Is the sea water that surrounds us a medicinal treasure chest? Recent research suggests it is, writes Clare O'Connell.
Forget the 1960s notion that the answer is blowing in the wind. In the 21st century, for medicine at least, the smart money is on finding the answers swimming in the sea.
Just as prospectors once panned river water for gold, scientists around the world are sifting through marine environments, searching for organisms that produce "bioactive" compounds with possible therapeutic applications.
Land-based organisms have traditionally provided a fertile biochemical hunting ground for discovering new pharmaceuticals, but as technological advances allow for greater mapping, sampling and screening of the oceans, the seas now offer the tantalising promise of a vast medicine chest waiting to be unlocked at a molecular level.
With oceans covering around 70 per cent of the earth's surface and supporting a diverse bounty of plants, animals and microbes, the marine biotechnology sector is set to grow considerably, according to Dr Peter Heffernan, chief executive of the Marine Institute.
"There's significant diversity in the type of habitats and the ecology in the ocean, and the unique physical and chemical properties that plants and animals would need to survive in such environments are very different from anything that would be experienced terrestrially. So it's generally expected that the diversity of species will be rich and diverse in the ocean, compared to what people would be used to in terrestrial situations," he says.
"The whole area of the oceans, particularly in the context of biodiscovery and biotechnology, has become increasingly important internationally and there has been much focus on it in science planning." In February, the Marine Institute unveiled its seven-year "Sea Change" research and enterprise strategy for Ireland, which will bolster efforts to plumb our ocean surroundings for potentially useful biochemical compounds.
It's a logical step, given that around 90 per cent of Ireland's territory lies under the sea. "To put it in perspective, we have a land area under the ocean of 200 million acres (80 million hectares), which is in excess of 10 times our terrestrial land bank," says Dr Heffernan.
And as luck or geography would have it, Ireland's marine territories offer plenty to make a bioprospector's eyes light up. For example, the Gulf Stream's warming influence encourages a diverse array of species assemblages off the west coast, and the region hosts the largest provinces of deep-water corals in the European Union.
The seas around Ireland are currently known to support around 450 types of seaweed and more than 3,000 marine animal species, says Dr Heffernan, and diversity figures are set to increase substantially as organisms are discovered in deeper areas.
Ireland also has a significant advantage in that already almost 90 per cent of our marine territory has been digitally mapped in the national seabed survey. "That gives a tremendous asset to the nation in such exercises as biodiscovery and bioprospecting," says Dr Heffernan. "When you have a digital map like Ireland has, it greatly enhances people's confidence."
Over the coming years the "Sea Change" strategy aims to harness those advantages for bioprospecting. "We have the hardware in the shape of our two national research vessels," says Dr Heffernan. "Then for the detailed sampling we will be acquiring a remotely operated vehicle that will operate down to more than 3,000m (9,840ft)."
THERE'S A GOOD chance that such sampling will turn up interesting goods - internationally, the sea has already yielded a number of bioactive compounds, proving that marine bioprospecting can pay dividends.
"There are good examples across the spectrum of medicines and pharmaceuticals in the areas of anti-virals, anti-inflammatories, anti-cancer agents, antibiotics, herbicides, sunscreens and fungicides," says Dr Heffernan. "The long-term prospects are very strong and it's a matter of having a carefully planned and joined-up programme going from sampling material all through the development chain. The key is you have to start. You will never achieve a result if you don't initiate it."
Since 2004, the Marine Institute has worked with experts to develop the national strategy for marine biodiscovery, which includes linking into existing scientific expertise and infrastructure in Ireland.
There have also been successful "dry runs" of sampling organisms off the Irish coast, then identifying and screening them for potential compounds. An initial focus of the programme is on marine sponges, explains microbiologist Prof Alan Dobson, director of the Environmental Research Institute at University College Cork.
"There's a long history of bioactive compounds, or compounds that could have pharmaceutical-type activity, being associated with sponges," he says. "Sponges filter bacteria from the environment - as much as 40 per cent of the sponge can be bacteria - and it's believed now that it's as likely to be the bacteria as the sponge themselves that are producing the compounds."
Finding one type of molecule in an entire sponge plus its microbial hangers-on might sound like looking for a needle in a haystack, but to narrow down the search, the scientists extract all the DNA from the sponge and then probe it for "signpost" genes that are often involved in making interesting compounds.
"For instance, polyketide synthases are a group of enzymes that are renowned for being involved in the production of bioactives," explains Prof Dobson. "We have just finished taking DNA from a Haliclona sponge from Galway Bay, and we have identified three or four polyketide synthase genes. So we think there are sponges off the west coast of Ireland that have bacteria associated with them that could potentially produce bioactives. That was the proof of concept." But sponges are difficult to harvest in large quantities and ultimately the scientists hope to sample bacteria directly from seawater, extracting and screening their DNA for signs of bioactive compounds, including anti-fungal and anti-bacterial agents, explains Prof Dobson.
"You would take 200 litres (44 gallons) of water from a particular marine environment and filter the water onto a membrane and then just extract all the DNA from the membrane and analyse that. So it's like filtering seawater for bacteria. There are large quantities of bacteria in seawater, and they are unique as well because they are able to grow in a high-salt environment."
Genetic analysis will also build up information on the ecology of marine microbes, particularly in relation to climate change. "These bugs are also involved in cycling of nitrogen and carbon in the environment, that's part of what their role is in nature," says Prof Dobson. "So rather than just exploiting these bugs we will also look and see what types of populations are present and then we can go back and look at those in five, 10 or 15 years to see if they will be the same."
MEANWHILE, IF THE marine organisms turn out to make potentially useful bioactives, the next step will be to produce the compounds in the lab, either by growing bacteria to make them or by synthesising the chemicals artificially. But Prof Dobson stresses that the approach is the beginning of a long journey, pointing out that even after a bioactive has been identified, it can take another 10 to 15 years to bring a pharmaceutical to market.
"This is the start of a marine biodiscovery initiative just to look and see can we use this vast resource that we have out there. It's a very competitive field so we have to be clever in the kinds of screens and expertise that we use, but that doesn't mean that we can't be successful," he says. "This is just at its infancy but it's very exciting."