Introduction: Build an Artificial Reef

By Survival Gardener
About: I hang out in Florida and Costa Rica and build fun sustainable, eco, survival related projects.....My main goal is to be able to feed the family totally off the system. I'm a big fan of Aquaponics and edibl…

Some reefs are erroneously constructed from car tires (a bad idea due to the toxicity of rubber disintegrating in salt water), and some are built using broken-down cars, old boats and scrap metal.  Our goal was to ensure that fish and other marine animals, such as crabs, octopus, and eels, looking for a place to live and reproduce had the best environment available.  The reef project chose cinder block because the block was much easier to handle than cars and other heavy industrial items and the Calcium content of concrete bolsters the growth of various plant and invertebrate life forms.  Also, logistically it made more sense because block is readily available.  The fish habitats are formed into an “igloo” and “caterpillar” shapes  which offer the best environment to live, breed and find protection. 




Step 1: Choose Location


The very first step is to choose a low current location that is conducive to undersea life, reproduction and feeding.

In 1985, a 60-foot tuna-fishing vessel of Mexican origin was anchored close to the beach in Playa Hermosa. A fire broke out aboard causing considerable damage and the boat sank. In 2002, fishermen living in Playa Hermosa knew the location of boat and helped discover the wreck and the remains of the fishing vessel. The wreck has a N-S direction. To the south is a drum with nets and ropes completely covered with vegetation and corals, at the center is the engine and various mechanical parts of the arms. At the other end, the north, one can see a metal cube of about 100 cubic feet that is most likely a fuel tank. The wreck lies about 400 meters west from the beach, facing the parking lot of the first entrance to Playa Hermosa. It sits at a depth roughly 20 to 30 feet depending on the tide. 12 fish habitats consisting of the igloo block structure are located around the wreck..

While the CondoFish project in Playa Hermosa Costa Rica obtained full government approval for the project, this may or may not be relevant in other international locations. Costa Rica is a very ecologically conscious country and anything regarding natural resources or wildlife requires approval and constant surveillance.


Step 2: Test Reef Design Outside of Water


While you may have a good idea of what your design will be.  We highly suggest testing your design outside of the water.  This will save valuable building time underwater. 

The following steps will show the design that the Playa Hermosa Artificial Reef Project used.  It seems to be good design to start with.  After a 3 month period, an explosion of aquatic life has occured in the in and around our "fish condos".

Step 3: Move Materials to Site

Move your materials to your building site.  We chose a clean patch of ocean floor and dropped the cinder blocks one by one.  Then we built the Reef structures by moving the blocks from the pile to the building site. 

Step 4: Build Your Base

Build your base on level sea floor.  Anchoring should not be needed if the location chosen is calm enough.

Step 5: Add Levels 2, 3, and 4

Build the sides up to the 4rd level.

Step 6: Add the 5th Level and the Center Support


Add the 5th level and the center support.  The 2nd image is a cutaway shot to show a better view of the center support.

Step 7: Monitor, Maintain and Protect


Now, monitor maintain and protect.  We make weekly visits to the site and constantly think of way to make things better.  Pending approval, we'll be building more structures and requiring more and more support.

Step 8: Progress Pictures After 1 Year

It's been nearly a year since we dropped the first blocks in the water.  What was once a bare sand bottom, is now teaming with life.  The blocks are covered with calcium based creature, soft corals, crabs, fish eggs and school of fish frequent the area.  Add to the that the life in the Benthic zone under and around the structures is doing very well.