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…
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).
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.
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).