Back from verge of extinction only to face a new threat

The Scotsman – John Ross

A FARMING crisis in Scotland could again threaten a rare bird that has fought back from the brink of extinction.

Corncrake numbers have risen to their highest in nearly three decades of monitoring, according to RSPB Scotland.

The population here now stands at 1,273 calling males, but bird numbers have seriously declined throughout most of western Europe.

The turnaround in Scotland follows a recovery programme started by the RSPB and crofters in 1993, when there were only 470 calling males in the UK and the species was in danger of being wiped out.

But experts say the species continues to be threatened by changes to agricultural support systems and a growing crisis in Scottish livestock farming.

The environmentally-fragile, peripheral areas in the north and west, particularly the islands, have already suffered some loss of cattle farming, as it has become ever more economically marginal and, in some cases, unviable.

The June agricultural census shows the number of cattle in Scotland has fallen to 1,898,280, from 2,078,900 in 1997. Sheep numbers have also dropped, from 9,563,190 to 7,490,870.

The RSPB says the environmental consequences of losing cattle from these areas would be severe. In addition to the grazing benefits these systems of farming produce, loss of cattle also means declining hay production and mixed farm practices, depriving corncrakes and other wildlife of the food resources and habitats they need.

Livestock diseases, and the restrictions that have resulted from disease control elsewhere in the UK, along with uncertainty for the future of support systems, are threatening to accelerate the decline into a “freefall”.

Stuart Housden, the director of RSPB Scotland, said: “

The corncrake and many other important species are very much dependent on extensive cattle rearing practices that characterise much of the Highlands and Islands.

“This type of farming has become ever more economically marginal because of changes in agricultural support systems. If we are to see this wildlife flourish, funding streams like the Less Favoured Areas Support Scheme and Rural Stewardship Scheme must be both retained and targeted to ensure that these extensive farming systems continue to produce benefits for the rich array of species and biodiversity found here.”

The corncrake’s strongholds are in the inner Hebridean and Argyll islands. Tiree’s population of calling males has increased by 23.4 per cent from 316 in 2006 to 390 in 2007.

Together with Coll, Iona, Mull, Oronsay, Colonsay and Islay, this area accounts for 59 per cent of the total Scottish population. The calling male population in the Outer Hebrides was also up by 22 birds, compared with last year.

• CORNCRAKES migrate to Scotland in April and May from sub-Saharan Africa, where they spend the winter.

They are found in herbs and tall grass, particularly in hay meadows.

Numbers of the birds began to fall towards the end of the 19th century. Although it was recognised that numbers varied from year to year, a link was noticed between the decline of bird numbers and the increase in the mechanisation of mowing.

By 1972, the corncrake had disappeared from most of mainland Britain, and population declines continued, except in Lewis, Coll and Tiree, where suitable hay meadow habitats and late mowing dates allow successful breeding.

Mussels face extinction as oceans turn acidic

The Telegraph – Richard Gray

Prized as a luxury treat in the best restaurants and a staple food in the human diet for thousands of years, oysters and mussels are now being threatened by rising levels of carbon dioxide.

By the end of the century many popular seafood dishes will disappear from our tables as shellfish become increasingly scarce, scientists warn.

They have found that the build up of carbon dioxide in the atmosphere is causing the oceans to grow more acidic as increasing amounts of the gas dissolve in sea water.

This change is reducing the ability of shellfish to make their protective shells. By 2100 some waters are expected to be corrosive enough to cause the shells to dissolve completely, making it impossible for them to survive.

Marine biologists warn that this could have a devastating effect on the ocean environment, as other creatures that eat shellfish will find food increasingly scarce while corals, which make reefs, will also be unable to build their hard external skeletons.

Dr Carol Turley, from Plymouth Marine Laboratory, will tell a conference of doctors at the Royal Society of Medicine that climate change is likely to have a profound effect on human ability to use the oceans as a source of food.

Speaking ahead of the conference later this month, she said the fishing industry would struggle to find supplies of scallops, mussels and oysters for restaurant tables due to ocean acidification.

She said: “The oceans take up carbon dioxide as we produce more and more into the atmosphere. They have already taken up half of the carbon dioxide released into the atmosphere since the industrial revolution.

