Deep blue sea

 

MARINE LIFE:WHEN YOU look out at the ocean, what do you see? On a calm day the sea can seem uniform, almost drab. And from the vantage point of dry land, many of us just let our minds skim the surface, not imagining what could lie beneath.

But what curious creatures, forces, foods and even medicines exist there, as yet undiscovered?

As a species, we spend billions on sending telescopes out into space and reading signals from the edge of the known universe – yet our own planetary ocean remains underexplored.

We might find out more about the mysteries of matter by looking to the skies, but the seas have been central to another fascinatingly rich story: the origin, evolution and support of life on Earth.

This watery blanket covers 70 per cent of the planet, swathing extreme environments – from the long, gash-like ridges where the Earth’s surface spreads restlessly amid quakes, scorching hydrothermal vents and volcanoes, to the icy clarity of polar waters. They also range from shallow, sunlit foreshores, where we can happily paddle, to the lightless pressured depths where no human could survive.

Explorations, however, are uncovering staggering biodiversity even in such seemingly unforgiving abodes.

Over the last decade or so, a concerted global effort has been under way to gather and expand our knowledge of what lives in those salty, watery realms, from shoreline to abyss.

The Census of Marine Life has seen about 540 expeditions chalk up roughly 9,000 days at sea, and more than 2,700 researchers from over 80 countries helped to work out a baseline of ocean life abundance, the locations of species, and how they are interconnected.

From its founding in 2000, the project was based around three grand questions: What did live in the oceans? What does live in the oceans? What will live in the oceans?

Researchers looked at oceans past and present, using modern technologies such as tracking systems and genetic analysis, as well as “backcasting” through historical records of fisheries, archaeological remains and even restaurant menus – all with the aim of better understanding marine life and predicting its future.

By last year, the census had encountered what it termed “an unanticipated riot of species” in our oceans – it collectively logged about 30 million observations of individual organisms in an online “digital address book” of 120,000 species, discovered an estimated 6,000 previously unknown species and identified hotspots and highways of marine life.

“We were prepared for surprises and we had them in buckets,” says Poul Holm, professor of environmental history at Trinity College Dublin, academic director of the Trinity Long Room Hub and a member of the scientific steering committee for the census.

“We were excited to discover new species, but perhaps the greatest surprise was how interconnected the oceans are – because large fish and mammals migrate over long distances, specific habitats are critical to the survival of many species.

“Super small and smart tags were invented to map migratory patterns and now we are on the cusp of great new discoveries with the installation of a global ocean observation system with arrays of sensors.

“In a way, we have just scratched the surface of the ocean. The frontier of knowledge is as much in the ocean as it is in space.”

Holm is also global chair of the History of Marine Animal Populations (HMAP), a segment of the census which he co-founded in 2000 and which has seen about 100 researchers work across 15 oceanic regions.

By combining historical written records with scientific and archaeological data, HMAP identified large-scale commercial fishery activity as far back as medieval Europe in the 11th century, and the project has also charted globally how marine fish stocks have been impacted upon through overfishing.

“You could look on fisheries as a gold-mining expedition, and we have targeted first near-shore and then the deeper waters, and then going to off-shore destinations and sourced from areas in the globe that have never been targeted before,” says Holm, who describes how post-industrial technologies have sharpened the tools to allow overfishing.

“And now we seem to be running out of geography – in the last 20 years we have been targeting some of the last remaining pristine waters in the globe, the seas of the South Pacific.”

He remains optimistic about the ocean’s ability to support the replenishment of species, but points out that this will happen only if we implement conservation policies to allow it to do so.

Aside from the common sense of preserving biodiversity as part of a larger, interconnected ecosystem and food web that includes humans, there may also be some specific tangible benefits to medicine if we protect and responsibly explore the marine environment, which offers a potential trove of new therapies against disease.

The enormous diversity of environments under the sea means we are finding organisms that have developed special talents to survive in those surroundings – and therein lies potential, explains microbiologist Prof Alan Dobson, who is director of the Environmental Research Institute at University College Cork.

“You have deep sea trenches where you have hydrothermal vents with very high temperatures, and you have the Arctic and Antarctic – a lot of marine animals and micro-organisms have evolved systems that have allowed them to grow there and survive, and they would typically have novel biochemistry and chemistry associated with them,” he says.

Interest has been growing in the potential for new therapeutics or biopharmaceuticals from marine microbes, explains Dobson, and we are finding new ways to exploit these organisms.

“We can only grow maybe 1 or 2 per cent of microbes that are in the average sample of seawater,” he says.

