Archive for May, 2010

Science roundup 31st May 2010

Monday, May 31st, 2010

Lots of new species, and excess nutrients encouraging algal blooms. I’ve avoided the oil-spill, which still contributes a lot to the scientific news, but I don’t have anything new or insightful to say on this. I’m afraid that disasters breed liggers even in the scientific community, all too often I find myself stripping out tenuous links to the disaster of the moment (climate change or oil-spill) added to spice up the press report, to try and find the meat of the scientific study…

Algal blooms

Sewage: From source to sea: In a recent study, engineers from Stanford University have shown that sewage can contaminate bathing beaches after percolating through groundwater from septic tank leach-fields. The main contaminants entering the seawater were nitrates, which cause localised blooms of phytoplankton, rather than bacteria, which might be a direct risk to human health. Overall, the authors did not cite a preference between septic tank and leach field vs piping to a sewage treatment facility, largely due to the lower energy costs of the former system. From ScienceDaily (May 25, 2010)

Algal blooms can hit the poor hard: The south west Indian coast is particularly prone to algal blooms. These are triggered by excess nutrients in the coastal seawater, from monsoon runoff from the land. The problem is amplified by the increased use of fertilisers. As Indian authorities encourage aquaculture along the coast to provide local income, and a source of protein for a booming population, it is becoming more important to understand how and when blooms are likely to occur, and how this might change in future, possibly as a result of climate change. From ScienceDaily (May 31, 2010)

New species discovered

Top ten new species in 2010: The new list from Arizona State University includes a multi-coloured frog fish (found in Indonesia), an electric fish (that had been used for demonstrations of the ‘electric effect’ for many decades, but not described and formally identified untill this year!) and a killer sponge. There is a nice photo of the spicules from this sponge (see ‘Why we have bones, and not spicules’ in evolution, below), but this is one you probably wouldn’t want to scrub your back with.

Six new antarctic gorgonians discovered: Gorgonians are cnidaria with large branched calcareaous skeletons, the surfaces of which are covered by tiny feeding polyps. The branches of a gorgonian are usually held in one plane across the current so the animal can capture food particles efficiently. This gives the animal a fan-like appearance, and they are commonly referred to as ‘sea-fans’. They are closely related to sea pens, which are common around the UK on muddy bottoms below about 20m depth. From ScienceDaily (May 30, 2010)

New fish species described: Nine new species of handfish – small fish that use their fins to ‘walk’ along the bottom – have been described in Tasmania. The discoveries are part of an urgent project to catalogue and protect Australia’s marine life. The discovery brings the total number of known handfish species to fourteen. From ScienceDaily (May 24, 2010).

Evolution

Genetic divergence in coral reefs: This study from PLoS 1 analyses changes in the DNA of individuals of the coral Seriatopora hystrix and its symbiotic alga (Symbiodinium). Their data show that there are changes in genetics of both coral and symbiont between individuals sited in diffferent locations on the same reef (e.g. back reef, deep slope and upper slope). However, inviduals on different reefs, but in a similar habitat, are genetically similar despite being isolated by distance. Similar changes have been documented before in Littorina (periwinkle), and I suspect this is quite common for a wide range of sedentary organisms (seaweed, anemones, sponges, tunicates). From Bongaerts P, Riginos C, Ridgway T, Sampayo EM, van Oppen MJH, et al. (2010) Genetic Divergence across Habitats in the Widespread Coral Seriatopora hystrix and Its Associated Symbiodinium. PLoS ONE 5(5): e10871. doi:10.1371/journal.pone.0010871

35 million years of whale evolution: Whales are a diverse bunch of marine mammals – showing great variations in size and a large number of different adaptations to the marine environment. The study shows that whale species diverged quickly shortly after adopting a fully marine life-style, and have since maintained a relatively conservative pace of change. From ScienceDaily (May 31, 2010)

