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).

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)

Shellfish growth stunted by more acidic oceans – the potential harm from ocean acidification is towards the top of the agenda at the moment. In this latest report increased levels of carbon dioxide are implicated in having an effect on shellfish reefs formed by the Olympia oyster. From ScienceDaily (Apr. 20, 2010).

Bivalves used to sense oil pollution: When mussels are exposed to pollution they start to close their shells, and the degree of closure is related to the concentration of polutants in the water. Norwegian company Biota Guard has developed a method for measuring the degree of closure, and so offering a quick and cheap sensor for monitoring discharges from petroleum platforms. From ScienceDaily (Apr. 26, 2010)

Protected reef offers model for conservation: A protected reef in Belize bucks the trend for deterioration and loss of fish stocks seen in neighbouring reefs, and worldwide. From New York Times. April 27, 2010

Ladybirds used as biocontrol agents in Galapagos: Indigenous vegetation on the Galapagos Islands has been suffering from attacks by an introduced insect pest called cottony cushion scale, which had resulted in some species disappearing. This damage appears to have been halted by the introduction of another insect, Rodolia cardinalis, a relative of the ladybird. Rodolia has already been used to reduce infestations of cottony cushion scale insect in California. From ScienceDaily (Apr. 22, 2010)

Should we hold marine mammals in captivity? The US congress is to explore the issues behind keeping marine mammals in captivity. There is growing feeling that entertainment is not enough to justify this practice, and that there must be some meaningful educational outcomes. From PressZoom 2010-04-27.
An important factor starting this debate was the death of a killer whale handler at SeaWorld Orlando in Florida (Telegraph 26 Feb 2010), but for killer whales at least the recent realisation of the fact that we have more than one species might also be a factor in reducing their popularity (New Scientist 02 May 2010). Apparently only one of the three species now recognised feeds on fish – so will people want to go to the zoo to see dolphins and seals being fed to the orcas?

Icelandic ash food for phytoplankton? Scientists are to study the recent volcanic ash fall from the Eyjafjallajökull volcano in Iceland to see if it has encouraged phytoplankton growth. A lot of people have said that we should look at artificially fertilizing the world’s oceans to try and increase carbon capture (greenhouse effect and all that), viewed in this light this work looks like a free experiment… From BBC News 27 April 2010

Environment driving speciation? An interesting essay in PLoS Biology on how environment and changes to the environment influence adaption or extinction events. The aim of the authors is to develop a predictive model for the effects of a climatic change on the species subjected to the change. There is quite a lot of interest in marine conservation circles about how recent bleaching of corals due to higher than normal summer temperatures might effect their long-term survival, whether or not the theory here might be applicable…
From Chevin L-M, Lande R, Mace GM (2010) Adaptation, Plasticity, and Extinction in a Changing Environment: Towards a Predictive Theory.
PLoS Biol 8(4): e1000357. doi:10.1371/journal.pbio.1000357
(See also our previous post on iron limiting productivity)

Seamounts – the latest frontier: Seamounts, mountains that rise from the seafloor, may rank as some of the most common ocean habitats in the world with more than 45,000 seamounts dotting the ocean floor worldwide. Latest research suggests that seamounts not only make up the largest area of ocean habitat, they are also highly productive environments that can serve as habitats for important commercial fish species like orange roughy and sablefish. (Authors note – it seems unlikely that seamounts make up more area than either abyssal plain or continental shelf, so perhaps I’ve mis-read this report). From Marine Conservation News, Monday, May 03, 2010.

As part of the current Marine ID course I’ve been running around trying to get together photos of some common seaweed for part 2… Unfortunately the local coastline is not at all hospitable to seaweed, the extensive mudflats of Morecambe bay are good for molluscs and worms, but offer few attachment points for the larger algal species (I think the phytoplankton might be a fascinating study – but that would be a bit outside the current remit!).

Never the less, I took my camera down to the beach at the weekend for the MCS walk from Warton Crag and round Jenny Browns Point by Silverdale (Saturday 24th April).

