Hundreds of Japanese species have now rafted to the United States on debris following the 2011 Tōhoku tsunami—the biggest biological rafting event ever witnessed. Scientists say this is due to the rise of plastics and other synthetic materials, which create highly durable rafts. The 2011 magnitude 9.1 earthquake off eastern Japan created a tsunami of up to 40.5 metres. In the past six years, US scientists have collected 620 pieces of debris from the tonnes that washed up after crossing the northern Pacific Ocean. Within the debris were more than 300 species from Japan—invertebrates and fish, swimming in boat compartments. Larger debris such as buoys, crates, posts, beams, boats and docks supported a higher number of species. Some short-lived species bred for several generations aboard the debris. Life forms have always rafted to other continents, especially after natural disasters. But while natural rafts are made of materials such as tree and kelp debris, modern debris from coastal development contains non-biodegradable materials such as fibreglass and plastic—tough rafts that last longer distances. When it comes to spreading invasive species, say the authors of the study, published in Science, these rafts are even more effective than boat ballast. They are slow-moving, giving the hitchhikers aboard time to grow and adapt to new conditions, and they can wash up on pristine coastlines. Lead investigator James Carlton says this transporting of invasive species by marine debris is set to become more common, with the increase in climate-change-driven storms likely to send more debris into the ocean.
The smell of a certain molecule in blood makes humans and mice recoil in horror, but drives wolves and blood-sucking flies into a ferocious frenzy. It’s a rare example of a scent signal that has the same effect across distant species. The molecule E2D forms when blood is exposed to oxygen in the air, and it has a metallic smell—interpreted as a warning by some species, and as a sign of food by others. A study by the Karolinska Institute in Sweden, published in Scientific Reports, isolated the molecule from pig blood and studied reactions to the scent across species. When wolves were given a piece of wood smeared with the molecule, they acted as they would with a fresh kill—licking, biting and guarding it. Humans, given a whiff, would unconsciously act like prey: lean back on their heels, sweat and become stressed. The study’s authors say the molecule probably evolved when humans were most similar to small, peaceful, insect-eating primates—before Homo Sapiens began to hunt.
Bone cancer may soon be treated using robotics and a 3D printer. Robot-assisted surgeons will remove the diseased bone, and while the patient is in the operating theatre, technicians will scan the removed piece of bone, design an implant that matches it and print it in titanium 64, or another biocompatible metal. Then, the surgeon will implant it in the bone. That’s the idea, anyway. Just in Time Implants is a five-year project that has only just got under way—a collaboration between global medical company Stryker, two Australian universities and a Melbourne hospital. “Our aim is to bring the technology to the theatre,” says lead researcher Milan Brandt, from RMIT University. “While patients are having their cancer removed in the operating theatre, in the next room, we are custom-printing an implant to precisely fill the space left after removal of the diseased bone.”
What’s an albatross’s favourite food? New research looking at DNA in albatross droppings found up to 50 per cent of it was jellyfish. An international group of researchers studied eight black-browed albatross colonies dotted around the Southern Hemisphere, including one on New Zealand’s subantarctic Campbell Island. Certain types of jellyfish (hydrozoa and scyphozoa) had been devoured in 42 per cent of samples—and up to 80 per cent in some sites. Some jellyfish was even fed to chicks, which surprised researchers as jellyfish is low-energy food compared with fish. Moreover, albatrosses chose jellyfish whether jellyfish were blooming or not—or in other words, they were not just making do when fish were crowded out by a jellyfish bloom. Previous studies of albatross diet focused on their stomach contents—hard beaks of cephalopods, crustacean exoskeletons and fish bones. Gelatinous sea life wasn’t found, probably because it is digested quickly.
