Many coastal communities are pondering what to do. Should they build massive seawalls in a bid to protect existing infrastructure? Do they give up on their current coastal locations and retreat inland? Or is there another way?
In the US, the US Army Corps of Engineers has proposed building a 20-foot high giant seawall to protect Miami, the third most populous metropolis on the US east coast. The US$6 billion proposal is tentative and at least five years off, but sure to be among many proposals in the coming years to protect coastal communities from storms.
But seawalls are expensive to build, require constant maintenance and provide limited protection.
Consider China, which already has a huge number of seawalls built for storm protection. A 2019 study analysed the impact of 127 storms on China between 1989 and 2016.
Coastal wetlands were far more cost effective in preventing storm damages. They also provided many other ecosystem services that seawalls do not.
How wetlands reduce storm effects
Coastal wetlands reduce the damaging effects of tropical cyclones on coastal communities by absorbing storm energy in ways that neither solid land nor open water can.
The mechanisms involved include decreasing the area of open water (fetch) for wind to form waves, increasing drag on water motion and hence the amplitude of a storm surge, reducing direct wind effects on the water surface, and directly absorbing wave energy.
Wetland vegetation contributes by decreasing surges and waves and maintaining shallow water depths that have the same effect. Wetlands also reduce flood damages by absorbing flood waters caused by rain and moderating their effects on built-up areas.
In 2008 I and colleagues estimated coastal wetlands in the US provided storm protection services worth US$23 billion a year.
Our new study estimates the global value of coastal wetlands to storm protection services is US$450 billion a year (calculated at 2015 value) with 4,600 lives saved annually.
To make this calculation, we used the records of more than 1,000 tropical cyclones since 1902 that caused property damage and/or human casualties in 71 countries. Our study took advantage of improved storm tracking, better global land-use mapping and damage-assessment databases, along with improved computational capabilities to model the relationships between coastal wetlands and avoided damages and deaths from tropical cyclones.
The 40 million hectares of coastal wetlands in storm-prone areas provided an average of US$11,000 per hectare a year in avoided storm damages.
The degree to which coastal wetlands provide storm protection varies between countries (and within countries). Key factors are storm probability, amount of built infrastructure in storm-prone areas, if wetlands are in storm-prone areas, and coastal conditions.
The top five countries in terms of annual avoided damages (all in 2015 US dollar values) are the United States (US$200 billion), China (US$157 billion), the Philippines (US$47 billion), Japan (US$24 billion) and Mexico (US$15 billion).
In terms of lives saved annually, the top five are: China (1,309); the Philippines (976); the United States (469)l India (414); and Bangladesh (360).
Other ecosystem services
Coastal wetlands also provide other valuable ecosystem services. They provide nursery habitat for many commercially important marine species, recreational opportunities, carbon sequestration, management of sediment and nutrient run-off, and many other valuable services.
In 2014 I and colleagues estimated the value of other ecosystem services provided by wetlands (over and above storm protection) at about $US 135,000 a hectare a year.
But land-use changes, including the loss of coastal wetlands, has been eroding both services. Since 1900 the world has lost up to 70% of its wetlands (Davidson, 2014).
Preserving and restoring coastal wetlands is a very cost-effective strategy for society, and can significantly increase well-being for humans and the rest of nature.
With the frequency and intensity of tropical cyclones and other extreme weather events projected to further increase, the value of coastal wetlands will increase in the future. This justifies investing much more in their conservation and restoration.
Our review of Australian animal welfare legislation, regulations, codes of practice and policies found a complex regulatory system that varies between states and territories. It’s a system that is fragmented, contradictory and inconsistent.
We believe Australia lags behind the developed world in animal welfare and animal law. This situation evolved haphazardly and is hampered by policies that rely on assumptions based largely on neither scientific nor factual evidence.
Current policy mandates that rehabilitated rescued animals must be placed into the wild. The survival of these animals after release depends on their behavioural and physical attributes, yet some could be ill-equipped to survive.
