Oil spills, chemical weapons, global warming, even toxic octopuses in this week’s episode. Just when you thought it couldn’t get any worse, a report has surfaced over the last two days that the levels of global marine primary production are in free-fall. This story links with our report last week, that phytoplankton actually start to bloom in the winter, when turbulence reduces the density of predators (Acepted theory of algal blooms wrong). This week global warming is blamed for increasing the temperature of surface waters, causing them to become more stratified, and reducing the chance of mixing with deeper cold water masses. The worrying thing is that this week’s report is based on evaluation of historic data for phytoplankton levels in seawater, so it looks like the feedback loop we predicted last week is already picking up speed… Our second article is a calibration exercise to allow us to quantify phytoplankton blooms from space more accurately, I hope that this will show up some errors in the estimates made in the first paper.

Phytoplankton in a fix

Global marine primary production falls by 40% in 60 years: Researchers at Canada’s Dalhousie University have reported that increased water temperatures correlate with reduced phytoplankton levels. The report is based on historic measurements of water transparency. Our Amazing Planet, Jul 28, 2010. A Further news release on this story is available through Science Daily (July 28, 2010). Here the decline in phytoplankton has been quantified as 40% reduction in the northern hemisphere since 1950.

Calibrating satellites for algal blooms: Phytoplankton are the primary producers of the world’s oceans, supporting very nearly all of the rest of the food chain (as well as mopping up carbon dioxide from the atmosphere). Most phytoplankton production seems to be concentrated in short-lived algal blooms, and the best place to detect and measure the extent of these is from space, as the algal blooms change the colour of the sea – but how much colour equates to how much phytoplankton? NASA’s ICESCAPE voyage to the arctic is in the process of improving the calibrations between what can be seen from space, and what is happening in the water. Improved data on primary production feeds into all areas of marine exploitation, as well as helping to refine climatic models which are essential to planning human interactions with the global ecosystem. ScienceDaily (July 26, 2010)

Following up the ash: Scientists set sail again to try and pick out the effects for the Iclandic ash cloud in the North Atlantic. The amounts of trace elements added to the water column from the ash should assist phytoplankton growth, and may lead to more extensive blooms this year. BBC News 20 July 2010

How do new species of phytoplankton occur? New species are often considered to arrise through geographical isolation. Many phytoplankton species, however, are ubiquitous, quietly drifting around the worlds oceans, so how do new species form in this case? Drawing on analyses of the DNA profiles from around the globe, this report indicates that in fact even ubiquitous species are formed of smaller localised populations which show a number of differences with more distant cousins. ScienceDaily (July 29, 2010)

Life at sea

Sampling beneath the ice: An autonomous vehicle has been used for the first time to record data beneath the polar ice-cap. The vehicle sensed temperature, salinity, light (and photosynthetic activity), micro-algal concentrations as well as taking a number of water samples during its journey. ScienceDaily (July 29, 2010)

Cold and venemous: Marine organisms are increasingly being exploited as sources for novel drugs. One area of interest are the venoms secreted by some antarctic octopuses. These venoms work at sub-zero temperatures, making them especially interesting. The new compounds improve our understanding of small molecule toxins and may, directly or indirectly, lead to new drugs for treating a range of illnesses. ScienceDaily (July 28, 2010)

Finding somewhere to live in the ocean’s deeps: Chemosynthetic environments in the worlds deep oceans are thinly dispersed geographically, and many are ephemeral. This causes the organisms that make use of these environments severe problems with finding them. This PLoS 1 paper looks reviews earlier published work to try and uncover how these environments get colonised. There are a range of habitat types, including cold seeps, hydrothermal vents and large falls of organic matter such as dead whales! Of these the cold seeps are longest lived, the other habitats lifespans being measured in decades. Most organisms living at these locations must have arrived as larvae, and settled there to develop into the adult organisms.
Metaxas A, Kelly NE (2010) Do Larval Supply and Recruitment Vary among Chemosynthetic Environments of the Deep Sea? PLoS ONE 5(7): e11646. doi:10.1371/journal.pone.0011646

Stress in the vertebrates: Researchers are studying lampreys, fish that have retained many primitive features of early vertebrates, to help uncover the way our endocrine system works. The endocrine system controls factors underlying our health – such as stress – by the release of corticosteroidal hormones. They have found that while humans secrete 32 corticosteroids, lampreys make do with only one. It is not clear whether or not lampreys have a more chilled existance in consequence. ScienceDaily (July 19, 2010)

Nautilus live: Speak live to marine archaeologists working in the Aegean and Easter Med. The site also has some video footage, including one of marine life from a previous survey.

