Lots of pollution – the Deepwater Horizon was now the largest spill ever (official). Problems with policing conservation policy. How alike are flocks and shoals? Read on…

General marine science

Swarms and schools: Fish schools and krill swarms take on the same general shapes, it is claimed. COmputer modelling indicates that this shape is a simple balance between getting enough oxygenated water, and avoiding being eaten! Author’s note: This implies that there may be significant differences in shape between schools and flocks of birds or flying insect swarms, as in air a group would have to be very dense indeed to prevent creatures getting enough oxygen… ScienceDaily (Sep. 18, 2010).

One species or two – let the sea decide! Cutthroat (Oncorhynchus clarki clarki) and rainbow trout (Oncorhynchus mykiss) share the same freshwater rivers to breed, and in many places hybridisation between the two species has been recorded. Telemetry studies in this paper show that the hybrids show differences in migration behaviour to both parent species. Their conclusion is that while the shared freshwater habitat provides opportunity for hybridisation, the experience of the fish in the marine environment weeds out the less fit hybrids, and so helps to define the two species as separate entities.
Moore ME, Goetz FA, Van Doornik DM, Tezak EP, Quinn TP, et al. (2010) Early Marine Migration Patterns of Wild Coastal Cutthroat Trout (Oncorhynchus clarki clarki), Steelhead Trout (Oncorhynchus mykiss), and Their Hybrids. PLoS ONE 5(9): e12881. doi:10.1371/journal.pone.0012881

The tick-tock of the circadian clock: The circadian clock is a system for regulating diurnal behaviour, and is found in most plants and animals. In this paper, the genes that sea anemones use to regulate the clock are shown to be very similar to those found in the ‘bilateraria’ (animals with bilateral symmetry – crustacea, insects, slugs, us). This indicates that our biological system for organising our daily rhythms started developing a very long time ago…
Reitzel AM, Behrendt L, Tarrant AM (2010) Light Entrained Rhythmic Gene Expression in the Sea Anemone Nematostella vectensis: The Evolution of the Animal Circadian Clock. PLoS ONE 5(9): e12805. doi:10.1371/journal.pone.0012805

Sticky oysters: Scientists have uncovered the formulation for the cement used by Crassostrea virginica to hold groups of oysters together in a stable bed. Unlike the proteinaceaous threads used by mussels in Morecambe Bay, these oysters use quite a hard cement largely composed of calcium carbonate. ScienceDaily (Sep. 23, 2010)

Mary Mary, quite contrary, how do your hydrozoa grow? The paper referenced here looks at reverse modelling the patterns that lichens make on rocks – but there are a number of encrusting marine species that might be modelled in a similar way. My first thought was of anemones, which commonly bud off to form fields of clones, often with quite distinct colours, but maybe pink encrusting algae and sponges might also be interesting topics of analysis. The nice thing is you can do the analysis on photos, after your dive (might be a nice project for the mathematically inclined marine biologist!)
Jettestuen E, Nermoen A, Hestmark G, Timdal E, Mathiesen J (2010) Competition on the Rocks: Community Growth and Tessellation. PLoS ONE 5(9): e12820. doi:10.1371/journal.pone.0012820

The worms they are a-turnin: A few years ago the Lancashire MCS made a trip out to Loch Creran Fyne to see if large groupings of sea mice occurred regularly at fixed times of year. Suffice to say the grouping is either short lived (and missed) or simply not an annual occurrence… This paper looks at a more fundamental level at how polychaet assemblages occur, and what environmental variables govern the spacies likely to occur in them. It doesn’t, unfortunately tell us when next we might dive with numbers of sea mice…
Benedetti-Cecchi L, Iken K, Konar B, Cruz-Motta J, Knowlton A, et al. (2010) Spatial Relationships between Polychaete Assemblages and Environmental Variables over Broad Geographical Scales. PLoS ONE 5(9): e12946. doi:10.1371/journal.pone.0012946

Irish sharks: New study on a sub-species of dog-fish common off the Irish East coast. ScienceDaily (Oct. 3, 2010)

60BPM – healthy reef: Sick and healthy reefs make different sounds – or so scientists at Exeter claim. Low frequency noise is correlated with the numbers of fish living on the reef, while higher frequency noise is an indication of coral diversity. ScienceDaily (Sep. 25, 2010)

Conservation

I am the law! – Judge Dredd said it, but in the marine conservation policy, who is the law, and how efficiently is it policed? Unfortunately illegal, unreported and unregulated (IUU) fisheries are a severe problem in many areas of the globe. This paper finds that where policies are more strictly enforced IUU fisheries often simply move to regions where enforcement is less efficient. As a consequence there is increasing need for a more holistic approach to conservation governance in the marine environment.
Österblom H, Sumaila UR, Bodin Ö, Hentati Sundberg J, Press AJ (2010) Adapting to Regional Enforcement: Fishing Down the Governance Index. PLoS ONE 5(9): e12832. doi:10.1371/journal.pone.0012832

Chagos Islands conservation zone secures £3.5M donation: The donation, from the Bertarelli Foundation, helps to fill a £750,000 per annum shortfall from tuna fishing revenues that previously helped pay for fisheries protection in the area. There is little doubt that without any protection the area will be very heavily exploited by boats of all sizes from around the Indian Ocean. We believe that reserves are necessary, but the Chagos raises an important question of how we pay to police them. With cuts to policing on our streets, are we be willing to dig into our pockets to pay to protect a marine reserve half the world away? The evidence is that there is very little political will to do this for reserves in our own waters, even when the evidence suggests that this would benefit our fishing industry in the medium to long term… The End of the Line, September 16, 2010

