Hundreds of shipwrecks are off the United States and Canadian coast, and many represent a terrible loss of life and property and pollution of the seas and shore. Over time, many of these ships become places of interest to divers, archaeologists, and anglers as they teem with wildlife.
Hundreds of species of plants and animals, including coral, crustaceans, fish, sharks, sponges, seaweed, and anemones, can live on and around shipwrecks.
Shipwrecks are teeming with a fantastic abundance of marine life. Many marine animals and plants need to attach themselves to something to live, and wrecks provide a home for them.
Shipwrecks of North America
Many wrecks are never found, and others may have broken down over time.
With two large oceans surrounding North America, ships are exposed to storms on both sides and are extremely dangerous to shipping.
Many plants and animals attach themselves to objects to reproduce, spreading by crawling, drifting, or floating along the ocean floor using spores and larvae. These tiny drifters can be seen hovering around, and when they find a wreck, they hold on much the same way they would use a rock.
What grows on a shipwreck depends on the position and depth of the wreck. A wreck provides a rigid substrate for them to live, which is essential for many plants and animals.
Shipwrecks that settle on a soft surface provide a surface for many plants and animals to grab onto in an otherwise empty landscape. Coral is generally found on rocks and not on the seafloor sediment, but shipwrecks give coral something to hold onto.
Many shipwrecks provide ocean habitats in sandy or muddy environments for sea anemones and fungi.
As wrecks generally stick out of the seafloor, many animals use the elevated surface to find food. As they are not so close to the cold ocean floor, they will also conserve energy, picking up the food from their elevated position. If you want to know where the current is coming from, look at how the shipwreck’s wildlife is pointing. They will have their mouths facing the wind to catch drifting food easily.
Shipwrecks don’t only happen at sea; the wildlife that lives on a shipwreck in sheltered waters will be different than a wreck in ocean waters or areas of high water movement.
Some animals will live in the wreck and damage the structure. Shipworms, a clam species, along with piddocks and a crustacean called the gribble, will burrow into wooden parts of shipwrecks, destroying them.
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Fish can always be found around shipwrecks, and many shoals of pouting can be found swimming around.
Larger fish also seem to like the dark shelter that the wreck provides. Amberjacks, along with barracuda and mutton snapper, can be found. Conger eels can be found, and although they won’t attack unless provoked, divers do have to be careful when feeling around a shipwreck.
Goliath groupers can also be found around shipwrecks, and these genuinely are goliaths as they can weigh up to 800 pounds. You can also find many species of groupers around wrecks, including the gag, black and snowy groupers.
Cod, along with Ballan wrasse, pollack, and the feather blenny, can also be found.
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There are also many predators lying in wait around a shipwreck. With so many plants and animals around a wreck, food is abundant, from small worms and crustaceans to larger fish.
Scorpionfish will make a meal of the smaller insects and crustaceans, while a predatory fish, the topknot, can also be found around wrecks. The top knot is a flatfish that blends into rocky areas and is also suited to impacts. The topknot may agree further if there is pink seaweed, as the topknot may use its pink spots as camouflage.
Cuttlefish can also be seen catching small fish and crabs, which they catch using their long tentacles. Lobsters can also be found around shipwrecks, while the sponges and hydroids provide food for sea slugs.
In North Carolina, sand tiger sharks can be seen around the Outer Banks. From May to October, sand tiger sharks can be found around the Aeolus wreck, sometimes in numbers up to 30. The Aeolus was sunk as part of an artificial reef program in 1988.
The lifespan of a Wreck
Shipwrecks can support a large, stable community of animals and plants. These communities can take many years to develop fully.
The first to arrive at a wreck are fast-living but short-lived species. These are then replaced over time by slow-growing but long-lived organisms.
Sea lettuce and some kelp species reproduce throughout the year and compete for space and light on a wreck. Both are the first colonizers of an impact. However, these are replaced by perennial kelp forests and small animal species over time.
Weather conditions can change a shallow wreck’s habitat and the communities that live there.
Wrecks can be colonized and recolonized by different species yearly or at other times.
Artificial reefs are built intentionally to attract marine animals and plants to areas.
Artificial reefs can be used to restore coral reefs. They provide a growing area for corals and a habitat for fish.
Artificial reefs can be built out of ships, large steel or concrete structures, or steel rebar or cement.
Artificial reefs are used for a variety of reasons. They can be used to control beach erosion or to provide better hydrodynamics for surfing. Other uses for artificial reefs are blocking ships’ passage and stopping trawling nets.
There is an ongoing debate about how good artificial reefs are for the environment, but a lot of this is due to the methods used to sink the artificial reef and the plans and type of construction.
Bryan Harding is a member of the American Society of Mammalogists and a member of the American Birding Association. Bryan is especially fond of mammals and has studied and worked with them around the world. Bryan serves as owner, writer, and publisher of North American Nature.