[StarfishKey]

I went to a lecture recently here in the Keys on the health of sponges, and the sponging industry.

I would bet a lot of people don't know much about natural sponges in the ocean, but they're pretty interesting.

Species of sponge are among the oldest living animals on Earth (yeah, they're animals), and they're also some of the longest-living animals, with some species living 2,000 years.

Sponges are natural filters for the ocean, with a single milk container-sized sponge filtering enough water to fill a swimming pool every single day. They keep our ocean (and reef) clean, and that's pretty essential especially today, with all the chemical and pet waste run-off, Rxs thrown into the ocean, trash, sludge, and slime that come from the humans that live nearby on land.

Sponges also provide the shelter needed for spiny lobsters and stone crabs to grow into adults - which are two of the most important commercial species we have in Florida.

In addition to filtering the whole ocean, some sponges have recently been identified as containing compounds for powerful new cancer-fighting drugs. So it behooves us to protect them.

In the old days, sponges were harvested out of the ocean in huge numbers for household use. The Keys for a while became the top producer of quality sponges, because of our exceptionally shallow, clear, calm water that made shallow sponge fishing easier using a sponge hook. The hook used to cause such damage that the remaining part of the animal could not grow back, and usually died. Only 3 species of sponge are really commercially marketable - the sheepswool sponge, the yellow sponge, and the grass sponge. They're generally covered in a black layer in the ocean, so if you don't know what to look for, you might miss them! They don't look like they do in the store! And they don't look like Spongebob either!

Then multiple algae blooms came along, plus a few blights, added to overfishing, and these sponges were nearly wipes out. The synthetic sponge was then invented, and the sponge market became a fraction of what is was. In recent years, the craze for natural products has returned some of the growth to the industry, but it's a more upscale and tiny market.

In the absence of the majority of sponges in the Keys, studies found something rather remarkable. When the sponge ecosystem was healthy, the ocean used to be NOISY! Divers could routinely hear a constant crackling of shrimp, which liked to hang out around the sponges. Their sounds drew the bigger fish, and thus the whole reef system was healthy, active, and thriving. The sound was measurable. When the sponges were gone, the crackling stopped, as the shrimp were gone, and so were all the other fish. The silence was also measurable, and deafening to avid divers who had been used to the noise prior to the 90s when the sponge population dropped off.

Since that time, one thing that scientists have learned is that harvesting only larger sponges (minimum 5 inches), and cutting them rather than ripping them right out of the ocean floor, allows them to regrow and keep the population - and the ocean - healthy. There are also projects trying to transplant sponges the same way coral is being transplanted. In the Keys, diving fr sponges is prohibited to protect the larger sponges found in deeper waters. If cared for properly, sponges can be a renewable and sustainable product.

For a long time the Florida Keys economy revolved around sponging, and it was one of the specialties of the many Bahamians who moved to the Keys. In time it also became known as a common "Conch" means of employment. Even today, commercial sponging still goes on in the Keys, but it is a far smaller industry, and is no longer the biggest sponging source in Florida.

Who knew the sponge was so important, both to the health of the ocean, and to the health of humans?

We need to actively preserve sponges, enforce protections on their harvesting, and do all we can to end algae blooms in our ocean which can overwhelm and kill off millions of sponges at a time. Ceasing to use chemical fertilizers and insecticides, properly disposing of pet waste, and strictly regulating industries that raise ocean temperatures (like nuclear reactors) and that dump masses of toxic chemicals into our waters, can help protect sponges AND people.




Loggerhead sponge



Four good articles on Florida sponges:
Sponges
https://www.flseagrant.org/news/2014...onge-die-offs/
Leaving a piece of the future intact | KeysNews.com
SGEF-169/SG095: Florida's Marine Sponges: Exploring the Potential and Protecting the Resource