Some reefs are poorly built with tires (a bad idea, due to the toxicity of this material when it disintegrates with salt water) and for others old cars and other metal debris are used, i even saw trains. The goal of an artificial reef is to make sure that fish and other marine life, such as crabs, octopuses or eels, have a place to live and breed in the best possible habitat.
Cement blocks were chosen for this reef project because these bricks are much easier to handle than cars and other heavy industrial objects, also because the calcium content of concrete promotes the growth of various forms of plant and invertebrate life. . .
Also, logistically it makes more sense because the blocks are always more available, they are easier to obtain. Fish habitats are formed in “igloo” and “caterpillar” structures, providing the best environment for living, breeding and finding protection.
Build an artificial reef.
Step 1: Choose the location carefully.
The first step of all is to choose a location that is not too crowded and can be good for marine life, with access to food.
In 1985, a 60-foot tuna vessel of Mexican origin dropped anchor off Playa Hermosa. A fire broke out on board, causing considerable damage and sinking the ship. In 2002, fishermen living in Playa Hermosa found the location of the boat and helped uncover this wreck and the remains of the fishing boat.
The shipwreck retained an NS address. To the south there is a drum with nets and ropes completely covered with vegetation and corals, in the center is the motor and various side mechanical parts. At the other end, to the north, you can see a metal bucket of about 100 cubic feet which is probably a fuel tank.
The wreck is located about 400 meters west of the beach, in front of the parking lot at the first entrance to Playa Hermosa. It is found at a depth of about 20 to 30 feet, depending on the tide. 12 different fish habitats coexisting in the igloo block structure found around this wreck.
While this project CondoFish in Playa Hermosa, Costa Rica it got full government approval, it may not be relevant in other places. Costa Rica is a country with a great ecological conscience and all matters related to natural resources or wildlife require prior approval and constant vigilance.
We therefore recommend that you check with the local authorities before undertaking such a project.
Step 2: Test the reef design out of the water.
While you are deciding what the design will look like, we recommend that you take a test out of the water. It will save you precious time when you are already building it in the water.
The following steps will show you the final design that was used in the Playa Hermosa artificial reef project. Seems like a good design to start with. After 3 months, an explosion of aquatic life occurred in and around our “fish bottom”.
Step 3: Move the materials.
You will need to move materials around the job site. For this project, the cement blocks were put down one by one. The reef structure was then built by moving the blocks from the pile to the construction site.
Step 4: Build the base.
Build your base at sea level. Anchoring should not be necessary if the chosen location is sufficiently quiet.
Step 5: Add levels 2, 3 and 4.
Build on the sides until you reach the fourth level.
Step 6: Add 5th level and support center.
Now add the fifth level and the central support. The second image is a photo cropped to show a better view of the center bracket.
Step 7: Monitor, maintain and protect.
Now you need to monitor, maintain and protect your reef. Visit weekly and think of ways to improve things.
Step 8: Progress after 1 year.
A year after its installation, what was once just a space with nothing but sand is now full of life. The blocks protect the sea creatures that benefit from the calcium, soft corals, crabs, fish eggs and schools of fish that frequent the area. In addition, it does very well for life in the benthic zone that is under and around structures.
Full instructions: instructables.com