Submarine Cables - Domestic Regulation

The laying and placement of submarine cables requires coordination, and the installation of cable in certain areas may have an adverse impact on cables already in place, as well as on fishing, navigation, the marine environment, and other valuable resources such as historic shipwrecks or areas of geologic significance. See U.N. Env’t Programme World Conserv’n Monitoring Ctr., Submarine Cables and the Oceans: Connecting the World, at 3, UNEP-WCMC Biodiversity Series No. 31 (2009) [hereinafter “UNEP Report”] offsite link.  To help ensure coordination of cable placement and mitigation of any adverse impacts, a number of U.S. agencies have authority to regulate the laying and maintenance of cable off of our nation’s shores. In addition, while this webpage focuses on the federal government’s authority to regulate submarine cables, it is worth noting that a number of U.S. states also exercise control over submarine cables that land on their shores. E.g.Undersea Cable – Regulatory Framework Created, Haw. Clean Energy Initiative (June 27, 2012) offsite link (discussing the creation of Hawaii’s submarine cable regulation program).  See also the Submerged Lands Act of 1953, 43 U.S.C. §§ 1301–15 offsite link (establishing states’ title to submerged lands generally out to three nautical miles from shore). Some cable protection measures have even been created by private agreement. See, e.g.About OFCC, Or. Fishermen’s Cable Comm offsite link., (noting that “[i]n July 1998, some concerned Oregon commercial trawl fishermen negotiated a cooperative agreement with [numerous private cable companies]” to create “[t]he Oregon Fishermen’s Undersea Cable Committee Agreement[,] . . . the first effort by two industries to discuss, describe and delineate their shared use of a community resource—the ocean”).


NOAA is authorized to regulate whether and how proposed submarine cables may be installed in National Marine Sanctuaries in accordance with international agreements to which we are a party and generally accepted principles of international law. See 16 U.S.C. § 1435(a) offsite link. The National Marine Sanctuaries Act (“NMSA”), 16 U.S.C. §§ 1431–1445c, authorizes the Secretary of Commerce to designate and protect areas of the marine environment with special national significance due to their “conservation, recreational, ecological, historical, scientific, cultural, archeological, educational, or esthetic qualities” as National Marine Sanctuaries.16 U.S.C. § 1431(a)(2) offsite link. The Secretary has delegated day-to-day management of these sanctuaries to NOAA’s Office of National Marine SanctuariesSee 15 C.F.R. § 922 offsite link. The primary objective of the NMSA is to protect marine resources, such as coral reefs, sunken historical vessels and unique habitats.  See 16 U.S.C. § 1431(b)(6) offsite link. The 14 sanctuaries designated to date are:

NOAA has also announced its intent to designate one new national marine sanctuary:

Under its NMSA authority to issue Special Use Permits for specified activities, NOAA is authorized to assess fair market value fees together with administrative and monitoring costs associated with the continued presence of commercial submarine cables in national marine sanctuaries, 16 U.S.C 1441See Fair Market Value Analysis for a Fiber Optic Cable Permit in National Marine Sanctuaries, 67 Fed. Reg. 55,201 (Aug. 28, 2002); Final Notice of Applicability of Special Use Permit Requirements to Certain Categories of Activities Conducted Within the National Marine Sanctuary System, 78 Fed. Reg. 25,957 (May 3, 2013). The Office of National Marine Sanctuaries also administers federal regulations for the Papahānaumokuākea Marine National Monument in concert with the U.S. Fish and Wildlife Service and the State of Hawaii’s Department of Lands and Natural ResourcesSee generally About Us, Papahānaumokuākea Marine Nat’l Monument (setting out the various legal authorities behind the creation of the Papahānaumokuākea Marine National Monument which was recently expanded).  The regulations governing the administration of the Monument are codified at 50 C.F.R. Part 404 offsite link.  They implement Presidential Proclamation 8031.  All activities within the monument, including the installation of a submarine cable, require a permit.  There are six available permit types: research, education, conservation and management, Native Hawaiian practice, special ocean use, and recreation.  Among other things, it is unlawful to deposit any material or other matter into the Monument without a valid permit and without meeting specified criteria.  50 C.F.R. §§ 404.7, 404.11 offsite link.  A special use permit is required, among other things, for the continued presence of commercial submarine cables on or within the submerged lands of any national marine sanctuary.  78 Fed. Reg. 25957 (May 3, 2013).

