* A Gulf in our Understanding * A Fish in Purgatory * Muscling Up for Mars * Fading Phytoplankton *

We're back after our summer break, and ready to launch our 36th season on CBC Radio - and Bob's 19th as host.  It was quite an eventful summer, science wise.
Oil slick in the Gulf of Mexico as seen from the International Space Station

One of the big stories was the successful effort to finally cap the Deepwater Horizon oil well, after months of futile attempts. The blowout last April caused an explosion that took 11 lives, and, of course, led to one of the worst environmental disasters in history.  This past week, BP released its report on what caused the explosion, and who they thought was to blame. But what scientists are continuing to investigate is what the impact of that massive flow of toxic of oil into the Gulf has been, and will be. And that's the focus of our feature documentary.  We also have another ocean-related study from this summer with both surprising and disturbing news about a massive worldwide decline is phytoplankton. We'll speak with the Canadian scientist who wrote the study. We'll also meet another Canadian scientist who studies what she calls "a mild-mannered super-hero" that lives in an oceanic purgatory.  Finally we'll hear why walking on Mars might be a physical impossibility for future astronauts.

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A Gulf in our Understanding

Last April, an explosion aboard British Petroleum's Deepwater Horizon oil platform in the Gulf of Mexico signaled the beginning of the largest marine oil disaster in history.  The blown-out well head, 1600 meters under water, gushed for 86 days, eventually pouring an estimated 4.9 million barrels of crude oil into the Gulf.  Five months later, scientists are starting to get a picture of what happened to all that oil, and what the impacts of the gigantic spill are likely to be.  

There's no good location for an oil spill, but according to Dr. Thomas Shirley, the Endowed Chair for Biodiversity and Conservation Science at the Harte Research Institute at Texas A & M University in Corpus Christi, this spill happened in one of the most species-rich areas of the Gulf, and threatened wildlife from the deepwater corals on the sea bottom to the seabirds on the surface, and from zooplankton to sperm whales.  

Part of the puzzle was understanding how the oil was spreading.  Even in a normal surface spill, oil has unpredictable behaviour because it's such a complex chemical mixture, according to Dr. Kelly Hawboldt, a Professor of Process Engineering at Memorial University in Newfoundland.  A spill 1600 meters below the surface, however, has even more exotic behaviour.  

Oil and gas under pressure, gushing from the well, created tiny bubbles in the water - a process probably accelerated by the chemical dispersant used by BP.  These bubbles created a giant plume of diluted oil in the water.  According to Dr. Kendra Daly, a Biological Oceanographer from the University of South Florida, the effect of this dilute oil on deepwater organisms, like zooplankton, was pretty much unknown.  So, much of the research she and her colleagues are currently doing is trying to understand the magnitude of the oil's impact on sea creatures.  

So far, the earliest results are suggesting that the impact might have been considerable, but it's difficult to anticipate how this will work out in the long term.  One piece of good news from the Gulf is that the dissolved plume of oil in the deep water seems not to have been very long lived.  Dr. Terry Hazen, Head of the Ecology Department at Lawrence Berkeley National Laboratory in Berkeley California, and his group, have found naturally occurring microbes in the plume that quickly digest oil.  Three weeks after the well was finally sealed, they could see no more trace of the oil plume in the water.  However, some of the heavier, less digestible oil will likely still remain in ocean sediments and wash on to coastlines around the Gulf for years to come.

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A Fish Survives in Purgatory

Bearded Goby, courtesy Hege Vestheim
The bearded goby is a fish that lives in the waters off the coast of Angola, Namibia and South Africa.  It is not a large fish, only about as long as your hand, but seems to possess remarkable, even super-hero-like qualities, according to Dr. Karin Pittman, a Canadian biologist at the University of Bergen in Norway.  It chooses to live in places where survival would seem remote.  During the day, it buries itself in, and actually eats some of the toxic mud on the bottom, where there is also methane gas and hydrogen sulphide, but very little oxygen. At night, it swims up to an oxygenated level where jellyfish live.  The umbrella of jellyfish provides protection: jellyfish eat a lot of other creatures, but are not interested in goby fish.  However, goby fish know what parts of the jellyfish it can safely nibble on.  But the real heroics of the goby fish may be the role it plays in transferring dead-end resources back into the food web.

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Muscling Up for Mars

Dr. Robert Thirsk exercising on the Space Station

A trip to Mars may be out of the question, at least until the problem of astronaut muscle atrophy can be solved.  Despite the fact that astronauts have a rigorous work-out regimen during their six-month stay aboard the International Space Station, the lack of load on some lower leg muscles, due to zero gravity, has a negative effect.  By studying before and after muscle fibres from ISS astronauts, Dr. Robert Fitts, a biologist from Marquette University in Milwaukee, found that the loss in mass, force and power translated into a decline of more than 40 percent in the capacity for physical work.  It is hoped that better fitness equipment, along with improved nutrition plans, will eventually solve this problem and even make the three-year round trip to Mars a reality. 

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Fading Phytoplankton

Marine diatoms - important phytoplankton, courtesy Dalhousie University
Phytoplankton, the single-celled photosynthetic plants that are ubiquitous in the oceans, are a huge and vital part of the Earth ecosystem.  They form the base of the marine food chain, they sequester carbon dioxide from the atmosphere and produce oxygen.  They are also, apparently, disappearing.  Dr. Boris Worm, a professor of Marine Biology at Dalhousie University in Halifax, and his group, have found that over the past half-century, phytoplankton abundance in the deep sea has declined something like 40% - approximately 1% per year.  This is an astonishing finding, and raises many important questions.  One is, why has this happened? Dr. Worm suspects warmer surface water temperatures, due to climate change, may be stratifying ocean waters and starving the plankton of nutrients found in deeper, colder, water.

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Theme music bed copyright Raphaël Gluckstein, Creative Commons License by-nc-nd-2.0