“But we can also take the ‘metagenomic’ approach – where you look at DNA from all the micro-organisms present within a sample. Then, based on the sequence, you see whether it contains DNA that could encode something that would be interesting, and you would try to express that DNA in another system.”

Dobson directs the Beaufort Marine Biodiscovery Programme, which is funded through the Marine Institute (MI) and involves UCC, NUI Galway and Queen’s University Belfast.

His own research has been looking at the potential for new bioactive compounds in marine sponges and bacteria harvested off the coast of Ireland.

“Marine sponges have a huge number of bacteria associated with them and it looks like these bacteria could produce interesting small molecules with bioactive properties,” he explains.

His team has collected deep-sea sponges from depths of about 3,000 metres, and they have been analysing the bacteria and fungi within.

“We have sequenced their genomes, and we have about five or six strains of bacteria from Irish waters where we have identified very good antibiotic activities, so we are now looking at mining these genomes,” says Dobson.

But while there is hope for new antibiotic and anti-cancer compounds from the vast untapped resources of marine organisms around the globe – and some marine-derived bioactives are currently in trials – there are often bottlenecks that need to be overcome, he cautions.

One is that the compounds derived from marine microbes could be too toxic for use in humans.

“There are hundreds of new small molecules identified each year from marine environment,” he says. “But to get those to go all the way through to the clinic, there are potential issues around toxicity, bioavailability, and whether you can specifically target the bioactivity to the correct target within the human system – it’s not as straightforward as just discovering it.”

Supply can also be a hurdle in some cases, he adds, particularly where the marine organism that produces a bioactive compound is not abundant, and the compound can’t be produced synthetically in the lab.

But Dobson is enthusiastic about developments in the area: “We have gone from the stage of maybe four or five years ago of saying, yes we have a potential resource there, to where we are now able to analyse and mine that resource using molecular approaches.”

And as we continue to discover that vast potential of the ocean, one of the next frontiers will be to get information about the seas in real time, explains Dr Peter Heffernan, chief executive of the MI.

While mapping projects are forging ahead and identifying potential locations to find new resources from the ocean, being able to gather real-time data from the seas remains a huge area for exploration. By way of example, Heffernan points out the vast majority of volcanic activity on Earth happens underwater, yet only a couple of undersea eruptions have ever been observed.

“The great, great challenge is the physical cost and the logistics of getting into the ocean in real time,” he says. “There’s a very substantial gap in our knowledge.”

The devastating tsunami damage in Japan earlier this year and the Gulf of Mexico oil leak remind us how big that gap is. “They were stark lessons about how little we really are in command of detailed, real-time knowledge of the ocean – and yet that’s where 98 per cent of the water on the planet exists,” Heffernan says He sees a new dawn for ocean discovery with developments in information and communications technology (ICT) and sensor technology to monitor areas of the ocean with new eyes.

“I think there’s the potential for a quantum leap forward in our real-time connection with what is happening in the ocean through sensor technology systems and observer systems,” he says, describing how some of those systems could be cabled and others moored, while yet others would have mobile connectivity. “We will see an absolute revolution in the next five years in the type of sensors, their ability to communicate, the nature of what they can measure.”

Ireland is up there in that area where the marine meets ICT, he adds, citing initiatives such as SmartBay, a network of real-time sensors deployed in Galway Bay, and the Irish SmartOcean project, a high-tech maritime cluster involving about 50 Irish-based multinationals and indigenous companies, with the aim to develop and deliver ICT applications for global markets.

More than 90 per cent of Ireland’s territories lie under the oceans, he says, and the MI has teamed up with the Geological Survey of Ireland through INFOMAR (INtegrated Mapping FOr the Sustainable Development of Ireland’s MARine Resource), a project to chart about 125,000km² of the inshore seabed.

“In many cases Ireland would be viewed as an exemplar in having undertaken the largest civilian seabed mapping project in the world over the last decade,” says Heffernan. “Can you imagine any development on the land mass of Ireland without an accurate map? But now, rather than being out of sight and out of mind, we have a map of it which makes it very real and tangible and there are many commercial development opportunities.”

More generally, Heffernan believes we are poised to unlock the information about the ocean we so urgently need to gather and understand – whether it’s to address climate change, create jobs, develop more sustainable ways of providing food and desalinated water for a growing population, or harness the energy of the seas.

“We are probably standing in a period where we could see a revolution in the pace at which mankind could get the knowledge of the ocean that we need, to understand how the planet really works, to deal with climate change and to take advantage of the many commercial opportunities associated with the ocean, which include such things as renewable ocean energies and deeper water sites and developments for aquaculture, which are going to be absolutely essential if we are to feed the growing populations of this planet,” he says.

