This roundup has a focus on oceanography, physical and chemical processes in the worlds oceans. The chemistry and biology of natural seawaters are very tightly linked, with most reactions being biologically mediated. The physical side, however, dominates what chemical species marine biology has to work with, an interaction that scientists are now claiming to be able to model. Many marine systems are rather less than ‘natural’, with a range of human influences. In the oceanography section we look at the underlying science of these man-made changes, whilst in our pollution section we look at the dirty stuff…

We finish on a few general papers that don’t fit into the two main themes for the week – living underwater, mapping the salmon genome, dolphins and ichthyosaurs. Finally, if you can only conserve one thing, what would it be? – This is the root of a difficult question facing coral reef conservators. Do you concentrate on the core of the reef? – science is starting to show that the fringes of the reef (an other eco-systems?) are more genetically diverse, and may offer a stronger pool of organisms better able to survive ongoing climatic change…

Oceanography focus

Phytoplankton blooms are one of the most important events in the ocean, some blooms consist of toxin producing species, but all are a vital component of the marine food chain! Despite their importance they are very difficult to model, as there is a complex interplay between nutrients (derived from land run-off, atmospheric precipitation and deep ocean currents etc.) and predators (starting with zooplankton, and working the way up to all of the other animals in the ocean). Scientists at the University of Glasgow beieve they have got a bit closer to being able to do this, using complex computer models of current patterns and mixing. ScienceDaily (June 22, 2010)

Polar oceans control tropical temperatures: Scientists have found a close link between changes in subpolar climate and the development of the modern tropical Pacific climate about 2 million years ago. The study looked at the levels of alkenones, produced by phytoplankton, in core samples. Phytoplankton adjust the amounts of the different alkenones they produce in response to temperature. The levels of these chemicals at different points along the core sample therefore reflect the temperature history of the location where the core was taken. From ScienceDaily (June 17, 2010)

How do we influence the chemistry of the oceans? The oceans are the ultimate sink for our agricultural, industrial and other consumer activities – even if they take place miles from the sea. This new report brings together many of the different strands of research following different pollutants as they make their way through the terrestrial and atmospheric systems into the oceans. The findings indicate that the pH of ocean waters is falling rapidly, due to carbon dioxide input, and fertilizer runoff is causing increasing problems with coastal hypoxia – where algal blooms that use up all of the oxygen in the water. ScienceDaily (June 21, 2010)

Changes to ocean chemistry threatens global ecosystem: How bad can it get? – With the oceans supplying 50% of our oxygen, and absorbing 30% of the carbon dioxide we are emitting, this emotive report suggests that it can get very bad indeed… ScienceDaily (June 19, 2010)

Western Med warms: Records from 1900 to present show that the Western Mediterranean has warmed consistently over the entire period. The warming appears to have accelerated since the 1970’s. THe scientists involved suggest that this is a good indicator/reflection of global climate change. ScienceDaily (June 18, 2010)

Antarctica should be in the spotlight: Claim scientists who are concerned that the oceans around this continent need to be better monitored. They report that 87% of the glaciers on the Western Peninsula are in retreat, and there is urgent need to monitor and understand what is happening. ScienceDaily (June 22, 2010)

How do oceanic currents work? The major currents of the world’s oceans are important in transporting surface water, but also influence ‘overturning’, where deeper water is brought to the surface (or vice versa). They are an essential component of the ocean/atmosphere dynamic model (also vital for phytoplankton blooms – see earlier). While the simple conveyor belt model does not appear to be incorrect, it is inadequate in explaining the dynamics of the process, particularly in response to wind stress on the ocean’s surface. As a consequence, current models are unable to predict overturning. New research is now planned to try an fill this gap in our understanding, in the hope that better models will aid our understanding of the global climatic system. ScienceDaily (June 20, 2010)

Tsunami warning: NASA has demonstrated a prototype system for improving Tsunami warnings. This satellite based system is able to track the displacement of sea level caused by the deep water wave with an accuracy of a couple of cm, good enough to predict the size of the tsunami. From ScienceDaily (June 14, 2010)

Freak waves: Waves at sea are extremely complex – being formed by dynamic combinations of waves from different directions, each with a different amplitude and wavelength. Every now and then these random combinations turn out an unexpectedly large and stable wave, which has the appearance of sweeping out of no-where. Such waves can be extremely damaging, sweeping away gear (and people) from apparently safe locations. Scientists are now been able to model these extreme occurrences. From ScienceDaily (June 17, 2010)

Marine pollution

Sea cucumber slaughter: Large numbers of dead seacucumbers have been found floating on the surface around the Deepwater Horizon oilspill site in the Gulf of Mexico. Sea cucumbers are benthic organisms, so rarely noticed when they suffer as a result of pollution. Possible reasons for the deaths are either direct toxicity of the oil, or oxygen depletion in the water column as the oil is metabolised by bacteria. From Scientific American, June 15, 2010

Seagrass relfects pollution levels in the Med: Meadows of seagrass (Posidonia oceanica) have been monitored in the Balearic islands, showing that the grass picks up heavy metal pollutants in the water. From ScienceDaily (June 17, 2010)

Antibiotic resistance prevalent in marine environment: When we think of pollution, we usually think of heavy metals or toxic polyaromatic compounds. An area we overlook is that of antobiotics – these are a small group of chemicals that are used heavily in both medicine and agriculture. They are very important to us medicinally, but the bacteria they are used against do have the capacity to develop resistance genetically. This resistance is a good measure of whether or not the bacteria have been exposed to the antibiotics in question. This recent study shows that seven species of fish and shark off Florida harboured antibiotic resistant bacteria… From From ScienceDaily (June 16, 2010)

Plastics at sea: Two tall sailing ships have been used by students to trawl for plastic in the North Atlantic. They were able to calculate from their results that levels of plastic contamination reached levels up to 200,000 pieces of plastic per square kilometre. From BBC (24 February 2010) (via Deep Sea News)

Warfare ecology: What happens to munitions dumped at sea? – Amongst other things, they become habitats. Examples are the scuttled warships at Scappa Flow – which are essentially just shipwrecks, though their thick armour plating contributes to their survival as recogniseable structures. Other things, however, include live munitions and chemical weapons. These can make for unpleasant surprises for fishermen (Deep Sea News June 14th, 2010), though where mapped, exclusion zones become interesting and quite diverse ecologies. Leading to the sad conclusion that mustard gas can be less damaging than fisheries practice… From Deep Sea News March 12th, 2009

General marine science

Quick ichthyosaurs: Ichthyosaur and dollphin skeletons look very similar, reflecting a similar way of life as active hunters. The similarity between the two animals has been increased by this study which suggests that ichthyosaurs were warm blooded. From ScienceDaily (June 15, 2010)

Salmon genome approaches completion: The atlantic salmon is close to having its genome fully mapped, due to work by an international collaboration of scientists from Canada, Chile and Norway. From ScienceDaily (June 15, 2010)

Gas scrubber: Wire rings (‘Dixon rings’) and seawater have been used to strip carbon dioxide out of breathing air. The development is designed to scrub carbon dioxide out of the air in undersea habitats and submarines, and removes the need for caustic chemicals, which have to be periodically replaced. While the system is quite compact, it probably won’t appear in your re-breather this year. From ScienceDaily (June 17, 2010)

Coral reef protection hot-list: If you can only save some reefs, how do you prioritise? This report looks at the biodiversity of reef-biulding organisms in the Caribbean, and suggests that periferal reef sustems have more biodiversity, and may be better equipped genetically to cope with environmental changes. From ScienceDaily (June 21, 2010)