All posts by Jill Studholme

Edits SCUBA News (ISSN 1476-8011), the monthly newsletter with articles on diving and marine science. She tweets as @SCUBANews. You can find her on Google+ at

Ocean Art Underwater Photo competition now open – $75000 of prizes to be won

The Underwater Photography Guide is now accepting entries for the 5th annual Ocean Art competition. Prizes worth over $75000 are on offer in 15 categories giving underwater photographers of all levels a chance to win.

For the less experienced photographers there are novice, compact camera and mirror-less camera categories. Then there are the wide-angle, macro, marine life portraits and marine life behaviour. More unusually, this competition also features categories of supermacro, cold or temperate water and nudibranchs.

Award winning nudibranch photo
Photo: Salvatore Lanniello

Winners from each category will be able to choose which resort, liveaboard or gear prizes they would most like to receive, making it more likely that winners will be able to win something they really covet. The prizes include liveaboards to Raja Ampat, the Solomon Islands and Fiji; diving resort packages at Papua New Guinea, Bali, Philippines, Roatan, Palau and elsewhere; and gift vouchers for photographic equipment.

Photo: Montse Grillo
Photo: Montse Grillo

Judges include world-renowned underwater photographers Tony Wu, Martin Edge, Marty Snyderman and Scott Gietler. Martin Edge is the author of The Underwater Photographer, one of the most useful books on underwater photography ever published. Marty Snyderman is an Emmy winner with work appearing in top publications like National Geographic. Tony Wu is the author of Silent Symphony whilst Scott Gietler is the owner the Underwater Photography Guide.

Photo: Christine Shepard
Photo: Christine Shepard

Photos must be submitted before the deadline on 24 November 2015.
Photo: Ron Watkins
Photo: Ron Watkins

More information and entry forms can be found on the Ocean Art Photo Competition page at

Elephant seals measure oxygen content of ocean

Female elephant seals are monitoring dissolved oxygen in the ocean.

Diving almost continuously at great depth during most of the year, and covering large distance through remote areas of the Southern Ocean, Kerguelen elephant seals have proved to be a great alternative to other instruments for monitoring the oceans. The seal-derived measurements of oceanic dissolved oxygen give better results than other methods, according to new research.

The current decline in dissolved oxygen concentration within the oceans indicates the effect of climate change on the sea. However the impact of its declining on marine life and ecosystems’ health is still quite unclear because of the difficulty in obtaining data, especially in remote areas like the Southern Ocean. French scientists are therefore using Southern elephant seals to monitor oxygen, temperature and salinity.

The scientists – Bailleul, Vacquie-Garcia and Guinet – attached sensors to five elephant seals. These seals delivered essential information about the water properties and reinforced the relationship between marine ecology and oceanography.

As the ocean waters get warmer, the solubility of oxygen drops. The warmer ocean waters are more stable, slowing down the ocean circulation system and reducing the vertical mixing processes between water layers. The result is less oxygen transported from the oxygen-rich surface layer (in contact with the air) into the deep ocean, where zones depleted in dissolved oxygen are expanding. In addition, the slowing down of the ocean’s circulation system also results in a reduced supply of nutrients from the deep layers into the ocean surface. The low availability of nutrients in the surface layers causes the decline of phytoplankton biomass and diversity – so less oxygen proucers – and hence, the level of oxygen at surface is bound to decline further. Dissolved oxygen is therefore a very sensitive indicator of changes in properties of the marine environment, but less is known about its affect on marine life.

Up to few years ago, accurate oxygen measurements were performed from infrequent and geographically-limited research vessel surveys. Recent improvements in sensor technology have nevertheless enabled a number of new bio-geochemical sensor packages to be deployed on new autonomous measurement platforms, such as profiling floats, gliders or moorings. However, despite these significant advances, some regions remain challenging to investigate using such observing systems. Because of its remoteness, regular harsh weather conditions and seasonal presence of sea ice, the Southern Ocean remains largely under-sampled by the conventional instruments: enter the elephant seals.

Southern Elephant Seal (Mirounga leonina) by David Cook
Southern Elephant Seals (Mirounga leonina) by David Cook

Ranging from sub-Antarctic to Antarctic waters through the Southern Ocean, elephant seals look to be efficient assistants for delivering information. They revealed as expected the higher solubility of cold Antarctic waters to oxygen compared to the warmer waters at lower latitudes. They also provided new additional information on the properties of the different water masses through which they passed.

