We’ve got a number of papers on different aspects of biodiversity in this issue, amongst these there is an estimate of global seafloor biomass (about 100 megatons), how plankton may form specialised regional sub-species, and how diversity decreases under climatic stress (on this occasion the cooling of the poles). We’ll start, however, with a nice bit of kit that looks quite buildable for anyone wanting to take a look underwater without having to dive…

Marine science

Habitat characterisation on offshore wind farms: A paper looking at the techniques available to monitor marine life in and around offshore energy installations. The authors have developed a towed sledge carrying video lights and cameras to record the bottom. The sledge has buoyancy tanks and a simple mechanical sensor to keep it at a fixed height above the bottom.
Sheehan EV, Stevens TF, Attrill MJ (2010) A Quantitative, Non-Destructive Methodology for Habitat Characterisation and Benthic Monitoring at Offshore Renewable Energy Developments. PLoS ONE 5(12): e14461. doi:10.1371/journal.pone.0014461

Guestimating seafloor biomass: The authors use data from the Census of Marine Life to develop a model that predicts the biomass on the seafloor, allowing for surface primary production, nutrient flows, topography and seawater quality. In preparing this report the authors acknowledge that the baseline data is skewed to European and North American shelf seas. For this dataset, however, some correlation was found between key environmental indicators and biomass. The paper contains some nice graphs showing how biomass changes with water depth, as well as the comparison between the environmental factors and biomass (which is surprisingly good). It then goes on to map predicted benthic biomass density across the worlds oceans. They calculate a global total of 110.3±48.2 megatons of living biomass based on these maps.
Wei C-L, Rowe GT, Escobar-Briones E, Boetius A, Soltwedel T, et al. (2010) Global Patterns and Predictions of Seafloor Biomass Using Random Forests. PLoS ONE 5(12): e15323. doi:10.1371/journal.pone.0015323

Diverse dinoflagellate: The genetics of the dinoflagellate Oxyrrhis marina has been studied to reveal its genetic diversity in greater detail. The study shows that the population of this species off North Wales is divided into two distinct sub-populations, a ‘stay-at-home’ and a more general UK-wide sub-population, with evidence of some interbreeding between the two.
Lowe CD, Montagnes DJS, Martin LE, Watts PC (2010) High Genetic Diversity and Fine-Scale Spatial Structure in the Marine Flagellate Oxyrrhis marina (Dinophyceae) Uncovered by Microsatellite Loci. PLoS ONE 5(12): e15557. doi:10.1371/journal.pone.0015557

Antarctic devolution: Ecosystem diversity reduces towards the poles, due to local extinctions that occurred as these regions became ice-bound in the early Modern period. In this study the details of how these extinctions effected the diversity of bivalves is investigated. It shows that species with smaller body-sizes tended to survive, whilst derived species were disadvantaged in comparison to core phyla.
Krug AZ, Jablonski D, Roy K, Beu AG (2010) Differential Extinction and the Contrasting Structure of Polar Marine Faunas. PLoS ONE 5(12): e15362. doi:10.1371/journal.pone.0015362

Minke migrations: The arctic and antarctic minke whales (Balaenoptera acutorostrata acutorostrata and Balaenoptera bonaerensis, respectively) migrate between their summer feeding grounds at the poles and their over-wintering areas in the tropics, and consequently never meet … except that this genetic fingerprinting analysis shows that occasionally they do get mixed up, and that here is at least one example of interbreeding…
Glover KA, Kanda N, Haug T, Pastene LA, Øien N, et al. (2010) Migration of Antarctic Minke Whales to the Arctic. PLoS ONE 5(12): e15197. doi:10.1371/journal.pone.0015197

Precambrian community: Sponges are amongst the earliest multi-cellular animals, and have had a lot of time to develop associations with microbial communities. This study focusses on associations between sponges and archaea. Due to the difficulty in culturing archaea, the study relies on rRNA finger printing to identify the microbial symbiont. The paper suggests that certain archaea may perform a useful role in oxidising ammonia, produced as a waste product by the sponge, and so reducing its toxicity to the sppnge.
Turque AS, Batista D, Silveira CB, Cardoso AM, Vieira RP, et al. (2010) Environmental Shaping of Sponge Associated Archaeal Communities. PLoS ONE 5(12): e15774. doi:10.1371/journal.pone.0015774

Just hanging around: We’re used to looking at species, but perhaps it is more sensible to look at gene families, the organism itself is just a disposable wrapper for its genetic code (after Richard Dawkins)! This report uses genetics to trace the evolution of life back over the 3 billion years preceding the Cambrian period, when we see the first good fossils. ScienceDaily (Dec. 20, 2010)

Look out – there is a shrimp about! The snail Hinea brasiliana is very unusual in producing a green light by bioluminescence. The colour is diffused by the snail’s shell, and may act as an alarm when predators are spotted. ScienceDaily (Jan. 2, 2011)

