A synthetic #sponge costs just a couple of dollars, but a hand-harvested #seasponge from the #MediterraneanSea could set you back $30. 🧽 #spongediving | Business Insider

Sea sponges: surprisingly busy, as it happens. By putting a non-toxic dye at the base of this sea sponge, you can see how quickly it's sucking in the surrounding sea water—one paper suggested that a sponge weighing just one kilogram (2.2 pounds) could filter up to 24,000 liters of water a day (6340 gallons) (1) A sea sponge is covered in tiny pores. From the water, it filters oxygen as well as microscopic particles of food, which get stuck on a sticky substance inside. It then expels the water—a