Half of the world’s forests lie within 500 metres from an edge—while 70 per cent have an edge less than a kilometre away. This is affecting forest-dwelling species, because a remnant doesn’t function in the same way as a larger piece of forest. Rather, a fragmented habitat usually loses half its plant and animal species within 20 years. Research published in Nature studied the edge sensitivity of 1673 species of mammals, birds, reptiles and amphibians in forests around the world and found 85 per cent of those were being affected by forest fragmentation. Forest edges are habitats that are hotter, drier and more exposed, compared to the forest core. Forest-core species, such as the Sunda pangolin, the long-billed black cockatoo, and Baird’s tapir, are being squeezed into tiny territories, and are more likely to be endangered. Core species must live at least 200 to 400 metres away from an edge—which means that to some, a forest 800 metres wide is no kind of home at all. Meanwhile, those thriving at the edges are more likely to be invasive species, such as the green iguana and the common boa.
Old barn owls have young ears, still sharp at an age when mammals would be deaf, according to new research by Germany’s University of Oldenburg. This is because all birds can regrow damaged hair cells in the inner ear, while mammals have lost the ability to do so. Barn owls (Tyto alba) locate and catch prey in darkness using their hearing alone, and their ears specialise in high frequencies—the region where humans and other mammals usually lose their hearing. When a range of barn owls of different ages were tested, all had flawless hearing—even an extremely old 23-year-old. Studies on elderly starlings and invertebrates have also shown inner-ear hair-cell regeneration. The human body has the ability to repair the ear’s vestibular system, which means that we retain our sense of balance, even in old age. Study author Ulrike Langemann says this suggests the genetic switch for hearing regeneration is still there in humans, but in “off-mode” for our inner-ear hair cells. The quest to switch it on is an active field of research.
Figuring out how to stop nutrients from fertiliser and animal wastes flowing from land into waterways is difficult, as it isn’t a question only of farming intensity, but also soil type, topography, groundcover, and a host of other variables. Now, a new software tool called LUCI—it’s short for Land Utilisation and Capability Indicator—can help predict run-off and offer solutions. Developed by Victoria University of Wellington researcher Bethanna Jackson (pictured), LUCI uses a farm’s geographic information system (GIS) data to estimate how much nutrient is entering nearby waterways. It does this by measuring ground cover, animal numbers, fertiliser amounts, slope, and soil types, in resolution up to five metres. Then it calculates the flow of water across and under farmland, and how much rain each part of the land can absorb. With this data, LUCI can predict how many animals each part of a farm can hold, and how much fertiliser can be applied, before run-off occurs. It also highlights areas where water could be slowed by features such as sediment traps, planting, or changes to tillage. If adopted widely, LUCI could later be used to predict the health of rivers and streams.
The Hunter Island penguin (Tasidyptes hunteri) was named in 1983 when four penguin bones were excavated from a midden on Hunter Island. Its ‘extinction’ was estimated to have occurred about 11,700 years ago. But the bones were in fact from other penguins, including two from New Zealand. Recent DNA analysis led by the University of Otago showed the bones were from three penguin species which are very much alive: the Australian fairy penguin, and two New Zealand species that are occasionally sighted in Tasmania, the Fiordland crested penguin and the Snares crested penguin. This year, ancient DNA has added species to the register as well as subtracting them. A new seabird, the kōhatu shag, and a native black swan, the poūwa—both extinct—were discovered by another team at the University of Otago.
Beneath Antarctica are thermal cave systems created by volcanic steam, where fungi and bacteria flourish. Now, researchers have discovered the remains of other life. Forensic analyses of cave soil on Mt Erebus by Australian National University researchers found DNA from mosses and green algae, as well as roundworms, earthworms, springtails, and an arthropod species unknown to science. Whether this life also exists in other caves remains to be seen, as Antarctica’s subglacial geothermal cave systems are little explored. Study author Ceridwen Fraser says there are more than 100 volcanoes in Antarctica, and many potentially have large caverns, subglacial ponds, streams or lakes. “There might be life, even unknown species, deep in the cave systems,” she says, but she’s quick to add that it will likely be similar to existing Antarctic life: “Mosses and small invertebrates—not Yeti.”