From our reading of current regulations, any such assessment of an animal’s suitability for release is either negligible or questionable.
There is also no reliable method of identifying animals after release. Indeed, most jurisdictions forbid it and, perhaps as a direct result, there is minimal monitoring to show what happens to released animals.
Return to where?
In general, all Australian jurisdictions require rehabilitated animals to be returned to the wild. But rather than using a more general definition of rehabilitation we should think of returning the animal to its natural habitat or state.
The distinction between these two possible destinations is far from semantic. It can be argued the natural habitat (or state) of a hand-reared orphan animal, is one of captivity.
Many wildlife carers releasing an animal and seeing it disappear into the wild may equate this with success, but this may be an unfortunate convenient illusion.
The released animal may not be the happy state that carers may prefer to assume. Vague assumptions that naturalness in releasing animals to the wild is reliably associated with better well-being are largely unfounded.
But wildlife carers have no choice in the matter. They are required to consign the animals, to which they have devoted hours of care, to an uncertain fate for which they may be very poorly prepared.
And they must do so even if their knowledge, experience and pragmatism directs their thinking to more favourable alternative solutions. These include allowing some native animals to be kept in large-scale facilities such as private fenced enclosures, nationalparks, islands and other fenced options.
Concern for orphans in the wild
The regulations make no distinction between animals that are injured, rehabilitated and released, and those that are rescued as orphans. These are often physically unharmed but require milk substitute feeding from a bottle and nurturing by – and possible inadvertently bonding with – humans prior to release to the wild.
Adult and juvenile native animals raised in the wild usually have all their innate and learned behaviour instincts intact when they are injured and rescued.
Unless they remain in captivity for a prolonged period, or are subjected to inappropriate housing and handling, their instincts generally persist and kick-in once they have been released. They have an opportunity to survive.
In contrast, the chances for orphans to survive after release seems remote.
Orphans that needed hand-rearing generally become habituated to the smells, sounds and sights of human presence and the captive environment.
The requirement to return orphans to the wild, with no account taken of their mental state, may be difficult to defend on conservation, ethical, moral and practical grounds.
Think of the carers
The physical and mental protection of Australian injured or orphaned native wildlife should be recognised as an important animal welfare issue. The physical and mental well-being of the wildlife carers who rehabilitate them is just as important as a humanwelfare issue.
In the absence of criteria that take into account the mental well-being of the animals and their carers, the current policy of releasing all hand-reared wildlife to the wild must be reviewed.
Using a One Welfare approach – that considers the the animals, the humans and the environment – would see a regulatory framework that balances the needs of rescued wildlife, wildlife carers and conservation.
The public and Australia’s extraordinary wildlife carers deserve to be confident that regulation is consistent among jurisdictions and reflective of best practice for the rescued wildlife and the environment.
For each shower, we give the forecast activity period and the predicted time of maximum. We also provide charts showing you where to look, and give the peak rates that could be seen under perfect conditions (known as the maximum Zenithal Hourly Rate, or ZHR).
The actual rate you see will always be lower than this value – but the higher a shower’s radiant in the sky and the darker the conditions, the closer the observed rate will get to this ideal value.
The Lyrids hold the record for the shower with the longest recorded history, having been observed since at least 687BC.
That longevity is linked to the orbit of the Lyrid’s parent comet, discovered in 1861 by A. E. Thatcher. Comet Thatcher moves on a highly inclined, eccentric orbit, swinging through the inner Solar system every 415 years or so. Its most recent approach to Earth was in 1861.
Compared with many other comets, Thatcher’s orbit is relatively stable, as the only planet with which it can experience close encounters is Earth. This means the meteors it sheds continue to follow roughly the same orbit.
Over the millennia, that shed debris has spread all around the comet’s vast orbit, meaning that for thousands of years, every time Earth intersects Comet Thatcher’s orbit, the Lyrids have been seen, as regular as clockwork.
