Living with Saltwater Crocodiles

Photo courtesy of Matt Clancy

Photo courtesy of Matt Clancy

Saltwater crocodiles are world-class hunters but less than enchanting neighbors. This lack of sociability drove the species close to extinction in the 1960’s. Their dramatic recovery and current stability is aided by a state program somewhere between ingenious and highly controversial.

Saltwater crocs, Crocodylus posorus to the experts, and “salties” to the locals, are the world’s largest reptiles. Salties get their nickname from their preference for brackish water. Their average length is an intimidating twelve feet, but there are confirmed reports of 20-foot males weighing up to two thousand pounds. They ambush their prey, generally employing the “pretend to be a log and then lunge” approach. Juveniles are limited to eating crustaceans and fish, but for adults nearly anything can be prey: monkeys, boars, and, regrettably, livestock. Several very publicized saltwater crocodiles attacks, including one where a 12-year-old boy was eaten, and another where an inadequately anesthetized zoo croc bit the arm off a vet, have contributed to their poor reputation.

Image Courtesy of Matt Clancy

Image Courtesy of Matt Clancy

Beginning in the 1940’s, crocodiles were hunted both for sport for the foolhardy and for their very valuable hides, culminating in a dramatic population decrease. In the Northern Territory the crocodile population plummeted from 100,000 to 5,000 over just a few decades. As a result, between 1969 and 1974 various Australian provinces completely banned recreational and commercial hunting, with exceptions made for subsistence hunting by Aborigines.

In 1969, a state-funded research crocodile farm in Queensland was erected to explore the possibility that crocodile farms could conserve saltwater crocodiles and provide employment for underserved populations. However, the ban on hunting endured until the 1990’s and is largely credited with the restoration of hardy salty populations. As a result, in the 1980’s crocodile attacks had become more commonplace, leading for calls to cull them. In response to this pressure, the crocodile management programs expanded to include education components, a job for some bold soul relocating troublesome crocodiles, and small-scale egg-collecting. Saltwater crocodile eggs are collected (an errand made complicated by protective and toothy mothers) and then sold to farms. Ultimately, the small number that hatch will be raised for their high quality leather and allegedly palatable meat.

Image courtesy of Tourism NT (http://www.travelnt.com)

Image courtesy of Tourism NT (http://www.travelnt.com)

In the mid-80’s, several populations of saltwater crocodiles in Australia were moved from Appendix I to Appendix II of CITES (Convention on International Trade of Endangered Speices). For the uninitiated, legally, harvesting saltwater crocodiles was no longer banned, just highly monitored. In response, collections scaled up to tens of thousands of eggs from the wild. In the mid 1990’s, limiting hunting of juvenile and adult crocodiles was permitted in the Northern Territory. Crocodile populations have continued to grow these past few decades behind this.

The philosophy behind these rulings is referred to as “sustainable economic use.” Landholders have limited and relentlessly regulated rights to crocodiles nesting, living, and inevitably hunting on their property. They can sell their crocodiles to leather and meat farms. This makes coexisting with salties profitable, if terrifying. Though saltwater crocodiles remain horrific tenants, at least now they’re paying their way. This model is still too young to have proven itself, but is certainly intriguing. If proven successful it may be applied to nightmare-inducing animals with human neighbors worldwide.

Image Courtesy of Brocken Inaglory

Image Courtesy of Brocken Inaglory

 

 

The Wisdom of Sea Urchins

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Black sea urchin courtesy of Wikimedia Commons user Lucen.

By Frances Hall

Sea urchins are almost comically unlovable: covered with spines that are known to break off within an unwary wader’s foot, eyeless and faceless, a mouth that looks like a jagged abyss, difficult to empathize with, distinctly un-cuddly. However, new research suggests that, when it comes to solution to climate change, we should have gone to them first.

For those few of you who haven’t yet heard: climate change, a process that experts from every natural science agree is caused by human activity,  is due to a collection of emissions known as greenhouse gases. The effects of these include global warming, ocean acidification, ozone layer depletion, and, possibly down the line, a new ice age in Europe. Arguably, the most insidious greenhouse gas is carbon dioxide (CO2). Carbon dioxide is produced by a number of processes, from heavy industrial process and driving most cars to the unavoidable pastimes of breathing and volcanic eruptions. What’s Your Impact? estimates that 87 percent of all human-produced emissions, which total an average annual 33.4 billion metric tons, originate from burning fossil fuels. Several countries, despite the political rigmarole and pervasive ignorance that surrounds the entire issue, have signed treaties or laws agreeing to limit their carbon emissions. The fact that many (but not all) of these countries ultimately put off reducing carbon emissions for the sake of the economy remains discouraging. There are a number of ways to slow this process, many of which a single person could elect to do: relying on solar panels or windmills instead of coal, taking the bus, even just eating less meat.

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A dissected sea urchin with visible eggs. Photo courtesy of Achim Raschka.

