By Yvaine Ye
Medill Reports

What mysteries lurk in the blue water that covers more than 70 percent of the earth’s surface? No one truly knows, not even scientists. But many suspect the next miracle cure could be swimming in vast oceans amongst tiger sharks and stingrays.

Scientists believe the ocean, which remains 95 percent unexplored, hides chemicals that can be turned into drugs to treat human diseases. But these yet-undiscovered substances are potentially being imperiled by climate change, which is influencing the ocean ecosystem in unpredictable ways, experts say.

“When climate changes then biodiversity is going to be influenced for good or for bad,” says Brian Murphy, a chemist at the University of Illinois Chicago. “When biodiversity is influenced, chemical diversity is also in turn influenced.”

Murphy’s work focuses on drug discovery from natural products, which are small chemicals produced by organisms in nature. Natural products serve as inspirational cues for scientists developing antibacterial and anticancer drugs.

“Organisms evolve to combat other organisms in their environment, and a lot of time they fight each other with natural products,” Murphy says.

The operating theory is that if other organisms can use these products to kill bacteria, why can’t humans? That promise has scientists looking toward uncharted waters. Compared to dry land, the ocean is barely explored because of physical and technological limitations. To scientists, the ocean is the Newfoundland — this time with a blue hue.

“The marine environment is a vast and barely scratched reservoir of useful leads for potentially all diseases of mankind,” says David Newman, former chief of the natural products branch at the National Cancer Institute. “Almost all of the agents initially used against HIV, and other viral diseases… owe their ‘chemical birth’ to work done with a Caribbean sponge.”

As the journey of fishing for new medicines in the ocean continues, climate change has led to warming water, ocean acidification and decreasing ocean oxygen content, according to Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research. Although it’s difficult to conclude the overall impact of climate change on the ocean due to a lack of good data, researchers have stated these changes are hostile to at least some organisms.

“About a quarter of carbon dioxide goes into the ocean. As a result, there is acidification of the ocean, which affects many organisms, especially organisms that produce bones and shells of all kinds,” Trenberth says.

Corals, whose skeletons are composed of calcium, are on the in-danger list. Ocean acidification can weaken their skeletons, so they may be washed away when a big wave strikes.

“Coral reefs are hubs of biodiversity,” chemist Brian Murphy says. “If you have a changing climate that impacts the coral reef and decreases the biodiversity, this in turn decreases the treasure chests I’m able to pick out of to find natural products.”

Acidification is just one of the threats. Increased ocean temperature and pollution could kill algae that grow on a coral. These algae give corals their colors and at the same time serve as their food source. As a result of environmental changes, corals become feeble and turn completely white, a phenomenon referred to as coral bleaching.

The U.S. lost half of its coral reefs in the Caribbean in one year due to a massive bleaching event in 2005. In total, 25 types of coral are listed as either endangered or threatened under the Endangered Species Act by the National Oceanic and Atmospheric Administration.

Will climate change impede scientists from finding the next miracle drug? Maybe. Maybe not.

As the changes happen above and below sea level, indigenous species may disappear or move to new homes while other microbes and organisms step up to take over the abandoned piece of land. That means the ocean still remains a place of possibility for inquisitive scientists.

“It is of concern, but you don’t know how much to say it’s a concern,” Newman says of the effects of climate change. “Yes, we are going to lose something, but we are also going to gain something.”