Although not directly used by air-breathing predators, such as elephant seals, dissolved oxygen is crucial for life of many other marine organisms, such as potential fish or squid prey of seals, and its direct measurement by predators could provide essential information on the distribution and the habitat of their prey.

Further Reading

Bailleul F, Vacquie-Garcia J, Guinet C (2015) Dissolved Oxygen Sensor in Animal-Borne Instruments: An Innovation for Monitoring the Health of Oceans and Investigating the Functioning of Marine Ecosystems. PLoS ONE 10(7): e0132681. doi:10.1371/journal.pone.0132681

Photo credits: David Cook, Liam Quinn

SCUBA Divers cause coral disease and damage – it’s official

SCUBA diving and snorkelling are amongst the fastest growing tourism sectors. The increasing numbers mean many more people are aware of the beauty and importance of the marine environment, but also puts a great strain on the coral. Not only is it damaged by inexperienced divers kicking it and pollution from boats and hotels, research also shows that coral is much more likely to become diseased in highly dived areas.

Australian and Thai researchers Joleah Lamb, James Trued, Srisakul Piromvaragornc and Bette Willis compared levels of coral diseases at high and low use dive sites around the area of Koh Tao in Thailand. The scientists surveyed 10,499 corals at ten dive sites around the island. They found twice as many healthy corals at little-dived sites (79%) as they did at the more popular dive areas (45%).

Dive sites around Koh Tao
Little-dived sites are shown in white, popular dive sites in black

They also found a three-fold increase in coral disease at high-use sites, as well as significant increases in sponge overgrowth, physical injury, tissue death from sediment and abnormally pigmented coral tissues.

Injured corals were more susceptible to “skeletal eroding band disease” only at high use sites, suggesting that the extra stress placed on corals by lots of divers increases the development of disease.

Perhaps even more worrying, divers kicking up sediment was “suffocating” coral tissue leading to its death. And this was was strongly associated with the prevalence of a devastating group of coral diseases – the so-called white syndromes – across all the sites studied.

With better management the coral could be better protected. For example limiting the number of dive operators visiting each dive site at the same time and reducing the pollution entering the water from boats would reduce the stress on the corals.

Further Reading

Joleah B. Lamb, James D. True, Srisakul Piromvaragorn, Bette L. Willis, Scuba diving damage and intensity of tourist activities increases coral disease prevalence, Biological Conservation, Volume 178, October 2014, Pages 88-96, ISSN 0006-3207,

State of Europe’s seas getting worse

Europe is woefully behind in its ambition of achieving a ‘good environmental status’ of our seas by 2020, according to a report published today by the European Environment Agency.

Only 4% of the marine species and habitats assessed have achieved the 2020 target of ‘good’ status.

A range of human-induced pressures are affecting the state of marine ecosystems directly. These pressures include

  • Physical loss and damage to the seafloor
  • The capture of fish and shellfish
  • The introduction of non-indigenous species
  • Pollution entering from land and the atmosphere
  • Marine litter
  • Underwater noise
Fish by Tim Nicholson - Bib
Photo by Tim Nicholson

Some of these pressures are showing signs of improvement. For example, since 2007 fishing pressure has been brought down back to sustainable levels for an increasing number of stocks in the North-East Atlantic Ocean and Baltic Sea.

The report reveals many distressing statistics

  • Only 9% of the marine habitats assessments are in ‘favourable conservation status’ compared to 66% in ‘unfavourable conservation status’.
  • Just 2% of of the assessed commercial stocks in Europe’s seas are in ‘good environmental status’. 58% are not in a good environmental state with the status of 40% of stocks not assessed due to lack of data.
  • In the Mediterranean Sea, 67% of resident marine mammal species, 42% of sharks, rays, and skates and more than 8% of native marine fish species are considered threatened.
  • 30–50% of the cold-water coral reefs found in Norwegian waters have been damaged to an observable extent by trawling.
  • Oxygen depletion in the Baltic Sea is ten times worse than a century ago, with hypoxic areas now covering some 60 000 km2 or 15% of the Baltic Sea. This development is in keeping with the global trend, whereby the area of dead zones due to hypoxia has doubled every decade since 1960s.

Environmental organisations like Oceana are concerned at the report.

Our seas cannot sustain the current pressure of human activities for much longer. It is not only for the sake of the environment, but also for our own – by pushing marine ecosystems to the limit, we are also gambling with our food security and economic growth,” said Lasse Gustavsson, executive director for Oceana in Europe. “The message to EU leaders is clear: with less than five years to bring our seas back to health, there is no time for dithering and delaying.