These days, the Lyrids are usually a moderately active shower, producing somewhere between 10 and 20 fast, bright meteors per hour at their peak. Occasionally, though, the Lyrids have thrown up a surprise, with rates climbing far higher for a period of several hours.
The best of those outbursts seem to occur every 60 years or so, with the most recent occurring in 1982 when observed rates reached or exceeded 90 per hour.
No such outburst is predicted for 2018, but even in quiet years, the Lyrids are still a fun shower to observe.
They are best seen from northern latitudes, but their radiant is far enough south for observers throughout Australia to observe them in the hours before dawn.
For observers at mid-northern latitudes, the Lyrid radiant reaches suitable altitude by about 11pm local time. Viewers in the southern hemisphere have to wait until the early hours of the morning before reasonable rates can be observed.
The forecast time of maximum this year favours observers in Australia and east Asia but the timing of maximum has been known to vary somewhat, so observers around the globe will likely be keeping their eyes peeled, just in case!
Active: July 17 – August 24
Maximum: August 12, 8pm UT – August 13, 8am UT = from August 12, 9pm BST (UK) = 10pm CEST (Europe) = 6pm EDT (East Coast, US) = 3pm PDT (West Coast, US) for 12 hours
For observers in the northern hemisphere, the Perseids are a spectacular summer highlight. At their peak, rates often reach or exceed 100 meteors per hour, and they are famed for their frequent spectacular fireballs.
The Perseids are probably the best known and most widely observed of all modern meteor showers. They are remarkably consistent, with peak rates usually visible for a couple of evenings, and fall in the middle of the northern hemisphere summer holiday season. The warm nights and frequent clear skies at that time of year make the shower a real favourite!
Like the Lyrids, the Perseids have a long and storied history, having been observed for at least 2,000 years. Their parent comet, 109P/Swift-Tuttle, is a behemoth, with the largest nucleus of the known periodic comets – some 26km in diameter.
It has likely moved on its current orbit for tens of thousands of years, all the time laying down the debris that gives us our annual Perseid extravaganza. It will next swing past Earth in 2126 when it will be a spectacular naked eye object.
This year the forecast maximum for the Perseids favours observers in Europe, although given the length of peak activity, any location in the northern hemisphere has the potential to see a spectacular show on the night of August 12.
But don’t despair if it’s cloudy that night, as the Perseids have a relatively broad period of peak activity, meaning that good rates can be seen for a few days either side of their peak.
In 2018, the peak of the Perseid shower coincides with the New Moon, and so is totally unaffected by moonlight, which makes this an ideal year to observe the shower.
The further north you are, the earlier the shower’s radiant will be visible. But reasonable rates can typically be seen any time after about 10pm, local time. The later in the night you observe, the better the rates will be, as the radiant climbs higher into the sky.
It is not uncommon for enthusiastic observers to watch the shower until dawn on the night of maximum, seeing several hundred meteors in a single night.
Active: October 6-10
Maximum: October 9, 12:10am UT = 1:10am BST (UK) = 2:10am CEST (Europe)
The Draconids are a fascinating meteor shower, although in most years, somewhat underwhelming. Unlike the previous showers, the Draconids are a relatively young meteor shower that can vary dramatically from one year to the next.
That comet was the first to be visited by a spacecraft, and has frequent close encounters with Jupiter, which continually nudges its orbit around. These encounters also perturb the meteor stream the comet is laying down, sometimes enhancing rates at Earth and sometimes diminishing them.
In the early 20th century, it was realised that Comet Giacobini-Zinner’s orbit comes close enough to Earth that we might be able to see meteors as we plough through the debris it leaves behind.
This led to the first predictions of Draconid activity. Sure enough, in 1920, the great meteor observer W. F. Denning confirmed the existence of the shower, with a mere five meteors observed between October 6 and October 9.
