Analysis of mtDNA haplotypes of kelp bass tests for sibling-dominated recruitment near marine protected areas of the California Channel Islands

Marine protected areas (MPAs) have been heralded as the next important fisheries management tool. Predicted benefits include increased fish biomass, increased species diversity, and enhanced recruitment to the MPA itself, as well as to proximal areas. Whereas MPAs have in fact been shown to increase biomass and species diversity, evidence of enhanced recruitment has yet to be seen. If MPAs are significantly enhancing recruitment, one would expect to see the recruitment dominated by groups of siblings arising from highly productive females predicted to eventually reside in MPAs due to the protection afforded them. If occurring, such sibling-dominated recruitment could be identified by significantly fewer mtDNA haplotypes and significantly fewer singleton haplotypes in population samples of recruiting juveniles compared to adult populations. We investigated a new approach for potentially determining whether MPAs might be significantly enhancing recruitment to proximal areas of Santa Cruz and the Santa Catalina islands in the California Channel Islands, by seeking evidence of sibling-dominated juvenile recruitment in mitochondrial DNA haplotype data of the kelp bassParalabrax clathratus. Our analyses found largely genetically mixed recruitment from the plankton, suggesting that recruitment to the sampled areas was not being measurably enhanced from point sources such as the nearby MPAs.