Early power cell: Researchers at the University of Leeds suggest that pyrophosphite might have been an important energy source for the earlies forms of life on earth. The mineral is thought to have played a similar role to that of ATP in modern cells. From ScienceDaily (May 25, 2010)

Why we have bones, and not silicate spicules: Sponges are very simple multicellular animals. So simple, in fact, that I am told that you can liquidise many of them, and the cells will slowly go back together again afterwards. For structure, and some measure of protection, sponges secrete silica or calcium carbonate ‘spicules’ (often quite intricately shaped, the microscopic examination of these structures is an important aid for their identification). Deposition of carbonate minerals – used to make the bones of many animals (including ourselves) – relies on αCarbonic Anhydrase enzymes, which have been shown to appear first in the sponges about 530 MYA. From Deep Sea News, May 27 2010.

Other stuff

Hurricanes stir the bottom at 90m: Hurricane Ivan, a category-4 storm, crossed the Gulf of Mexico in 2004, right over a network of sensors laid by the US Navy. These showed sediment clouding the water column to a height of 25m above the bottom at 90m, indicating considerable scouring even at this depth. The hurricane set up powerful currents in the deep water that persisted for a week after the event. The authors suggest that these currents may be a threat to oil pipelines. From ScienceDaily (May 26, 2010)

Jellyfish in motion: Video of jellyfish from the Monteray acquarium, California. From KQED, May 25 2010

Scripps Institution of Oceanography Library available through Google books: About half of the Scripps Institution of Oceanography Library has been digitised – focussing on rare out of print publications and expedition reports. Unfortunately, it appears that this resource is only freely available in the US. From Library Journal 5th May 2010. (Link to Google Books)

Shark attack Sunday: Apparently sharks are more likely to attack people on Sundays during a new moon. Other statistically significant parameters included depth of water (less than 6ft/2m) and colour of bathing costume (black and white preferred). From ScienceDaily (May 27, 2010)

Historical Atlas of Marine Ecosystems (HMAP): The Historical Atlas of Marine Ecosystems shows where species and ecosystems have been reported to occur, with data displayed on a Google World view. They have recently added areas showing where Sperm whales were caught between 1760 and 1920. (I think this might be a really useful resource, but I found it hard to use).

Mid May dive weekend

Thursday, May 27th, 2010

A  dive weekend held in conjunction with Preston SAC  to the sea lochs north of Oban was held over the third weekend in May. Diving in the Kerrera Sound and Loch Creran was quite interesting with the usual tremendous diversity of marine life although it was quite gloomy with underwater visibility down to only a couple of metres at best. A dive on the underwater cliff about 200 metres  to the west of the old railway pier at Kentallon inLoch Linnhe was the highlight of the trip. Underwater visibility was at least five metres at the top of the the wall which plunges down in a series of steps to approx. 35 metres deep. The wall is covered in a profusion of life, with vast numbers of peacock  worms Sabella pavonina & sea squirts,  Ciona intestinalis. This was an excellent dive to conclude the weekend. Many thanks to Gordon Fletcher for organising the trip to co-incide brilliant sunny weather.

Catalogue of life

Wednesday, May 26th, 2010

Homarus gammarus, with simplified taxanomic tree (click for large version)

As anyone attending our ID course will know, species names are undergoing considerable upheaval currently, as a consequence of DNA analysis. This is resulting in species disappearing (for example the ‘breadcrumb sponge – a single species with 50+ scientific names) or appearing (for example with cryptic species ), or are moved between genuses.

The ‘Catalogue of Life’ is a potentially helpful resource for anyone wanting to check on a scientific name for a species, as it permits searches against an extensive library of scientific synonyms (so it should tell you if you have an older name, and what the current name should be). It is not entirely infalible – it still quotes Laminaria saccharina as the accepted scientific name for ‘sugar kelp’, where I believe this has recently been updated to Saccharina latissima based on DNA evidence (this is a recent change though – so probably just not have come through yet).

