Biodiversity and sustainability along the Macintyre River in Inverell will be helped along with a dose of funding.
Macintyre River, Inverell, NSW. Photo: Cgoodwin, Wikimedia Commons
Inverell Shire Council has secured a grant for $13,625 to eradicate weeds from the river’s banks. The project will focus on woody weeds along an 800 metre stretch between Clive Street and the Tingha Bridge.
Removing weeds will make room for native vegetation, and improve fish habitat by providing shade, cover, water temperature regulation and a food source for native fish.
The funding comes from the NSW Department of Primary Industries, out of $570,000 awarded to recreational angling clubs, community groups, landholders and local councils for 30 fish habitat projects.
Minister for Agriculture Katrina Hodgkinson said projects cover many popular coastal and inland fishing spots in NSW, with nearly $1.1 million committed as in-kind support from the successful applicants.
“These grants are funded through the Recreational Fishing Trusts,” Ms Hodgkinson said.
“The program was highly competitive with 71 applications submitted and there was strong support by local recreational anglers for the applications.”
Weed control activities along the Macintyre River will be completed during 2014 and will include initial weed control and follow up spot spraying activities on any re-growth.
Inverell council general manager Paul Henry said the project is one of many identified when completing the council’s river plan. A river planner targeted 15 trouble spots.
Mr Henry said local community groups have expressed interest in addressing specific issues along the river.
“The Inverell Rotary Club put their hand up to look at the area near John Northey look-out/Kurrajong Park. They looked at repairing that area and planting out the areas with native plants to try to rejuvenate (it) and create a link all along the river for birds and animal habitat.”
He said the grant money will tackle invasive introduced weeds along the high bank level. Once cleared, replanting may begin.
Phil Sutton is the environment compliance co-ordinator for council and indicated the project has other benefits besides environmental restoration.
He said the project would help to increase public awareness about the weeds control and prevention.
“It’s an effort to provide a flow-on benefit to landholders and communities further down the river. Obviously if you don’t treat (weeds) now, they go further down the river.”
Contract sprayers will be engaged to treat the weeds and Phil said it will be a 12 month project with wildlife sustainability in mind.
“What the area will be treated with is a weed-control agent that is a bioactive control, which doesn’t affect the riparian area; it doesn’t affect the water or the frogs or anything like that.”
How do we get the most out of our marine reserves? The government is in the process of reviewing Australia’s network of marine protected areas. The review focuses on zones that exclude recreational fishers, and whether those fishers can be allowed back in.
While we don’t know much about oceans off north west Australia, we know they’re important. Photo: Australian Institute of Marine Science
However, fishing isn’t the only threat to marine life: oil and gas developments also influence offshore waters. Separating marine protected areas and regions with oil and gas potential leads to an unrepresentative reserve system. But working with oil and gas companies could work out both for industry and our ocean.
Like oil and water
Striking the balance between biodiversity conservation and industry is never easy. It is particularly difficult in regions that support both important biodiversity values and industry assets such as oil and gas resources and important commercial and recreational fisheries.
While the current management review will focus on fishing, a very different challenge exists in Australia’s northwest marine region. Here, some of the world’s most pristine and biologically diverse marine ecosystems overlay internationally significant oil and gas reserves.
Australia’s gas production has almost doubled since the turn of the century and is expected to quadruple by 2035. In a time of transition, following a decade-long mining boom, the government is seeking to maximise access to the nation’s oil and gas resources. With the majority (92%) of Australia’s conventional gas resources located in Australia’s northwest, finding the right balance between biodiversity conservation and industry interests is difficult and potentially expensive.
In fact, disasters have happened. In 2009, this region experienced the worst offshore oil spill in Australia’s history. The blowout from PTTEP’s Montara wellhead, located 250km off the Kimberley coast, resulted in 10 weeks of continuous release of oil and gas into the Timor Sea.
In total, the oil spill was estimated to cover an area of 90,000 square kilometres. Ongoing aerial spraying with dispersants was the primary early response to the spill with tens of thousands of litres of chemical dispersants sprayed into Australian waters.
We learned two very important lessons from the spill. First, the threat of an oil spill was realised and one of our most pristine and ecologically diverse marine environments was put at risk of irreversible damage.