Conservation

Reef Resilience – how to fight climate change? This is a difficult one, starting with the question of ‘what is ecosystem resilience?’. An ecosystem is degraded when one or more species die out in response to stress, common stresses are pollution, fishing, disease, extreme weather etc. This process leaves other species that are either lucky, or in some way more robust to the damage being inflicted. Over time these survivors may colonise the space left by the ‘weaklings’. The authors hypothesise that the resultant ecosystem, while poorer in species, may, however, be able to withstand further stress better than the original ecosystem. The models they use to evaluate this hypothesis are tropical reefs, comparing how well pristine reefs recovered in comparison to degraded reefs, after a thermal bleaching incident (commonly blamed on global warming).
This is a provocative paper, and flies in the face of accepted reasoning, which argues that ecosystems retain the ability to recover right up to some critical level of damage, beyond which they collapse, effectively irrecoverably. There is certainly evidence for critical collapse scenarios in fisheries, where loss of a single key species has had significant and damaging knock on effect on the whole ecosystem (Cod off the grand bank, and sardines off Namibia – see Change of scene, change of species from last weeks post), but perhaps if true this paper may be a thin gleam of hope for the many damaged reefs around the tropics…
Côté IM, Darling ES (2010) Rethinking Ecosystem Resilience in the Face of Climate Change. PLoS Biol 8(7): e1000438. doi:10.1371/journal.pbio.1000438

Boundaries on a map: While many organisms have a concept of territory, their boundaries rarely match our own geopolitical boundaries. While this might seem to be obvious it can spring a nasty trap for the unwary population biologist or conservator! The reason is that species reporting on two sides of a political boundary is rarely equivalent, with both quantitative and qualitative differences being common. Often the area around a national park (or hopefully designated marine site) may have little or no useable data, so tempting the conservator to treat the park in isolation. In this paper the authors find that running population modelling studies in an area with tight artificial boundaries leads to inaccurate results, and even a buffer zone comprising randomly generated habitats yields a more accurate model.
Koen EL, Garroway CJ, Wilson PJ, Bowman J (2010) The Effect of Map Boundary on Estimates of Landscape Resistance to Animal Movement. PLoS ONE 5(7): e11785. doi:10.1371/journal.pone.0011785

How to manage the coral triangle: The coral triangle is said to have 10 times the biodiversity of the Great Barrier Reef. There are, however, some problems with develping a conservation strategy for the area, which is bounded by East Timor Indonesia, Malasia, the Philipines and Papua New Guinea. There are funding shortfalls, and questions as to whether some of the established reef conservation strategies are suitable for developing countries. Marine Conservation News, July 17, 2010

Pollution

Drugs take their tole: The pharmaceuticals/drugs we take are commonly quite persistent in the environment. Designed to work at low doses, they continue to work long after they have had their desired effect. Recently scientists have started to look at a range of behaviour altering drugs. It is probable that these do not make shrimps happy, but there is increasing evidence that common drugs such as flouxetine and seratonin do change their behaviour at the concentrations common in sewage waters. This post is based on an article in Aquatic Toxicology, and has some nice illustrations and an easy to follow discussion (so a bit more information if you liked last weeks post on depressed crustacea). Deep Sea News, July 19th 2010

Munitions dump survey: Following our previous note on battlefield ecology, here is a report of a survey of HI-05, or Sea Disposal Site Hawaii Number 5. It is thought that (amongst other things) up to 16,000 100lb bombs loaded with mustard gas were disposed of on the site. The survey took water, sediment and biological samples from the area, using deep water submersibles and ROV’s (depths about 500m). The survey noted extensive corrosion on many of the munitions, but only got one unconfirmed positive for mustard. ScienceDaily (July 29, 2010)

Sub-tropical swimmers go sick: Even when there is no measurable level of pollution, swimmers in sub-tropical waters experienced higher rates of fever or skin complaint compared to those who did not enter the water. ScienceDaily (July 28, 2010)

Oil leak(s)

Health impacts to resident humans: A survey of Louisiana’s coastal communities suggests that the primary causes of oil spill related ill health related are psychological in nature. ScienceDaily (July 20, 2010)

