We start this issue with a look at a new species of archaea – where we learn how difficult it is to find out anything specific about these organisms. We put phytoplankton on ice, and in ice, use them to make pretty patterns and find them hard to kill; unlike blue sharks, which just wind up dead by accident.

Our conservation section starts with a look at alien species and threat networks, and has news of a new marine protected area off Costa Rica, before links to some personal accounts of manatees and the sex life of groupers (amongst other subjects).

Marine science

Prizing data out of archaea: It is no longer an event when someone sequences a bug genome, but the archaea apparently represent some unusual challenges. Because the cells are so small – less than 1×10^-6m in length – the workers had to isolate single cells using optical tweezers within a microfluidic separator. This ensures that they only amplify one species genome. They then used a knowledge of gene function to work out what type of cell they were looking at – for example they surmise that the presence of a number of genes associated with movement in other bacteria implies that their target was also motile… The archaea are a vital component of the global biosystem, this paper helps us understand one species amongst countless millions that remain to be investigated.
Blainey PC, Mosier AC, Potanina A, Francis CA, Quake SR (2011) Genome of a Low-Salinity Ammonia-Oxidizing Archaeon Determined by Single-Cell and Metagenomic Analysis. PLoS ONE 6(2): e16626. doi:10.1371/journal.pone.0016626

Algal ice-carvings: The agla Melosira arctica, which is found in the Arctic, over-winters in pores and channels that it sculpts in the sea ice. It does this by secreting an anti-freeze mucus that can keep water liquid to well below – 10°C. The algae bloom in the spring when they are released from the protective ice, and provide the basis of the marine food chain in this area. ScienceDaily (Mar. 7, 2011)

Current polarised plankton: Many planktonic species group together to form extended chains; in still water the chains will point in random directions, but if there is a current present, then the chains will orient themeselves along the flow lines. This results in swirl patterns that can be seen in a flask of microbes in the laboratory – or in satellite images of the world’s oceans. The orientation effects light penetration into the water – increasing the amount of light back-scattered by more than 30% at low shear rates. ScienceDaily (Feb. 25, 2011)

Back from the dead: When the going gets tough diatoms form spores in which form they can wait out any adverse conditions. Researchers have now revived diatom spores from 100-year old sediment, showing that they are capable of waiting a very long time indeed for favourable conditions to recur. Perhaps most surprisingly, the researchers found that there were no genetic differences between diatoms that had been dormant for 100 years and those that had been active over this period. The period of 100 years is equivalent to 40 000 generations of diatoms, equivalent to 0.8 million years in human terms, which indicates that this species of diatom is incredibly resistant to genetic drift. ScienceDaily (Mar. 5, 2011)

Nautilus not a yoyo: Ultrasound telemetry and direct video tracking of Nautilus pompilius show that its diving behaviour is rather more complex than previously reported. Animals appear to spend most of the day at a fixed depth of 200m, with rapid dives occuring in the evening, followed by variable diving practice at night, reaching their deepest depths around dawn.
Dunstan AJ, Ward PD, Marshall NJ (2011) Vertical Distribution and Migration Patterns of Nautilus pompilius. PLoS ONE 6(2): e16311. doi:10.1371/journal.pone.0016311

The life and times of the blue shark: Prionace glauca is a common by-catch of the North Atlantic long-line tuna and swordfish fisheries, and may account for 50% of the total weight of the catch. Despite this, very little is known about it. In this study 40 sharks were captured and fitted with pop-up transmitters that record dive depth, temperature and light intensity for up to 6 months after the shark is released. The migration pathways taken by the sharks were reconstructed from the depth/temperature profile after relocating the transmitter after release. From this it was apparent that the sharks spent the summer on the continental shelf and then entering the Gulf Stream front in autumn and winter. On the continental shelf the sharks held an average depth of approximately 90m. On entering the Gulf Stream front the variability in depth profile increased dramatically, with some dives of over 1000m. The sharks also dived significantly deeper during full moons.
Campana SE, Dorey A, Fowler M, Joyce W, Wang Z, et al. (2011) Migration Pathways, Behavioural Thermoregulation and Overwintering Grounds of Blue Sharks in the Northwest Atlantic. PLoS ONE 6(2): e16854. doi:10.1371/journal.pone.0016854

