Potential cancer cures from the deep sea threatened by high seas bottom trawling

Date: May 2, 2005

A report released by Marine Conservation Biology Institute (MCBI) and Natural Resources Defense Council (NRDC), suggests that deep sea life holds major promise for the treatment of human illnesses (1). But scientists are increasingly concerned that bottom trawling may be destroying medically beneficial species before they are even discovered.

“Scientific interest is increasingly turning to the potential medical uses of organisms found in the deep sea, much of which lies in international waters,” said Sara Maxwell, conservation scientist at MCBI and principal author of the report. “These organisms have developed unique adaptations that enable them to survive the in cold, dark and highly pressurized environment of the deep sea. Their novel biology offers a wealth of opportunities for pharmaceutical and medical research.” 15,000 natural products have so far been discovered from marine microbes, algae, and invertebrates. (2) The report suggests that the most exciting potential uses lie in the medical realm (3). To date, most marketed marine products have come from shallow and often tropical marine organisms, but compounds derived from both shallow and deep-sea marine species could be used in treating Alzheimer’s disease, asthma, pain, and viral infections, among other human ailments. Shallow water compounds have already produced pharmaceuticals being used in the treatment of cancer, and deep sea organisms show incredible cancer-fighting promise. The majority of marine-derived compounds are obtained from either micro-organisms or stationary bottom-dwelling organisms such as corals, sponges, and tunicates. Unable to evade predators through movement, stationary organisms rely heavily on their chemical defense mechanisms to protect themselves – mechanisms that are proving interesting in the search for cancer treatments. Two compounds originally isolated from deep sea organisms are now in human clinical trials as anticancer compounds. Several others are in preclinical stages and show considerable promise. (4) Another compound, Topsentin, isolated from a deep-water sponge, which lives at depths of 990 to 1,980 feet (300 to 600 meters), shows promise for use as an anti-inflammatory agent to treat arthritis and skin irritations. It is also being investigated as a treatment for Alzheimer’s disease and to prevent colon cancer and is currently in preclinical evaluation. Deep sea sediment bacteria are also interesting to scientists searching for new antibiotics. 60 years of research on soil-dwelling actinomycete bacteria resulted in the discovery of almost 70 percent of the world’s naturally occurring antibiotics. However, the rate of new discoveries has dropped dramatically and the search for new actinomycete strains and the antibiotics they produce, has been extended to new environments – including the oceans. To date interesting compounds have been isolated from marine actinomycetes and other novel microbes found at depths of up to 1,500 meters (495,000 feet). (5) More than 60 new chemical compounds have been isolated from marine actinomycetes over the last 10 years and ten new genera of microbes have been discovered from which 2,500 new strains have been isolated. The deep sea is, therefore, potentially a huge source of medically important compounds, a source that science has only just begun to explore. But this potential underwater pharmacy is already being destroyed. Just as the technology has evolved to enable scientists to slowly venture into one of the earth’s last frontiers, so the latest technology now enables the fishing industry to reach the previously unreachable. Advances in bottom trawling technology mean that it is now possible to fish the breathtaking deep sea landscapes of mountains, hills, ridges and troughs that very few of us will ever see. Equipped with more powerful engines, bigger nets, more precise mapping and advanced navigational and fish-finding electronics, deep sea bottom trawlers drag fishing gear across the ocean floor as much as two kilometres (1.2 miles) deep in search of a few commercial fish and crustacean species. “One sweep of a bottom trawl can uproot and pulverize a thriving deep ocean ecosystem and the unique life it sustains”, said Lisa Speer of NRDC. “Fragile coral systems in particular stand no chance against these ruthlessly effective underwater bulldozers. Once destroyed, slow-growing deep-sea species are either lost forever or are unlikely to recover for decades or centuries”, Speer warned. Alarmed that species and ecosystems are being destroyed by bottom trawling, before their potential can be tapped, in 2004 a group of 1,136 marine scientists from around the world signed a statement urging the United Nations to adopt a moratorium on high-seas bottom trawling. Now, moved by the failure of the international community to take such action, a number of these scientists, among them MCBI’s President Elliott Norse, are touring Europe in April 2005 in order to bring their concerns directly to decision makers and underline their call for an immediate UN GA moratorium. The MCBI/NRDC report repeats the call for an immediate moratorium until enforceable regulations to identify and protect sensitive deep sea ecosystems are in place. “Because much of the deep sea lies beyond the zones of national jurisdiction, it is up to the international community to act to protect and manage the deep sea,” concludes Maxwell. “All mankind should benefit from a potentially huge source of medically important compounds that science is only beginning to explore.” Notes: (1) Medicines From the Deep: The Importance of Protecting the High Seas from Bottom Trawling, NRDC issue paper, March 2005. Principal author Sara Maxwell, conservation biologist, MCBI. MCBI (Marine Conservation Biology Institute) is a non-profit organization dedicated to advancing the science of marine conservation biology and promoting cooperation essential to protecting and recovering the earth’s biological integrity. MCBI is headquartered in Redmond, Washington, and has offices in Glen Ellen, California, and Washington, D.C. www.mcbi.org. NRDC (Natural Resources Defense Council) is a national, non-profit organization of scientists, lawyers, and environmental specialists dedicated to protecting public health and the environment with offices in New York, Washington, Los Angeles, and San Francisco. www.nrdc.org. (2) Salomon, CE, NA Magarvey, DH Sherman. 2004. Merging the potential of microbial genetics with biological and chemical diversity: an even brighter future for marine natural product drug discovery. Natural Products Report 21: 105-121.. (3) More than 28 marine natural products are currently being tested in human clinical trials, with many more in various stages of preclinical development. Newman, DJ and GM Cragg. 2004. Marine natural products and related compounds in clinical and advanced preclinical trials. Journal of Natural Products 67: 1216-1238. (4) Page 6 of the MCBI/NRDC report Medicines From the Deep: The Importance of Protecting the High Seas from Bottom Trawling (5) 1500 meters is just the depth to which scientists have been able to sample, but microbes are found much deeper than this.

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