The Sydney Barrier Reef: engineering a natural defence against future storms


Rob Roggema, University of Technology Sydney

The risk of more severe storms and cyclones in the highly urbanised coastal areas of Newcastle, Sydney and Wollongong might not be acute, but it is a real future threat with the further warming of the southern Pacific Ocean. One day a major storm – whether an East Coast Low or even a cyclone – could hit Sydney. The Conversation

With higher ocean temperatures killing and bleaching coral along the Great Barrier Reef to the north, we could also imagine where the right temperatures for a coral reef would be in a warmer climate. Most probably, this would be closer to the limits of the low latitudes, hence in front of the Sydney metro area.

We should then consider whether it is possible to help engineer a natural defence against storms, a barrier reef, should warming oceans make conditions suitable here.

Ocean warming trend is clear

The oceans are clearly warming at an alarming rate, with the unprecedented extent and intensity of coral bleaching events a marker of rising temperatures. After the 2016-2017 summer, coral bleaching affected two-thirds of the Great Barrier Reef.

On the other side of the Pacific, sea surface temperatures off Peru’s northern coast have risen 5-6℃ degrees above normal. Beneath the ocean surface, the warming trend is consistent too.

The East Australian Current keeps the waters around Lord Howe Island warm enough to sustain Australia’s southernmost coral reef. The waters off Sydney are just a degree or two cooler.

With the East Australian Current now extending further south, the warming of these south-eastern coastal waters might be enough in a couple of decades for Nemo to swim in reality under Sydney Harbour Bridge.

This shift in ocean temperatures is expected to drive strong storms and inland floods, according to meteorologists.

On top of this, when we plot a series of maps since 1997 of cyclone tracks across the Pacific, it shows a slight shift to more southern routes. These cyclones occur only in the Tasman Sea and way out from the coast, but, still, there is a tendency to move further south. The northern part of New Zealand recently experienced the impacts this could have.

Think big to prepare for a big storm

If we would like to prevent what Sandy did to New York, we need to think big.

If we don’t want a storm surge entering Parramatta River, flooding the low-lying areas along the peninsulas, if we don’t want flash-flooding events as result of river discharges, if we don’t want our beaches to be washed away, if we want to keep our property along the water, and if we want to save lives, we’d better prepare to counter these potential events through anticipating their occurrence.

The coast is the first point where a storm impacts the city. Building higher and stronger dams have proven to be counterproductive. Once the dam breaks or overflows the damage is huge. Instead we should use the self-regenerating defensive powers nature offers us.

Thinking big, we could design a “Sydney Barrier Reef”, which allows nature to regenerate and create a strong and valuable coast.

The first 30-40 kilometres of the Pacific plateau is shallow enough to establish an artificial reef. The foundations of this new Sydney Barrier Reef could consist of a series of concrete, iron or wooden structures, placed on the continental shelf, just beneath the water surface. Intelligently composed to allow the ocean to bring plants, fish and sand to attach to those structures, it would then start to grow as the base for new coral.

This idea has not been tested for the Sydney continental flat yet. But in other parts of the world experiments with artificial reefs seem promising. At various sites, ships, metro carriages and trains seem to be working as the basis for marine life to create a new underworld habitat

The Sydney Barrier Reef will have the following advantages:

  1. Over decades a natural reef will grow. Coral will develop and a new ecosystem will emerge.

  2. This reef will protect the coast and create new sandbanks, shallow areas and eventually barrier islands, as the Great Barrier Reef has done.

  3. It will increase the beach area, because the conditions behind the reef will allow sediments to settle.

  4. It creates new surfing conditions as a result of the sandbanks.

  5. It will protect Sydney from the most severe storm surges as it breaks the surge.

  6. It will present a new tourist attraction of international allure.

Let’s create a pilot project as a test. Let’s start to design and model the pilot to investigate what happens in this particular location. Let’s simulate the increase of temperature over time and model the impact of a cyclone.

Let’s create, so when Sandy hits Sydney, we will be better protected.

Rob Roggema, Professor of Sustainable Urban Environments, University of Technology Sydney

This article was originally published on The Conversation. Read the original article.

What dragonflies say about our ignorance of the natural world


Klaas-Douwe B. Dijkstra, Stellenbosch University

Of the 8.7 million species of animals, plants and fungi thought to live on Earth, we have only named 1.2 million: 86% of the natural world is uncharted.

For most people, both this incredible richness and our ignorance are hard to fathom. Imagine that each of the 6.5 million species thought to live on land – the rest is marine – had an equal share of it. Each species’ plot – also that of the human species – would cover an area only one-quarter the size of Manhattan. Expressed this way, we as humans have not just far overstepped our bounds, but mapped only the equivalent of Europe, India and China, which make up about 14% of global land surface.

What’s worse, the habits and status of only 80,000 species are known well enough to really assess our impact on them. Of those, 29% risk extinction. So, returning to the metaphor, the species that we’re actually familiar with equal only the combined area of Spain, France and Turkey. And if 29% of all species died out, that would equate to the entire New World voided of life.

In other words: while we’ve had an apocalyptic impact on the biosphere already, it has been charted as well today as the globe was in Columbus’s day. This matters because knowing other species can provide a moral counterweight to life’s runaway exploitation: intact biodiversity is the undeniable proof that humans can inhabit Earth without destroying it.

