Ships that have sunk to the bottom of the ocean, lakes, or rivers create unique artificial habitats that can become home to many marine creatures, including fish. As vessels rust and deteriorate over time, they provide solid surfaces, crevices, and sheltered areas where fish can find food and protection. While most fish are not specifically adapted to live in sunken ships, many generalist species are able to utilize these spaces if the conditions are right. The ships essentially become artificial reefs.
Quick answer
Yes, many species of fish are able to live in and around sunken ships if the environment provides their necessary food, shelter, space, and water conditions. The ships create a habitat attractive to generalist fish looking for places to hide, feed, and breed. Structures like sunken ships are frequently used in efforts to intentionally create artificial reefs.
What types of fish inhabit sunken ships?
A wide variety of fish species have been observed living and feeding in and around sunken ships and other underwater structures. Some commonly seen groups include:
Wrasse
Wrasse are a large, diverse family of small reef fish. With their flexible bodies and constantly-growing teeth, they are able to fit into tight spaces and scrape food from hard surfaces. Sunken ships provide ideal habitat for many wrasse species including clown wrasse, rock wrasse, and pencil wrasse. Their diet of bivalves, crustaceans, and other invertebrates can be found on deteriorating wood and metal.
Blennies
Bottom-dwelling blennies are well adapted to utilizing the spaces provided by sunken ships. They have eel-like bodies allowing them to slither into narrow holes and their eyes are set high on their heads to see out from crevices. Blennies eat algae, detritus, and small crustaceans. Rusty blennies and peacock blennies are blenny species known to inhabit shipwrecks.
Gobies
Like blennies, gobies are small bottom-dwellers adept at squeezing into tight spaces. Their fused pelvic fins create a suction-cup effect allowing them to cling to vertical and overhanging surfaces. Gobies found on shipwrecks may include blackeye gobies, clown gobies, and bluebanded gobies. They consume small invertebrates picked from the structure surfaces.
Groupers
Several grouper species may take up residence in and around larger sunken ships. They appreciate the sheltered spaces created by overhangs, holes, and narrow passages. Groupers are ambush predators that eat mostly small fish and crustaceans. Young Nassau grouper in particular are strongly associated with shipwrecks and other artificial structures.
Snappers
The shelter provided by sunken ships appeals to many snapper species as well. Schooling fish like yellowtail snapper congregate around the exterior of wrecks. Solitary fish like mutton snapper may claim territory inside open spaces and attack intruders. Snappers are voracious predators feeding on a combination of smaller fish, shrimp, crabs, and more.
Grunts
Grunts, which get their name from the sounds they produce, are another fish group attracted to shipwrecks. Bluestriped grunts, French grunts, and white grunts all utilize the protection of sunken structures to avoid predators. Grunts use their strong teeth to feed on hard-shelled prey like snails, bivalves, and urchins.
Damselfish
Small, colorful damselfish establish territories around structural features like sunken ships. They farm algae for food and aggressively defend their claimed space. Beaugregory damselfish, bicolor damselfish, and threespot damselfish commonly inhabit shipwrecks in warm ocean waters.
Cardinalfish
Nocturnal cardinalfish spend their days sheltered in holes, crevices, and passageways within sunken ships. Species like masked cardinalfish and apostlefish emerge at night to prey on small crustaceans in the open water. The structures allow them to safely hide from predators during daylight hours.
Eels
Moray eels and snake eels make use of the small enclosed spaces within submerged wrecks. Their slender, snake-like bodies allow them to enter openings inaccessible to many other species. They lay in wait to ambush prey with their strong jaws and many sharp teeth.
Why do fish live there?
There are several key reasons sunken ships make attractive habitat for marine fish seeking shelter:
Protection from predators
The enclosed spaces, narrow openings, overhangs and other maze-like passages formed as ships deteriorate create places for small fish to hide from larger predators. Larger predatory fish may claim territory in and around wrecks as well, using the sheltered location to launch ambush attacks on prey while also having a place to retreat.
