin from degradation.

Domoic acid gets broken down easily in water and by sunlight, but once the clumped algae are buried in the sediment, the toxin may stay protected until a bottom-dwelling organism eats it.

"Domoic acid is a rich amino acid that will be tasty to worms and other critters, who may suffer no ill effects from it," says Benitez-Nelson.

Raphael Kudela at the University of Santa Cruz in California says that the new work is "the missing link to explain why domoic acid also shows up in bottom-dwelling organisms like crabs and flatfish. These contain lots of commercially important species, but they are not yet monitored for domoic acid."

The new data warrants studies to test if these species should be included in future monitoring efforts, according to Kudela. So far, only shellfish that live close to the water surface are monitored.

To Benitez-Nelson, the most important next step now is to work out in more detail how much longer the domoic acid sticks around and into how many more organisms it gets.

"It is clearly a lot more prevalent and spread out than we thought before and this problem affects many areas, not just California. On top of this, all signs seem to point to further increases in the future as people dump more and more algae feeding nutrients into the ocean."

Friday, 01 March 2019 08:05

Alien like Portugese man-of-war

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This strange sea creature is the amazing Portuguese man-of-war (Caravela Portuguesa) –.

Despite its outward appearance, the Portuguese man o’ war is not a jellyfish Despite its outward appearance, the Portuguese man o’ war is not a jellyfish

A jellyfish-like marine cnidarian of the family Physaliidae. Its venomous tentacles can deliver a powerful sting.

The venomous tentacles can deliver a painful sting. The venomous tentacles can deliver a painful sting.

Despite its outward appearance, the Portuguese man o’ war is not a jellyfish but a siphonophore, which differs from jellyfish in that it is not actually a single multicellular organism but a colonial organism made up of many highly specialized minute individuals called zooids. These zooids are attached to one another and physiologically integrated to the extent that they are incapable of independent survival.

Friday, 01 March 2019 07:46

Counting whales from space

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A new method for detecting whales using satellite imagery that’s more reliable and efficient than counting whales from ships or shore.

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A team of scientists from the British Antarctic Survey have demonstrated how new satellite technology can be used to count whales, and ultimately estimate their population size.

The team used Very High Resolution (VHR) satellite imagery, alongside image processing software, to detect and count whales breeding in part of the Golfo Nuevo, Peninsula Valdes in Argentina. Whales are extremely difficult to count on a large scale. Traditional methods, such as counting from ships or land, can be costly and inefficient.

The researchers analysed a single WorldView2 satellite image of a bay where southern right whales gather to calve and mate. The image had a resolution of 4 pixels per 11 square feet (1 square meter), covered an area of 44 square miles (113 square kilometres) and picked up on a broad spectrum of colors, including light from the far blue end of the spectrum which penetrates deep into the water column.

The team first manually identified whales from the image and found 55 probable whales, 23 possible whales and 13 other underwater objects that were not whales, such as rocks. They then tested a series of automated image-processing systems. The scientists say that the best of the methods automatically located 89 percent of the probable whales that they had counted manually.

 

Whale satellite images compared with aerial photographs at the same scale (top right) Image credit: British Antarctic Surevy Whale satellite images compared with aerial photographs at the same scale (top right) Image credit: British Antarctic Survey

Southern right whales, driven to near extinction, have made a limited recovery following the end of whaling. In recent years, however, many deaths have been seen on their nursery grounds at Peninsula Valdes. Their population size is now unknown but with this sharp increase in calf mortality, estimates are needed. The enclosed bays in this region contain calm, shallow waters which increase the chance of spotting the whales from space.

Spotting Whales from Space -British Antarctic Survey 12 February 2014 Scientists have demonstrated how new satellite technology can be used to count whales, and ultimately estimate their population size. Using Very High Resolution (VHR) satellite imagery, alongside image processing software, they were able to automatically detect and count whales breeding in part of the Golfo Nuevo, Peninsula Valdes in Argentina.

The new method, published this week in the journal PLoS ONE, could revolutionise how whale population size is estimated. Marine mammals are extremely difficult to count on a large scale and traditional methods, such as counting from platforms or land, can be costly and inefficient.

