Gibraltar Artificial Reef

[citation needed] It consists of a collection of sunken wrecks designed to give marine wildlife an environment to breed and colonise.

This was followed by sinking of cars and monitoring the effects of sealife upon them, including a Mercedes-Benz that was towed out behind a boat prior to being sunk, driven by diver and instructor Steven Hensaw.

[1] The last major addition was the remains of the MV New Flame, a mid-sized bulk carrier that foundered off Europa Point in 2007.

In 2013 a new type of reef was created by sinking of concrete blocks, with metal spikes attached.

Spain regularly "deployed hundreds of [concrete blocks] to protect its waters" from fishing trawlers.