Here there is some hard ground, allowing seaweed to get a hold. Highest up the rocks appeared Blidingia (filamentous green stuff) and small amounts of Ulva intestinalis (fatter tubular green stuff), followed by Pelvetia canaliculata (channel wrack), at the base of the sequence was Fucus spriralis (spiral wrack) – beyond that stretched the mud as far as the eye can see…

The complete sequence was over in about 30cm of height – so extremely truncated!

Thanks to Hilary for organising the walk (my feet have almost forgiven me!)

The chlorophyl pigments have long been believed to be the basis for all autotrophy/phototrophy on earth, and these pigments therefore pretty much prop up the rest of the food chain (including yours truly). We know eukaryotic algae have a range of ‘helper pigments’ – this is why red algae are red, and not (usually!) green, but these transfer energy to the chlorophyl system, rather than drive metabolic pathways directly.

In 2000 a new group of membrane based proteins the proteorhodopsins were discovered in some cyanobacteria (blue green algae). These were shown to have the ability to drive a trans-membrane proton pump using only sunlight. Initially believed to have a sensory function, the latest work published in PLoS Biology indicates that the proton gradient created by the pump can drive the ADP-ATP conversion, and so be used as a general energy source for the cell. The long and the short of it is that cyanobacteria that have proteorhodopsin survive starvation in sunlight better than those that don’t, implying strongly that the proteorhodopsin generates real nutritional value for the bacterium.

This paper reinforces my prejudice that the prokaryotes are advanced organisms. These little guys might not have gone in for massive cellular machinery, but the chemistry they can do is really top notch!

Gómez-Consarnau L, Akram N, Lindell K, Pedersen A, Neutze R, et al. (2010) Proteorhodopsin Phototrophy Promotes Survival of Marine Bacteria during Starvation.
PLoS Biol 8(4): e1000358.doi:10.1371/journal.pbio.1000358

Each week I scan several thousand blog and news posts, picking out ones of interest to me and writing a bit about them – if I have time. Two problems – selfish interest, and lack of time! Here I’m going to try something a bit different, and be a lot less selective, but only write a very short tag for each item. This way hopefully you get a chance to find stuff of interest w/o having to scan everything…

Here goes my marine science roundup #1:

Plankton’s importance for carbon fixation: In the marine ecosystem both eukaryotes and cyanobacteria are important for fixing carbon at the base of the food chain. This article indicates that the eukaryotes (diatoms, dinoflagellates, protozoa and ‘seaweed’) are responsible for a bit under half the total carbon fixation in the world’s oceans (via ScienceDaily, Apr. 16, 2010).

Seabed Biodiversity in Oxygen Minimum Zones: Lack of oxygen in the water column favours some unusual organisms, and can increase biodiversity (as long as the areas are not too large). From ScienceDaily Apr. 19, 2010.

Smart fish adapt to environmental changes: Living in a changing or dynamic environment seems to favour smarter fish. From PLoS Biology 8(4): e1000351. doi:10.1371/journal.pbio.1000351.

Masses more bugs: The number of microbial species in the world’s oceans may be one hundred times greater than previously estimated. From Nature News, April 18, 2010.

New species of bacterium discovered: I guess given the increase in the number of microbes now expected, reporting each discovery individually might have to go by the wayside – so make the most of it! This one was found in the gut of a worm that lives in a Swedish fjord…

Junk food: A beached whale that died in Puget Sound (US) was found to have a pair of trousers, a golf ball, surgical gloves, small towels, and more than 20 plastic bags in its stomach. The problem with plastic litter is not confined to the US, the MCS organises beach litter surveys around the UK to monitor the state of our seas, and bring pressure to bear to get them cleaned up. You can help – see our diary pages for the next beach cleanup!

Fish oil supplements provide no benefit: The largest ever trial of fish oil supplements has found no evidence that they offer benefits for cognitive function in older people. The trial author noted that the duration of the trial might not have been long enough for any true beneficial effects to be detected amongst this test group of initially healthy older people. From ScienceDaily Apr. 21, 2010.

