New Device Can "Smell" Sea Sponges

Sea sponges are constantly shedding chemicals into the sea, and now researchers can “smell” them.

With the help of a new device, the In Situ Marine moleculE Logger, or I-SMEL, researchers at Station Marine d’Endoume, Marseille, have been able to collect sea sponge compounds with newfound ease.

Their findings were published in ACS Central Science.

What lives in a sample under the sea?

Submersible devices that can capture and analyze underwater compounds are nothing new; they’ve been around for 40 years or so. But these early devices could only operate in shallow water and would take a relatively long time to process samples. 

The research team at Station Marine d’Endoume believe that their I-SMEL device improves upon these prior devices. It is handheld, can be used at depths of up to 65 feet (20 meters) and it doesn’t need to be held flat to work.

It collects underwater compounds by pumping seawater through its solid-phase extraction disks, which filter out the water and capture any other chemicals. These chemicals can then be analyzed by a mass spectrometer in a lab.

To test their creation, the researchers took a dive 50 feet (15 meters) down to investigate the spongey walls of a sea cave in the Mediterranean.

They collected several metabolites, including brominated alkaloids and furanoterpenoids, both directly from the sponges and from the surrounding seawater. When these metabolites were later analyzed in the lab, the research team observed some unexpected differences. The chemical aeroplysinin-1, for example, was around 20 times more abundant in the seawater than within a yellow cave-sponge extract.

Many sea sponge chemicals have gone on to form the basis of medical drugs. Examples include the breast cancer-fighting drug Halaven and the inflammation-reducing drug Inflazyme. The Station Marine d’Endoume researchers say the I-SMEL could open “new prospects” for the discovery of more natural sponge products, which could go onto form the basis of new drugs.

To further their research – and to better equip the underwater expeditions of others – the researchers say they intend to bolster I-SMEL and adapt it for autonomous long-term seawater filtration and remote operation in deeper waters.

Reference: Mauduit M, Derrien M, Grenier M, et al. In Situ Capture and Real-Time Enrichment of Marine Chemical Diversity. ACS Cent. Sci. 2023. doi: 10.1021/acscentsci.3c00661