Noise distracts fish: Bursts of noise startled sticklebacks, and caused them to make mistakes, though they showed little fear, and did not reduce overall food consumption.
Purser J, Radford AN (2011) Acoustic Noise Induces Attention Shifts and Reduces Foraging Performance in Three-Spined Sticklebacks (Gasterosteus aculeatus). PLoS ONE 6(2): e17478. doi:10.1371/journal.pone.0017478

Magnetic turtles: Turtles can use local variations in the Earth’s magnetic field to position themeselves both in latitude and longitude. In doing this they monitor both the inclination of the magnetic field and its intensity. ScienceDaily (Feb. 28, 2011)

Update on wave modelling: The widely used wave simulation programs SWAN (available on GNU GPL licenses) has been extended to include simulation of breaking waves right up to the shore (SWASH). Modelling can be used cinematographically, or to gain an accurate physical understanding of wave generated currents right into the shore. ScienceDaily (Feb. 28, 2011)

Conservation

Aliens are eating our vegetables! Areas of barrens off the coast of Turkey are due to the presence of herbivorous fish, Siganus luridus and S. rivulatus, that have entered the Mediterranean from the Red Sea via the Suez Canal. Barrens usually occur where urchins have grazed upstanding macro-algae from a rocky sea-bottom, leaving only coralline red-algae. The authors suggest a fishery targeted on Siganus spp. to restore the more diverse macro-algae based ecosystem.
Sala E, Kizilkaya Z, Yildirim D, Ballesteros E (2011) Alien Marine Fishes Deplete Algal Biomass in the Eastern Mediterranean. PLoS ONE 6(2): e17356. doi:10.1371/journal.pone.0017356

Alien adaptation: The sea-squirt Styela clava has been introduced around the world from the NW Pacific, where it is considered a native, and is now considered a nuisance species in some areas. This study looks at the range in genetic diversity seen in Styela colonies, as determined by analysis of the mitochondrial cytochrome oxidase gene. Colonies show the complete range of possible colonisation patterns, from those associated with the introduction of a single individual, to those derived from multiple introductions of genetically differentiated individuals. Frequently the indrocuded species is found to have a higher genetic diversity than that found in its native range, possibly due to repeat introductions from a range of source populations. This provides the invader with a broad genetic war chest, and breaks the simple expected pattern of diversity increasing with date of initial colonisation.
Goldstien SJ, Dupont L, Viard F, Hallas PJ, Nishikawa T, et al. (2011) Global Phylogeography of the Widely Introduced North West Pacific Ascidian Styela clava. PLoS ONE 6(2): e16755. doi:10.1371/journal.pone.0016755

Threat networks monitor estuaries: Only 16% of the estuaries in the Western USA are not threatened by human activity – a similar figure to that in Europe. This study aims to identify conservation actions that might be useful in a regional/coordinated context, rather than as a local/emergency response. It attempts to do this by placing the estuary into a geographical context, identifying its catchment areas, and tabulating how human activity in these influence the nature of the estuary. The work identifies the main threats to estuaries in the region, and groups them by the type of threat(s) present.
Merrifield MS, Hines E, Liu X, Beck MW (2011) Building Regional Threat-Based Networks for Estuaries in the Western United States. PLoS ONE 6(2): e17407. doi:10.1371/journal.pone.0017407

Costa Rica Park: Information about a new marine protected area in the Eastern Tropical Pacific, which covers more than 2 million acres around the Cocos Islands, including a number of seamounts. Seamounts are considered important for marine biodiversity, often hosting large congregations of top predators such as hammerheads and reef sharks. By Elizabeth Weise in USA Today, Mar 04, 2011 via Marine Conservation News

Manatee conservation: A personal view of the conservation program for manatees in Crystal River, Florida, USA. The article provides a bit of background information, including the best times to see the manatees. The main threat to manatees is posed by boats, most animals bear scars from propellers. By Nadia in Project Blue Hope, 7th March 2011

Reef link protects fish: Maintaining links between reefs in the South China Sea will help fish larvae migrate and re-stock depopulated areas, helping species survive exploitation and climate change in the area. ScienceDaily (Feb. 26, 2011)

