Rare coral species may be saving themselves from extinction by hybridising with other coral species, says Australian scientist Zoe Richards. Richards and his colleagues have studied 14 rare[1] and eight common coral species of the genus Acropora in the Indo-Pacific.

In order to find out more about hybridisation among corals, the team did a phylogenetic analysis using the highly polymorphic single-copy nuclear Pax-C 46/47 intron and the mitochondrial DNA (mtDNA) control region as markers.

The analysis showed that many of the rare species are polyphyletic for both Pax-C and mitochondrial phylogenies, and this is seen as a clear sign of interspecific hybridisation.

The results of the study “Some rare Indo-Pacific coral species are probable hybrids” by Richards, Oppen, Wallace, Willis and Miller were published in a recent issue of the journal PLoS ONE[2].

In their paper, the authors explain how “[t]he results presented here imply that a number of rare Indo-Pacific Acropora species are the products of recent hybridisation events, and highlight the significance of hybridisation in coral diversification. Whether these species have hybrid origins or have evolved and then hybridised in the absence of conspecific gametes remains to be elucidated.”

“In summary, although it has often been assumed that small populations have a decreased potential for adaptation, our analyses imply that some rare acroporid corals may actually have increased adaptive potential as a consequence of introgressive hybridisation, and therefore may be less vulnerable to extinction than has been assumed.”

Vast amounts of creatures looking like jelly balls have begun to appear off the eastern coast of Australia, and researchers now suspect that these animals may help slow down global warming by moving carbon dioxide from the atmosphere to the ocean floor.

The proper English name for this “jelly ball” being is salp. A salp is a barrel-shaped free-floating tunicate that moves around in the ocean by contracting and relaxing its gelatinous body. Just like the other tunicates, the salp is a filter feeder that loves to eat phytoplankton and this is why it has caught the attention of scientists researching global warming.

Phytoplankton are famous for their ability to absorb carbon dioxide from the top level of the sea, and a salp feasting on phytoplankton will excrete that carbon dioxide in the form of faeces. The faeces will drop to the ocean floor; thus lowering the amount of carbon dioxide present in the upper part of the ocean. Since the carbon dioxide found in this level of the sea chiefly hails from the atmosphere, phytoplankton and salps are a great aid when it comes to removing carbon dioxide from the air. Salps will also bring carbon down to the ocean floor when they die, which happens fairly often since the life cycle of this organism is no more than a few weeks.

Salp species can be found in marine environments all over the world, but they are most abundant and concentrated in the Southern Ocean near Antarctica where it is possible to encounter enormous swarms of salp. Over the last 100 years, krill populations in the Southern Ocean have declined and salp populations seem to be replacing them in this cold ecosystem. According to researcher Mark Baird of the Australian Commonwealth Scientific and Research Organization (CSIRO), the amount of salps in the waters off Australia are also on the increase, at least according to a survey carried out last month by CSIRO and the University of New South Wales.

While salp may help slow down global warming, their increase may also cause problems. Salp has a fairly low nutrient content and salps replacing nutrient rich krill in the Southern Sea may therefore prove detrimental for oceanic animals higher up in the food chain.

According to University of Queensland marine biologist Professor Ove Hoegh-Guldberg, recipient of the prestigious Eureka science prize in 1999 for his work on coral bleaching, sea temperatures are likely to rise 2 degrees C over the next three decades due to climate change and such an increase will cause Australia’s Great Barrier Reef to die.

Hoegh-Guldberg’s statement is now being criticized by other scientists for being overly pessimistic, since it does not consider the adaptive capabilities of coral reefs. According to Andrew Baird, principal research fellow at the Australian Research Council’s Centre for Excellence for Coral Reef Studies, there are serious knowledge gaps when it comes to predicting how rising sea temperatures would affect the coral.

Great barrier reef

“Ove is very dismissive of coral’s ability to adapt, to respond in an evolutionary manner to climate change,” says Dr Baird. “I believe coral has an underappreciated capacity to evolve. It’s one of the biological laws that, wherever you look, organisms have adapted to radical changes.”

According to Dr Baird, climate change would result in major alterations of the reef, but not necessarily death since the adaptive qualities of coral reefs would mitigate the effects of an increased water temperature. “There will be sweeping changes in the relative abundance of species,” he says. “There’ll be changes in what species occur where. But wholesale destruction of reefs? I think that’s overly pessimistic.”

Marine scientist Dr Russell Reichelt, chairman of the Great Barrier Reef Marine Park Authority, agrees with Dr Baird. “I think that he’s right,” says Dr Reichelt. “The reef is more adaptable and research is coming out now to show adaptation is possible for the reef.”