Second, it highlighted what we don’t know. We lack the ecological data for the region to be able to identify and manage the impacts of an oil spill.
The proposed strict no-take marine reserves for Australia’s northwest leave many ecological communities unprotected. Image: Cordelia Moore
Protecting hidden reefs and biodiversity hotspots
After the spill, scientists hurried to start filling the gaps in what we know. While we lacked pre-existing ecological data, there was little evidence of a substantial impact from the oil spill. To improve this process in the future we now have some baseline monitoring sites in place. In addition, we have a new regulator focused on the implementation of more stringent oil spill response plans and risk management procedures and individual companies have had to upgraded their response and management plans.
One important discovery was the rich coral reef communities of the submerged banks and shoals. These abrupt geological features pepper the continental shelf and shelf edge. However, as these underwater mounds plateau beneath the sea surface they have previously gone unnoticed, hidden beneath the waves.
Intensive post-spill surveys revealed the shoals to support fish diversity greater that that seen on similar features within the Great Barrier Reef. They are also positioned to act as important stepping stones for biological connectivity across Australia’s north west and may serve as an important refuge for species vulnerable to climate change.
However, the current national marine reserves system offers almost no protection for these areas (less than 2% fall within the no take marine reserves).
“World’s largest marine park network”
The previous government aimed to create the “world’s largest marine park network”. With the current network falling just shy of 30% of Australia’s territorial waters, they came very close.
Although, as Bob Pressey detailed in his article on Australia’s marine protected areas, size isn’t everything.
Last month I lead a workshop at the University of Western Australia to assess the marine park network to the north west of Australia (north of Broome). The workshop included universities, government and industry.
During the workshop we assessed just how representative the marine parks of this region actually are. With little data available on biodiversity, we used the proxy of undersea geomorphology.
What we found is that of 19 different ecological communities, only four are adequately represented, two are over-represented, seven are under-represented and six aren’t represented at all.
Because we don’t exactly know what’s under the sea, we use geomorphology as a proxy. Image: Cordelia Moore
The most vulnerable section of our marine region is the continental shelf (less than 200m depth), where threats to biodiversity are concentrated. Despite this, the majority (75%) of the proposed no take areas focuses on the abyssal plain 3000-6000 metres below the surface.
Why? Protecting biodiversity to the north west of Australia comes with substantial opportunity costs to the oil and gas industry and commercial fishers. As a result, the proposed marine reserves of Australia’s north west have weighed heavily in favour of industry.
A way forward
With a reserve system already struggling to be representative, there are very real concerns associated with making any changes outside a robust conservation planning process. Currently the federal government proposes to maintain the outer boundaries of the marine parks network, while changing zoning within the reserves to allow recreational and commercial fishers access. But without closing alternative areas, this will only compromise our limited ability to manage threatening processes and conserve biodiversity.
Examining a small fraction of the problem will only ever provide a small fraction of the solution.
At the workshop in WA, we tried to come up with a better solution. We looked at a way to maximise representativeness, while minimising costs to user groups using an advanced systematic conservation planning approach.
Preliminary analyses demonstrated that entirely excluding whole regions prospective for oil and gas reserves makes a system of marine protected areas unrepresentative while including these regions makes a reserve system very expensive.
One cost-effective solution could be found for this region by bringing industry users into the management process and agreeing that prospective areas for oil and gas extraction are not incompatible with marine biodiversity conservation. Oil and gas developments often have stringent biodiversity protection targets and with people present on most sites all the time, enforcement of adjacent no take areas is potentially far cheaper.
The possibility for the oil and gas industry to be actively engaged in the protection of marine biodiversity may be a way of offering presently unrepresented marine ecosystems some level of protection too. In general the industry’s infrastructure footprint is quite small. Major oil spills from exploration and production activities world-wide are relatively rare with just one occurring on the west coast of Australia. While the risk is low, the consequences can be high. Therefore implementing multiple protected areas is one way of ‘hedging our bets’.
In a region highly valuable to industry the costs of biodiversity protection will be high if we continue to see oil and gas interests as incompatible with conservation. But leaving these unique ecosystems without management and protection may cost us even more in the long term.
