Emerald Sea Photography
Cloud Sponges (Aphrocallistes vastus), are deep-water animals that form large, billowing growths up to ten feet in diameter and nearly seven feet high. They belong to a group of primitive organisms that use silica to form glass-like spicules to form the support structure of the sponge. Cloud sponges are found from Alaska to Mexico, typically in inlets, on rock walls and ledges at depths of 100 feet and deeper. Occasional specimens are found in the 80 – 100’ depth range, but they do not seem to survive long at that depth.
Cloud sponges belong to an ancient family of animals that were present long before the time of the dinosaurs. Because these sponges are a deep dwelling organism, very little is actually known about them. In a few areas around Puget Sound and the inlets of British Columbia, cloud sponges can be found within the depth limits of recreational divers. This allows us a unique opportunity to view and study an animal which has not changed much in hundreds of millions of years. Cloud Sponges grow about 2” per year in nutrient rich waters. In areas with poor circulation ( like Hood Canal ), growth rates are much slower, so the cloud sponges you see may be 100’s of years old. Divers should be very careful when swimming near a cloud sponge, as an errant kick could easily destroy an ancient animal that is far older than we are.
The “mittens” of Cloud sponges tend to form in a “vertical” orientation, which helps avoid sediment accumulation on the sponge. The sponges must keep themselves clean in order to circulate water and capture nutrients. Cloud sponge colors typically range from white to dark yellow. The sponges you see that are dark brown and covered with sediment are usually dead sponge skeletons. The only known predator of Cloud Sponges is the “Wrinkled Sea Star” (Pteraster militaris).
Sponges filter sea water to eat, breath and excrete waste products. They trap plankton using the cilia surrounding their cells. Sponges have complex water canal systems running throughout the body, with smaller inhalant (ostia) and larger exhalant pores (oscules). Sponges are able to actively pump up to 10 times their body volume each hour, making them the most efficient vacuum cleaners of the sea. Sponges are like living fossils, with the largest known individuals thought to be around 5,000 years old .
My favorite sites for observing Cloud Sponges are Snake Island Wall in Nanaimo, B.C., Sponge Hill and Flagpole Point in Hood Canal. (see photos). Sponge cavities frequently host a variety of other animals, such as rockfishes and a wide variety of invertebrates, so keep your eyes open. Observing and photographing cloud sponges requires divers to venture into the darker depths below 100’ in our cold Puget Sound waters, but are well worth the visit.