The site also permits you to browse through the taxonomic tree of marine life – which is fun, though without keys you will need some knowledge of the biological classification to use it. The site also carries broad distribution data, and links to off-site resources.

Image top right: The common lobster Homarus gammarus, with inset a simplified taxanomic tree from the Catalogue of Life.

Catalogue of Life: 2010 Annual Checklist You will need Javascript enabled to use this site.

Science roundup 24th May 2010

Monday, May 24th, 2010

Soft bodied fossils, invasive species, and fishing stocks, some of the science reported over the last ten days:

Invasive tunicates in Oregon: Didemnum vexillum has been added to Oregons’s most dangerous species list. This is an unusual status for a tunicate, a group of animals that usually live a blameless existance filtering seawater for food. Apparently, however, vexillum is an alien species that grows over surfaces and can block water intakes and foul fishing nets. The species can also grow over clams and oyster beds, killing them. From ScienceDaily (May 13, 2010)

Fossil haul illuminates Ordovician ocean: 1500 fossils of soft bodied marine animals, including sponges, annelid worms and molluscs, have been found in southeastern Morocco. The animals date from the Ordovician (490-440 MYA), a period that saw many of the groups we know today establish themeselves. The absence of Ediacaran organisms confirm that these unusual early life forms had become extinct by the start of the Ordovician period. From ScienceDaily (May 14, 2010)

Personal care products polute rivers: Biocides and aroma chemicals added to modern personal care products are finding their way into our fresh-water systems. From ScienceDaily (May 14, 2010). While the European study did not believe that their findings posed any risk to humans, research in the States indicates that the common antibacterial agent triclosan is contributing to rising levels of dioxins in river sediments in the Missippi. From ScienceDaily (May 18, 2010).

Coral larvae listen out for reefs: Coral larvae swim towards the sounds of coral reefs. From ScienceDaily (May 16, 2010)

Altantic swordfish stocks recover: A small number of fish stocks saw an improvement in the latest NOAA fisheries report to Congress. For the first time since 1997 no additional species were added to the overfishing list. From ScienceDaily (May 17, 2010)

Greatest grand-daddy: The largest study to date confirms Darwin’s conjecture that all life originates from a single common ancestor. The study was based on the analysis of 23 ‘essential’ proteins, which are found to be related in a simple way accross the entire range of organisms, including eukaryotes (like ourselves), bacteria and archaea. From ScienceDaily (May 17, 2010)

Crews remove lost nets: Fishing gear abandonned or lost at sea, called ‘ghost gear’, continues to ensnare and kill marine animals, as well as posing a risk to boats. Resistant to degredation, the only way to end the cycle of death is to physically remove the gear. From USA Today, May 18, 2010, via The Spill.

Orkney trip

Monday, May 24th, 2010

Marine life in Scapa Flow.

Prior to this trip I had thought that diving the Scapa Flow wrecks would be a bit dull – large piles of scrap iron in the deep dark cold of Scapa Flow. I was wrong. The wrecks are covered in life – thick fields of plumose anemones, sea-firs, colourful feather stars and fish adorn the hulls, which are coloured with orange rust and pink encrusting algae. And in amidst it all, you catch the occasional glimpse of ordnance, or the the viewing slot of the armoured bridge, just to remind you that you are, after all, diving a state of the art killing machine from the early years of the last century…

Thanks to Lewis Bambury for organising and inviting us along on this trip, and to all the members of Lunesdale Sub-Aqua Club who made us feel so welcome!

More information on the wrecks in Scapa Flow from Scapa Map

Irish Sea Conservation Zones

Thursday, May 13th, 2010

Thanks to Laura Bates for coming to our meeting on 12th May to tell us more about the Irish Sea Conservation Zones project. The project has a group of 41 delegates, each looking after a specific interest group – fishing, gas, conservation etc. Their remit is to establish a set of conservation zones in the Irish sea, that will ultimately link to similar zones around the UK. The purpose of the current phase is to identify areas of high conservation potential, and determine what level of protection might be appropriate to minimise the impact of any legislation on other activities.