Hugh Possingham receives funding from The Australian Research Council, The National Environmental Research program and several NGOs. He is affiliated with The Wentworth Group, Trees For Life SA, BirdLife Australia and WWF Australia.
Cordelia Moore and Euan Harvey do not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article. They also have no relevant affiliations.
Marine protected areas aren’t doing their job. Photo: Charlievdb/Flickr
Marine protected areas have been created across the globe to stem the loss of biodiversity in our oceans. But are they working? Now, thanks to a six-year survey involving over one hundred divers, we know that the global system of marine protected areas still has much to achieve.
Problems out of sight
The marine environment lies out of sight and is expensive to survey, so its true condition is very poorly known. What we do know is that multiple threats — most notably introduced pests, climate change, fishing and pollution — are pervasive.
We also know that conditions are deteriorating. Numbers of many Australian marine species have collapsed since European settlement. Some species haven’t been seen for decades, such as the smooth handfish, which was once sufficiently abundant to be collected by early French naturalists visiting Australia but hasn’t been seen anywhere for more than 200 years.
If this were a mammal, bird, reptile, frog or plant, it would be listed under Commonwealth and state threatened species acts as extinct. As a marine fish, it has not been considered for any list.
We also know that marine species that build habitat for other species are declining. Coral cover across the Great Barrier Reef has been reduced by about 25% between 1986 and 2004. Global seagrass and mangrove cover have declined by 30% over the past century, with losses accelerating. And oyster reefs have largely disappeared worldwide, as have giant kelp forest ecosystems on the Tasmanian east coast.
Fishery catch statistics also show major population declines in commercially important species such as scallops, rock lobsters, barracouta, trumpeter, abalone, warehou, gemfish and sharks.
These snapshots all consistently indicate major detrimental change in our oceans.
Surveying the threats
Twenty years ago, in a bid to understand the magnitude of this change, I and my Institute for Marine and Antarctic Studies colleague Neville Barrett began regularly surveying rocky reef communities in collaboration with management agencies across southern Australia. These surveys were focused inside and outside marine protected areas, to disentangle effects of fishing from broader environmental changes.
We found that each marine protected area was different. Recovery within protected areas depended on a variety of local factors, including protected area size and age, how much fishing had occurred prior to regulation, the type of regulations, and whether they were enforced.
To separate these individual factors properly required investigation of tens to hundreds of protected areas, many more than we could logistically cover with our limited scientific resources.
Coral reefs are the most diverse ecosystems in the ocean. Photo: Wilson Loo Kok Wee/Flickr
Enlisting citizen divers
This led to the idea of enlisting support from the recreational diving community, and our new study was born.
With pilot funding from the Commonwealth Environment Research Facilities program, and on-ground direction from colleague Rick Stuart-Smith, we sought help from experienced recreational divers across Australia who are passionate about marine conservation.
More than 100 divers agreed to donate their time, learning scientific underwater survey techniques, using their weekends and holidays to collect new data, and spending long hours afterwards identifying species and entering data onto computer spreadsheets.
To facilitate this program, an independent organisation called Reef Life Survey was established. It aimed to train and support member divers during field surveys, and to distribute information collected to improve knowledge and management of marine species. An incredible amount has been achieved over the past six years through the generous efforts of Reef Life Survey divers.
Most importantly, we have established a quantitative baseline describing the current state of inshore biodiversity around Australia. Numbers of more than 2500 species of fish, seaweeds and invertebrates (such as lobsters, abalone, sea urchins and corals) at more than 1500 sites have been documented.
This is the largest marine ecological baseline for any continent worldwide. It provides an invaluable reference that can be referred to through the future for tracking impacts of climate change, pollution, introduced species, and fishing.
The Reef Life Survey baseline has also now extended globally through collaboration with scientists in 18 countries, and with additional survey data collected by trained volunteer divers during their overseas holidays.
Clownfish and anemone. Photo: Paul from www.Castaways.com.au/Flickr
Parks on paper, not in the ocean
Still the question remains: how effective are marine protected areas at conserving marine life?
We recently analysed data from 40 countries to understand better the underlying factors that make marine protected areas effective as conservation tools, with results published in the journal Nature today.
