One long-standing challenge to any scientist looking at the benefits of artificial reefs is to address the issue of “attraction vs. production”. No one disputes the fact that fish are found at artificial reefs. However, if the fish are merely attracted to the reef from other locations, this is not generally viewed as beneficial to the fish population. In fact, it can be detrimental if this allows for easier capture of the fish through fishing. On the other hand, if the reef produces fish, this can indeed be beneficial to fish populations.

The scientific research on the platforms has provided answers to this question of reef function. It has been established that the platforms both attract and produce fish. It has also been determined that the nearby natural reefs also attract and produce fish. Thus, the platforms perform the same functions with regards to fish populations as natural reefs, although the magnitude and degree of these functions may differ.

Both platforms and natural reefs have resident adult rockfish of reproducing age. These fish produce larval offspring that are carried away by ocean currents and are destined to become the next generation of juvenile rockfish. This is an element of “production” carried out on both platforms and natural reefs.

When the larval fish being carried in the ocean currents locate a reef site, they truncate their journey and take up residence on the reef. This process is called “recruitment”. Each year many of these larval fish recruit to both offshore platforms and to natural reefs. In this way, both the platforms and natural reefs “attract” fish.

However, if the reef to which the larval fish recruited had not existed and the larval fish would have otherwise perished, then it can be said that the existence of the reef actually “produces” fish. Again, this is a function performed by both platforms and natural reefs.

As they mature, rockfish generally move to deeper water. This may entail moving between natural reefs and between platforms and natural reefs. This overall movement of fish between sites is a function of “attraction” and occurs at both platforms and natural reefs.

As to the magnitude of these functions, the research shows that in both recruitment and larval production, platforms may currently be more important than natural reefs.