Hammerhead on the move: In the first successful satellite tracking of a hammerhead shark, a single animal was followed for 62 days, during which time it travelled more than 12,000 km, and increased the geographical range previously known to be occupied by the species. ScienceDaily (Feb. 28, 2011)

Grouper sex: A personal account of a mass spawning of groupers off the Cayman Islands. Mass spawnings are a fantastic site, but as they occur on fixed lunar dates, fisheries easily target them. Fishing at this time effectively wipes out the population, which is prevented from breeding by being caught. Apparently the practice is hard to stop, however.
Marine Conservation News, March 01, 2011

Greening your life: A short-list of things to do/avoid to reduce damage to the global ecosystem. Marine Conservation News, February 28, 2011

Fisheries and exploitation

Dinoflagellate titration: A PCR technique has been developed that allows quantitative estimation of the concentration of the dinoflagelate Ostreopsis sp., which can form toxic blooms. Results appear comparable to those obtained by microscopy.
Perini F, Casabianca A, Battocchi C, Accoroni S, Totti C, et al. (2011) New Approach Using the Real-Time PCR Method for Estimation of the Toxic Marine Dinoflagellate Ostreopsis cf. ovata in Marine Environment. PLoS ONE 6(3): e17699. doi:10.1371/journal.pone.0017699

Acrtic tender: A new vessel type has been designed to cope with the demands of servicing sub-sea installations in the arctic. It has a covered ‘moon-pool’ design, providing sheltered access to the sea for workmen on the ship. ScienceDaily (Feb. 28, 2011)

A little bit of fish oil helps the medicine go down? A daily 2g dose of fish oils reduced average weight loss to zero in cancer patients undergoing chemotherapy, this compares to an average weight loss of over 2kg in patients not given a fish oil supplement. Trial only covered 40 patients, it does not appear to have been double-blind. ScienceDaily (Feb. 28, 2011)

Too hot for cod? A range of natural cod stocks have been equipped with thermometers to check out the temperature range they are happy in. This work has found different stocks to frequent water between -1.5°C and 20°C – the latter being far warmer than previously considered to be part of their range. Whilst adult cod can tolerate this warm water, they are far fussier about the spawning temperature, all stocks required a temperature range of between 1 and 8°C to spawn. ScienceDaily (Feb. 25, 2011)

Pollution

Bugs and oil: This experimental study shows that different species of micobes naturally present in mangrove sediments respond differently to oil contamination. In this study Proteobacteria were largely unaffected by the presence of the oil, whilst Chromatiales decreased in abundance. Some genera increased in abundance on exposure to oil. The authors postulate that quantitative PCR might be used to identify contaminated sediments.
dos Santos HF, Cury JC, do Carmo FL, dos Santos AL, Tiedje J, et al. (2011) Mangrove Bacterial Diversity and the Impact of Oil Contamination Revealed by Pyrosequencing: Bacterial Proxies for Oil Pollution. PLoS ONE 6(3): e16943. doi:10.1371/journal.pone.0016943

Climate change

Plankton on an ice-edge: Phytoplankton blooms close to the ice edge in the Arctic Ocean have been seen by satellite. The phytoplankton appear during the spring thaw, as the sea-water here is diluted by melting ice. Phytoplankton form the base of the food chain, but at present it is not clear how the reduced amounts of ice in the Arctic will influence this. ScienceDaily (Mar. 4, 2011)

Bloomin’ early: Phytoplankton blooms have been happening earlier every year for the last decade, and are now are occurring 50 days earlier in some areas than they were ten years ago. A map of bloom occurrence shows that early blooms are concentrated at higher latitudes, whilst phytoplankton blooms at lower latitudes tend to be happening later in the year. Changes in timing of blooms are likely to have an impact on the life cycles of most other organisms in the sea. ScienceDaily (Mar. 3, 2011)

Forams in hot water: During the Paleocene-Eocene Thermal Maximum (PETM), 56 million years ago, global sea surface temperatures increased by 5°C. It appears that this temperature increase prompted a major change in the foram populations of the Arctic Ocean, with cold water species being displaced by warm water ones. Sediment cores from Spitzbergen indicate that Arctic waters also became more stratified, with fresh water overlying more saline deep waters. ScienceDaily (Feb. 27, 2011)