The far-reaching benefits of tiger sharks for the climate

 Here is a report from the BBC website:

 

 

 

 

 

 

 

Worldwide, shark populations are on the decline. Boosting their numbers could have a cascade effect to help sink carbon and make the oceans more resilient to climate change.

On the westernmost tip of Australia in the aptly named Shark Bay, at least 28 species of shark swim through the clear waters and undulating seagrass meadows – the largest in the world. Tiger sharks in particular are common frequenters of the jagged inlets of Shark Bay. These mammoth predatory fish brush their 15-ft-long (4.5m) bodies through the seagrass, occasionally snatching a majestic grazing sea cow for a meal. While the presence of tiger sharks is a threat to their prey, these predators are crucial to the health of the marine ecosystem that supports both species.

In fact, despite sharks' notorious reputation among humans, they could also be a powerful ally in curbing climate change.

It all comes back to the wispy strands of seagrass that sway with the waves in the shallows of Shark Bay. This seagrass is food for the sea cows, or dugongs, who each graze on roughly 40kg (88lb) of seagrass a day – as well as for manatees and green sea turtles.

Off Australia's north-east coast of Queensland, tiger sharks are estimated to have fallen by at least 71%

Dugongs, which can weigh as much as 500kg (1,100lb), are a rich source of food for tiger sharks. By keeping the sea cow population in check, tiger sharks in Shark Bay help the seagrass meadows thrive. A flourishing seagrass meadow stores twice as much CO2 per square mile as forests typically do on land.

 

 

 

 

 

 

 

 

Shark Bay experienced an intense heatwave in 2011, causing waters to rise by up to 5C for two months (Credit: Getty Images)

But globally, tiger shark numbers are declining, including some populations in Australia. Off Australia's north-east coast of Queensland, tiger sharks are estimated to have fallen by at least 71%, largely due to overfishing and bycatch. A reduction in tiger sharks means more seagrass grazing by herbivores, which means less carbon is sequestered in sea vegetation. In the Caribbean and Indonesia where shark populations have dwindled, overgrazing by herbivores like sea turtles is already a profound threat to seagrass habitats, and has led to a 90 to 100% loss of seagrass.

As well as meaning less carbon is absorbed, the loss of seagrass also makes the habitat less able to recover from extreme, climate change-driven weather events, such as heatwaves.

Shrinking shark numbers

There is clear evidence that shark populations are     declining the world over, and humans are largely to blame. A recent reassessment by the IUCN Red List found that 37.5% of all shark and ray species are now threatened with extinction. Catherine Macdonald, marine conservation biologist and a lecturer at the University of Miami, points out that oceanic sharks and rays have declined in abundance by 71% since 1970.
Overfishing is their biggest threat, but loss of coastal habitats, prey loss and declines in water quality are also contributing factors.

One of Western Australia's worst heatwaves hit in 2011, with ocean temperatures rising by 5C for two months. The heatwave was catastrophic for the bay's dominant species of seagrass, Amphibolis antarctica, which forms rich, dense meadows that hold sediments and provide food for grazers. More than 90% of the Amphibolis antarctica was lost, the largest loss known across the bay.

This loss of seagrass was, perversely, a treat for the bay's sea cows, who love a smaller and harder-to-find type of tropical seagrass that was ordinarily shielded from access by the tall, dense Amphibolis antarctica. When tropical seagrass is more accessible, sea cows in their enthusiasm are known to forage for it in a destructive way known as "excavation foraging", digging up the rhizomes of their preferred seagrass, and making it harder for dense Amphibolis antarctica beds to reform.

In Shark Bay, the tiger sharks were somewhat able to restore the balance by keeping sea cow numbers down, and not all the bay's seagrass was lost. But it begged the question: What if sharks were absent from the bay – would the Amphibolis antarctica dominated ecosystem survive?

To find out, researchers led by Rob Nowicki of Florida International University, spent time in Eastern Australia, where shark numbers were lower and sea cows grazed largely undisturbed. There, divers went down and plucked the seagrass, simulating the sea cows' grazing when there are no predators to stop them – the enthusiastic, destructive excavation foraging. Sure enough, they observed a rapid loss in seagrass coverage, particularly of Amphibolis antarctica, and the ecosystem began to shift to a more tropical picture dominated by tropical seagrass.

"We learned that when unchecked, dugong grazing can rapidly destroy wide areas of seagrass when they perform excavation foraging," says Nowicki. These changes can be long-lasting. “When the seagrass recovers, the seagrass community looks different, with different species dominating than before."

Those findings underlined the role that sharks were playing in Shark Bay. "Without tiger sharks keeping the dugongs in check, the bay would likely convert to mostly tropical seagrasses," says Nowicki.

Let´s hope that the world wakes up properly and not just drowsily like it is now and really take a long hard look and make changes.  I am not talking just about companies and  governments  but about all of us. Everyone alive today has some part to play in making changes, even really small ones to help put the brakes on.