Big Seas, Big Trouble? An extended article about the effects of increased CO₂ on Ocean Acidification, and how that will effect life in the oceans in the coming decades. From Santa Barbara Independent Thursday, April 22, 2010

Carbon dioxide emissions causing ocean acidification: US congressional report finds that CO₂ emissions will have unknown effects on marine life (see also previous article). From ScienceDaily Apr. 22, 2010.

What are you eating? DNA analysis shows that a large proportion of the fish eaten in Dublin is mis-sold as something it isn’t. Similar results have been reported in the US, and the problem is likely to be global. From ScienceDaily Apr. 22, 2010.

More than one killer whale? recent DNA profiling data suggests that there is more than one species of killer whale.

We don’t usually try to ID bacteria, but this does not mean that they are unimportant. While each bacterium might be tiny, they can group together in enourmous numbers, and contribute a significant proportion of the biomass of any ecosystem. One recent discovery was a microbial mat lying on the sea floor off the coast of South America that covered an area the size of Greece!

The Census of Marine Life (previously blogged here) estimates that between 50 and 90% of the entire biomass of the marine system is in the form of microscopic organisms.

Our next Marine ID lecture on Wednesday 12 May the will look very briefly at some microscopic algae (phytoplankton), before turning to try and give pointers on how to identify some common (large and easily spotted) seaweeds!

More information:
Giant Undersea Microbial Mat (via Science Daily)
Census of Marine Life
MCS Diary – more lectures/meetings and events

An octopus? We’re aware of the amazing art of mimicry cuttlefish have, blending into their backgrounds, but their close relative the octopus may go one better again, by pretending to be a fish! The Atlantic longarm octopus, a caribean species, has been filmed mimicing flounder and other bottom-dwelling flat-fish. It is not clear why they do this, but video is available on the National Geographic website. The story is also picked up byt the BBC World Service’s Science in Action. Links for more information:

National Geographic: Atlantic Octopus Mimics Flounders—A First

Science In Action: 12/03/2010 (Ivory trade…)

The ‘common’ skate has been in serious trouble for some time, due entirely to over fishing. In 2008 ICES recomended that there should be no more target fishing, and that by-catch needed to be limited. Unfortunately, it now looks as though what fisheries statistics were labelling as the ‘common’ skate is in fact two species, with distinct morphologies and life histories. This change in classification means that we have two endangered species. One of these species (Dipturus cf. intermedia) is now thought to be in immediate risk of extinction.

It is sad that we know so little about our seas, and yet do them so much damage.

Ref: Iglésias S.P., Toulhoat L., Sellos D.Y. Taxonomic confusion and market mislabelling of threatened skates: important consequences for their conservation status. Aquatic Conservation: Marine and Freshwater Ecosystems, (in press) via Science Daily

More information: UK biodiversity Action Plan on the Common Skate

Is there something you can do? – The ‘Your Seas Your Voice’ programme, sponsored by the Co-Op, allows you to lend support to proposed marine reserves around the UK coasts. Reserves with strong no-take policies are the only way that many species, like the common skate, will survive. Showing you care about the seas around us is the only way we will get the political action necessary to offer them this protection:

Your Seas Your Voice

We were enticed into the calm, sheltered blue waters of Lady Bay (Mull of Galloway) on Saturday (29th September 2009), only to find that conditions were pretty much un-diveable, with lots of suspended silt giving a visibility of about 10cm! You could see which way was up, and that was about it…

Having got wet, however, I decided to try and get some samples for microscopy, and got a rather nice sample of sea mat on a laminarian. Sea mat is an ectoproct, a colonial animal that is commonly found forming white reflective sheets on kelp fronds, look closer and you’ll see that the sheet is formed of lots of tiny cell-like structures, but that is about as much information as you’ll get with the naked eye.

Under the microscope, however, we can see that each cell is an individual animal – the colony being formed by numerous clones living tightly packed together. When feeding, each animal extends a cone of tentacles, which are quickly retracted if it is disturbed.

Above right: Two micrographs of Mambranipora membranacea (L): Top showing extended feeding arms of the lophophore. Bottom, showing the growing edge of the animal, on Laminaria sp.

Barry