Lots of interesting articles over the last week, some physiology – how sharks and seals find their food, and how far can crocodiles migrate? Prehaps my favourite was the article on classifying arrow-worms, a group I knew nothing about them before the article. There is also a nice set of maps of North Americal marine ecosystems, which you can view on Google Earth. Maps almost had a separate section this week, with 3D maps of the oil-spill being computed by the University of Texas at Austin. Unfortunately the article was so uninformative that I couldn’t see any point in referencing it…

Marine life

The seal’s whiskers: The BBC reports that Harbour seals can spot fish 100m away – just by picking up vibrations through their whiskers! The research involved getting the seals to wear masks and headphones, to ensure that they couldn’t spot the fish any other way. The researchers reported that the seals were well bribed, and came to enjoy putting their goggles and head-phones on… From BBC News 11 June 2010

How sharks scent food: Sharks use scent to home in on prey, and they can do this by measuring the difference in time a scent reaches each nostril, so they know which direction the scent is coming from. Previously it had been thought that sharks followed scent gradients, heading towards where the scent is strongest. From ScienceDaily (June 10, 2010).

Crocodiles go with the flow: Estuarine crocodiles (Crocodylus porosus) travel the world on ocean currents. The estuarine crocodile lives in mangroves and estuaries in South East Asia. Its large range has been a matter of interest, as it relies on land for food and water, and is not a strong swimmer. Recent tracking studies, however, have shown that this animal can ride surface currents between islands. Journeys of several hundred km seem to be quite common for individuals of this species, the timing of journeys indicate that it has some understanding of the tides, and possibly even seasonal currents. From ScienceDaily (June 7, 2010)

Chaetognaths give scientists the run-around: Fitting the Chaetognaths (or arrow worms) into the classification system is proving difficult, with even DNA analysis is showing conflicting results. This is at least partly due to the fact that the group splits off at the early period of species radiation when the deuterostomes (urochordata, including us, and echinoderms), true worms and the cnidaria all split apart. Mapping exactly when they split out is, however, proving difficult. There is a very nice video of an arrow worm feeding on this Japanese site ‘the biology of the chaetognaths‘.

Might these organisms be amongst the first macroscopic animals to show a complex poly-phylogenetic origin? – Probably not, but that would be very exciting!

The rude dolphin: We’re pretty sure that dolphins can talk to each other, but we don’t undertand much of what they are saying. Some sounds appear to be used to socialise, and may position themeselves within the social heirarchy, (perhaps a bit like identifying themeselves – my name is?). Others are used to coordinate hunting. One group of sounds appears to be associated with stand-offs between dolphins. These tell animals lower down the social heirarchy to move aside… From ScienceDaily (June 9, 2010)

Man and the sea – climate change, ecology and marine management

1m sea level rise by 2300? New predictions, based on measurements of current ice loss in the West Antarctic Ice Sheet, give a range of between 0.5 and 1.5m rise in sea level by the end of the century, affecting 150 million people. From ScienceDaily (June 10, 2010)

How does environmental protection affect poverty? Environmental protection often comes at a cost, an activity is restricted or taxed. It is not obvious that this will help the poorest people in society, who are least able to cope with increased costs or restrictions on their fishing or farming practices. This podcast at Research Blogging reviews a paper that argues that environmental protection may indeed help alleviate poverty in some of the poorest areas of the world… (June 8th 2010)

0.1°C drop in temperature caused famin: A protracted la nina event in the Pacific, in which surface water temperatures fell by an average of 0.1°C was associated with the Great Famine from 1315 to 1320 in Europe. From ScienceDaily (June 9, 2010)

Three quarters of americans still believe in global warming: Results showed a small decrease in people convinced by global warming in this survey by Stanford, that has been repeated every year since 2006. Reasons for this may include the coldest winter for many decades, plus an increase in scepticism following the conduct of UK climate scientists at University of East Anglia. From ScienceDaily (June 9, 2010)

North America maps marine protected areas: Most countries are coming round to the idea that they are going to have to manage their marine ecosystems in partnership with neighbouring states, or see them be totally degraded. As part of the North American (Canada, Mexico and US) program, they have defined and mapped broad scale ecoregions, as well as the marine protected areas. The priority conservation areas defined are quite extensive, and each has a short description explaining why it should be conserved. Whether or not there is the political will to provide adequate protection for these areas remains to be seen. At a broader level, ecoregions are also defined, again with short descriptions of each, and the rational behind its definition. Maps and descriptiona can be downloaded as KML files for Google Earth.

Bugs eat oil: A new bacterial strain has been discovered that is particularly good at eating polycyclic aromatic hydrocarbons – some of the most toxic components of oil spills. Oddly the strain is from the species Pseudomonas aeruginosa; this species is better known for serious hospital infections, though neither hospitals nor humans are its natural environment. Of course the natural degredation of oil spills relies on many species of bacteria. One of the problems with the deep sea spill in the Gulf of Mexico is that as the oil is eaten by bacteria the oxygen in the water column is getting used up, making it hard of other organisms to survive. From ScienceDaily (June 11, 2010)

Biotech opportunities in Irish waters: Scientists have recently sampled marine habitats from the edge of the Irish continental shelf at depths between 400 and 3000m. Using an ROV (remote operated vehicle), they mapped habitats and took samples for later study and identification. The advantage of the ROV is that it could sample life in canyons, nooks and crevices that are traditionally difficult to sample with corers or trawl nets. Despite the claims of the biotechnologicl importance, it looks like the study was more concerned with sensible science – monitoring nutrient flows in these habitats, for example, though they may discover some interesting compounds amongst the samples materials! From ScienceDaily (June 11, 2010)