We found no difference between fish communities present in most of 87 marine protected areas studied worldwide, when compared with communities in fished areas with similar environmental conditions.
Many protected areas thus seem to be “paper parks” — lines on the map that fail to achieve desired conservation outcomes.
However, some protected areas are extremely effective, with massive numbers of large fish and extremely high conservation value. These effective protected areas are typified by the same recurring features: no fishing, well enforced, more than 10 years old, relatively large in area, and isolated from fished areas by habitat boundaries (deep water or sand).
Protected areas with these characteristics, such as Middleton Reef off northeastern New South Wales, had on average twice as many species of large fish per transect, eight times more large fish, and 20 times more sharks than fished areas.
Getting marine parks right
Management agencies around the world clearly need to focus on creating more of these effective protected areas. At the same time they need to alter the design and management of the many existing protected areas that aren’t working. The few conservation gems are presently hidden amongst protected areas that are ineffective because of inadequate regulations or poor enforcement.
We also need to improve broad-scale environmental management more generally, considering how fast our oceans are deteriorating outside of protected areas.
Fishing is one of the last direct connections between humanity and the natural world. As a fisher who supports fishing, I see no incongruity in advocating that 20% of the marine environment be placed in effective no-take protected areas. Leaving 80% open to fishing hardly qualifies as threatening fishers’ interests.
Among other benefits, including acting as irreplaceable scientific reference areas, protected areas provide some insurance for future generations against ecosystem collapse.
I have little doubt that 50 years from now fishers will regret the slow pace of developing effective marine protected areas. They will also bemoan consequences of blanket opposition against any protected areas by some politicians and industry lobbyists, and an over-reliance of fisheries managers on computer models that attempt to maximise economic returns with little margin for error in an era of change when model variables increasingly fall outside known bounds.
Graham Edgar has received funds from Commonwealth and State agencies for research activities associated with marine conservation. He fishes, and many years ago worked commercially as a deckhand for an abalone diver. His University of Tasmania job is part-time, and diving surveys for the global study described here were undertaken in his spare time as a volunteer for the Reef Life Survey Foundation. He is also a director of an environmental consulting company, Aquenal Pty Ltd.
SUNSHINE Coast conservation groups have laid out the red carpet for thousands of turtle hatchlings due to hit local beaches in coming weeks.
Volunteers collected 220kg of rubbish yesterday, after scouring the sand from Shelly Beach to Buddina, and cleaning up the waterway around La Balsa Park.
Sunshine Coast Turtle Care, Reef Check Australia, Sunshine Coast Council, UnderWater World SEA LIFE Mooloolaba and members of the public teamed up for the first time to clean up for the turtle hatchlings.
Council conservation officer Kate Winter said cigarette butts, fishing debris, cans, clothing and hard plastics, including water bottles, were the most common items found.
“I truly am surprised by the amount that has come up here. It’s far greater than I had expected,” she said.
Ms Winter said the collection of hard plastics was the focus of yesterday’s effort.
“We want to make sure we get as many hatchlings out to the water and in 30 years back to our beaches as nesting turtles,” she said.
“Those hard plastics float on the surface and in the pelagic phase of a turtle’s life, that’s when they’re feeding on the surface.”
There are 23 nests from Shelly Beach to Buddina, each producing between 100 and 200 hatchlings in the next two months.
The first is due in the next couple of days.
UnderWater World animal health man-ager Emily Thomas said the last thing they wanted was for the turtles to head out into a “big sea of rubbish”.
Reef Check Australia community engagement officer Jodi Salmond donned her diving gear to clean up the Mooloolah River mouth from La Balsa Park.
She came ashore with bags of fishing debris, tackle, broken glass, cans and lots of degradable plastic bags caught among the rocks.
“It’s important to have an idea of what’s not just on the beach but what’s making its way into the water,” she said.
The clean-up information will be collated into the Australian Marine Debris Initiative database.
“When they autopsy turtles, we find out what’s in their guts and then we start to see what’s on the land and what’s in the water,” Miss Salmond said.
“We can start to source track where these things are coming from and how we can make real differences.”