The report shows that Europe’s seas cannot be considered healthy, clean and undisturbed today and are unlikely to become so in the future given the current trends. This will also affect their future capacity to remain productive for supporting the growing ‘blue’ economy.

Further Reading

State of Europe’s Seas, European Environment Agency

Marine monitoring can save lives at sea

Six research organisations have joined forces to save lives at sea by providing a world-class marine monitoring and forecasting service.

The consortium, led by the Met Office, has won a European Union funded contract to provide data on currents, temperature, salinity, sea level and biogeochemistry. This will build on five years of developmental work.

Dr Jason Holt, the National Oceanography Centre (NOC) science lead on the project, and co-chair of the National Partnership for Ocean Predication, said “We are really pleased to be part of this service, which will enable the NOC’s world-leading research on predicting the shelf sea environment to have direct social and economic benefits”.

The other partners are; Plymouth Marine Laboratory; Institute of Marine Research, Norway; the Federal Maritime and Hydrographic Agency of Germany and ENVITA. The data they provide will be available free of charge at, under European North West Shelf Seas. There are ten categories of data – Ocean Temperature, Ocean Salinity, Ocean Currents, Sea Ice, Sea Level, Winds, Ocean Optics, Ocean Chemistry, Ocean Biology and Ocean Chlorophyll.

Photo credit: Royal Navy/MOD

Tell us about plastics in luxury body care

After success in convincing many retailers to remove microplastics from their washes, lotions, scrubs, creams, gels, moisturisers and pastes, the Marine Conservation Society (MCS) is now turning its attention to luxury personal care goods. They want you to check the labels on products on your shelves and upload photos of any offenders to their Scrub it out! web page.

Microplastics are tiny bits of plastic. These end up in the sea where they gather toxins on their surface before being ingested by zooplankton and other animals, which in turn are eaten by creatures further up the food chain – and ultimately, us.

Look out for these plastic ingredients: Polyethylene / Polythene (PE), Polypropylene (PP), Polyethylene terephthalate (PET), Polymethyl methacrylate (PMMA), Nylon or Polytetrafluoroethylene (PTFE). The MCS definition of luxury does not seem to be that expensive, just anything which isn’t a shop’s own brand.

Dr Laura Foster, Pollution Programme Manager at MCS, says the fact that over the last twelve months most retailers have been happy to have the conversation about the problems with microplastics is very encouraging: “A year ago, on World Oceans Day, we formed the Marine Litter Action Network which brought together other NGOs, industry and retailers to look at the issues of litter in our seas and oceans and come up with workable solutions. One of the critical discussions was about microplastics.”

Dr Foster says the ‘Scrub it Out!’ campaign, a joint initiative with Fauna & Flora International (FFI), was a direct result of the Network: “Thousands of members of the public have pledged to ditch products which contain microplastics, whilst we decided to focus on UK retailers to give a date when all their own-brand products would be plastic free.”

Among the retailers who have pledged to get rid of plastics from their own brand personal care products are Waitrose, Boots, Asda, Marks & Spencer, Superdrug, Tesco, Sainsbury’s, Cooperative, Lush, Morrisons, and L’Occitane.

Discussions are still underway with Aldi and Lidl but MCS hopes they too will set a date for plastic free own-brand products.

Plastic free skin care is a reality. Some brands have never used microplastics, including Ali Mac Skincare, ALL NATURAL SOAP Co., ARK Skincare, all brands of Botanical Brands, Bulldog Skincare For Men, Elements Natural Skincare For Men, Green People, Neal’s Yard Remedies, Palmer’s, PHB Ethical Beauty, Sodashi, Sukin and Trilogy.

MCS says the Scrub it Out! Campaign will now move on to luxury personal care products: “It’s possible that consumers assume the more expensive the product the better is for you, and the more natural the ingredients it contains. But we don’t believe this is always the case. A supporter of MCS contacted Olay regarding the polyethylene listed in a face wash she uses and was told that as polyethylene is commonly used they won’t be phasing it out until alternatives are identified and qualified. We’ll be contacting the company to explain why a delay is detrimental to the ocean.”

Sunscreen nanoparticles harm sealife

Materials commonly used in clear sunscreens harm marine life. Research shows sea urchin embryos, plankton and coral all affected.

Sea Urchins at Risk

According to a study published in the journal Environmental Science and Technology, nanoparticles commonly used in sunscreens are making sea urchin embryos more vulnerable to toxins,

Researchers from the University of California showed that Zinc Oxide Nanomaterial (ZnO) made developing sea urchin embryos more sensitive to other chemicals, blocking transporters that would otherwise defend them by pumping toxins out of cells.