Coral bleaching expected in Caribbean: NOAA’s Coral Reef Watch monitoring system is showing above average temperatures through much of the Caribbean. High temperatures result in heat-stress for the corals, which expell their algal symbionts. This event often leads to the death of the coral itself. ScienceDaily (Sep. 29, 2010)

Land-use and disease: This paper finds evidence that land use, particularly agricultural practice that results in nitrogen entering coastal water, is associated with disease in marine turtles. The increase in disease prevalance seems to be due to a change in diet, towards eating the macro-algae that are favoured by increased nutrient levels.
Van Houtan KS, Hargrove SK, Balazs GH (2010) Land Use, Macroalgae, and a Tumor-Forming Disease in Marine Turtles. PLoS ONE 5(9): e12900. doi:10.1371/journal.pone.0012900

Conserving Pacific Salmon: In any conservation strategy there must be concern to maintain a genetically diverse population, as populations with low diversity tend to have poor responses to environmental stresses, such as disease. This paper presents a mathematical model for evaluating genetic diversity in wild Pacific salmon stocks.
Cenik C, Wakeley J (2010) Pacific Salmon and the Coalescent Effective Population Size. PLoS ONE 5(9): e13019. doi:10.1371/journal.pone.0013019

Fisheries and exploitation

Do powerlines have an effect on fish? Or, indeed, any other animals living in the sea. With the increased use of off-shore power, I guess we will need to know this! ScienceDaily (Sep. 20, 2010)

Histidine may prevent cateracts in farmed salmon. ScienceDaily (Oct. 1, 2010)

Migrations of Pacific salmon: Migration is a means for fish to find new food sources, but it is coupled with a very much increased risk of predation. This work reveals that salmon have a range of migration strategies, and these strategies are modified by upbringing – with farmed salmon having moving down-river at a different rate to wild salmon, and migrating in different directions when entering the ocean. This appears to be due to natural selection pressures on their wild counterparts – the farmed fish don’t have a recent roadmap to the best food sources.
Melnychuk MC, Welch DW, Walters CJ (2010) Spatio-Temporal Migration Patterns of Pacific Salmon Smolts in Rivers and Coastal Marine Waters. PLoS ONE 5(9): e12916. doi:10.1371/journal.pone.0012916

Pollution

Antibiotic seagulls: Antibiotics are very extensively used in medicine and animal welfare, but the antibiotics themeselves are finding their way into the ecosystem after use. This has the effect of exposing bacteria to low-levels of antibiotic, to which they can develop resistance. In this latest of a series of studies, bacteria in migratory seagull droppings are found to be antibiotic resistant. Spreading ‘super poo’ all around the world… ScienceDaily (Sep. 22, 2010)

Gulf oil spill – “the largest ever”: Independent review puts the amount of oil leaking from the well to be between 56,000 and 68,000 barrels per day, until it was first capped on 15th July. ScienceDaily (Sep. 23, 2010)

Gulf dead-zones … caused by agriculture? The Gulf of Mexico is plagued by hypoxia events, where oxygen levels in the water column fall to very low levels, killing most of hte animals living in it. This is not due to oil spills, however, but to the pattern of agriculture in the Mississippi basin. Nitrate run-off from the corn belt is now considered to be the prime supect. This farming practice is characterised by a tile drainage pattern, which permits nitrates to run-off the land very quickly. The easiest way of rectifying the problem would be to slow and dilute nitrate loaded run-off. ScienceDaily (Sep. 27, 2010)

The hunt for oil … spills: New technique for identifying oil in sediments using a hand-held infrared spectrometer, which gives instant readouts of levels of contamination. ScienceDaily (Sep. 29, 2010)

New laws to increase culpability: Currently stalled in the senate, but new laws in the US may raise the $75m cap on damages payable after an oil spill (BP has offered to pay $20B – but were not obliged to do so under law). and increase the level of assessment required prior to getting a drilling license. The Spill, September 27, 2010

Where did the oil go? A research cruise has documented that the oil from the well head dispersed in four large plumes, which headed in different directions away form the well head. The major component of the spill was in hydrocarbon gasses, in a shallow water accident these gasses would have bubbled directly to the surface. The depth of the Deepwater Horizon well-head, however, meant that these gasses were dissolved in the water column. Ethane, propane and butane were the components of the spill most readily digested by bacteria, and so responsible for most oxygen depletion. The rate of oxidation of methane, the largest component of the spill, increased from an innitially low level only as the other gasses were depleted. The fate of the methane and larger liquid hydrocarbons is currently unknown, but likely to still be at large in the deep water column due to their slower oxidation rates. ScienceDaily (Sep. 16, 2010)

Oil impact on the Gulf: Good – coastal habitats seem to be recovering well. Bad, oil being found in crab larvae, and layers of oil found overlying the sea floor up to 80 miles from the well head (everything is, unsurprisingly, dead under this layer). Deep Sea News, September 16th, 2010

Environmental catastrophe; no jobs lost. No comment. The Spill, September 16, 2010

Climate change

Sea ice minimum for 2010: There was more sea ice this year than in 2007 or 2008, putting this year third in terms of the extent of sea ice coverage since satellite measurements began in 1979. ScienceDaily (Sep. 16, 2010)