“The problem this causes has only really emerged very recently.

“Many shellfish use calcium carbonate to make their shells, but the more carbon dioxide in the ocean, the less carbonate is available to those organisms that use it.

“A lot of shellfish are an important food source for fish as well as humans. The impacts of shellfish disappearing could be massive.”

Shellfish produce their shells by absorbing calcium carbonate from the water and depositing it around their bodies. Carbon dioxide, however, produces an acid when it is dissolved in water that reduces the availability of calcium carbonate, causing shellfish to grow far more slowly.

Dr Turley explained that in colder seas around the poles, the reaction is more profound and the water may even act to dissolve the shells of shellfish.

Scientists had originally hoped that by dissolving excess carbon dioxide in the oceans it might be possible to reduce the effects of climate change on the planet, but oceanographers now fear the move could be devastating.

Mussels, clams, scallops and oysters are expected to be the worst-hit as the oceans grow more acidic. However prawns, crabs and lobsters will escape unharmed as they produce their shells in a different way.

Coral reefs will also be hit as the coral polyps use calcium carbonate to create the hard skeletons that provide shelter and some of the most diverse habitats in the oceans.

Climate change scientists warn that ocean acidification will add to the other impacts of global warming. Many species can only survive in tight bands of water temperature so as the seas heat up, fish will be forced to find cooler waters.

Ocean acidification is also expected to affect the ability of fish to fertilise eggs.

Around 150,000 tons of shellfish are caught by UK fishing vessels every year and it now accounts for around 40 per cent of the fishing industry’s catch as cod and haddock stocks have declined.

Dr Ian Totterdell, an ocean modeller at the Met Office’s Hadley Centre for Climate Research, said: “Carbon dioxide naturally dissolves in the oceans, but we have been tipping the balance by releasing more carbon dioxide into the atmosphere.

“For a long time this was seen as a good thing as it was helping to protect us from the full effects of greenhouse gases on the climate, but it now seems shellfish are suffering as a side effect.”

Taipei residents call for better protection of butterfly colonies

Taipei Times – Peggy Lu

DWINDLING SPECIES: Urban development has dealt a blow to the number of butterfly colonies in Taiwan, which used to be known as a key habitat

Thousands of Taipei residents flocked to Dajia Riverside Park yesterday, gathering together to form the shape of a giant butterfly while urging the public to save the creatures from extinction.

Shining Culture and Education Foundation Chairman Lai Cheng-i (賴正鎰) said that the number of butterfly colonies in a country are an index of the soundness of its ecosystem.

Taiwan used to be known as the “Butterfly Kingdom,” Lai said, but many of its species, including birdwing butterflies and broad-tailed swallowtail butterflies, now face extinction because of urban development.

“In our prime we used to have more than 400 species of butterfly,” Lai said.

extinct “Now some 20 of them are extinct — a signal that we need to start taking the preservation of our ecosystem more seriously,” Lai said.

More than 10,000 people joined the activity yesterday, donning orange, teal, blue and yellow caps before standing in corresponding color zones to create a gigantic butterfly almost 60m wide.

It was the largest butterfly assembly involving the largest number of people and covering the biggest area, Lai said.

The foundation has an online poll to find the 10 most beautiful butterflies in the country, Lai told participants, with the Birdwing butterfly currently leading with 98,314 votes.

He urged participants to go to the foundation’s Web site to vote and learn more about Taiwanese butterflies.

eco-preservation Chinese Nationalist Party (KMT) presidential candidate Ma Ying-jeou (馬英九) echoed Lai’s words on ecosystem preservation and commended businesspeople such as Lai for their regular donations to charity and public welfare.

“Environmental conservation should be a joint effort undertaken by all members of society,” he said. “The grand prize for entering the butterfly vote is a car. May I suggest that we give out eco-friendly bicycles next time?”

“There are bicycle trails that extend from the Dajia Riverside Park westward to Guandu (關渡) and Tamsui (淡水), or eastward to Nangang (南港). I encourage you to explore the city and appreciate its beauty that way,” he said.

To join the poll, visit http://www.shininggroup.com.tw/butterfly/vote.php.