Nanozinc oxide is used as an additive not only in sunscreens but in toothpastes and beauty products as well. Another nanoparticle commonly used in sunscreen is titanium dioxide (TiO2).

Nanomaterials are tiny chemical substances, which are about 100,000 times smaller than the diameter of a human hair.

Plankton also affected

When people wearing sunscreen go to cool off in the sea, the nanoparticles in sunscreen wash off. Research by Spanish scientists David Sánchez-Quiles and Antonio Tovar-Sánchez has shown that titanium dioxide and zinc oxide nanoparticles from the sunscreen produce significant amounts of hydrogen peroxide, a strong oxidizing agent that generates high levels of stress on marine phytoplankton.

Conservative estimates for a Mediterranean beach reveal that tourism activities during a summer day may release on the order of 4 kg of TiO2 nanoparticles to the water, with direct ecological consequences on the ecosystem. The researchers concluded that titanium dioxide from sunscreen was largely responsible for a dramatic summertime spike in hydrogen peroxide levels in coastal waters.

And Coral

Titanium dioxide nanoparticles also increase stress in reef-building corals. Adding to the warming pressures they already face in parts of the world.

Coral Reef
Photo credit: Tim Nicholson

Why Nanoparticles?

Zinc oxide and titanium dioxide have been used in sunscreens for decades, but in the form of big particles. They reflect not only ultra-violet light but visible light making them and the sunscreen appear white. When used as minute nanoparticles, the sunscreen looks clear. This type of sunscreen is popular because people can spray it on, it feels lighter and it needs reapplying less frequently. But evidence is mounting of the harm it does to marine life.

Further Reading

Copper Oxide and Zinc Oxide Nanomaterials Act as Inhibitors of Multidrug Resistance Transport in Sea Urchin Embryos: Their Role as Chemosensitizers
Bing Wu, Cristina Torres-Duarte, Bryan J. Cole, and Gary N. Cherr
Environmental Science & Technology 2015 49 (9), 5760-5770
DOI: 10.1021/acs.est.5b00345

Sunscreens as a Source of Hydrogen Peroxide Production in Coastal Waters
David Sánchez-Quiles and Antonio Tovar-Sánchez
Environmental Science & Technology 2014 48 (16), 9037-9042
DOI: 10.1021/es5020696

Tovar-Sánchez A, Sánchez-Quiles D, Basterretxea G, Benedé JL, Chisvert A, Salvador A, et al. (2013) Sunscreen Products as Emerging Pollutants to Coastal Waters. PLoS ONE 8(6): e65451. doi:10.1371/journal.pone.0065451

Jovanovi?, B. and Guzmán, H. M. (2014), Effects of titanium dioxide (TiO2) nanoparticles on caribbean reef-building coral (Montastraea faveolata). Environmental Toxicology and Chemistry, 33: 1346–1353. doi: 10.1002/etc.2560

US Makes Progress on Over-Fishing: Fish Stocks Recovering

The number of US fish stocks listed as overfished, or subject to overfishing, has dropped to an all-time low since NOAA Fisheries began monitoring began in 1997. Their report, released this week, highlights the United States’ continued progress towards sustainably managing fish stocks.

NOAA Fisheries maintain three lists: Overfishing, Overfished and Rebuilt. A fish stock is on the overfishing list when the annual catch rate is too high. It’s on the overfished list when the population size of a stock is too low, whether because of fishing or other causes. The Rebuilt list holds stocks that have previously been on one of the other lists but have now recovered.

“This report illustrates that the science-based management process under the Magnuson-Stevens Act is working to end overfishing and rebuild stocks,” said Eileen Sobeck, assistant NOAA administrator for fisheries. “While we have made tremendous progress, we know there’s more work to be done — especially as we continue to document changes to our world’s oceans and ecosystems. We will continue to strive toward sustainable management of our nation’s fisheries in order to preserve our oceans for future generations.”

Twenty-six fish stocks, though, are still on both the Overfished and Overfishing lists. These include bluefin tuna, bigeye tuna, striped marlin, Atlantic cod, red snapper, white marlin, blue marlin, scalloped hammerhead, Atlantic halibut and Atlantic salmon.

Further Reading

Status of Stocks 2014. Annual Report to Congress on the Status of U.S. Fisheries by NOAA Fisheries

Sensor sniffs out methane in deep-sea vents and cows

Methane is a potent greenhouse gas that traps heat about 20 times more effectively than carbon dioxide.

