Natural sea sponges are harvested from the bottom of the ocean by fishing boats that specialize in sponge fishing. These boats are often owned and operated by families who have been sponge divers for decades, or, in some cases, even centuries. In many areas around the world, sponge diving has been a family tradition for thousands of years.
What Are Sea Sponges
Sea sponges are aquatic animals that cling to a hard surfaces on the sea floor such as rocks or coral and, once attached, do not move around. They are classified as animals, but have neither a central nervous system nor brain. The processed sponges that are sold and used for cleaning are only part of the animal. Living sponges are coated with a dark elastic skin that has pores through which they move water to feed or filter nutrients. Between the inner and outer skins of the living sponge is a gray gelatinous substance called gurry. Processed sponges have had the outer skin and the gurry removed from the structural element or skeleton of the sponge. And it is that skeleton that we use as a sponge.
Sea Sponges are Harvested Sustainably
Sea sponges are harvested by divers using specially designed cutting hooks or knives. These leave enough of the base of the sponge for it to quickly regenerate. Once cut, the divers gently squeeze the gurry out of the sponge and take them back to the boats. The sponges are then pounded to clean them, and then covered with wet burlap sacks on the deck of the ship, where the heat from the sun releases a gas that rots the sponges’ skins so that they can be more easily removed.
Sea Sponge Harvesting Techniques
Sea sponges are harvested in many different countries using a variety of methods, but in the United Sates, sponges are harvested using sustainable methods that actually help the sponge population as a whole. Specially trained divers, who regularly and systematically rotate fishing grounds, sustainably harvest sponges by cutting the sponge to ensure that the base is left intact, which will allow the sponge to quickly regenerate. Rotating the harvesting or fishing grounds allows the sponges time for healthy and productive regrowth, without impacting the natural habitat the sea sponge colonies are harvested from.
Sea Sponges are a Sustainable and Quickly Renewable Resource
Scientific studies have consistently confirmed that the regular harvesting of natural sponges actually enhances the health and population of the sponges by increasing the population and removing older sponges. Properly harvested, or cut, sponges will re-grow within a few years, producing a bigger and healthier sponge than it was originally. Pieces of sponge that are broken off in the harvesting process that settle back to the ocean floor and reattach to a hard object, can regrow into completely new sponges. Studies have repeatedly demonstrated that harvested colonies actually increase in their population density, and through this practice the overall sponge population.