Poo pump: whales as ecosystem engineers
Jul03

Poo pump: whales as ecosystem engineers

The brown cloud bursts forth among the pod of sperm whales, dispersing a wealth of nitrogen and iron into the surface waters over the deep ocean. The whale-borne windfall is eagerly received by phytoplankton, the microorganisms at the foundation of the ocean food chain, which quickly capitalize on the surge of fuel. Poop packs a powerful energetic punch. And an adult sperm whale packs a lot of poo. Enough to dump 50 metric tons of iron into the ocean every year, according to Trish Lavery and colleagues at Flinders University in Adelaide. Sperm whale poop is particularly rich in iron thanks to the whales preferred diet of squid and fish. Scarce iron is essential to the growth of phytoplankton, the photosynthesizing primary producers of the sea. (The other major source of iron in the ocean is wind-borne desert dust.) Sperm whales dive over 2000 meters to hunt squid, but defecate at the surface, transporting nutrients between ocean realms. Blue whales also act as a “whale pump”, diving to 150 meters to capture krill (small, shrimp-like crustaceans, which in turn feed on phytoplankton). The turbulence of diving, surfacing and exhaling stirs the water column as well. In their migrations, the baleen whales transport nutrients latitudinally, from the food rich summer feeding grounds of the polar oceans to the safer, but hungry, tropical waters. Mother Humpbacks fast through birth and lactation, burning through their summer fat stores, and leaving behind the waste products of their metabolism in the warm coastal waters. Great whales exert powerful effects on the environment as predators, prey, and bodies sinking to a final rest in the deep dark, sometimes boosting the productivity of ecosystems in non-obvious ways. The mass disappearance of the great whales in the last few centuries, leaving them at a tenth of their historical numbers, has likely changed the functioning of ocean itself. A group of marine ecology heavyweights led by Joe Roman review the science on the influence of whale on ocean ecosystems for Frontiers in Ecology and the Environment in an article published online today. Read more from the University of Vermont news site.   Joe Roman, James A Estes, Lyne Morissette, Craig Smith, Daniel Costa, James McCarthy, JB Nation, Stephen Nicol, Andrew Pershing, and Victor Smetacek (2014). Whales as marine ecosystem engineers. Frontiers in Ecology and the Environment (e-View 3 July; scheduled for August print edition) http://dx.doi.org/10.1890/130220  ...

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Animal-made art, medicine and language

An impressive work of wasp art is discovered in an ordinary attic, lizards that use venom to lower the blood pressure of prey could contribute to new medications, researchers translate prairie dog alarms and discover a language, contestants submit ideas for bridges designed to prevent wildlife from becoming roadkill and street art in China raises awareness of wooden chopstick waste. Here are stories in ecology and the environment from the end of January 2011. Intricate wasp nest design: Some wasps create nests by creating a paper-pulp-like material from saliva and wood fibers. The colorful nest pictured above was discovered by a plumber in an attic in the United Kingdom. Luckily for the photographer and the plumber, the wasps that created this massive nest had already abandoned their home by the time it was found.  Read more or visit the original photo stream on Flickr. Medicine from lizard venom: By surveying two dozen species of anguimorphs, researchers have found that some lizards previously thought to be nonvenomous actually are able to administer toxins. The results—published in the journal Molecular and Cellular Proteomics—provide insight into the venom delivery mechanisms of lizards. In addition, the researchers suggest the potential for developing new blood pressure medications. That is, peptides in the lizards’ venom immobilize prey by lowering its blood pressure. Read more at “Researchers take lizard venom to heart.” Prairie dog language: A recent National Public Radio (NPR) article, describes the work of Con Slobodchikoff of Northern Arizona University, who has been studying the warning calls of prairie dogs for 30 years. Using computer programs to analyze sounds, Slobodchikoff and colleagues have found that these social rodents have more than just a couple of alarms—they seem to have an entire language. At one point, the researchers recorded prairie dog responses to four humans dressed exactly the same except for the color of their shirts. As Slobodchikoff explained in the NPR article, “Essentially they were saying, ‘Here comes the tall human in the blue,’ versus, ‘Here comes the short human in the yellow.'” Read more and hear the calls at “New Language Discovered: Prairiedogese.” Wildlife crossing: Architects and designers submitted entries to the International Wildlife Crossing Infrastructure Design Competition to develop the most effective structure to transport wildlife across highways. The goal of the competition was to create bridges, tunnels and other paths that would encourage wildlife to safely traverse roads, thereby reducing incidents of vehicle collisions with wild animals. As described by The New York Times, the winning “bridge is broad enough to allow for strips–lanes, actually–that resemble forests, shrubs and meadows, with the aim of satisfying the tastes of any of the...

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From the Community: waste and the environment

Turning wasteful Styrofoam packaging into biodegradable, mushroom-based materials, the current news on Hungary’s alumina sludge disaster, Frito Lay changes back to original chip bag packaging after consumer complaints about the “eco-friendly” bags and cities wasting water and using new technology to turn wastewater into energy.

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