Oil Platforms - A Unique Home for Endangered CA Rockfish / by Amber Jackson

Can you spot the Cabezon hiding on the leg of Platform Gina? Offshore oil and gas platforms are essential habitats and nurseries for several overfished species, including rockfish in Southern California. 

Commercial fishing in California has been on the decline since 1970. In that year, California's share of the U.S. harvest, based on the dollar value of commercial landings, was 14 percent; However by 1990, the state's share had dropped to just 4 percent; and by 2001 it had declined even further to 3 percent. In order to begin to restore this declining population, federal fisheries authorities instituted an offshore rockfish closure along the continental shelf off California's coast.

In a detailed six-year study, experts in this field concluded that, "platforms act as de facto marine refuges." In fact, oil platforms appear to be "functionally more important as nurseries" than natural rock outcrops. Juvenile rockfish, several species of which are currently recognized as over-fished in the state of California, were actually found in higher densities at several of the platforms as compared to nearby natural reefs. 

In some locations, platforms may provide much or all of the adult fishes of some heavily-fished species and thus contribute disproportionately to those species larval production
— Dr. Milton Love, UC Santa Barbara

Historically, surveys of platforms in California waters have revealed that oil and gas platforms harbor rich assemblages of marine organisms, including many fishes and invertebrates that typically occur on natural rocky reef substrates. The particular species present on any given platform are directly tied to the biogeographic setting of the platform, its depth, and several other factors. Despite the fact that platforms host an abundant variety of marine life, it is the platform’s contribution to regional stocks of species that is critical in evaluating its complete ecological impact. This is due to the fact that most marine species are made up of a series of local populations that are connected by the dispersal of juveniles in the water column, subject to currents, geological features and other biological factors. This means that impacts at any one location must be evaluated within a regional context. Unfortunately, this means most assessments regarding the possible enhancement of fish populations on platforms are fundamentally flawed because they focus on local and not regional effects. Based on these assessments, it can be concluded that artificial reefs on oil and gas platforms have the potential to enhance overfished populations of resident fish. 

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