Wayne Foster, from Golden Beach, was among the lay volunteers, cleaning up the northern tip of Bribie Island after finding a few turtle nests on his daily walk.
“A lot of people come and have a lovely day, but they’ll always leave two or three pieces behind,” he said.
“We try and go across and if we see something we’ll pick it up and bring it back.”
One of life’s great questions is about to be answered… “What’s going on below the surface of the Noosa River?” That would be the baffling question I’m sure we’ve all pondered for hours. Yes, I see you nodding as you read. Well, don’t worry, the Noosa Underwater Biodiversity Assessment—the NUBA—has begun its mission to find the answers.
Following the “think global, act local” mantra, my life’s ambition to film every fish in the Indo-Pacific (formally, the planet) has followed me home to the Noosa River.
Why film every species in the Noosa River? Would anyone even care? I reckon the reason people don’t care much about what’s underwater is that they never learned about it in school, and they can’t see it for themselves as they walk the dog on Gympie Terrace. Yet, I’ve rarely shown underwater footage without getting a “Wow, what’s that?”… with a further “And what’s that?” to my reply. The nudibranchs and ascidians and other mysterious critters that live in every square inch of underwater habitat are fascinating to learn about and observe. And since I’ve never seen any of the thousands of annual visitors or residents of Noosa scuba diving in the river (although I’m sure they are out there and I’d love to hear from them), I have to assume that most people don’t get in to see it firsthand. So it’s up to me to bring the vision up to the surface. To give a voice to my unseen little aquatic mates. To help my fellow fishermen have greater fishing success while leaving a smaller impact. To raise awareness with the locals and foster community-wide stewardship of the river.
Once we know what we have, and combine that with research into what we used to have (through historical fishing and other records), then we can begin to bring our river back to its former glory. Which means a healthier river and coastal ecosystem, with more and bigger fish for everyone. That’s my goal for every community, starting with my own.
Since moving to Noosa, our local diving efforts have been somewhat limited, mostly due to the closure of both dive operators and the unusually poor visibility from flooding that hit Queensland in recent years. However, select days over the past few months have provided some filming opportunities: when the moon and tides and winds combine to create those magic Noosa River days where kayakers and outriggers can see the river bottom over vast stretches of shallow seagrass and sand bars teaming with… what exactly? Not sure really. Flathead, whiting and bream… but what else?
Generations of fisherfolk and visitors know and proudly show what we can catch here, but there’s more to the system than that. What about the stuff that doesn’t take the hook or get caught in the net? Those other creatures that are quietly working away to keep our river ecosystem ticking nicely along?
This little highlights video shows some of what I’ve found so far, almost all filmed at the river mouth car park rockwall. My species count to date is 102 (73 of them being fish).
I’m fairly confident I can film the majority of the 122 previously recorded fish species, and most likely come up with at least a few more. I’ll be keeping the stats with links to the footage of each species updated on the NUBA webpage as the project progresses: http://www.underseaproductions.com/no…
This is a long term project that I hope will involve a wide range of river community groups, schools and businesses. My initial presentation to the Noosa Integrated Catchment Association (NICA) was enthusiastically received, and I’m looking forward to speaking to other members of the community over the coming months.
Last year was Australia’s hottest on record and this year started with heatwaves. Animals feel the heat too – so how will they cope and adapt as the climate changes?
Sea turtles and climate change are not a good mix. Photo: SteFou
Take, for example, sea turtles. These large reptiles have swum the oceans for more than 150 million years and survived numerous climatic changes, from warmings to ice ages. Yet human-induced climate change may lead to their downfall.
Historically, turtles were everywhere. They were so abundant in the Caribbean when Columbus first sailed to the Americas, it was said his crew complained of lack of sleep due to the continuous thudding as his ship bumped into sea turtles at night.
A species under threat
Today, sea turtles are threatened on a number of fronts. Rapid climate change expected in the coming century could seal their fate once and for all.
Over the past century, populations of all seven species have declined dramatically, according to the IUCN Red List. Over-harvesting of turtles and eggs, accidental capture by fisheries, pollution, and nesting habitat loss through coastal development, have all played their part.