That’s why naming species is important. Names harness the power of recognition. They acknowledge the other exists. They introduce familiarity. As someone once exclaimed to me, “you don’t notice species until you know they can have a name!”

In an era of extinction, there are no greater priorities than to uncover our millions of cohabitants and to share our knowledge of these species. This can be done through research, books, websites, Red Lists of threatened species, field courses, teaching materials and other media. But while every human relies on this knowledge, even if only by reaping the benefits of agriculture and medicine, few see its advance as their primary responsibility.

Few animals can raise that moral awareness of biodiversity better than dragonflies, literally rising from healthy freshwaters in colour and splendour.

Breaking the anonymity trap

Most of what is unknown is not just unseen, but not even being looked for.

There are 6,000 named dragonfly and damselfly species worldwide. These charismatic aquatic insects are regarded as well-known. But last December we published 60 new species in one article. This added one species to every 12 known ones in Africa.

Known from only one site near Cape Town, the endangered damselfly Spesbona angusta needs all the ‘Good Hope’ (Spes Bona in Latin) it can get.
Copyright Jens Kipping

Of course these species existed already, but were not noticed and documented before. Most unknown species may seem indistinct or concealed, requiring meticulous lab-work to uncover, but the 60 were found in accessible places all over Africa and are often recognisable even from a photo.

This May, English nature broadcaster Sir David Attenborough was given a new dragonfly species from Madagascar for his 90th birthday. In the scientific journal Nature I explain that both the dragonfly and Attenborough’s legacy stand for a selfless and unconditional love of nature.

I am often asked what the “use” of dragonflies is. They are not studied because they are not proxies of human psyche and society like ants and apes. They are not feared and persecuted like mosquitoes and snakes. They do not feed people like fish, nor pollinate crops like bees.

Rather, the beauty and sensitivity of these creatures – and so many others – stand for the state and needs of nature before our own. Like the instant sense of insignificance when counting stars, biodiversity stretches our perspective on life. Each species is a world parallel to our own, evoking a sense of being among equals.

What’s in a name

If species embody sustainability and names give them faces, those tags best be memorable. The sparklewing damselfly Umma gumma, named for the rock band Pink Floyd’s album “Ummagumma” (slang for making love), is a special favourite. The longleg dragonflies Notogomphus kimpavita and N. gorilla were named for the patron saint and conservation flagship of their Angolan and Ugandan regions respectively.

But who is out discovering species and introducing them to mankind? Nature is held hostage by humanity’s growing demands and so conservationists barely have time to find out who they really work for. Environmental consultancy is captive to the market. Many biologists have retreated into the lab. Without funds for discovery and disclosure, even natural history museums are giving up.

Only nine of our 60 new dragonflies were found while one of us worked for a university or museum. The other 33 were found while doing consultancy and 18 were found by a teacher. Much of the best biodiversity research and outreach now comes from devoted amateurs and academics working in their free time, showing how close biodiversity is to the human heart.

In a society governed by money, charity is what we do for others for free. But just as we cannot expect volunteers to protect the environment or eradicate poverty alone, we cannot continue life’s elementary and enlightening exploration without support. Nature needs more explorers.

The Conversation

Klaas-Douwe B. Dijkstra, Honorary research associate Naturalis Biodiversity Center and, Stellenbosch University

This article was originally published on The Conversation. Read the original article.

Hunter Region Botanic Gardens


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Southern Wetlands

ABOVE: The Southern Wetlands Boardwalk – Hunter Region Botanic Gardens

Late last week I decided I should do something with the final day of my annual leave that I had taken this time round, so I thought I’d pop into the Hunter Region Botanic Gardens near Raymond Terrace in New South Wales, Australia. I had been here before, but that was a long time ago. I wasn’t impressed on that first visit, so after more then a decade had it improved? Well that was the question I was keen to answer.

Rotunda

ABOVE: The Rotunda  BELOW: Succulents Section

Succulents

There was a $4.00 ‘escape’ fee, which would allow a token to be purchased and then the boom gate would rise once it was placed into the proper slot at the exit. So no entrance fee, just an exit fee. I was willing to pay this for a quick look and…

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Greenland: Natural Resources Exploitation Rapidly Advancing


The article below reports on the opening up of Greenland for oil and mining exploration.

For more visit:
http://www.guardian.co.uk/environment/2012/jul/31/europe-greenland-natural-resources

Blackbutt Reserve


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Since I was unable to visit Gap Creek Falls the other day, I decided I might pop in to have a look at the new animal enclosures at Blackbutt Reserve near Newcastle. I will say straight off the bat that I do have something of a prejudice against Blackbutt Reserve, as I see the place as nothing like a natural bush setting, it being far too ‘corrupted’ by human activity, weeds and the like. Having said that it is a good place for a family or group outing/event. It certainly has its place, but it is not a true nature reserve (in my opinion).

Visitor Centre

ABOVE: Visitor Centre

I do think that some well designed animal and bird enclosures at Blackbutt could lift the value of the reserve dramatically and make it a really great place for families, especially young families. There are opportunities for educational visits for kids, possible environmental…

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