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).