For more information, or to make your views heard, please see the Irish Sea Conservation Zones website:

Irish Sea Conservation Zones

Science roundup 13th May 2010

Thursday, May 13th, 2010

A mixed bag this week, we still have a few fringe posts on the Gulf oil spill – this is now news, and any science we get from this will be in studying the effects, though perhaps there will be trials with some of novel mitigation strategies suggested, so we may be able to tidy up better in future. Otherwise quite a lot of interesting stuff, including a bit of a shark’s tail…

Hiding your true identity: Cryptic species are those that look identical, but do not interbreed, and have different DNA, as demonstrated by this article about a new species of hermit crab, discovered at Stanford University. From Mercury News 05/09/2010.

Wave power problems: Recent research into wave power has concentrated on deep-water (50m) generators, which studies had suggested could generate twice the amount of power of shallow generators (in 10m water depth). A recent study reported in New Scientist, however, has suggested that the actual power output might only be about 20% greater than the shallow generators, and still incur the greater deployment and maintenance costs for a deep-water site. The reasons for the reduced forcast are that waves in deep water are not focussed by bottom topography, so a generator cannot be optimised for a given wave direction. Also, early energy estimates included storm waves, when the plant will probably have to be shut down to prevent damage. From New Scientist, 8th May 2010, p22.

Mediterranean reserves protect coral: Marine protected areas (MPA) in the Mediterranean, where fishing is prohibited, have helped bring back the Mediterranean red coral (Corallium rubrum). The coral grows slowly, so monitoring its recovery within the MPA’s has been very difficult, however, current results suggest that the stocks in the oldest MPAs are now healthy, though the sizes of the corals are still far smaller than those harvested in the 1960’s. From ScienceDaily (May 11, 2010)

Killer weed: In a normal marine ecosystem there is interplay between a number of diferent species generating a diverse range of plant and animal life. In the tropics this balance has been upset by overfishing, which has reduced the grazing of seaweeds. Left ungrazed, the seaweeds grow faster than the corals, and kill them. A new study has shown that many seaweeds kill by poisoning the coral, rather than simply over-growing them. The researchers were surprised that some of the chemicals secreted by seaweeds are poisonous to corals, having assumed they were simply anti-bacterial. The author notes that Coral, however, are closely related to seafirs (both in the class Cnidaria) which are common epiphytic pests on seaweeds – so perhaps they should have expected this? From ScienceDaily (May 12, 2010)

Oilspill closes gulf fisheries: This interesting blog post from John Collins Rudolf examins the broader question of the environmental health of the Gulf. It is clear that in the Gulf the oil spill is not the only environmental problem, and the effect of a fishing ban may actually benefit some species, such as the red snapper. Given the damage the oil spill is likely to cause to wildlife as a whole, however, this does seem to be scrapping the very bottom of the barrel for a positive message. From the New York Times May 11 2010.

Nuke the oil: Trust Slashdot to dig up a truely mad way of solving the Gulf oil spill – nuking the well head! Apparently this technique was used in Soviet Russia, and worked on four out of the five occasions it was deployed… From Slashdot, May 11 2010.

Collosal squid take life in the slow lane: Collosal squid – weighing in at 500kg or more – live in the ocean deeps. Here their large body size means that their metabolisms are slow, to make best use of the available food and oxygen. They are thought to be patient, ambush predators, surviving on the occasional passing fish, rather than active predators. From Wired (May 12 2010).

The long tail of the thresher: The thresher shark (an occasional visitor to UK waters) is characterised by the extended upper lobe to its tail fin – which can reach the length of the shark’s body. The reason for the tail has puzzled biologists, but now video footage clearly shows that it is used to hit and stun smaller fish that are the shark’s prey. Video is available on the BBC site (see title link). From BBC News 13th May 2010.

