Marine science update 31-1-2011

January 31st, 2011

This issue we have tantalizing news of a new algal group – the rappemonads, which are reported to be common in both fresh and marine ecosystems, and goes to show the power of DNA based analysis. In conservation we have an article on seagrass in Northern Europe, which suggests that the eutrophication of coastal waters is an important factor. Seagrass (Zostra spp.) beds have largely disappeared from British waters, though I believe that disease has also been implicated here…

Finally, we end up in both hot and cold water in our section on climate change!

Marine science

New algal group: The discovery of new species is fairly common, but the rappemonads are reported to be quite diferent to other algae. They were first detected by DNA analysis, and have now been found in both fresh and marine ecosystems. ScienceDaily (Jan. 20, 2011)

The green generation: Many algae have complex life histories, with alternating sporophyte and gametophyte generations. In this study it was found that the gametophyte expresses more rubisco – a key enzyme in fixing carbon dioxide – than the sporophyte generation. In higher plants the number of copies of genes is often proportional to gene expression – wheras here we see that there is more rubisco being expressed in the haploid gametophyte plant than in the diploid sporophyte.
Wang C, Fan X, Wang G, Niu J, Zhou B (2011) Differential Expression of Rubisco in Sporophytes and Gametophytes of Some Marine Macroalgae. PLoS ONE 6(1): e16351. doi:10.1371/journal.pone.0016351

Colour me not interested: The tendency of staghorn coral larvae to settle down is related to the colour they fluoresce under ultra-violet light. Why this should be is a mystery. ScienceDaily (Jan. 27, 2011)

Cold corals: The distribution of corals on seamounts in the Drake passage between South America and Antarctica has been evaluated using towed camera surveys. The coral communities were found to be distinct to those of the Antarctic peninsula.
Waller RG, Scanlon KM, Robinson LF (2011) Cold-Water Coral Distributions in the Drake Passage Area from Towed Camera Observations – Initial Interpretations. PLoS ONE 6(1): e16153. doi:10.1371/journal.pone.0016153

Food from the land: Dead vegetation washed into the aquatic ecosystem from land may be a more important source of food in lakes. ScienceDaily (Jan. 24, 2011) [I wonder how important a source of food leaves are in parts of the Morecambe Bay marine ecosystem, particularly up-stream of the viaduct, where we commonly have more oak and beech leaves washed up in the strand line than seaweed]

The bugs from Brazil: DNA assays are increasingly popular means of evaluating the quantities and diversity of bacterioplankton, which are an important marine food source. Here samples in upwelling regions (rich in nutrients) are evaluated. The results suggest that human influence at some sites is reducing the diversity of bacterioplankton present.
Cury JC, Araujo FV, Coelho-Souza SA, Peixoto RS, Oliveira JAL, et al. (2011) Microbial Diversity of a Brazilian Coastal Region Influenced by an Upwelling System and Anthropogenic Activity. PLoS ONE 6(1): e16553. doi:10.1371/journal.pone.0016553

Premium polyphosphate: Bacterioplankton in low nutrient (oligotrophic) environments are more able to use polyphosphates than those found in other (more benign) environments.
Temperton B, Gilbert JA, Quinn JP, McGrath JW (2011) Novel Analysis of Oceanic Surface Water Metagenomes Suggests Importance of Polyphosphate Metabolism in Oligotrophic Environments. PLoS ONE 6(1): e16499. doi:10.1371/journal.pone.0016499

The middle-aged bird catches the fish: In penguins it appears that both fitness and experience are important in catching a meal, with middle-aged birds having to spend less time diving for food than either younger or older birds.
Zimmer I, Ropert-Coudert Y, Kato A, Ancel A, Chiaradia A (2011) Does Foraging Performance Change with Age in Female Little Penguins (Eudyptula minor)? PLoS ONE 6(1): e16098. doi:10.1371/journal.pone.0016098

Depth reset: New technique for allowing for drift in depth-time sensors attached to diving animals.
Luque SP, Fried R (2011) Recursive Filtering for Zero Offset Correction of Diving Depth Time Series with GNU R Package diveMove. PLoS ONE 6(1): e15850. doi:10.1371/journal.pone.0015850

Conservation

How seagrass responds to environmental change: Seagrasses such as Zostera marina are an important ecosystem, capable of trapping sediments and helping to clear surrounding waters. Here researchers have brought data together from Northern Europe to try and quantify the important factors in the establishment of successful seagrass habitats. Eutrophication due to nitrogen pollution seems to be the primary cause of problems.
van der Heide T, van Nes EH, van Katwijk MM, Olff H, Smolders AJP (2011) Positive Feedbacks in Seagrass Ecosystems – Evidence from Large-Scale Empirical Data. PLoS ONE 6(1): e16504. doi:10.1371/journal.pone.0016504