Understanding the sources of methane, and how the gas is formed, could give scientists a better understanding of its role in warming the planet.

Now a research team including scientists at the Massachusetts Institute of Technology, the Woods Hole Oceanographic Institution, the University of Toronto and elsewhere has developed an instrument that can rapidly and precisely analyse samples of environmental methane to determine how the gas was formed.

The method detects the ratio of methane isotopes, which can provide a “fingerprint” to differentiate between two common origins: microbial, in which microorganisms, such as might live in the guts of animals, produce methane as a metabolic byproduct; or thermogenic, in which organic matter, buried deep within the Earth, decays to methane at high temperatures.

The researchers used the technique to analyse methane samples from lakes, swamps, groundwater, deep-sea vents and the guts of cows, as well as methane generated by microbes in the lab.

“We are interested in the question, ‘Where does methane come from?’” says Shuhei Ono, an assistant professor of geochemistry in MIT’s Department of Earth, Atmospheric and Planetary Sciences. “If we can partition how much is from cows, natural gas, and other sources, we can more reliably strategise what to do about global warming.”

The group noticed something surprising and unexpected in some samples. For example, based on the isotope ratios they detected in cow rumen, they calculated that this methane formed at 400 degrees Celsius — impossible, as cow stomachs are typically about 40 C. They observed similar incongruences in samples from lakes and swamps. The isotope ratios, they reasoned, must not be a perfect indicator of temperature.

Researching Methane Origins
Researching Methane Origins

Instead, study author David Wang and his colleagues identified a relationship between a feature of the bonds linking carbon and hydrogen in methane molecules — a quality they deemed “clumpiness” — and the rate at which methane was produced: The clumpier the bond, the slower the rate of methanogenesis.

“Cow guts produce methane at very high rates — up to 500 liters a day per cow. They’re giant methane fermenters, and they prefer to make less-clumped methane, compared to geologic processes, which happen very slowly,” Wang says. “We’re measuring a degree of clumpiness of the carbon and hydrogen isotopes that helps us get an idea of how fast the methane formed.”

Wang added “Now we have a baseline that we can use to explore how methane forms in environments on Earth and beyond”.

The study is published this week in the journal Science.

The ocean floor is teeming with methane, the natural gas that fuels our homes. According relatively modest changes in global ocean temperatures or sea level could trigger a massive release of oceanic methane. If a rise in water temperatures passes a certain threshold, sizable methane hydrate deposits could decompose rapidly and release a large quantity of heat-trapping gas back into the atmosphere.

Photos: Danielle Gruen (edited by Jose-Luis Olivares/MIT); MIT

Further Reading:
MIT News
When Seafloor Meets Ocean, the Chemistry Is Amazing, Oceanus Magazine, Vol. 42, No. 2, Apr. 2004

Basking shark seen for first time in Indonesia

A recent stranding of a basking shark (Cetorhinus maximus) in north-western Bali is the first confirmed record of this large, filter-feeding shark species in Indonesian waters.

The shark was an adult male. It is possible that the Indonesian throughflow – the warm ocean current which moves water from the Pacific to the Indian Ocean – is an important route for basking sharks during their migrations.

Once thought of as a strictly cool-water species, basking sharks move to tropical seas each winter. While commonly sighted in surface waters in northern Europe and America during summer and autumn months, they disappear during winter. An article in 1954 even suggested that they hibernate on the ocean floor during this time.

Basking shark in European waters by Tim Nicholson
Basking shark in European waters (Isle of Man) by Tim Nicholson

More recently satellite tagging showed that basking sharks instead migrate through tropical waters, travelling at depths of 200 to 1,000 meters and unseen by humans.

The basking shark is the second largest shark after the whale shark (Rhincodon typus). It can grow up to 11 metres long and weigh up to 7 tonnes. It feeds by filtering plankton through its gills whilst swimming with its huge mouth open.

Basking shark
Basking shark and snorkellers by Chris Gotschalk

Further Reading
Marine Biodiversity Records / Volume 8 / 2015DOI:, Published online: 28 January 2015

Transequatorial Migrations by Basking Sharks in the Western Atlantic Ocean. Skomal, Gregory B.; Zeeman, Stephen I.; Chisholm, John H.; Summers, Erin L.; Walsh, Harvey J.; McMahon, Kelton W.; Thorrold, Simon R.

Images: Green Fire Productions CC by 2.0, Tim Nicholson, Chris Gotschalk