One of the oddest things you will find washed up on a beach around New York Harbor is the remnant of a Red Beard Sponge. Although the most common sponge in the estuary, I doubt many folks are familiar with it, let alone that sponges actually exist in the cloudy waters of the harbor.
Yes, sponges do indeed exist in New York Harbor. Globally, there are more than 5,000 species of sponges, and a few of them can be found right here. Often with mysterious and curious names like boring sponges, finger sponges, dead man’s finger sponges, palmate sponges, and bowerbank’s halichondria (one of my favorites, also known as the crumb of bread sponge because it usually crumbles into small pieces when touched and it forms crusty chimneys on top of soft-shell clams). These are just the one’s I know for sure. There are almost surely other sponges living in the estuary waiting to be discovered.
The red beard sponge (Microciona prolifera) is the one that most beach walkers stumble upon around the harbor and nearby sandy beaches. The odd name comes from its thick intertwined hair-like branches that fan out to resemble a wild looking long beard.
When dead, the red beard sponge is dim and dreary in color, a dry brown. It’s more fascinating, as all things are, to find when alive.
They look like nothing else living in the estuary. Quite odd and bizarre. Their color is frequently a wild bright red or orange, which really stands out in turbid waters. When snorkeling you may come across a blazingly colored colony of red beards made up of many individuals living together as a cluster on rocks, shells, pilings, or other hard objects in shallow parts of the estuary, including in or near salt marshes.
Look closely at one that is alive and you will discover tiny openings or pores into the hollow body. Sponges are filter feeders. Water flows in and out of these small pores from currents or tidal action in the bay. As water moves through the sponge, small, slender hair-like structures called cilia will trap oxygen for the sponge to breathe. Cilia will also trap phytoplankton, algae or bacteria as food for the sponge. Waste and carbon dioxide is carried away from the many openings on top of the sponge’s body.
Even how sponges reproduce is a little bizarre. According to the Chesapeake Bay program website, red beard sponges “reproduce both sexually and asexually. Asexual reproduction takes place when branches are damaged or broken off. The sponge fragments bud into new sponges. During sexual reproduction, eggs are fertilized within the sponge. Free-swimming larvae eventually settle to the bottom, where they find a hard surface to attach themselves to. Young sponges are usually thin and flat, rather than thick and branching.”
No doubt these are incredible animals, or are they plants? The first naturalists centuries ago were unsure. Today there is still some question, but many naturalists I know will call sponges an animal, not a plant, but a very primitive form of life made up very simple multicellular animals that lack organs, including eyes and a brain (sorry Sponge Bob!).
Of course everything on Planet Earth has a role to play. For sponges, the nooks and crannies among their branches provide important habitat for shrimps, worms, crabs, small fish, and other tiny creatures seeking a safe hiding place from hungry predators. Since sponges are filter feeders, they also play a role in helping to improve water quality in the harbor by removing algae, bacteria, and particles. Cleaner water will allow other life in the estuary to thrive.
Like all animals, sponges need food, shelter, living space and oxygen to live and have young. Red beard sponges are no different. Over time, they have become one of the hardiest critters in New York Harbor, able to withstand very polluted waters. They have become perfectly adapted to living life in these stressful tidal waters. But who knows, maybe one day when our waters are really clean Sponge Bob will show up for a visit.