Professor Hoegh-Guldberg responds to the criticism by saying that the view “that reefs somehow have some magical adaptation ability” is unfounded. He also raises the question of how big of a risk we are willing to take. “The other thing is, are we willing to take the risk, given we’ve got a more than 50 per cent likelihood that these scenarios are going to come up?” professor Hoegh-Guldberg asks.”If I asked (my colleagues) to get into my car and I told them it was more than 50 per cent likely to crash, I don’t think they’d be very sensible getting in it.“

As we release more and more carbon dioxide from fossil fuel into the atmosphere, the world’s oceans become more and more acidic. Exactly how this will affect marine life remains unknown, but a paper published this week by marine chemists Keith Hester and his co-authors at the Monterey Bay Aquarium Research Institute is now shedding some light on how a change in acidity affects sound waves under water.

Beluga Whale

So, why is the speed of sound underwater of any interest to Monterey Bay Aquarium researchers? As sounds travel faster, the amount of background noise in the sea will increase and this could affect the behaviour of marine mammals. Many marine mammals, such as whales, dolphins, and porpoises, relay on sounds for communication and food location.

According to conservative projections by the Intergovernmental Panel on Climate Change (IPCC), the chemistry of seawater could change by 0.3 pH units by 2050. According to Hester and his colleges, such a change in acidity would allow sounds to travel up to 70 percent farther underwater in some areas, especially in the Atlantic Ocean. The paper also states that sound may already be travelling 10 percent farther in the oceans than it did a few centuries ago.

According to Hester et al, a change by 0.3 pH units by 2050 will have the greatest effect on sounds below about 3,000 cycles per second. This range includes most of the low frequency sounds that marine mammals are known to use, but it also includes a lot of sounds produced by human activity, such as boating, shipping, and certain military activities. As if acidification of the ocean wasn’t enough, the amount of underwater sound produced by human activities has increased dramatically over the last 50 years. So, even if acidification would make it possible for sound produced by marine mammals to travel farther than ever before, it might also cause these sounds to be effectively drenched by a cacophony of human generated low frequency noise. In such a noisy sea, a marine mammal’s ability to locate prey animals and a suitable mate and could be severely impinged on.

The paper will be published in the October 1, 2008 issue of Geophysical Research Letters.

Tidal movements involve immense amounts of energy and are as reliable as, well, the tide. If we could find an efficient way of harnessing these mammoth forces, tidal action might become an important source of renewable energy for populations world wide. With this in mind, a team of engineers from Oxford University have worked together to develop a new and more robust turbine design that will make it both easier and more cost-effective to take advantage of this natural resource.

The turbines developed by the research team have been labelled “second generation” tidal turbines since they are less expensive to build and maintain compared to traditional tidal turbines, and capable of harnessing more energy. Unlike today’s underwater turbines – which are built like underwater windmills with blades that turn at right angles to the flow of water – these second generation tidal turbines are centred on a cylindrical rotor which rolls around its long axis as the water ebbs and flows. The Oxford team calls their new creation Thawt, short for Transverse Horizontal Axis Water Turbine.

Producing enough energy for 12,000 average UK family homes using traditional turbine design would today require 10 generators and five foundations. With the new Thawt, only one generator and three foundations would be enough, according to estimates done by the Oxford team.

Steph Merry, head of marine renewable energy at the Renewable Energy Association welcomed the new design but also cautioned against the costs of environmental monitoring to safeguard the ecology of tidal areas. “We have to get it in proportion, you can’t have an unlimited budget for environmental monitoring when every engineering company has to work to a budget for any project. At the moment, there is no limit to the monitoring that can be imposed.”

A carbon capture and storage facility has been built at the Schwarze Pumpe coal-fired power plant in Germany. The facility is built as a test to see how well the technology work and will be ran as a pilot project over 3 years. Another test facility will be built in France next year.

The carbon capture and storage facility uses a technique where coal is burned in pure oxygen and CO2 instead of regular air. This results is a by product of almost pure CO2 that can be collected and stored underground. The test facility in Germany is expected to capture up to 100,000 tons of CO2 each year. The CO2 is to be stored in a nearby gas field. The power plant the new carbon capture and storage facility has been built at produces 12 MW of electricity and 300 MW of thermal power which sustain about 1000 homes. The potential capture of 100,000 tons CO2 from this power plant alone might show the effect carbon capture and storage facilities might have on global CO2 emissions if they are found to be effective. Experts do however expect it to take a long time, at least 10 years, before this technology gains widespread use. Some experts also raise security concerns about the technology and the practice of burying large pure CO2 deposits underground.

