They performed tests on sea sponges by artificially increasing water temperatures, adding pollutants or modifying the acidity levels. The results have been red by looking for any changes in the cellular structure of the sponges (biomarkers).
“Sponges are more sensitive than other marine creatures because they’re filter-feeding organisms, they suck in about 20 times their own volume of water every minute to get food so they’re more exposed to the water and as a result more sensitive to the conditions,” said Yang.
Unlike fish, sea sponges can detect even trace amounts of oil, just because they don’t move around, but soak it.
The biomarkers that the researchers are looking for are any change in color, shape, size, attachment and a certain protein that the sponge releases when stressed.