PISCO scientists have been engaged as scientific advisors to California’s Marine Life Protection Act (MLPA) Initiative since 2004. In this capacity, PISCO science has informed the “rules of thumb” for design of effective MPA networks and helped to answer a variety of scientific questions that have arisen in the process of MPA design.
MPAs should encompass a variety of marine habitats across a range of depths and environmental gradients
PISCO’s monitoring programs have helped to elucidate how ecosystems and the communities they support vary across space and time. This information has been used to define biologically distinct regions within California and to identify the scales across which habitats should be replicated within MPAs for effective protection of the full diversity of marine communities in California.
MPAs should be large enough that adults don’t move out of them too frequently and become vulnerable to fishing
The movement range of fish and invertebrate species has implications for MPA size guidelines. By understanding the mobility of a wide range of species, scientists can predict which species will likely be protected by an MPA of a given size. A review and analysis of the fish movement literature conducted by PISCO graduate student Jan Freiwald evaluated movement information for 25 west coast temperate reef fishes. This work informed the MPA size guidelines used in the MLPA process.
MPAs should be close enough together that sufficient larvae can disperse from one to the next
PISCO’s genetic and recruitment studies have helped to define larval dispersal distances. PISCO scientists applied genetic models and a synthesis of the literature on population genetics of marine species to generate estimates of larval dispersal distances for algae, invertebrates, and fishes. These dispersal distances were used to generate guidelines for spacing adjacent MPAs.
How well will an ecosystem be protected if a specific fishing activity is allowed within an MPA?
Applying their extensive knowledge of California’s coastal marine ecosystems, PISCO scientists and coordinators helped to develop a conceptual model to classify the potential impacts of extractive activities on marine communities. The conceptual model considers both direct impacts (e.g. habitat destruction) and indirect impacts (e.g. community alteration due to removal of a top predator) through a series of questions in a decision tree. The answers to these questions, derived from diverse sources including published life-history and species movement information, catch records, gear-type information, and discussion with scientists and fishers, lead to an assigned “level of protection” for each use proposed within an MPA.
How much habitat is needed to protect the biological community associated with that habitat?
PISCO scientists used a variety of information sources, including PISCO kelp forest and rocky shore monitoring data to assess the relationship between habitat size and biodiversity for a variety habitats. Using this relationship, the MLPA Science Advisory Team was able to set thresholds for the amount of each habitat needed to encompass 90% of the associated biodiversity. This information helped to inform habitat replication and spacing analysis for MPA network design evaluations.