The only known glass sponge reefs in the world live in the waters off the coast of British Columbia. Canadian scientists recently discovered fields of glass sponges, something thought to have disappeared 65 million years ago. Near Vancouver, Howe Sound has glass sponges that our research divers can observe and measure over time.
What’s so Special About Sponges?
Scientists have come to recognize sponges as “the first animal” – an animal so simple that it has no head, heart, gills, or even a nervous system. They can’t even move, and people can get them confused with rocks or plants. Howe Sound is home to a special type of sponge that has a skeleton made of “glass” – the silica that washes down from ancient granite mountains into our waters.
By studying these simplest of animals, we can find out more about how life evolved billions of years ago. However, we know almost nothing about how quickly the sponges grow, or why they prefer to perch on one rock over another. Our research is looking into the effects of damage that humans cause, although we are still exploring the question of whether sponges can heal themselves.
What We Don’t Know
The current understanding has been that structural damage to the sponge could lead to their death; damage to their delicate structure causes their body fluids to leak out. However, we’ve been intensely studying a small sponge by Bowen Island in Howe Sound to study how sponge tissues heal. For an animal that cannot move and eats by filtering huge amounts of water, this process takes months and years.
There are strong indications that the poor capacity to recover from physical damage had occurred during El Ninõ events, when the local temperatures are mild and warm, even in the winter. Our past two winters have been the colder, La Niña events, and it appears that the healing and growth rates of sponges occur more rapidly under these conditions. We suspect that El Niño southern oscillation (ENSO), a pattern of warming and cooling that occurs every few years, may play a profound role in how these glass animals grow and multiply throughout Howe Sound, even in shallow waters that divers can access.
One of the most exciting moments as a scientist is being shown when we’re wrong, as it makes us look at old information in a new light. Until now, we have suspected, but have been unsure of, what role ENSO events play in marine ecosystems. The simplest of animals can play a pivotal role in our understanding of the oceans; by studying an animal that cannot move and has a body made of glass, scientists have access to a living, growing record of our local climate and water conditions.