Sponges may not look like a high-end commodity – in fact, they often look more like an ornate rock or a strange seaweed than an animal – but a sponge in general might save your life one day. These groups of organisms produce immeasurable amounts of antibacterial, antiviral, antifungal, antimalarial, or anti-inflammatory chemicals, making them fascinating candidates for future drugs.
Unfortunately, humanity has been treating this natural resource irresponsibly, and now we run the risk of destroying many future savior sponges before we know its full potential.
Sponges are irregular creatures with different forms that stay on the ocean floor. They do not have a complex nervous system, digestive system, or circulatory system. However, they shouldn't be mistaken for plants or pretty stones – they actually belong to one of the oldest animal lineages on Earth.
More than 5,000 described sponge species have been found in Earth's oceans (and some freshwater areas), but scientists may not have recorded thousands of undocumented sponge species, each of which could be full of benefits. It is estimated that more than 200 new bioactive chemicals are found in sponges every year, some of which have proven to be useful drugs in recent decades.
The compound isolated from a lumpy sponge called Tectitethya crypta was approved by the FDA in 1969 as the first sponge-derived drug. This compound, called arabinibomethylating agent, is used by scientists to treat leukemia and lymphoma tumors in a basic way, effectively killing cancer cells. To this day, it remains one of the main treatment options for leukemia patients. In 1981, acyclovir, an antiviral compound extracted from Caribbean sponges, was approved for the treatment of herpes, chickenpox and shingles. Later that decade, the FDA approved AZT, the world's first drug for the treatment of HIV, derived from a chemical secreted by a sponge.
Even today, scientists are using these sponges to discover new drugs. In October 2023, researchers demonstrated that Mauritian sponge neobiotics have been shown to selectively kill liver cancer cells with minimal damage to healthy cells.
Another promising avenue is the use of sponges to discover new antibiotic drugs, which could help alleviate the problem of antibiotic resistance.
Dr Eleanor Best, a veterinary surgeon at the University of Bristol, said earlier in a statement: "The deep ocean contains the vast majority of the world's microbiome. But much of our antibiotic research is focused on terrestrial microbiotas, so there is great potential for potential new antibiotics from deep-sea sources. There are a large number of new bacterial species in the sponge, which compete for nutrients and produce antibiotics to fend off the competition."
You might think that we should go all out to protect this "marine pharmacy". However, growing industrial activity poses an existential threat to many known and unknown sponge populations.
In May 2023, scientists announced that they had discovered more than 5,000 new marine species, including many sponges, in the ocean known as the Clarion-Clipton Zone (CCZ).
Unfortunately, this area is becoming a target for deep-sea mining activities, as it has the world's largest deposits of manganese, nickel, cobalt and other metals, which are essential for battery manufacturing. If deep-sea mining continues, the consequences for ecosystems and their much-needed sponges could be catastrophic.
Beyond the CCZ, the diversity of sponges is also threatened by infrastructure development, pollution, and climate change. The good news is that sponges are surprisingly resistant to low oxygen and warming waters, suggesting that they may be able to tolerate the shocks of climate change far more than corals and other marine species.
However, their amazing resistance should not obscure the fact that, despite their enormous potential, these living drug factories have a very tricky future ahead of them.