Human activity is having disastrous effects on sea turtle populations. Photo: flickr/ SteFou
Add climate change to the mix, and sea turtles’ future is not looking bright.
As a reptile, sea turtles rely on their environment to regulate biology. Rising temperatures will disrupt a whole suite of different processes. Temperature impacts every stage of a sea turtle’s life – and as such, a rising global average will likely upset many important ecological and biological actions.
Girls like it hot
Temperature even controls the sex of sea turtle hatchlings. Instead of being set by genetic factors (such as X and Y chromosomes), the gender of a turtle is determined by the temperature that the eggs experience while in the nest.
So if sex is determined by temperature, how will global warming cause a problem?
Warming temperatures will heat beaches and make nests hotter. Hotter nests produce more females, to the point where there may be no males left at all.
In 50 years, sea turtle hatchlings may be all female. Photo: USFWS Southeast
Martina Fuentes from James Cook University examined green sea turtles nesting on islands along the Great Barrier Reef. She found that these beaches were likely to produce exclusively female offspring by 2070. Similar predictions exist for loggerheads in Western Australia and from our own results on olive ridley turtles from the Northern Territory.
Now we know what is happening, is there anything that can be done?
Couldn’t they just dig deeper?
This is the most frequent question we get asked about our research – along with “couldn’t they just move beaches or lay eggs in winter?”
These are important questions – much speculation has focused on whether the turtles will be able to change their behaviour to combat warming temperatures. However, these theories are difficult to test due to the very long lifetimes of sea turtles (think Crush in Finding Nemo).
Some of the possible behavioural changes also have issues associated with them:
Digging deeper: smaller turtles, with shorter flippers, cannot physically dig their nests any deeper. Digging deeper also takes longer. Beaches are risky places for lumbering sea turtles, and they can physically overheat or get eaten by big crocodiles.
Moving beaches: female sea turtles return to the beach they hatched from to lay their eggs. A change in beaches only occurs when a turtle makes a navigation mistake, which is unlikely to occur often enough to result in cooler beaches.
Changing the time of nesting: some evidence of changes in nesting time has already been shown. We speculate that warming oceans could alter signals to turtles so that they begin breeding at different times on the year – whether this will do any good, however, is yet to be established.
Considering that often mother turtles will sometimes nest in completely inappropriate locations (like in the water) – we must take their ability to choose the perfect location with a grain of salt.
What we stand to lose
The loss of sea turtles would be felt by humans and the environment alike. Sea turtles are an important part of their habitat, and in particular, they play a key role in the regulation of seagrass beds (a key habitat for a multitude of organisms).
Sea turtles are also important culturally. They are a significant resource for northern indigenous cultures in Australia, as well as being a highlight for many tourists visiting the Great Barrier Reef.
Understanding and predicting what will happen is the first step, but now we must plan for it. Unfortunately, management is difficult due to the widespread and remote habitat of these species.
Much like many other species, the survival of sea turtles now relies on humanity’s ability to reduce greenhouse gas emissions. This is the key step we must take if we want to mitigate disastrous effects on sea turtles and their habitat.
Tim Dempster receives funding from the Commission of the European Communities 7th Research Framework Programme, Norwegian Research Council, Herman Slade Foundation, Mazda Foundation, Fisheries Research and Development Corporation and the Norwegian Fisheries and Aquaculture Research Fund.
Ella Kelly is affiliated with The Conversation, working as an editorial intern on the Science and Technology desk.
Tim Jessop has received funding from the Mazda Foundation and ANZ Charitable Trusts.
Researchers have revealed the antics that hatchling crocodiles get up to when they think they are not being observed.
While some species use quite violent techniques to prove their dominance, others seem to be quite refined and gentle, says first author of the study, PhD student Matthew Brien from Charles Darwin University.
The shocking truth about how these young saltwater crocs behave after dark has been revealed. Photo: Jemeema Brien.
The research supported by Wildlife Management International is published today in PLOS ONE.
Little is known about the behaviour of crocodiles especially in their first year or two of life, says Brien.
Because hatchling crocodiles are so vulnerable to prey, they are more secretive and harder to observe than adults.
In a previous study, Brien and colleagues used “big brother style” filming techniques to study the interaction of juvenile saltwater crocodiles (‘salties’).