NOAA also administers the Coastal Zone Management Act, 16 U.S.C. §§ 1451-1466 offsite link (CZMA), a federal law providing for management of the nation’s coastal resources to balance economic development and environmental conservation. The CZMA provides that no federal agency may grant a license to conduct an activity affecting a coastal area until a state concurs or is presumed to concur with the applicant’s certification that a proposed activity is consistent with the state’s coastal management plan. 16 U.S.C. § 1456(c)(3)(A).  If, for example, a state includes Federal Communication Commission (FCC) cable landing licensing in its coastal management plan, FCC licensing would be considered a “listed activity” and the state would have six months to review and either concur with or object to the certification that is required if CMZA state consistency review is triggered by the filing of a cable landing license with the FCC. 15 CFR § 930.53.  If the state does not include FCC cable landing licensing in its coastal management plan, such licensing is an “unlisted activity” for which NOAA rules require that the state notify the relevant federal agencies, applicant(s), and the Director of NOAA’s Office of Ocean and Coastal Resource Management of the state’s request to review the activity.  15 CFR § 930.54.

NOAA’s National Marine Fisheries Service (NMFS or NOAA Fisheries) acts as a trustee for coastal and marine resources including commercial and recreational fisheries, marine mammals, and endangered and threatened species and their habitats.  In many cases, NOAA Fisheries’ review or consultations may be required in connection with cable laying operations under the Endangered Species Act (ESA), Marine Mammal Protection Act (MMPA), or Magnuson Stevens Fisheries Conservation and Management Act (MSA).  An authorizing or permitting agency (such as the FCC or U.S. Army Corps of Engineers) will make the determination whether to seek consultation with NOAA under these laws and to explain how that agency is meeting its environmental compliance mandates.  See, e.g., 16 U.S.C. § 1536 offsite link.

NOAA must be consulted whenever the laying of a submarine cable may impact an endangered or threatened species.  Under the Endangered Species Act offsite link (ESA), 16 U.S.C. §§ 1531–1544, every federal agency must ensure that any action it authorizes, funds or carries out is not likely to jeopardize the continued existence of any endangered or threatened species or result in the destruction or adverse modification of the habitat of such species.  16 U.S.C. § 1536(a)(2) offsite link.  As a lead agency in a cable-permitting situation, the FCC, for example, would consult with NOAA on marine species over which NOAA has jurisdiction where there is a potential for impact from the cable installation.  NMFS will issue a biological opinion as to whether the action of laying the cable is likely to jeopardize the continued existence of listed species.  NMFS will suggest Reasonable and Prudent Alternatives (RPAs) if an action is determined to adversely modify critical habitat.  See, e.g.,“NOAA Fisheries’ Reasonable and Prudent Alternatives Table of Actions.” NOAA may provide an exemption for take when RPAs are followed to minimize impact.  NOAA regulations to guide an agency through the process are found at 50 CFR Part 402

A NOAA permit will be required where the laying of a submarine cable may result in incidental take of marine mammals. The Marine Mammal Protection Act (MMPA), 16 U.S.C. §§ 1361–1423h, prohibits the take of marine mammals unless exempted by the MMPA or authorized under a permit issued by NOAA.  Take is broadly defined.  It means “to harass, hunt, capture, or kill, or attempt to harass, hunt, capture or kill.”  16 U.S.C. § 1362(13).  MMPA Sections 101(a)(5)(A) and (D) allow NOAA to authorize the incidental taking of marine mammals that occurs during otherwise lawful activities if it is found that the total taking will have a negligible impact on the affected species (or stock) and that the total taking will not have an “unmitigatable” adverse impact. 16 U.S.C. § 1371(a)(5).  In the case of a submarine cable installation, an MMPA section 101(a)(5)(D) Incidental Harassment Authorization (IHA) is the most likely permit sought.  See, e.g., Quintillion Subsea Operations, LLC, Biological Opinion and Associated Proposed Issuance of an Incidental Harassment Authorization (May 18, 2016).  A request for authorization is reviewed and cleared by the NMFS Office of Protected Resources.  If approved, the IHA will authorize incidental harassment, but not mortality, and identify permissible methods of taking and mitigation, as well as monitoring and reporting requirements.  It is valid for up to one year.  See, e.g., Incidental Harassment Authorization issued to Quintillion Subsea Operations, LLCIncidental Harassment Authorization issued to Deepwater Wind New England, LLCDeepwater Wind Block Island, LLC (2014-2015)(2015-2016), (2016-2017)(Deepwater Block Island developed the Block Island Wind Farm which consists of five 6-megawatt wind turbine generators, a submarine cable interconnecting the generators, and a transmission cable.  Each permit was good for one year from the date of issuance.) See also Incidental Take Authorization issued to Bay State Wind LLC.

