Rockfish Young of the Year (YOY) Monitoring

When monitoring rockfish, it is important to consider the population as a whole in order to have a greater understanding of the overall health of a species. While the number of adults in a given area provides critical information, the number of juvenile and Young of Year (YOY) is just as crucial and informative.

In fish species, egg production increases with size and in Rockfish, some of largest females are capable of producing millions of eggs annually! Survival of a species is therefore reliant on a healthy abundance of larger, mature individuals to sustain the population. Unfortunately, it is often these individuals which are disproportionally targeted intentionally or unintentionally through fishing, affecting the level of recruitment in a particular area.

When baby rockfish are born, they also enter a pelagic existence where they remain in the upper levels of the water column, and are swept by ocean currents before settling after many months. Survival during this stage can be heavily impacted by various oceanic conditions such as temperature and food availability, leading to fluctuations in YOY strength and population growth. Long term monitoring of YOY species is therefore able to provide insight in a myriad of conditions such as fishing pressure, changing environmental conditions, and effectiveness of management strategies.

Different habitat types are also known to be preferred by younger members of rockfish populations with certain habitats serving as important refuges and nursery sites. Greater understanding of these associations will improve our understanding of these critical species and where conservations measures will be most effective, not just for rockfish but the ecosystem as a whole.

With all the information that can be gained from monitoring baby rockfish, MLSS kickstarted a YOY monitoring program in 2023, in conjunction with our adult Rockfish monitoring program. Our YOY project was developed in close partnership with the PAUA Marine Research Group who have successfully built and run a YOY survey program in Washington state for the past ten years. More information about their incredible work can be found on their website.

Interested in becoming a part of this important work? Conducting YOY surveys can be done by any recreational diver in British Columbia! Not only can they be conducted during any dive, they can also be done in combination with adult rockfish surveys and LEMs! Find out more here!