Abundant food sources
Sunken ships become oases of life as algae, plants, and sessile invertebrates like barnacles, mussels, and tube worms colonize the structure over time. This attracts grazing fish and smaller organisms up the food chain providing food for the larger predatory fish. Schools of smaller fish may also congregate around the exterior of wrecks, drawing in larger hunters.
Hard substrate
The solid surfaces of sunken vessels provide attachment sites needed by sedentary marine organisms like mollusks and anemones that many fish feed on. The growth of these sessile creatures turns the ship into a reef-like habitat. The attached organisms also release eggs and larvae contributing to the available plankton food sources.
Protection from currents
The bulk of a sunken ship buffers fish from strong currents and wave surge which can quickly whisk smaller organisms away. Residing in the lee of a wreck allows more sedentary fish to avoid being swept off suitable habitat. The structure also provides visual reference points.
Vertical structure
Unlike much of the seafloor which is flat, the upright surfaces, overhangs, and complex profiles of sunken ships provide gradients of light, water flow, and access to food sources from the seafloor up into the water column. More niches across these vertical zones can support a greater diversity of species.
Do any adaptations help fish live there?
While most wreck-dwelling fish are generalist species without specific adaptations for shipwreck habitats, some do have relevant adaptions that aid survival in and around sunken vessels:
Flattened bodies
Many fish living in tight quarters like crevices and passages have laterally compressed or extremely slender bodies. This improves maneuverability and ability to swim into narrow openings. Examples include blennies, gobies, eels, and cardinalfish.
Ability to attach
Some fish can attach themselves using modified fins, suction, or secreted mucus. This helps them hold position securely inside confined spaces where currents may be accelerated. Clingfish and remoras have suction cup fins. Gobies and blennies use fused fin structures.
Flexibility
Spineless fish like eels and smaller wrasses can wiggle and twist their flexible bodies to fit through incredibly narrow gaps and crevices inaccessible to more rigid fish. Their lack of hard fin spines also helps prevent jamming.
Strong jaws
Many shipwreck fish like groupers, snappers, and grunts have extremely strong bite force and robust teeth. This aids feeding on hard-shelled organisms attached to the wreck surfaces. Their formidable jaws also help fend off competitors.
Acute vision
Fish that inhabit dark enclosed spaces often have enlarged eyes and enhanced low-light vision. This helps them find food and avoid predators when ambient light is low. Cardinalfish and squirrelfish are examples with excellent night vision.
Camouflage
Fish like scorpionfish and stonefish have mottled skin that perfectly blends with the encrusted surfaces of a shipwreck. This camouflage allows them to remain concealed from both prey and predators. Their ambush hunting strategy relies on not being noticed.
Conclusion
Sunken ships create a unique habitat niche that a diverse array of opportunistic fish species have adapted to occupy. While no fish rely exclusively on shipwrecks, many are able to thrive in and around them due to ample food sources and protection from predators. Structural complexity and surface encrusting organisms essentially turn wrecks into artificial reefs. Fish use holes, overhangs, and other spaces to hide, feed, breed, and avoid currents. Purposefully submerged vessels have been used to successfully restore or enhance fish populations. So overall, many fish are able to live happy lives calling sunken ships their home.
| Fish Group | Example Species | Key Adaptations |
|---|---|---|
| Wrasse | Clown wrasse, rock wrasse | Flexible bodies, constantly regrowing teeth |
| Blennies | Rusty blenny, peacock blenny | Eel-like bodies, upward facing eyes |
| Gobies | Clown goby, bluebanded goby | Fused pelvic fins create suction cup |
| Groupers | Nassau grouper | Large size, strong jaws |
| Snappers | Yellowtail snapper, mutton snapper | Form schools or claim territory, voracious predators |
| Grunts | Bluestriped grunt, white grunt | Robust teeth for eating hard-shelled organisms |
| Damselfish | Beaugregory damselfish, bicolor damselfish | Establish and defend small territories |
| Cardinalfish | Masked cardinalfish, apostlefish | Nocturnal, find shelter in shipwrecks during the day |
| Eels | Moray eels, snake eels | Slender, snakelike bodies to enter small openings |
