The Bureau of Ocean Energy Management (BOEM) recently published its 2023 Environmental Studies Year in Review Report. This report covers scientific publications from October 2022 through December 2023, of which CSA Ocean Sciences Inc. (CSA) contributed to three.

Project 1: Shallow-Water Geophysical Mapping by Autonomous Vehicles

Coastal restoration often involves engineering solutions to mitigate sediment movement in the coastal environment. This can include shoreline replenishment, which requires proper source sediment selection to best ensure replenishment success. Autonomous surface vehicles (ASVs) and autonomous underwater vehicles (AUVs) are used in offshore environments to search for appropriate sediment. Working with APTIM Federal Services, LLC, CSA conducted a feasibility assessment on available ASVs and AUVs, examining aspects such as cost, advantages, and constraints on available ASVs and AUVs.

The report then provided guidance for project managers on ASV and AUV selection, management, and operation in a broader consideration of project cost, time, and deliverables. This guidance identified, for example, which ASVs and AUVs were better suited for shore operations and which for vessel-based operations. The report concluded with additional considerations such as emergency management, vessel strike risk for protected species, and other potential conflicts with fauna.

Project 2: Submarine Canyons of the United States Exclusive Economic Zone (EEZ) Atlas

The exclusive economic zone around the United States includes many submarine canyons, which are relics of global changes in sea level and plate tectonics. CSA assembled an atlas of over 40 canyons throughout these areas, which include EEZs of U.S. Commonwealths, territories, and possessions in portions of Polynesia, Micronesia, and the Caribbean. Utilizing two types of delineation methods, the bathymetry and extent of each canyon was presented in addition to relevant nearby features, such as National Marine Sanctuaries or BOEM Planning Areas. This atlas will assist energy managers in considering areas of the outer continental shelf for energy development. This atlas was built off previous work by CSA for BOEM that mapped canyons abutting all U.S. coastal states.

Project 3: Benthic and Epifaunal Monitoring During Operation at the Block Island Wind Farm – Year 4

The Block Island Wind Farm has been a site of intense environmental study since its installation nearly a decade ago as the nation’s first offshore wind farm. CSA has been studying changes in the benthic fauna community around the wind farm structures by comparing benthic faunal communities to control areas utilizing vessel-based and diver surveys and comparative spatial organization of epibionts (on the turbine structure). As benthic fauna are also tied to local sediment conditions, this report included any potential changes in sediment composition surrounding the turbine structures.

The report describes the results of the 2021 study that examined these areas. Statistical analyses of changes in sediment, including size and organic content, and a benthic community assessment was performed. These analyses contributed to biotic assessments that had resolution to phyla or species level as possible, in addition to producing general benthic biodiversity metrics. The report also discusses the results of each turbine in the larger context of the entire wind farm.

The material discussed in this last report was recently published by CSA scientists in the Journal of Coastal Research with support from BOEM. To read more, visit: https://doi.org/10.2112/JCOASTRES-D-23-00096.1

For more information about CSA’s energy sector services, visit: https://www.csaocean.com/markets/energy