Pathogenic algae: Not all algae are photosynthetic, Prototheca cutis is a newly identified species that very occasionally causes skin ulcers and lesions. Non-photosynthetic algae usually live in soil water and sewage, rather than open oceanic waters. From ScienceDaily (May 10, 2010).

Science roundup 9th May 2010

Sunday, May 9th, 2010

A bit more science from the ocean floor – and, indeed, elsewhere in the water column, with this week’s roundup. The history of fishing is a popular topic, with work from the MCS on evaluating how much effort the fishing industry is having to put in to catch an ever diminishing resource, and with a new project to see how fish stocks have changed since medieval times…

Climate change will speed the spread of invasive fish to northern Europe: Spanish and French researchers have evaluated the spread of the invasive mosquitofish Gambusia holbrooki, which is native to the United States and lives in Mediterranean rivers in Spain and France. The species, which prefers warm waters, is abundant throughout all the countries in the Mediterranean basin, but has yet to become established in the United Kingdom, where the water is currently too cold. Gambusia spp. have caused the decline of many native fish and amphibian species worldwide. From ScienceDaily (Apr. 29, 2010)

Why are some farmed fish deformed?: Norwegian researchers have been uncovering some of the reasons for malformed farmed fish such as cod and salmon. It appears that fast currents in the tanks when the fish are young give rise to spinal injuries, and so deformed adult fish. From ScienceDaily (Apr. 30, 2010)

Fewer fish means the fleet works harder : Researchers from the University of York and the MCS used UK Government data on the amount of fish caught and the size and number of boats involved (an estimate of the fleet’s fishing power) to analyse the change in fish stocks since 1889. By this estimate the modern UK trawl fishing fleet has to work 17 times harder to catch the same amount of fish today as it did when most of its boats were powered by sail. The peak in fish landings occurred in 1937. From ScienceDaily (May 4, 2010)

Water ferns help design efficient ships: Superhydrophobic surfaces have been known for some time – these prevent water wetting a surface, and have the potential for reducing drag very dramatically. Unfortunately the effect is not very stable, with water breaking through the barrier after a few hours of use. A small water fern called salvinia molesta may show a way forward. This has finy hairs that are hydrophobic for part of their length – repelling water, but have hydrophilic tips. The effect of the tip is to pin water as the outside later in a sandwich, holding the trapped air between the plants skin and the water in place. It is claimed that surfaces based on this principle may reduce fuel usage by shipping by as much as 10%, equivalent to reducing the total global energy requirement by 1%.

A history of fishing: A new research project by scientists at Cambridge University is to analyse fish bones from archaeological settings to work out where the fish were caught. The intention is to piece together a history of the usage of fish stocks in Europe over the last 1000 years.

National Maritime Museum exhibition: Boats that Built Britain: In conjunction with BBC4 television series about maritime Britain. Exhibition starts 8th May 2010.

Ancient lead shields modern detector: Lead from a Roman shipwreck is to provide shielding for the neutrino experiment located under the Gran Sasso mountain in central Italy. The radio-isotope lead-210 that was originally in the ingots has almost completely decayed over 2000 years on the floor of the Mediterranean, making it an ideal material for protecting the new sensitive detector.