In 1933 and 1946, the Draconids produced two of the greatest meteor displays of the 20th century – great storms, with peak rates of several thousand meteors per hour. In those years, Earth crossed the comet’s orbit just a month or two after the comet passed through perihelion (closest approach to the Sun), and Earth ploughed through dense material in the comet’s wake.
After 1946, the Draconids went quiet, all but vanishing from our skies. Jupiter had swung the comet onto a less favourable orbit. Only a few Draconids were seen in 1972, then again in 1985 and 1998.
The late 1990s saw a renaissance in our ability to predict and understand meteor showers, born of enhanced activity exhibited by the Leonid meteor shower. Using the techniques developed to study the Leonids, astronomers predicted enhanced activity from the Draconids in 2011, and the predicted outburst duly occurred, with rates of around 300 meteors per hour being observed.
This year comet Giacobini-Zinner once again passes through perihelion and swings close to Earth’s orbit. The chances are good that the shower will be active – albeit unlikely to produce a spectacular storm.
Modelling suggests that rates of 20 to 50 faint meteors per hour might be seen around 12:14am UT on October 9. Other models suggest that rates will peak about 45 minutes earlier, with lower rates of 15 to 20.
The Draconid radiant is circumpolar (that is, it never sets) for locations north of 44°N, and is highest in the sky before midnight. This year, the Moon is new at the time of the forecast peak, which is ideally timed for observers in Europe.
If skies are clear that evening, it is well worth heading out at around 11:30pm BST on October 8 (12:30am CEST on October 9) and spending a couple of hours staring north, just in case the Draconids put on another spectacular show.
Active: September 10 – December 10
Maxima: October 10 (Southern Taurids); November 12 (Northern Taurids)
Of all the year’s meteor showers, the one that dumps the greatest amount of dust into Earth’s atmosphere are the Taurids. The inner Solar system contains a vast swathe of debris known as the Taurid stream. It is so spread out that Earth spends a quarter of the year passing through it.
In June, that debris spawns the Daytime Taurid meteor shower, which (as the name suggests) occurs during daylight hours, and is only really known thanks to radio observations.
After leaving the stream for a little while, Earth penetrates it again at the start of September, and activity continues right through until December. Hourly rates fluctuate up and down, with several distinct peaks and troughs through October and November.
The Taurid stream is complex – with at least two main components, known as the northern and southern branches. Typically, the Southern Taurids are active a little earlier in the year and reach their peak about a month before the northern branch.
The Taurids are slow meteors and feature plenty of bright fireballs. So even though their rates are low, they are well worth looking out for, particularly when other showers are also active, such as the Draconids, the Orionids and the Leonids.
Put together, these showers make the northern autumn or the southern spring a great time to get out and look for natural fireworks.
Twice a year, Earth runs through the stream of debris littered around the orbit of Comet 1P/Halley. Throughout the month of October this gives rise to the Orionid meteor shower.
The Orionids are a fairly reliable meteor shower with a long, broad maximum. Typically, peak rates can last for almost a week, centred on the nominal maximum date. Throughout that week, Orionid rates can fluctuate markedly, leading to a number of distinct maxima and minima.
Orionid meteors are fast – much faster than the Taurids that are active at the same of year. Like the Taurids, they are often bright, the result of the high speed at which the meteoroids hit Earth’s atmosphere.
The Orionid radiant rises in the late evening and is only really high enough in the sky for reasonable rates to be seen after midnight. As a result, the best rates are usually observed in the hours before dawn.
This works well this year, as the Moon will be in its waxing gibbous phase, setting some time after midnight and leaving the sky dark, allowing us to watch for pieces of the most famous comet of them all.
