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Farmed Salmon Develop Ear Deformities All Around the World
By Roberta Attanasio Salmon farming is the fastest growing food production system in the world—accounting for 70 percent (2.4 million metric tons) of the market. Increasing demand is leading to the gradual development of responsible practices to minimize its negative impacts on the environment. Indeed, salmon farming is known to pollute the oceans, use toxic pesticides to control the spread of sea lice, foster diseases caused by viruses and bacteria, allow escapees, and deplete the stocks of forage fish—depending on the production region, 1.5 – 8 kilograms of wild fish are needed to produce one kilogram of farmed salmon. However, despite the development of the open and transparent production practices…
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Small Predator Diversity Plays a Significant Role in the Spread of Infectious Diseases
By Roberta Attanasio Biodiversity is a term coined to describe the diversity of all living things, from human beings to microorganisms. A New York Times editorial published almost two decades ago aptly describes the importance of the biodiversity concept: “Biodiversity is a hugely important concept that stresses the coherence and interdependence of all forms of life on earth and a new willingness to appraise the meaning of that interdependence, not just for humans but for every one of life’s component parts.” The editorial goes on to illustrate the alarming effects of biodiversity loss: “Biodiversity is a way of talking about what scientists have long understood and a way of reminding…
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Tasmanian Devils: Contagious Cancer Drives the Risk of Extinction
By Roberta Attanasio In November 2013, a team of biologists scattered 15 plastic cylinders in the fields of Maria Island, three miles off the east coast of the Australian island state of Tasmania. Each cylinder contained a healthy Tasmanian devil, a marsupial species that until then lived only in Tasmania. Soon, the 15 devils emerged from the containers, becoming the first ever to inhabit Maria Island. The biologists were planning to take more devils to the island. Why? To establish a healthy colony, needed for the survival of the entire species. The Tasmanian devil is on the brink of extinction because of an unusual disease — a contagious cancer that is spreading very quickly.…
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Ivory Poaching Drives the Global Decline of African Elephants
By Roberta Attanasio Poaching — the illegal killing of wild animals — is responsible for the death of tens of thousands of African elephants a year. Poachers kill elephants to hack off the tusks, which are then sold to make valuable ivory trinkets, mostly for Asian markets. In 2012, Jeffrey Gettleman wrote in the New York Times that Africa is in the midst of an epic elephant slaughter. How many African elephants, then, are slaughtered every year for their ivory? Results of a new study (Illegal killing for ivory drives global decline in African elephants) published a few days ago in the journal Proceedings of the National Academy of Sciences show…
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Minute 319: The Delta of the Colorado River Gets a New Life
By Roberta Attanasio For six million years, the Colorado River ran from the Rocky Mountains to the Gulf of California—through 1,450 miles of mountains, deserts, canyons, and the lush delta in Mexico. Now, it no longer reaches the sea. The once vast and fertile delta of the river is dry—a parched wasteland. In 1931, the United States Bureau of Reclamation built the first of a series of large dams along the lower Colorado River, which now provides water to two states in Mexico and 30 million people in seven U.S. states. Until the 1950s, the delta was still a network of freshwater and marine wetlands with meandering river channels—an opulent habitat…
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Wasting Syndrome and Starfish Die-Off
By Roberta Attanasio Up and down the U.S. and Canada Pacific coastlines, starfish are disappearing, dying by the millions of a mysterious disease that makes them “turn into goo.” The disease — starfish wasting syndrome — initially causes white lesions that lead to death of body tissue. Eventually, the arms twist and tear off — and they do not regenerate (healthy starfish may shed their arms, but then new ones are formed in a relatively short time). At the end, the entire body of the wasting starfish disintegrates. The wasting syndrome affects about a dozen starfish species, but has been noticed mostly in sunflower starfish (Pycnopodia helianthoides) and ochre stars (Pisaster ochraceus). Starfish…
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A Toxoplasma’s Journey: From Cats to Sea Otters
By Roberta Attanasio Toxoplasma gondii is a single-celled parasite that infects most warm blooded animals. In 2012, it landed in the news because of its ability to hijack the arousal circuitry of rats — the parasite activates a part of the brain normally engaged in sexual attraction. Rats infected with it are not afraid to approach cats and behave as they would in the presence of a sexually receptive female rat. What happens next? The cat easily catches and eats the infected rat and, in doing so, also catches the parasite — the parasite is happy as it reproduces sexually only in cats. The parasite’s oocysts — sometimes called “eggs”…
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Sustainability in Action: Christmas Trees Provide Habitat for Coho Salmon
By Roberta Attanasio There are many remarkable features of salmon, and one of these is their ability to travel thousands of miles in the ocean, struggle with river currents and waterfalls, and finally reach their hatching place. Indeed, salmon live in the ocean, but are born and spawn in freshwater rivers and streams. The young salmon spend at least some of their early lives in freshwater, before swimming to the sea — where they grow and mature. With a few exceptions, Pacific salmon spawn only once and die within days of digging their nests in the gravel and mating. Coho salmon — one of seven species of Pacific salmon — is famous for its…
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The Great Global Die-Off: Frogs and Lymphocytes
By Roberta Attanasio Frogs and other amphibians – salamanders and caecilians – have been declining worldwide during the past few decades at an alarming rate. According to a June 2012 assessment by the International Union for the Conservation of Nature and Natural Resources (IUCN), about 41 percent of amphibian species are at risk of extinction, and some are already extinct. Like many other inhabitants of our planet, amphibians have been hit hard by climate change and habitat loss – and not only. Amphibians have also been decimated by the spread of chytridiomycosis, which is defined by the IUCN as the single most devastating infectious disease of vertebrate animals. In a…
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Global Reforestation: How Likely Is It?
By The Editors Forests are plant communities dominated by trees and, because of their nature, rely on dynamic associations of living organisms that undergo constant change – deforestation may be easily followed by reforestation, either natural or man-driven. How likely is it that global reforestation will occur? According to a recently published study entitled “Outlook on a worldwide forest transition“, it is not likely. Results of the study indicate that — unless we substantially boost agricultural production or we consume less food — the forest cover of the planet will continue to decline over the next two centuries until it stabilizes at 22% of global land cover and 1.4% of wild pasture. In…