“It is a technological challenge, but if we focus our minds on it, and there are initiatives to do that, there will be huge dividends – it will pay back mankind many times over to unlock the potential of the oceans and wisely steward the resource we are endowed with.”

PURPLE ISa colour we associate with royalty and pomp – and with good reason: a coveted and costly purple dye of old was derived from secretions of marine snails.

The dye, called Tyrian purple, has the major chemical component 6,6’-dibromoindigo, which was identified in 1909. To give a sense of how difficult it was to obtain from the natural source, an experiment from that time needed 12,000 Murex brandaris snails to produce just 1.4g of pure pigment.

Scientists have long been working on ways to synthesise the dye cheaply in the lab, and last year a paper published in Molecules described a “reasonably simple and efficient synthesis of Tyrian purple which opens the way to the production of large quantities of the dye with minimal hazards and at low cost”.

Rogue waves cast in a new light

ROGUE OR freak waves must be some of the most bizarre events of the open sea. The surface might be relatively calm, but large waves can suddenly appear over a small area – and they are sometimes forceful enough to threaten ships.

Rogue waves have long been part of mariners’ lore, but they are relatively rare and were not scientifically measured until the 1990s.

Now a European Research Council-funded project is taking a new approach to figuring out these dangerous oddities. They are synthesised from light to study their behaviours and possibly work out how to predict them, explains Prof Frédéric Dias, an applied mathematician at University College Dublin who specialises in ocean waves and hydrodynamics.

He is jointly leading the €1.8 million Multiwave study with optics expert Prof John Dudley from the University of Franche-Comté and Le Centre National de la Recherche Scientifique in France.

Using laser-based experiments, the project will look at the conditions under which these freak waves can arise, and use the optical findings to work out what conditions at sea would foster such rogue patterns, and so improve shipping forecasts.

The project also hopes to build an optical “wave farm” to analyse the potential impacts rogue waves could have on wave energy-harnessing devices.

Deep sea soldiers

THE DEEPsea is no place for the faint of heart – at least it looks that way to us land dwellers. But many creatures call those dark and pressured depths their home.

They include some curious beings, such as the Kroyer’s deep sea anglerfish, which lives at depths of about 1 to 2km. Anglerfish get their name from a protrusion on the female that dangles out in front, like an angler’s rod and reel, and uses bioluminescence to attract dinner. Their courting rituals also seem a little alien: a male literally attaches by its jaws to a female in a parasitic relationship.

The fangtooth is another deep-sea fish that’s not likely to win too many beauty contests above sea level, and its relatively oversized and jagged teeth form the arresting feature that earns the fish its name.

But one of the oddest-looking creatures of the deep is the “Dumbo” octopod - specimens have been hauled up from waters at the mid-Atlantic Ridge. The “ears” that gave the creature its nickname are actually fins. One “jumbo Dumbo” seen on a Census of Marine Life expedition was estimated to be nearly 2m in length and weigh 6kg.

And perhaps the coolest dude of the deep is the yeti crab. A recent paper in PLoS One describes how the crustacean “farms” bacteria on its claws by waving them in methane that seeps from the sea bed and nourishes the bugs.

New vents discovered

EARLIER THISyear, an Irish-led expedition discovered a field of hydrothermal vents spewing hot, mineral rich water at the mid-Atlantic Ridge.

In 2008, a British expedition got a hint something interesting might be at the site when they detected a plume of heated water coming up from the deep.

The Marine Institute-funded expedition aboard research vessel Celtic Explorer went to find out more, using a remotely operated vehicle (ROV) to explore at depths of about 3km.

What they found was a system of hydrothermal vents which they called the Moytirra vent field, after a battlefield in Irish mythology. The vent is the first to be explored along the ridge north of the Azores, a Marine Institute release said.

Such hydrothermal vents can form where cracks in the Earth’s crust allow seawater into areas of underground volcanic activity. The seawater gets heated and permeated with dissolved minerals, then gushes back up into the ocean, giving rise to “smokers” that look like miniature erupting volcanoes. Hydrothermal vents can be home to a variety of marine life that thrives in darkness on bacteria fed by chemicals.

The mission, led by Dr Andrew Wheeler from University College Cork, found the vent field on the first dive. “Being the first to discover something no one has seen before is always amazing, but what we saw was spectacular,” Dr Wheeler told The Irish Times.“The scale of the metal sulphide chimneys and volume of erupting fluids makes this a major find.”

Jon Copley from the University of Southampton described organisms they saw there – “writhing scale-worms, swirling mats of bacteria and eel-like fish” and “unusual orange-bodied shrimp crawling around the chimneys, among clusters of tiny green limpets”. It all amounted to “a riot of life in this unlikely haven on the ocean floor”.