Understanding Biological Connectivity Among Offshore Structures and Natural Reefs

Award Period
Award Amount
Agency Name
USDI Bureau of Ocean Energy Management (BOEM)
Award Number
PI First Name
PI Last Name
Paige Miller
Rachel Simons
Robert Miller
Jennifer Dugan
Area/s of Research
Ecology and Evolution

The overall purpose of this award is to use field surveys, molecular genetic tools, and
biophysical modeling to evaluate the connectivity of populations of two invertebrate species, the
non-indigenous bryozoan species (NIS) Watersipora subatra and the native rock scallop
Crassadoma gigantea among artificial and natural habitats in the Pacific OCS (Santa Barbara
Channel/Santa Maria Basin and San Pedro Basin). These two species have larvae that bracket a
representative range of planktonic larval durations (PLD) for marine invertebrates. Thus, this
study will use results on Watersipora subatra and Crassadoma gigantea as models in a
biophysical and genetic analysis of population connectivity that will apply more broadly for
species with limited and longer planktonic larval durations. Specifically, this study will 1) use
molecular genetic tools to test predictions of larval connectivity derived from biophysical
modeling, among populations of Watersipora on offshore oil and gas platforms, other artifical
habitat, and natural reefs of the mainland coast and Santa Cruz Island in the Santa Barbara
Channel, 2) expand previous biophysical modeling of potential larval connectivity to include
Crassadoma, 3) include the San Pedro Basin for both taxa, 4) use information on genetic
differentiation of Watersipora and Crassadoma populations, and widely applied statistical tools,
to evaluate genetic connectivity of Watersipora and Crassadoma populations among selected
offshore oil and gas platforms and natural subtidal rocky reefs and 5) examine the visible skeletal
structures of Watersipora colonies to relate any phenotypic variation observed in the field to
genotypic variation.

Information developed during this study will be incorporated into environmental reviews
regarding managing the spread of a non-indigenous species, Watersipora, at ongoing operations,
during decommissioning of oil and gas platforms, and at potential renewable energy facilities. It
will also identify the role that offshore infrastructure may play in facilitating the dispersal of
native species, such as Crassadoma, to natural reef habitats. Information from this study will
elucidate the role that offshore artificial structures may have in affecting the connectivity of
biological communities. This information is needed for use by the State of California to evaluate
decommissioning options under California legislation AB 2503 (the California Marine Resources
Legacy Act). The Act requires California to consider reefing OCS oil and gas platforms, if their
ecological value warrants, before decommissioning and potential removal. The information is
also needed to comply with the duties of Federal agencies that are outlined in Section 2 of
Executive Order 13112 (Invasive Species).