Research Technical Report

Monitoring MPAs in Deep Water Off Central California: 2007 IMPACT Submersible Baseline Survey

Starr, R., M. Yoklavich, et al. (2008)

California Sea Grant College Program, Publication No. T-067

INTRODUCTION

Deep rocky banks and outcrops, underwater pinnacles, and submarine canyons, ranging in depth from 30 m to >1,000 m, are important habitats in California waters. These deepwater habitats comprise 75% of the seafloor in state waters within the Central Coast region, and are home to hundreds of species of fishes and macroinvertebrates. Flatfishes, combfishes, poachers, and eelpouts are the dominant fish taxa on soft sediments, along with invertebrates such as sea pens and seastars. Rocky areas are dominated by more than 40 species of rockfishes and many invertebrate taxa such as feather stars, anemones, and gorgonian corals. Although deep habitats on the continental shelf and upper slope contain a high diversity of species that have been fished for decades, far less is known about these habitats and associated communities than those occurring in shallow water.

On September 21, 2007, 29 marine protected areas (MPAs) were established off Central California, including two types in deep water: State Marine Reserves (SMR) and State Marine Conservation Areas (SMCA). These MPAs are a result of the 1999 California Marine Life Protection Act that increased protection to coastal marine habitats and species. The creation of this large network of MPAs is a new approach to marine resource management, and has been initiated with a scientific monitoring program that will be used to evaluate the effectiveness of the MPAs and the network.

In 2007, through a competitive grant program, the California Ocean Protection Council and the California Department of Fish and Game provided funding for our team to collect baseline data in the deep portions of eight of the new MPAs and associated Reference sites. We used the manned submersible Delta to survey all fishes and structure-forming invertebrates (e.g., deepsea coral communities) in 164,000 m2 of seafloor habitats from 24–365 m deep in Monterey Bay and along the Big Sur coast. During 337 quantitative transects, we observed nearly 66,000 fishes from 110 taxa, and 158,000 aggregating and 14,000 structure-forming invertebrates from 70 taxa. This comprehensive baseline will be used in the future to critically evaluate the effectiveness of the new MPAs by assessing changes in the diversity, density, and size composition of species using seafloor habitats in the new MPAs.