Active: December 4-17
Maximum: December 14, 12:30pm UT = Australia: December 14, 8pm AWST (WA) = 10:30pm (QLD) = 11:30pm AEST (NSW/ACT/Vic/Tas) = United States: December 14, 7:30am (EST) = 5:30am (PST) = 2:30am (Hawaii)
As the year comes to a close, we reach the most reliable and spectacular of the annual meteor showers – the Geminids. Unlike the Perseids and the Lyrids, which have graced our skies for thousands of years, the Geminids are a relatively new phenomenon.
They were first observed just 150 years ago, and through the first part of the 20th century were a relatively minor shower. But since then rates have improved decade-on-decade, to the point where they are now the best of the annual showers, bar none.
The reason for their rapid evolution is that their orbit (and that of their parent body, the asteroid Phaethon) is shifting rapidly over time, precessing around the Sun (wobbling like a slow spinning top). As it does so, the centre of Phaethon’s orbit, and the centre of the Geminid stream, are moving ever closer to Earth.
For northern locations, the radiant rises shortly after sunset, and good rates can be seen from mid-evening onwards. For observers in the southern hemisphere, the radiant rises later, so good rates are delayed until later at night (as detailed in our 2015 report on the shower).
Although the time of maximum this year seems to favour observers in the Americas and Australia, peak rates from the Geminids usually last around 24 hours, and so good rates should be visible around the globe.
This year the maximum falls a day before the Moon reaches first quarter so the best rates are visible (after midnight, local time) when the Moon will have set and moonlight will not interfere.
Given that rates from the Geminids continue to climb, the estimated ZHR of 120 is likely to be somewhat conservative. Rates in excess of 130, and even as high as 200 per hour, have been seen in recent years.
Geminids are medium-speed meteors and are often bright. The individual meteors also seem to last just that bit longer than other showers, a fact likely related to their parent object’s rocky nature.
Wherever you are on the planet, the Geminids are a fantastic way to bring the year to an end, and we will hopefully be treated to a magnificent display this year.
So I was right about my day when I spoke of it yesterday. Not a lot going on today, so today’s post will be more about yesterday. I hope that makes perfect sense to everyone – it sounded even worse with the original way I was going to write it (I was trying to be clever, so went for simplicity in the end).
The Punt at Bombah Point On the Punt
To get to Bulahdelah from Hole in the Wall, you need to go via Bombah Point and the ferry service there. I guess you could also call it a punt. Many people still call it that. Anyhow, as the pictures show, it doesn’t cover a great distance. How much is the charge for this journey – at the moment it’s $5.00 AU. Seems a little excessive for something that’s over in less than 5 minutes. Still, there is a…
Today was spent chiefly at Dorrigo National Park, where I spent nearly 5 hours on a bushwalk through the wilderness surrounding the Never Never Picnic Area. This is a spectacular area within the Dorrigo National Park. I could quite easily have spent far more time there trekking up both Sassafras Creek and Rosewood Creek. These are some wild streams that cut there way through the heart of the national park. Given all of the recent rain in the region, they were truly at their best today.
The new camera got a work out today, but I am not completely sold on it – though as a camera for panoramic photos it is fantastic and well worth buying for that function alone. The photo I have included with this post is of Rosewood Creek directly above Coachwood Falls. It is a brilliant place and very wild indeed.
I did pick up several leeches throughout the day, with one attaching itself to me just below the left knee. It wasn’t found for some time and had a good feed and I a good bleed after it was removed. Several more were found in my socks but they weren’t able to force their way through.
I’ll be working on the various photos and videos over the next week or so and putting together various packages for the website, Flickr, YouTube, the Blog, etc. There are some really terrific photos and videos among them. Hopefully today’s shot will whet the appetite for the rest of them.
Being the size that it is, it is hard to believe that Saolas are rarely seen. Not only is it rarely seen, but the Saola was only discovered in 1992. The Saola is best described as a large antelope-like creature.
The Saola lives in the mountains of the Laos and Vietnam border region.
One of these rare Saolas was captured by Laotian villagers in August 2010 and sadly died in captivity.