Here on Menorca we have measures in place to preserve the poseidon grass that protects our ocean around the island.  Unfortunately this year we had a ridiculous amount of boats around the coastline, which did nothing to help.  It is not a problem if they realise their part in the maintenance and destruction of this vital sea grass,but many of them have no idea, as they turn up on their massive boats, without a care in the world and because they have nothing to do with the day to day running of it, don´t even think about where all the waste is going.  There is a campaign to limit the amount of boats but obviously this needs to be controlled and Menorca must do this if we are to keep this island of biosphere status.

The blog song for today is: " Seven Seas of Rye" by Queen

TTFN

The blog song for today is

 

 

 

Fossil fuel subsidy explainer- more ammunition for us!

 

fossil fuel subsidy explainer

By Jake Coleman

Most of us know little of the murky world of government funded business, but it is often the things that happen behind closed doors in private offices that cause the most damage. In the case of fossil fuel subsidies, the funds that are funnelled to companies by financial manoeuvres and tweaking tax tariffs lie behind a veil of secrecy that has only recently begun to be lifted.

The fossil fuel industry has grown to such a scale that the economy as a whole has become deeply entangled with the success and continued growth of fossil fuel companies. Globally, there’s a web of intricate and opaque measures designed specifically to directly and indirectly support these companies, making the overlap between fossil fuel interests and governments’ interests a grey zone that’s hard to navigate and unknot.

Subsidies can be divided into two main categories: producer subsidies and consumer subsidies.

Consumer subsidies are defined as when a government controls the price of fuel for consumers in their economy. Low fuel prices drive up consumption of fuel and fuel products, boosting the economy in the short term. Governments often justify these cost controls by saying they reduce transport costs, household electricity bills and general living costs. But these ostensible ‘social benefits’ come at a cost. Price controls are often applied to products only the relatively rich can afford at quantity, such as petrol, which further advantages the ability of the rich to accelerate their own wealth as those who are still priced out fall further behind. So effectively, price controls of this kind often function as a money transfer from the average taxpayer to the 1%, further increasing societal inequalities.

Producer subsidies are far more complex matter, as they can be awarded to companies in a variety of more indirect ways. Direct budgetary transfers are government stimuluses for the industry, which can be spent in any way companies choose, from helping to improve the efficiency of their operations — to handing out gigantic bonuses to their CEOs. Tax breaks on capital investment allow oil companies huge tax breaks on investments in machinery and the construction of new power plants. Having a lower share of profits given as tax means fossil fuel company profits are taxed at a lower rate than standard companies, if they are seen to be developing a resource such as a new oil source. Investment by state owned enterprises often isn’t counted as a subsidy at all — meaning that organisations that are owned by, but not a specific branch of, the government (including banks like NatWest Group), can invest in fossil fuel companies without their considerable support even being accounted for as a government subsidy. Finally, tax breaks manifest themselves even in lower VAT rates — while the UK’s VAT rate is 20%, the fossil fuel industry gets a generously discounted 5%.

For years, governments relied on the fact that it takes a team of diligent accountants to find all the ways subsidies benefit fossil fuel companies. But more and more people are starting to understand, if not all the ways subsidies are transferred, then at least the eye-watering amounts of money involved and how destructive their effects are.

how fossil fuel companies use government money

Fossil fuel companies use most of the money from these massive tax breaks and handouts to secure their dominant position at the heart of society. Large fossil fuel companies, like Exxon Mobil and Koch Industries, have funnelled funds into climate denial institutions — Exxon Mobil paid $686,500 to the Heartland Institute, a vocal anti-climate action policy think tank, between 1997 and 2006 — to discredit climate change science and protect their profits. Exxon also fund political campaigns that pledge to guarantee the future of fossil fuels in a certain region — Texas governor Greg Abbott recently exonerated fossil fuel companies from blame for the Texas power outages after receiving $26m in campaign donations from fossil fuel companies in the past 6 years.

BP and Shell also used the money to fund advertising campaigns to greenwash their products and reduce negative publicity around crises like the Deepwater Horizon oil spill. Fossil fuel companies are delaying decisive action from being taken by painting themselves as “rethinking the future of energy” - using cosmetic brand gestures like adding green colour to their logos and using vague, eco-friendly slogans to obscure the damage they are doing to the planet. This must end now. Government-backed methods of controlling public perception can only be combatted with an engaged popular movement that fights for policies that impose significant fines on companies who use greenwash in their advertisements.

 

 Greenwashing ads like the above BP example disguise the fact that companies like Exxon mobil are using government money to finance climate denial.

This is something that affects us all, even the families of those people running and working for those companies.  Let us hope that the long awaited COP 26 taking place from tomorrow really does address all these issues and not brush them aside for the next generation to deal with. 

The blog song for today is : " No quarter" by Led Zeppelin

TTFN