50 Years Later: Clearing Tires from Cocos Lagoon

Posted Thu, 02/13/2020 - 15:56

Guest blog by: Renee Schnabel Crisostomo, Biologist at the Guam Environmental Protection Agency

If you take a stroll down to Guam’s southernmost village of Merizo, you will be met with the breathtaking beauty that is Cocos Lagoon. Cocos Lagoon is the island’s only shallow water atoll-like lagoon covering an area of more than 10km² (3.9 sq. mi). The lagoon houses significant marine resources and is an important recreational and subsistence fishing area, as well as a popular area for numerous tourism operations. Cocos Lagoon also provides important habitats for a few Endangered Species Act (ESA)-listed species, such as the green and hawksbill sea turtles, and is a NOAA Habitat Focus Area Site and Coral Reef Conservation Program priority.

A view of a very blue ocean from the waters surface looking at an island in the distance.
Cocos Lagoon and Cocos Island located in the southern village of Merizo (Photo: Guam EPA).

In 1969, a team of Guam fisheries scientists decided to install an artificial tire reef within Cocos Lagoon as a way to reuse old rubber tires. The experiment was intended to increase fish stocks at two different areas within the lagoon. However, after four years of close monitoring, the scientists decided to discontinue the project since it did not demonstrably improve fish stocks as intended. Over fifty years later, the tire reef still sits on the bottom of the lagoon. 

In 2019, the Guam Environmental Protection Agency (EPA) in partnership with the Guam Department of Agriculture, Division of Aquatic and Wildlife Resources (DAWR) were awarded a NOAA Marine Debris Program Removal grant to remove and dispose of approximately 2,500 tires within Cocos Lagoon. Currently, Guam EPA is in the process of awarding a contractor to perform the removal and disposal of the tire reef. Minor coral growth has been observed on the tire reef which Guam EPA, along with other local resource agency partners, will also work to thoroughly assess, remove, and transplant corals to an ideal recruitment site within Cocos Lagoon.

Guam EPA believes that removing the tire reef from the lagoon will prevent any possible damage to the surrounding coral reef habitats and sensitive shoreline areas, prevent any loose tires from becoming human safety hazards as a result of a storm or high wave energy event, and eliminate any risk factors that the tire reef poses as a source of heavy metal contaminants in the lagoon.

Removal of the artificial tire reef is an important step to ensure that no additional harm is done to the surrounding ecosystem that may negatively impact the biological, economic, and cultural importance of Cocos Lagoon. This project is a huge opportunity for the island to build upon its capabilities to more effectively address marine debris issues. Guam EPA will also use this removal and disposal effort as a way to educate the public on the effects and prevention of marine debris. Efforts, such as this, that work towards prioritizing and addressing key threats to the island’s natural resources will help further build long term resilience in both marine and local communities in Guam.

A SCUBA diver swims over the more than 100 tires piled on the ocean floor.
The Cocos Lagoon Tire Reef to be removed and disposed of (Photo: Guam EPA).


50 Years Later: Clearing Tires from Cocos Lagoon

Posted Thu, 02/13/2020 - 15:56

For citation purposes, unless otherwise noted, this article was authored by the NOAA Marine Debris Program.

The Marine Debris Blog is no longer accepting comments but continues to display past contributions.


Fri, 03/06/2020 - 09:20

Obviously, marine life have senses beyond human recognition.
Discarding chemical laden tires into pristine waters was a short sighted solution.


Mon, 09/28/2020 - 18:38

Amazing, that the Guam EPA allowed this "mistake" to exist for 50 years. I'm sure that following the end of the Vietnam War there were still large contractors on the island of Guam to have handled the job. One can expect a need for experienced workers, perhaps their children at this stage.

Anjana 69 years ago

Tue, 04/06/2021 - 00:39

We have to stop ocean pollution!!


Tue, 12/14/2021 - 13:52

Wow, that's awful

Joan cabreza

Thu, 01/27/2022 - 00:25

I worked for GEPA from about 1975-1979. That tire reef was never ever on our radar. I don’t think I ever heard of it in the context of work and we never went to look and see whether it was working. and I never really knew where it was. amazing that fisheries never went down there to check and see whether it was working as habitat or not. It seems intuitive to me that animals would not use that as a habitat.If it was approved and placed in 1969 it was not a EPA because it wasn’t formed yet.

Jim T

Thu, 08/25/2022 - 23:29

...Washington Scuba Alliance in Washington state is working with government agencies to locate and remove the estimated 500,000 tires from our waters. Was there any best practices and protocols that Guam used to remove their tires? If so, is there a way to get access to them so we don't have to re-invent the wheel to do the work here? Thanks

Hi Jim, thanks for reaching out about this. The logistics are going to be different of course (the tires were in relatively shallow (<30ft) and warm water in this scenario), but you can find details about their operational approach in the 2022 Final Report Narrative. Visit the project profile in our Marine Debris Clearinghouse and at the bottom in the Downloads -Documents section you'll find the final report PDF. Let us now if you have any follow up questions (marinedebris.web@noaa.gov).