Effects from underwater noise and from surface and underwater vessel activity are examples of impacts that are reviewed by NMFS under the MMPA.  NMFS uses acoustic thresholds to indicate at what level of received sound marine mammals are likely to incur hearing loss or be behaviorally disturbed. 

Regulations for MMPA takings exemptions are found at 50 CFR 216.  In the case of harassment of marine mammals that are listed as endangered or threatened species, permits under both the MMPA and ESA are required.  Although MMPA and ESA require the applicant to provide similar information, the requirements are not identical and the applications will be evaluated independently.  Reviews of ESA requests are generally conducted in the Regional Fisheries Office, while MMPA authorization requests are reviewed at NMFS Headquarters. 

Federal agencies must also consult with NMFS on any action that may adversely affect “Essential Fish Habitat,” including actions related to the laying and maintenance of submarine cables.  Habitat loss is one of the greatest long-term threats to commercial and recreational fisheries.   Under the Magnuson Stevens Fishery Conservation and Management Act (MSA), 16 U.S.C. §§ 1801–1891d, Essential Fish Habitat (EFH) is defined as “those waters and substrate necessary to fish for spawning, breeding, feeding, or growth to maturity.”  16 U.S.C.§ 1802(10).  EFH is designated by Fishery Management Councils and described in Fishery Management Plans (FMPs).  Under 16 U.S.C §1855(b)(2) offsite link of the MSA, Federal Agencies must consult with NMFS on any action or proposed action that a federal agency authorizes, funds, or undertakes that may adversely affect EFH.  NMFS will work with the agency to identify ways to avoid, minimize, mitigate, and offset any impacts from the proposed action.  Some subsets of EFH merit special attention and are identified as Habitat Areas of Particular Concern (HAPCs) based on criteria provided in NMFS regulations.  50 CFR § 600.815(a)(8).  HAPCs are high priority areas for conservation, management, and research.  The HAPC designation does not confer any specific habitat protections, but it can help focus habitat conservation efforts through several pathways, and it can be used as a tool for focusing habitat research and monitoring efforts.

Regulations for EFH consultations are found at 50 CFR Part 600, Subpart K.  Pursuant to 50 CFR §600.915, NMFS compiles and makes available maps and descriptions of the locations of EFH.  Those maps and descriptions can be found at the NMFS Essential Fish Habitat Mapper.  If a federal agency determines that action will adversely affect EFH, it must provide NOAA Fisheries with a written assessment of the effects of the action on EFH, in detail commensurate with the complexity and magnitude of the potential adverse effects of the action.  50 CFR §600.920.  See Preparing Essential Fish Habitat Assessments: A Guide for Federal Action Agencies.  NMFS will provide EFH Conservation Recommendations to the federal agency including measures that can be taken by that agency to conserve EFH.   50 CFR §600.925.  EFH Conservation Recommendations may include actions to avoid, reduce, or compensate for the impacts that submarine cables may have on EFH.  Federal agencies should contact their regional NOAA Fisheries Habitat Conservation Division for advice and consultation, and initiate discussions with the regional Fishery Management Council offsite link, in order to minimize conflict with local fishing activities.  See NOAA comments on the Cape Wind Energy Project.