Unfortunately, none of those steps are going to eliminate the carbon dioxide that’s already in the atmosphere. Several natural processes, such as photosynthesis and carbon fixation, can, and do reduce atmospheric CO2. However, they simply cannot keep up with the rate of human emissions. One proposed solution is Carbon Capture and Storage (CCS). According to the Global CCS Institute, this involves the separation of CO2 from other gases at the source, such as steel mills and coal plants. The CO2  is then compressed and transported to a more suitable site. Finally, it is injected into underground rock formations, often at least 1 km below the surface. The idea is that the  CO2 will remain there indefinitely. However, this is just as expensive as it sounds and there is always the possibility that the CO2 will leak out at some later date.

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Chalk quarry in Crete. Image courtesy of Wikimedia Commons user Wouterhagens.

Sea urchins may be showing us an alternative. Physicist Dr. Lidija Siller was studying the reaction that combines gaseous CO2  and ocean water into carbonic acid, the process that leads to ocean acidification and all of its diversity-crushing side effects. She was also investigating how sea urchins convert CO2  into calcium carbonate shells. When her team analyzed the surface of sea urchin larvae, they found a high concentration of nickel nanoparticles. When tiny particles of nickel were added to a carbonic acid solution, the result was a complete removal of CO2  with only water and calcium carbonate, also known as chalk, as products.

The team has patented this into a process where waste gas from industrial processes is passed through a water column rich with nickel particles where the chalk will gather at the bottom. This appears to be a nearly ideal solution: chalk is a stable material widely used to make products as varied as cement and plaster casts the nickel particles could theoretically be reused indefinitely. It wouldn’t be possible to attach one of these to every bus and truck, but these could be used to reduce carbon output from most major source. According to Dr. Lidija Siller via BBC news, “It seems too good to be true, but it works.”

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Water melon sea urchin. Image courtesy of Marco Busdraghi.

Saving Penguins after Oil Spills

Rena_Spill_Cleanup New Zealand Defense Force

Rena Spill Clean-up. Photograph courtesy of New Zealand Defense Force.

By Frances Hall

At first, the story is familiar: an unnamed sea captain is defined by his moment of carelessness and the enduring consequences that followed. His ship, the Rena, was 775 feet long and heavily burdened with shipping containers, several of them full of hazardous materials. She ran aground a mapped coral reef near the Port of Tuaranga on the North Island, near New Zealand. The collision caused several stress fractures along the bottom of the Rena. As a result, she tilted to the side, losing several non hazardous shipping containers. Oil started to leak into the surrounding waters, known to be a preferred locale for whales, dolphins and penguins. Worse, bad weather prevented any serious efforts at controlling the oil spill for almost a week. Consequently, various estimates state that about 234 tonnes of oil, enough to fill three or four 21-foot long pools, leaked into the ocean before the leakage was controlled. According to several articles, the Environment Minister of New Zealand, Nick Smith, called it “New Zealand’s worst environmental disaster in many years.”

Seabirds were especially affected by the disaster. According to ABC news, a mere two weeks after the disaster an estimated 1,000 seabirds had already died. Many of the dead seabirds were charismatic Eudaptyla minor, commonly known as the Blue or Fairy Penguin. All birds have feathers, however those on penguins are distinct–they are incredibly dense and of various lengths, interconnecting into a natural wetsuit. According to Kevin McGowan of Cornell University Lab of Ornithology, via ABCnews.com, even  a single drop of oil on this feather coating can compromise it, “It’s like a hole in the penguin’s wetsuit.” Hunting in water is essential to the survival of these birds, yet if they’re oil-coated, both the water and cold can penetrate. Additionally, any oil incidentally ingested can be just as detrimental.

Fairy_Penguin_Cat

Photograph courtesy of Cat via Wikimedia.

The solution to preventing these effects following an oil spill seems obvious: remove the oil from the birds. However, this process is more involved and finicky than is generally known. Prior to washing, the penguins are kept overnight, in order for them to rest and better handle the stress of being scrubbed. Since the oil from the Rena was especially thick, the Fairy Penguins were initially hosed down with canola oil to break up the larger bits of oil. The penguins were then scrubbed carefully with specially imported detergent. During the average washing, the water is changed four or five times. The detergent is then washed off, and the penguin is checked for any missed spots. One vet is required just to hold the bird still. Washing takes 45 minutes to an hour per bird. Finally, the bird is sent to live in a clean water tank until healthy enough to be released.

The waiting period is a part of the problem: an oil-soaked bird can die in the queue. Nearly every species of bird has an uropygial–oil–gland in the small of its back. Birds use their beaks to stimulate and spread the oil from this gland around their feathers, an essential behavior referred to as preening. However, when oily birds preen their contaminated feathers, they can ingest oil, thus poisoning themselves. The common practice to address this sounds like something a Barbie fan club rather than a scientific committee would have come up with: tiny, adorable, penguin-sized sweaters. When these sweaters are put on penguins awaiting release, they are unable to preen themselves through the wool, preventing the oil ingestion.