It is claimed that this is the first carbon capture and storage facility in the world but I am unsure about this as Norway supposedly have been depositing CO2 underground for years. Anyone that can shedd some light on this is welcome to comment.

Researchers at Arizona State University have received a $3 million grant to further develop their aviation fuel derived from algae. The development of algae jet fuel is already progressed quit far and researchers have already moved past the laboratory stage and are working on a pilot project to scale the process. They hope to be able to create large quantities of economically competitive jet fuel as soon as possible. The research team says that cost reduction benefits are greater than with kerosene produced from petroleum.

The breakthrough in the research to create algae jet fuel came when the researchers identified algae strains that can convert pieces of their cellular mass into oil containing high concentrations of medium chain fatty acids. The hydrocarbon chains that are created when the oil is deoxygenated are very similar to those created when regular kerosene goes through the same process.

Researchers hope that this type of jet fuel might end up being cheaper than regular kerosene based jet fuel as an expensive process (thermal cracking) isn’t necessary to make jet fuel from algae oil.

The new fuel can be used in most jet planes when mixed with a small amount of fuel additives.

I will post a more complete introduction to algae oil before the end of this week. (I Hope)

European Union

In December 2007, the EU commission presented their suggestion for a new law that would force car manufacturers to decrease the average carbon dioxide emissions from new cars down to 130 grams per kilometre by 2012. This draft does however come with one gigantic loop hole – the new law would only target cars weighing less than 2,610 kg (5,754 lbs). This could actually prompt car manufacturers to start building even heavier cars than today, just to avoid the new law. Another possible escape route is to make slight alterations to the cars in order to make it possible for them to be registered as light trucks. When a similar law was put into action in the United States during the 1970s, car manufacturers immediately responded by producing large quantities of SUVs that could evade the law by registering as work vehicles. The Swedish Society for Nature Conservation (SSNC) is now urging the EU parliament and the national governments to take action and remove these loop wholes from the final draft of the law.

By moving from the surface of the sea down to deeper layers, Antarctic krill transport carbon down from the surface to the depths of the ocean. Scientists from the British Antarctic Survey (BAS) and Scarborough Centre of Coastal Studies at the University of Hull have now discovered that Antarctic krill venture between the surface and the deep sea several times per night. Earlier, they were believed to do so only once per night. The more times they head for the deep with their bellies filled, the more carbon they will remove form the surface, so this is interesting news for anyone worried about too much carbon in the atmosphere and upper ocean. According to Dr Geraint Tarling from BAS, Antarctic krill transport an amount of carbon equivalent to the annual emissions of 35 million cars.

Krill swims to the surface to feed on phytoplankton (which must stay fairly close to the surface since they rely on photosynthesis) but they do not spend all their time close to the surface because that would make them easy targets for predators. Instead, krill regularly sink down to greater depths where the risk of being eaten is lower. When krill excrete carbon rich waste products at such depths, the waste will sink down to the ocean floor.

Other studies have shown that adding iron to the water could allow the krill populations to increase in size which would cause them to remove more CO2 from the atmosphere. Adding iron can also help trigger algae growth that further removes CO2 from the atmosphere and can help fight global warming. We do however know too little about the potential side effects of adding iron to the water to make it a viable alternative at this time.

In the United States, the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service (NOAA) have decided to investigate if the ribbon seal should be protected by law, according to an article in the San Francisco Chronicle. NOAA will also investigate the situation for three other species of ice seal: the bearded seal, the spotted seal and the ringed seal. The decision is a response to a petition from the Center for Biological Diversity, a San Francisco based environmental group. According to the Center for Biological Diversity, the sea ice in the Bering and Okhotsk Seas off Alaska and Russia where the ribbon seals spend the winter season is threatened by global warming.

You can read more about this in the San Francisco Chronicle

http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/03/27/BAC0VR2CK.DTL

The ribbon seal (Histriophoca fasciata) inhabits the Arctic parts of the Pacific Ocean and almost never come to land; it spends most of its life in the ocean and on sea ice. During winter and early spring, it lives on the pack ice of the Bering and Okhotsk Seas where it molts (sheds) and breed. When the summer comes, the ribbon seals head for the open water and stay there until next winter. Young ribbon seals are hunted for their fur, but efficient hunting is difficult since this species does not live in herds. For most hunters, the herd living Harp seal is a much more convenient target. In 1969, the Soviet Union limited the hunt on Ribbon seals and this has also had a significant positive impact on the populations.