“The first night we filmed, we were shocked at the level of aggression and interaction in the salties,” says Brien.
Brien and colleagues decided to extend their research to looking at the social and aggressive interactions between juveniles from seven species of crocodiles and alligators from around the world.
They studied Australian freshwater and saltwater crocodiles, the American alligator, the South American dwarf caiman, a New Guinea freshwater crocodile, an Indian gharial, and a Siamese crocodile.
The researchers put animals in groups of four in an enclosed tank containing an area of water and then used cameras to observe what happened throughout the day and night.
During the two-year study they found that both male and female animals tended to have aggressive interactions for short periods of 5 to 15 seconds, mostly in the water, and mostly between the hours of 4 pm and 11 pm.
“While there are certain behaviours that are shared by a lot of species, some species have their own unique behaviours,” says Brien.
For example, he says the narrow-snouted Australian freshwater (‘freshie’) avoided getting its delicate thin jaws embroiled in arguments.
“They would raise their head out of the way when they engaged in any sort of battle,” says Brien.
To show its dominance, the freshie would climb on top of other crocs and push them down, while keep its vulnerable snout out of the way.
By comparison, the Australian saltwater crocodile used its broad snout to hit others over the head.
“More than any other species, the saltie would swing its head quite violently into the other like a side head strike and bite. They were by far the most aggressive,” says Brien.
Brien says these behaviours seemed to “instinctive and innate”, and were confirmed in saltwater crocodiles by comparing footage taken in the lab with that taken in the field.
“The next most aggressive was the New Guinea crocodile.”
To show its dominance, this species would raise itself up as far as its legs extended, and swish its tail violently from side to side as it chased and bit the other crocs.
“It’s basically a display to say ‘I’m coming to hurt you so you better get going’,” says Brien.
By contrast, the bizarre looking narrow-snouted gharial rarely interacted.
“The gharial are real sweethearts,” says Brien.
Juvenile alligators and Siamese crocodiles were also not aggressive.
“Siamese spent most of the time lying together and hanging out,” says Brien. “They would talk to each other, and lightly nudge or rub each other.”
Brien says such findings provide useful information for raising crocodiles in captivity.
“For example you can’t raise salties like you do alligators,” he says. “You can have more alligators in enclosures and they’re okay with each other, but salties are not as tolerant of each other.”
Knowing more about the behaviour of juvenile crocs could help optimise densities and design enclosures, for example with barriers or separate compartments, to improve survival of juveniles in captivity, says Brien.
An academic studying Australian water pollution, is encouraging people to use less single-use plastic products in order to reduce marine pollution.
The University of WA’s Julia Reisser says every square kilometre of Australian surface sea water is contaminated by around 4,000 tiny pieces of plastic.
A recycling symbol on the side of a water bottle. Julia Reisser is encouraging people to reduce single-use plastics such as disposable water bottles. Photo: Giulio Saggin, ABC News
The research found most of the particles were a result of a breakdown of disposable products such as water bottles, plastic cups and fishing gear.
‘The sun and the heat makes the plastic weaker and it breaks down with time,” she said.
“So let’s say a plastic bottle that someone throws at the beach goes into the ocean and as it gets older and older it breaks down into little particles.”
Ms Reisser says the plastics soak up pollutants, are harmful to marine life and also humans that ingest the seafood.
“When they are in the ocean it acts like a sponge for oil pollutants, for example fertilisers, so any oil pollutants that float in the water with the plastic will be attracted to the surface of the plastic and then this plastic is loaded with many kinds of pollutants,” she said.
“When an animal eats it, it can be released to the animal and will intoxicate the animal, not only in the animal that ingested the plastic but also any predator of this animal, so this problem can even come to us as we eat seafood.”
She says water bottles and plastic cups are a large part of the pollution.
“The solution is not simple and can involve more than one action, but I still believe that one important point is to decrease the amount of plastic waste that we are producing and to do so perhaps one of the easiest ways will be to decrease the amount of single use throwaway plastics that we use,” she said.
“We need to decrease plastic waste and toxicity, regulate plastic disposal on land at an international level, and better enforce the laws prohibiting dumping plastics at sea.”