Tiny increases in the amount of carbon dioxide in the atmosphere caused dramatic changes in global temperature during the last ice age, according to new research published in Nature Geoscience. During an 80,000-year-long ice age that ended 20,000 years ago, global average temperatures occasionally shifted by as much as 15°C across a few decades. It was thought that this was caused by changes in glacial meltwater flowing into the Atlantic, which affected ocean circulation. However, this theory overlooked the effect of carbon dioxide on the oceans. Researchers showed that a rise in carbon dioxide, even an incremental one, could have prompted an El Niño, which would have warmed the eastern Pacific at the equator. This would have started a chain reaction, whipping up trade winds across Central America, which sucked moisture from the Atlantic, making it saltier and denser, kickstarting stronger ocean currents and causing warming across the entire North Atlantic region. Today’s tipping points are unknown, says study co-author Stephen Baker. The northern ice sheets are now much smaller, and have different dynamics. “If a system is close to the threshold and you don’t know that, it could make a sudden transition that you didn’t see coming,” he says. “We might not always have a lot of warning.”
Octopuses are solitary, except for when they breed. But gloomy octopuses (Octopus tetricus) have been spotted shacking up together in a mass settlement—for the second time. Up to 15 octopuses live within arm’s reach on rocky outcroppings in Jervis Bay on the south coast of New South Wales, in dens they have sculpted from shells and other remains of their prey. The settlement has been named Octlantis. The first one, discovered in 2009 with up to 16 octopuses and also located in Jervis Bay, was named Octopolis—and was considered an anomaly. It’s not clear why the octopuses have decided to keep close company. Interactions filmed between them involve antagonistic colour changes, morphing, and chasing.
Ancient whales had ferocious teeth—so how did some become baleen-bearing filter feeders? University of Monash researchers have shed light on this evolutionary mystery. Thirty million years ago, their theory goes, some whales began sucking in their prey instead of biting, slowly losing their teeth in the process until only thick, horny gums remained. A fossilied whale tooth, below, shows horizontal marks thought to have been caused by suction rather than biting. When the Antarctic Circumpolar Current formed, small prey boomed, and these more intricate gums filtered it better. Baleen was born.
Language and kapa haka are likely reasons for low rates of dementia among Māori.
Researchers have already figured out how to build infrastructure on Mars, in anticipation of humans eventually colonising the red planet. Using simulated Martian dirt, they created bricks stronger than reinforced steel. The researchers, from the University of California San Diego, say Martian habitats would ideally be constructed from locally available soil, with no additives or heat treatments. So they made a Martian-soil simulant, called Mars-1a, which had high amounts of nanoparticulate iron oxides and oxyhydroxides. (These are also the compounds which give Mars its reddish colour.) When compressed at high pressure, the nanoparticulate iron oxides bonded together, resulting in extremely strong bricks.
Turning over the soil to prepare it for planting is a fixture of the agricultural calendar, but it’s also devastating for earthworms. Conventional tillage uses a plough to invert the soil and bury weeds and leftover crops, but it also exposes earthworms to predators and harsh weather, compacts the soil, and destroys organic matter rather than leaving it to decompose. Afterwards, earthworm numbers take up to ten years to recover. By contrast, in land planted without tilling—usually by drilling seeds into the soil—earthworm numbers are 137 per cent higher, according to research published in Global Change Biology, which looked at 215 field studies from 40 countries, from as far back as 1950. Organic matter in the soil was also up 196 per cent. No-tillage is becoming more popular around the world, because it conserves soil structure and reduces erosion, although more herbicides are generally used to kill weeds. Anecic worms, which take food from the surface but dive deep between soil layers and set up permanent burrows, were particularly affected by conventional tillage, as were epigeic worms, which live in surface mulch. While earthworms found in cultivated land in New Zealand are non-native, these guests now have a critical ecosystem role, recycling organic matter, making nutrients more available to plants, and improving soil structure.
Tea plants make large amounts of caffeine and flavonoids compared to other varieties of camellia, and it does this it by copy-pasting particular genes like crazy. When scientists from China’s Kunming Institute of Botany sequenced the genome of tea, Camellia sinensis, they discovered it was unusually long. At 3.02 billion base pairs, it is four times the size of the coffee genome. More than half of these base pairs are ‘jumping genes’, which replicate themselves over and over again. Inside some of these repeated pieces of DNA are genes which make catechins, flavonoids and caffeine, and contribute to stress tolerance—all-important for flavour and for the adaptation of tea to plantation sites all over the world.
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