Lead author Peter Fretwell from the British Antarctic Survey (BAS), which is funded by the UK’s Natural Environment Research Council (NERC), explains;

“This is a proof of concept study that proves whales can be identified and counted by satellite. Whale populations have always been difficult to assess; traditional means of counting them are localized, expensive and lack accuracy. The ability to count whales automatically, over large areas in a cost effective way will be of great benefit to conservation efforts for this and potentially other whale species.

” Previously, satellites have provided limited success in counting whales but their accuracy has improved in recent years.

The BAS team used a single WorldView2 satellite image of a bay where southern right whales gather to calve and mate. Driven to near extinction, these whales have made a limited recovery following the end of whaling. In recent years, however, many deaths have been seen on their nursery grounds at Peninsula Valdes. Their population size is now unknown but with this sharp increase in calf mortality, estimates are needed.

The enclosed bays in this region contain calm, shallow waters which increase the chance of spotting the whales from space. Three main criteria were used to identify whales: objects visible in the image should be the right size and shape; they should be in the right place (where whales would be expected to be) and there should be no (or few) other types of objects that could be mistaken as whales.

Whales in the image were manually identified and counted, finding 55 probable whales, 23 possible whales and 13 sub-surface features. Several automated methods where then tested against these numbers. A ‘thresholding’ of the Coastal Band of the WorldView2 image gave the greatest accuracy. This part of the image uses light from the far blue end of the spectrum which penetrates the water column deeper and allows us to see more whales. This technique found 89% of probable whales identified in the manual count. This is a semi automated technique that needs some user input to identify the best threshold.

Future satellite platforms will provide even high quality imagery and Worldview3 is planned to be launched this year. This will allow for greater confidence in identifying whales and differentiating mother and calf pairs. Such technological advancements may also allow scientists to apply this method to other whale species.

Friday, 01 March 2019 07:16

Deep Sea Crop circle mystery solved

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Deep sea crop mystery Deep sea crop mystery

Mysterious geometric patterns on the sandy ocean floor, not created by a human, but an unexpected underwater artist!

Puffer Fish creating circles

The impressive geometric sand patterns are nearly six feet in diameter and at a depth of 80 feet .

The female puffer fish lay their eggs in the centers of the geometric circles The female puffer fish lay their eggs in the centers of the geometric circles

Puffer fish is creating the deep sea circles by flapping a fin and is making a circle, apparently for mating purposes. The female puffer fish lay their eggs in the centers of them.

Friday, 01 March 2019 07:10

Tiny cameras attached to the back of gannets

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Tiny cameras attached to back of gannets Tiny cameras attached to back of gannets

Researchers attached the tiny cameras to the gannets, to learn more about their habits and how they survive flying up to 300 miles out at sea. They found that the seabirds circle at 30 meters high before diving into the water at speeds of up 60mph.

Gannets are seabirds comprising the genus Morus, in the family Sulidae, closely related to boobies. The gannets are large black and white birds with yellow heads; long, pointed wings; and long bills. Northern gannets are the largest seabirds in the North Atlantic, with a wingspan of up to 2 metres. The other two species occur in the temperate seas around southern Africa, southern Australia and New Zealand.

Gannets are large black and white birds with yellow heads and pointed beaks. Gannets are large black and white birds with yellow heads and pointed beaks.

Gannets hunt fish by diving from a height into the sea and pursuing their prey underwater. Gannets have a number of adaptations which enable them to do this:

  • they have no external nostrils, they are located inside the mouth instead;
  • they have air sacs in their face and chest under their skin which act like bubble wrapping, cushioning the impact with the water;
  • their eyes are positioned far enough forward on their face to give them binocular vision, allowing them to judge distances accurately.

 

Friday, 01 March 2019 07:03

There’s no such thing as a jellyfish

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Jellyfish with its venemous tentacles. Jellyfish with its venomous tentacles.

By all accounts, jellyfish are creatures that kill people, eat microbes, grow to tens of meters, filter phytoplankton, take over ecosystems, and live forever. Watch the video…

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Because of the immense diversity of gelatinous plankton, jelly-like creatures can individually have each of these properties.However this way of looking at them both overstates and underestimates their true diversity. Taxonomically, they are far more varied than a handful of exemplars that are used to represent jellyfish or especially the so-called “true” jellyfish. Ecologically, they are even more adaptable than one would expect by looking only at the conspicuous bloom forming families and species that draw most of the attention.

In reality, the most abundant and diverse gelatinous groups in the ocean are not the ones that anyone ever sees.

 

 

 

 

 

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