Should you feed the sharks? Shark feeding stations provide tourists with the opportunity to see sharks, and appear to concentrate numbers of mature animals in the environs of the feeding station. This may be beneficial, but more study is required.
Brunnschweiler JM, Baensch H (2011) Seasonal and Long-Term Changes in Relative Abundance of Bull Sharks from a Tourist Shark Feeding Site in Fiji. PLoS ONE 6(1): e16597. doi:10.1371/journal.pone.0016597

Coral response to heat stress: This paper looks at how the expression of genes associated with programmed cell death (apoptosis) changes on exposure to stress.
Pernice M, Dunn SR, Miard T, Dufour S, Dove S, et al. (2011) Regulation of Apoptotic Mediators Reveals Dynamic Responses to Thermal Stress in the Reef Building Coral Acropora millepora. PLoS ONE 6(1): e16095. doi:10.1371/journal.pone.0016095

Fisheries and acidic oceans: Are predicted to be the two big challenges for life in our planet’s oceans. Research blog by Kevin Zelnio in Deep Sea News, January 24th, 2011

Mauritanian fisheries: Monk seal and hump-backed dolphin are at risk from fisheries activities off the West coast of Africa. ScienceDaily (Jan. 21, 2011)

Fisheries and exploitation

Fish farms and wild fish: This study on Norwegian salmon fish farms looked at how they impacted wild cod and siath, which are attracted to the farms by the abundance of food. The broad conclusion is that the farms do not have an adverse effect on the wild fish.
Dempster T, Sanchez-Jerez P, Fernandez-Jover D, Bayle-Sempere J, Nilsen R, et al. (2011) Proxy Measures of Fitness Suggest Coastal Fish Farms Can Act as Population Sources and Not Ecological Traps for Wild Gadoid Fish. PLoS ONE 6(1): e15646. doi:10.1371/journal.pone.0015646

Pollution

Mercury in the Bay: A new fingerprinting technique is being used in San Fransisco Bay area to work out the sources of mercury contamination. The Bay has had a high historic load from gold mining, and this is being topped up by modern industries including power plants, manufacturing and oil refining. The technique appears to be based on isotope abundance [from press review]. ScienceDaily (Jan. 25, 2011)

Can I have prozac with that? Another city wakes up to the fact that the drugs its inhabitants take are going to end up in sewage. In the case of Montreal, these drugs end up in the St Lawrence. Here analysis shows that fish concentrate certain of these – notably the anti-depressants – and these effect the fishes behaviour. Perhaps we should add a feel good factor to the benefits of a fish diet… ScienceDaily (Jan. 21, 2011)

Plastic mole-hill: While the problem with plastics in the world’s oceans should not be underestimated, it looks like some people have been applying a deal more hyperbole than the reality on the ground (or in the water) actually merits. Further, it has led to some calls for action, such as filtering vast volumes of surface waters, that would be greatly more damaging than the presence of the plastic. ScienceDaily (Jan. 5, 2011)

Blow-out report: A viewpoint on the causes of the Gulf Oil Spill. By Megan in MCN, January 21, 2011

Oysters to clean up estuaries? It seems that some species of oyster may be capable of removing significant amounts of the pollutants, including nitrogen, phosphorous and carbon, commonly found in land run-off
ScienceDaily (Jan. 23, 2011)

Persistent dispersant: Large amounts of dispersant were injected directly into the well head during the Gulf Oil Spill, to permit access to the site. Recent research shows that whilst they are very extensively diluted, they they have not degraded at all. ScienceDaily (Jan. 26, 2011)

Climate change

Acidic waters impact coral: This study shows that coral larvae are adversely effected by seawater that has been acidified by adding excess carbon dioxide to pH’s of 8.0, 7.6 and 7.3, which are expected to occur over the next 300 years. While the survival and oxygen use by the larvae were not effected, larvae in acidic waters were a lot slower to metamorphose, and many failed to develop beyond the larval stage at all.
Nakamura M, Ohki S, Suzuki A, Sakai K (2011) Coral Larvae under Ocean Acidification: Survival, Metabolism, and Metamorphosis. PLoS ONE 6(1): e14521. doi:10.1371/journal.pone.0014521

Hot and cold water: While ocean temperatures have been rising in general, there are exceptions. One such is area is along the 24.5° parallel in the Atlantic Ocean. Here temperatures fell by 0.15°C between 1998 and 2006. The fall is attributed to increased wind speeds contributing to evaporative cooling. ScienceDaily (Jan. 26, 2011). In contrast, the waters of the North Atlantic and entering the Arctic ocean are warming rapidly, and are now hotter than they have bee for 2000 years! ScienceDaily (Jan. 28, 2011)

Posted in Conservation, Marine science update, Science