BP photoshopped disaster control centre photo: The photo of the control centre had a couple of dead screens, so BP photoshopped pictures onto them to make it look like more was happening. Then got caught doing it. Which is the lesson you will take home? BBC 21 July 2010

Chinese oil spill: There has been a serious oil spill in China, when approximately 1500 tonnes of oil escaped after a pipeline explosion. The loss of the pipeline is thought to be of significant economic importance. Local weather paterns have kept the spill close to the shore. Reports from BBC (21 July 2010) and News.com (28 July 2010)

To disperse, or not to disperse? – That is a question:

Was it right to use dispersants? Vast amounts of dispersant were used to try and break up the spill from the DeepWater Horizon. Dispersants help the oil disolve so it can be mixed into seawater, rather than forming a slick on the surface. This reduces the impact of the spill on sea birds, which get oiled when they land on the slick, or attempt to fish through or in it. It is possible, however, that it will increase the impact on fish, as the finely dispersed oil is still toxic. Where it has probably had most deleterious impact is in benthic fauna, however, both due to direct toxicity, and because as the finely dispersed oil decomposes in the water column it takes the oxygen out of the water. This is clearly going to be fatal to anything that cannot move away from the slick. It is claimed that dispersants are not especially toxic in themeselves, but they do have a big impact on where the oil ends up, and how it effects marine life. Corp Watch, July 19th, 2010

Oil dispersants not toxic: US government researchers report that the dispersants used in the Gulf of Mexico show low toxicity in tests on mammalian cells. As noted above, however, much of the worry about using dispersants is that they allow oil to enter the water column, and the combined toxicity (to marine life rather than people) of oil+dispersant may be worse than that of oil alone. ScienceDaily (July 22, 2010)

Exploitation and sustainability

Marine collection tested for new drugs: Scientists are testing extracts from organisms collected from the deep waters off the FLorida coast for compounds active against the malaria parasite. ScienceDaily (July 20, 2010)

Fishermen slam Clyde report: More on the state of fisheries in the Clyde – here the Chief Executive of the Scottish Fishermen’s Federation is reported to have poured scorn on the report by York University that draws attention to dangerously depleted levels of both fish and . Anecdotal reports from anglers in the same article do seem to support the view that the fish stocks in the area are at an historically low level, however, and that this is associated with commercial fishing activity. Dunoon Observer 23 July 2010.

No sex please, we’re for the table: Sterile fish are being bred for aquaculture, the fish will not be able to breed in the wild, reducing worries about accidental releases. ScienceDaily (July 23, 2010)

Russian reefs boost fish stocks: The first artificial reefs were deployed in the Possiet Gulf in 1977, and long term observations have shown that these resulted in increased productivity of the coastal waters. Russia IC, July 28 2010

Oyster shell reefs: Fishermen are dumping shucked oyster shells to form new reefs in Brunswick County US. The objective is that these reefs will encourage future oyster settlement, improve water quality, provide a habitat for fish and help protect coast lines from errosion. There is an ongoing scientific investigation, which has carried out baseline monitoring before the scheme, and will continue monitoring for a period after its completion. Lumina News, July 19, 2010

Climate change

Surveying arctic passages: As sea ice recedes sea traffic in the arctic is expanding, but much of it depends on charts prepared in the 1800’s using sounding leads, where it has been surveyed at all. NOAA has dispatched the RV Fairweather to update many of these charts this summer. ScienceDaily (July 20, 2010)

A blast of sanity: Apparently intense cosmic gamma ray bursts can kill phytoplankton to a depth of 75m – but if this occurs we are more likely to be dead than worrying about the damage to the climate caused by the loss of the phytoplankton… Chad Orzel, Uncertain Principles, July 24th 2010.

Marine biodiversity linked to temperature: Pre-report of a Nature article due for publication on 28th July. ScienceDaily (July 28, 2010)

Tree ring data from Russian arctic indicate fast warming: The pattern of temperature change in the Arctic over the last 400 years is complex. Some areas have shown cooling until comparatively recently, now tree-ring samples from Russia’s Kola peninsula, coupled with other tree-ring studies from Lapland and the Taimy peninsula, demonstrate that this cooling period ended around 1990, and subsequently almost all areas show an increase in temperature. ScienceDaily (July 29, 2010)