Wires and Wildlife: Transmission Development and the Benthos Report

The Biden Administration established a national target of generating 30 gigawatts (GW) of offshore wind by 2030—enough to power 22,500,000 homes— and 100 GW by 2050—enough to power 75,000,000 homes. Interconnecting these offshore wind projects to the onshore power grid will require robust transmission development—building a substantial amount of new infrastructure and expensive upgrades to existing infrastructure.

Offshore transmission lines allow energy generated by offshore wind to reach the onshore grid—our homes, businesses, and schools. When constructing these transmission lines, the benthos (the organisms that reside on the ocean floor) is directly affected, as these power lines are typically buried in the seabed.

The benthos literally shoulders marine ecosystems. The benthos plays an important role in nutrient cycling, food webs, and ecosystem health. The benthos even underpins food sources for large predators, and provides nursery areas for their young. Such species could not survive without the fish, invertebrates, and other marine life that depend on a healthy benthos to reproduce, grow, and thrive. Benthic habitats also support many economically important species. In 2022 alone the U.S. Atlantic lobster fishery harvested 120 million pounds of lobster, representing $519 million in value.

Despite this, benthic habitats are both understudied and under threat. There has been a 29 percent loss of global seagrass habitats, an 85 percent loss of oyster reefs, and widespread and increasing coral reef depletion. The destruction and depletion of the benthos puts the vital ecosystem services they provide, and the valuable industries the benthos supports, at risk.

Natural seasonal variations and climate change also impact the benthic ecosystem, and the animals that live there.

With all these factors affecting the benthos, balancing the evolving needs of wildlife and much-needed transmission development is crucial.

Blue-banded goby
Blue-banded goby swimming over the seabed. Credit: Jeff Foote/Getty Images

In National Wildlife Federation’s new report, Wires and Wildlife: Offshore Transmission Development and the Benthos, we explore how the U.S. can responsibly develop offshore transmission to balance the need for development with the evolving needs of the benthos. This report provides recommendations for industry and decision makers to balance the need for transmission development with the climate crisis, the biodiversity crisis, and the needs of the marine ecosystem.

Key Findings

  • Benthic resources and habitats are critical to marine ecosystem health and resiliency.
  • Using the best available science and assessing climate and cumulative impacts of development makes it possible to conserve wildlife and build an interconnected offshore power grid that can benefit people and wildlife.
  • Offshore transmission has varied impacts on benthic habitats and resources, including direct mortality and habitat loss. These impacts can be mitigated with techniques such as avoidance, micrositing, and proactive planning, which is critical for protecting benthic species specifically, as much scientific attention has historically focused on other areas like marine mammals and commercial fishing.
  • There are two regulatory pathways to build transmission; neither allows for urgently needed proactive interregional planning and instead focuses on singular project-specific development.
  • The Bureau of Ocean and Energy Management’s (BOEM) requirements for benthic mitigation at the leasing stage vary tremendously and have evolved over time.
  • Collaboration from decision-makers and industry to conduct and share research on environmental impacts of offshore transmission on benthic resources is necessary to resolve outstanding knowledge gaps.

Learn more about NWF’s offshore transmission advocacy here.