Oceanographers survey marine landslide: Researchers plan to create the first detailed maps of the submerged volcanic landslides around the Soufriere Hills volcano, Montserrat. Modern volcanic activity has been tame in comparison to what has happened over the last millenium, with landslides involving over five cubic kilometres of material that travelled underwater for tens of kilometres. Scientists are interested to learn how and why large volcanos of this type occasionally collapse into the sea. From ScienceDaily (May 5, 2010).
Location of Soufriere Hills volcano in Google maps


How does a shark smell?
The way fish smell their environment is quite different to the way we do. We breath air through our nose, while a shark swims, and sweeps its head from side to side, to drive a constant current of scent bearing water around its nasal cavity. From ScienceDaily (May 5, 2010)

NASA explores inner space: NASA is to use the Aquarius Underwater Laboratory, Key Largo, to simulate activity on another planet. From Space.com, (4th May 2010)

Marine ecology special issue: This open issue of the journal Marine Ecology looks at how habitat heterogeneity is important in generating and maintaining biodiversity on continental margins. While the survey areas for the studies are deeper than we would be interested in diving(!), there are some interesting survey ideas – such as looking at numbers of species along transects and comparing this to bottom types – with which we are pretty familiar from the standard MCS seasearch form.

Countries ranked by environmental impact: A new study by the University of Adelaide’s Environmental Institute ranks countries by the damage they are doing to the environment. The indicators used were natural forest loss, habitat conversion, fisheries and other marine captures, fertiliser use, water pollution, carbon emissions from land use and species threat. From ScienceDaily (May 4, 2010)

Genetic diversity the key to coral survival: The symbiotic relationships between the algae and coral is central to the survival of the coral, with the algae providing the coral with energy, whilst the coral provides protection and nutrients to the algae. This relationship is, however, very sensitive to changes in temperature. In recent years high sea temperatures have lead to bleaching events, where the aglae have died. The susceptibility of the coral to these damaging, and potentially fatal, bleaching events is in part dependent upon the genetic diversity of the algal partners available to the coral. From ScienceDaily (May 7, 2010)

Gulf oil slick update

Thursday, May 6th, 2010

The spillage of oil into the Gulf of Mexico continues unabated, though to date it has not hit the coast on a large scale. The effects are likely to be devastating – to wildlife certainly, but there will also be damage to commerce, as shipping is disrupted. Engineers work heroically to try and stop the spillage, while scientists raise worries about cleanup operations. Meanwhile the local fishermen start to map how the spill is effecting them. Fossil fuels are valuable, but they are also expensive

Oil spill cleanup worries: Wetland experts are saying that the detergents used in cleanup operations may cause more damage to coastal wetlands and beaches than the oil spill itself. From ScienceDaily (May 4, 2010). Alternative bioremediation strategies have been put forward. ScienceDaily (May 4, 2010).

Satellites monitor oil spill movement: Fears grow that the slick may soon enter the Loop Current in the Gulf of Mexico, and so threaten the Florida Keys. From ScienceDaily (May 5, 2010)

Oil spill disrupts shipping channels: Seventy percent of all US shipping goes through the Port of New Orleans, which is currenty rather difficult to get to due to the slick and the booms intended to contain it. From ScienceDaily (May 5, 2010).

Oil spill engineering overview: Booms, dispersants and a giant dome that has to be lowered through 5000 feet of water to cap the oil leak. From Google hosted news/Associated Press.

Kenyan web tool helps fishermen map oil spill problems: A free mapping application, originally developed in Kenya to map political violence, has found a new use in the Gulf, allowing fishermen to report the position of the oil spill and its effects ‘on the ground’. The mapping software allows reports to be made by SMS-text, email or through a web form. From BBC News 5 May 2010

You can track the spill and its effects through Google Maps: Link

Anatomy of an evolving disaster

Tuesday, May 4th, 2010

Oil rig spill worry: On 23rd April it was reported that BP was ready to deploy more than one million feet of boom and 32 surface vessels to try and contain the aniticipated spill from a drilling rig that sank after a fire in the Gulf of Mexico. The accident had little impact at first, but by the start of May is was clear that the situation was very much more serious with the White House taking a bigger role in the cleanup, and with the marshalling of resources from the United States Navy to supplement an operation that already consisted of more than 1,000 people and scores of vessels and aircraft. Today Governor Arnold Schwarzenegger is reported to have withdrawn his support for drilling off the Californian coast, as a direct response to the disaster.