Chew on this! Apparently sea urchins have self-sharpening teeth – which they use to scrape algae off rocks, but can also use them to cut hollows into rocks for protection against predation and currents in the littoral environment. ScienceDaily (Dec. 26, 2010)

Conservation

MPA‘s span the ocean: Many species have planktonic larvae, which may be carried for some distance before settling. This study shows that distant fishing grounds may be seeded by fish larvae from MPA’s
Christie MR, Tissot BN, Albins MA, Beets JP, Jia Y, et al. (2010) Larval Connectivity in an Effective Network of Marine Protected Areas. PLoS ONE 5(12): e15715. doi:10.1371/journal.pone.0015715

Fisheries and exploitation

Fishing in the coastal zone: This study focusses on coastal fisheries in the developing world, and emphasises the importance of being able to monitor factors such as fishing effort in developing sustainable fisheries management policies.
Stewart KR, Lewison RL, Dunn DC, Bjorkland RH, Kelez S, et al. (2010) Characterizing Fishing Effort and Spatial Extent of Coastal Fisheries. PLoS ONE 5(12): e14451. doi:10.1371/journal.pone.0014451

Seamounts and tuna: Tuna have long been known to collect around certain seamounts, this study attempts to evaluate the importance of seamounts to tuna fisheries in the Pacific ocean, and identify features of seamounts that make them especially attractive to the fish. In conclusion the authors note the importance of the concentration effect on fisheries effort, and how this may conceal an overall population crash that focussed purely on catch without taking into consideration the location from which the catch is being taken.
Morato T, Hoyle SD, Allain V, Nicol SJ (2010) Tuna Longline Fishing around West and Central Pacific Seamounts. PLoS ONE 5(12): e14453. doi:10.1371/journal.pone.0014453

New technique for identifying IPN: Infectious pancreatic necrosis (IPN) is a disease that causes enormous losses to salmon farmers every year, and having caught the disease, any surviving fish can harbour the disease and cause new outbreaks. The new technique detection technique, based on real time polymerase chain reaction (RT-PCR) makes it possible to screen fry to prevent infections being moved from hatcheries to farms. ScienceDaily (Dec. 29, 2010)

Pollution

Better roots reduce fertiliser requirements: A big problem for estuarine and coastal waters is excess nitrogen run-off from agriculture, this over-stimulates marine algae, which strip oxygen out of the water column when they die, killing everything else in the water. This is a perennial problem in places like the Gulf of Mexico. This study looks at how crops can be grown on different root-stocks to reduce their nitrogen requirement, so reducing pollution at source. The aim is to be able to screen root-stocks for those that are the most environmentally friendly. ScienceDaily (Dec. 31, 2010)

You shouldn’t do it like that, do it like this! You cannot but have some sympathy for the people who managed the Gulf oil spill. Whatever their decision, there are a lot of people who are sure that they have messed up. Here are claims that adding corn-starch to the top-kill attempt might have cut the duration of the spill, and the damage done, very considerably. Apparently corn-starch would convert the drilling mud into a shear thickening ‘quicksand’, that would have helped seal breaks in the well. ScienceDaily (Dec. 23, 2010)

Gasp, choke! Hypoxic zones in the Atlantic are expanding, and reducing the living space available to several important commercial fish stocks. Researchers have found that the hypoxic zone of the West Coast of Africa is growing, and increasing sea temperatures, which reduces oxygen solubility in sea water, would make the problem worse. ScienceDaily (Dec. 23, 2010) [While many hypoxic zones are caused by agricultural run off, as in the Gulf of Mexico, over fishing is probably responsible for the West Coast hypoxic zone]

Climate change

Corals ring out changes: Just like trees, many corals show annual growth rings that are related to how well the coral grew that year. Studies on the growth rings of deep sea corals in the NW Atlantic have now shown that there have been drastic changes in the prevailing currents in this region since the 1970’s, and that these changes are unprecedented in the previous 2000 years… The researchers believe that the changes now being observed are a direct link between the ocean current regime and global warming. ScienceDaily (Jan. 4, 2011)

Is my house safe? Lets be brutal, we clearly don’t have much stomach for cutting CO₂ emissions, so assuming that 99% of all climate scientists are not lying, climate change is happening now. One facet of this that is going to be important to people living on the coast is sea-level rise. As this study from Chesapeake Bay shows, however, sea-level rise is complicated by local factors. It all makes for an exciting real-estate lottery for our children! ScienceDaily (Dec. 22, 2010)

Carbon and nitrogen: Study that shows that ammonia reduction rates are reduced as sea water becomes more acidic. As fixed nitrogen in the form of its oxides (nitrates and nitrites) and ammonia are limiting nutrients over much of the ocean, the increased abundance of ammonia may result in a switch in importance of the two forms of nitrogen, and fundamental changes to the marine ecosystem. ScienceDaily (Dec. 21, 2010)