Marine citizen science on a San Diego artificial reef

A short history

In 2000, the HMCS Yukon, a 366ft-long Canadian warship, was sunk off the coast of San Diego to become an artificial reef, after being cleaned and decontaminated according to Canadian environmental standards. Holes were also cut into the hull at regular intervals to provide divers with daylight by which to navigate while within the wreck. Since then, the ship has transformed into a home for marine life, while becoming an international diving destination. At 100ft, it should only be dived by divers certified to that depth and never penetrated without additional training. There have been several diver fatalities over the years.

Scientific studies

In 2004, a joint study by the San Diego Oceans Foundation (SDOF) and Scripps Institution of Oceanography was undertaken to better understand the effects the reef was having on the surrounding marine life.

Back then, there were not many sessile (attached) invertebrates, and fish were only just beginning to make the wreck their home. In the intervening years, however, the Yukon has become an ecosystem unto itself, home now to dozens of species of invertebrates and fish, and even the occasional salp chain or mola mola (sunfish) passing through.

Noting that 11 years had passed since the original study was commissioned, which began in 2015, Ocean Sanctuaries began the Yukon Marine Life Survey, intending to update the data on the marine species that have established themselves on the Yukon since 2004, using a citizen science app called iNaturalist.

This is the way it works:

Advanced divers, who are certified to 100ft, dive the Yukon as they normally would and simply photograph invertebrates that are attached to the vessel (such as anemones and sea fans), as well as any vertebrates (that is, fish) seen on their dive. Fixed transect lines are not used.

Upon returning home, divers go to their previously created account with iNaturalist and upload the photographs taken on their dives to: https://www.inaturalist.org/projects/yukon-marine-life-survey.

iNaturalist is run by the California Academy of Sciences (CAS) and has both resident marine scientists as well as experienced divers/naturalists who can assist in the identification of species in the uploaded images. This is known as a "community identification process." Final determinations are made by CAS scientists.

Image

Because the Yukon rests on the bottom at 100ft, only advanced divers are qualified to go to that depth, so the pool of regularly contributing divers is small: nine so far—but it is hoped that this number will be increased moving forward. However, because many of these divers are extremely proficient with a camera underwater, they are able to photograph quite a number of species on a single dive, so a large pool is not always a requirement for this study.

As of August of 2021, Ocean Sanctuaries has collected data from 237 observations, successfully identifying 59 individual species on the wreck.

To further our understanding of the marine environment, Ocean Sanctuaries encourages and supports citizen science projects that empower local divers to gather marine data under scientific mentorship. In addition to the Yukon Marine Life Survey, Ocean Sanctuaries has two citizen science projects that are shark-related—"Sharks of California" and the "Sevengill Shark ID Project"—and offers basic courses in marine citizen science.