The Life Cycle of a Wreck
What is the life cycle of a wreck once it sinks? How do wrecked ships impact the environment and how are they incorporated into the rich marine life around Vancouver Island? Several factors determine what happens to a wreck, but the two most important are the location of the wreck and the materials of the vessel.
On the rugged west coast of Vancouver Island, the breakers pound the metal of a ship into the sea bed. Over time, it can flatten and cover the ocean floor, almost like a second skin. If the vessel is made of wood, not much will remain. It has to contend with the tides and currents, which often carry wooden pieces hundreds of miles away.
On Vancouver Island’s east coast, where the waters are much calmer, steel and metal boats often have a better chance of remaining intact underwater. Pieces drift off of wooden boats in much the same way as on the open coast, especially after marine life attacks and weakens the wood.
As a result, a shipwreck can be hard to identify, but given practice and experience, divers can locate and map the remains. Drawings called “site maps” show what a shipwreck looks like under water. Compare this image with a before drawing and see the dramatic difference.
Another reason shipwrecks look different under water is because they become host to a diverse ecosystem. In effect, the shipwreck becomes an artificial reef. Beautiful animals such as orange and white anemones often cover whole sections and strange looking white tubeworms can make a wreck look otherworldly. The wooden parts of a wreck also provide food for this new ecosystem. Marine borers such as toredoes, clams (shipworms) and isopods (gribblers) gnaw away at the wood.
Even though a ship may disappear from sight, a new life awaits it on the bottom of the sea, and it can still serve as a vehicle for discovery!