Fairy_Penguin_Whalespotter

Photograph courtesy of Whalespotter via Wikimedia.

A Kiwi yarn shop, Skeinz, put out a knitting pattern and a call via the Internet to the crafty and concerned. And the Internet stepped up. An October 17, 2011 headline from the shop’s blog reads “It’s raining jumpers” and, without listing any precise numbers, refers to the number of sweaters received as a “deluge.” An article posted later that same day, a mere 12 days after the oil spill, stated that the shop had reached “critical mass” of jumpers. The excess jumpers that continued to pour in after this announcement were either saved for the next disaster, or put on stuffed penguins that were sold to raise money for on-the-ground efforts to aid spill clean-up.

Two years later, the wreck of the Rena has not been fully salvaged. However, the surrounding beaches seem to be completely tar-free. Early research suggests that both the immediately adjacent beaches and surrounding islands have recovered very well. A more intensive 18-month study by University of Waikato Professor Chris Battershill will hopefully reveal more.

Saving Coral Reefs

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Coral Reef in Timor. Photograph courtesy of Nick Hobgood.

By Frances Hall

Coral reefs provide a number of services to humans beyond colorful aquarium accessories: they protect coastlines from storms, provide an enormous variety of unique medicinal compounds, and support the economy of many developing countries through tourism. Furthermore, the fish that the coral reefs support are a source of vital income and calories: one study estimated that a quarter of the food of 1 billion Asians is reef-supported fish. It will come as no great shock that human activities imperil these reefs in a number of ways,

Carbon dioxide, the primary greenhouse gas, does more than trap heat in the atmosphere. About one quarter of all Carbon dioxide emissions are dissolved into the ocean, where they trigger a reaction that ultimately reduces the available carbonate in ocean water. While this may not sound dire out of context, calcium carbonate forms the skeletons of reef-building coral as well as shelled marine animals, such as urchins and oysters. (Coral refers to the living organism and reef refers to the rocky structure they live on, primarily formed by the skeletons of coral). The lack of it leaves these animals unable to excrete a shell, making them unlikely to survive, and can cause the structure supporting a coral reef, comprised of coral skeletons, to collapse.

Bleached Moofushi Coral

Bleached Musifi Coral. Photograph courtesy of Bruno de Guisti.

Corals also respond poorly to rising sea level temperatures. Many corals have living within them: the corals provide shelter, and the dinoflagellates convert sunlight into as much as 95 per cent of the energy its host requires. Often, in a misinformed stress response to heat, corals expel their dinoflagellates, the equivalent of kicking out all your renters the same day you lose your job. This leads to the often-pictured “coral bleaching” because corals without their boarders are pale and usually dying. If this heat stress is mild, corals can often regain their dinoflagellates before irreparable harm is done. Regrettably, climate change is rapidly reaching a point where “mild” will no longer describe the resulting temperature changes.

These findings beg the question: are coral reefs even capable of recovering from such damage? Natural weather events give scientists an excellent opportunity to study this. El Niño happens every two to seven years and is characterized by warmer waters in certain areas, with far reaching effects on both land and sea. In both 1982 and 1997 there were unusually severe El Niño cycles, characterized by temperature fluctuations greater than two degrees Celsius, that lasted for months. This forces corals to exist temporarily under conditions that climate change may one day make permanent. A 2004 study looked at sections of a coral reef in the Cocos Island that had been severely impacted by the 1982 El Niño to the point that certain sections only had three per cent live coral cover. The heat stress of the El Niño had bleached and ultimately killed most of the live coral on the reef.

Palmyra Atoll Coral Reef

Coral at Palmyra Atoll. Photograph courtesy of Jim Maragos of the US Fish and Wildlife Service.

In 2004 scientists calculated live coral cover on these same reefs. Some reefs collapsed and one showed no measurable recovery at all. However, others exhibited and average live coral cover of 18 to 21 per cent, an enormous gain in only twenty years. One coral reef had increased to 50 per cent live cover. Furthermore, in some reefs coral diversity, arguably a good measure of reef health, had increased with the appearance of three coral species that hadn’t previously been seen off the Cocos Island. These findings led the scientists to conclude that reefs “have the capacity to recover from severe disturbances” and even increase diversity in the face of them.

Florida Coral Reef

Florida Coral Reef. Photograph courtesy of Jerry Reid of the Fish and Wildlife Service.

To accept the conclusions of one study as absolute truth is to live in a desert and assume you’ve seen every kind of plant. Still, even if these findings only apply to the Cocos Islands, or certain kinds of coral, they are cause for celebration. Previous studies estimated that coral reefs would need lifetimes or even centuries to recover. It’s not too late, and as long as there are even patches of healthy corals it probably won’t be. We can still fix this, so of course it’s worth it to try.

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Frances

Francis has just joined the team at The Ecotone Exchange. She currently works as an outdoor educator at the Pali Institute in Running Springs, California. She graduated earlier this year from Earlham College with a B.A. in biology. In her spare time she hikes, runs, sings, cooks, and reads many, many books.