The U.S. Army Corps of Engineers is another federal agency with authority over undersea cable laying.  The Corps is empowered to regulate artificial islands, installations, and “devices” (which can include cables) on the seabed of the United States’ outer continental shelf by section 10 of the Rivers and Harbors Appropriations Act of 1899 offsite link (RHA), 33 U.S.C. § 403, as amended by the Outer Continental Shelf Lands Act of 1953 (OCSLA), 43 U.S.C. § 1333(e). The Corps’ regulatory review is focused on cables’ potential impacts on navigation and national security, see 33 C.F.R. §§ 320.2, 320.4(j)(2) offsite link, but it also carries out environmental analyses pursuant to the National Environmental Policy Act (NEPA), 42 U.S.C. §§ 4321, 4331–35 offsite link, unless another agency has primary authority over the permitting of the cable in question.


Depending upon the nature of the proposed cable, or its location, the regulatory authority of other federal agencies may also be implicated. For example, section 388 of the Energy Policy Act of 2005 (EPAct), 43 U.S.C. § 1337(p), amended OCSLA to give the Department of the Interior’s Bureau of Ocean Energy Management (BOEM) authority to regulate cables set down in “support [of the] production, transportation, or transmission of energy from sources other than oil and gas” on the U.S. outer continental shelf. See id. § 1337(p)(1)(C).  Section 388 of the EPAct also gives BOEM authority over activities carried out in “support [of the] exploration, development, production, or storage of oil or natural gas” on the shelf, meaning that cable laid in connection with the construction and maintenance of structures such as oil or gas platforms also falls under BOEM’s authority. See id. § 1337(p)(1)(A).  BOEM has interpreted its regulatory authority under the EPAct to extend to submarine cables laid in connection with most exploration and production facilities under the Department of the Interior’s purview. See generally BOEM Requests Comments on Draft Form to Streamline Authorization Process for Cable Projects, Bureau of Ocean Energy Mgmt. (noting that BOEM considers its authority to extend even to “construction and use of a cable . . . for transmitting electricity or other energy product generated or produced from renewable energy,” including wind farms).  Both the Department of the Interior (via BOEM) and the U.S. Army Corps of Engineers have authority over such cables; when authorization from BOEM is necessary, the Corps’ review is generally limited to the cables’ potential impacts on navigation and national security. See 33 U.S.C. § 403; 43 U.S.C. § 1333(e).

The Department of the Interior also manages the nation’s National Wildlife Refuge System, as well the National Parks System.  Cable operators may seek to route proposed cables through terrestrial or marine areas that are part of a national wildlife refuge or a national park.  The Department of the Interior has authority to grant rights-of-way and special use permits that would be required for such installations.  The determination of whether to grant such a right-of-way is unique to each of the Department of the Interior’s bureaus and the laws and regulations governing their land systems and individual units.

The Fish and Wildlife Service manages the National Wildlife Refuge System under the National Wildlife Refuge System Administration Act of 1966, 16 U.S.C. §§ 668dd-668ee, as amended by the National Wildlife System Refuge Improvement Act of 1997, Pub. L. No. 105-57.  The mission of the System is “to administer a national network of lands and waters for the conservation, management, and where appropriate, restoration of the fish, wildlife, and plant resources and their habitats within the United States for the benefit of present and future generations of Americans.”  16 U.S.C. § 668dd(a)(2).  Of approximately 560 national wildlife refuges in the System, 180 are ocean or coastal refuges.  The Secretary of the Interior is authorized to “permit the use of any area within the System for any purpose, including but not limited to hunting, fishing, public recreation and accommodation, and access whenever he determines that such uses are compatible with the major purposes for which such areas were established.” 16 U.S.C. § 668dd(d)(1)(A).  Regulations governing the granting of rights-of-way are found at 50 C.F.R. Part 29.   The Secretary of the Interior may also “permit the use of, or grant easements in, over, across, upon, through, or under any areas within the System for purposes such as, but not necessarily limited to, power lines, telephone lines, canals, ditches, pipelines, and roads, including the construction, operation, and maintenance thereof, whenever he determines that such uses are compatible with the purposes for which these areas are established.” 16 U.S.C. § 668dd(d)(1)(B). A Compatible Use “means a wildlife-dependent recreational use or any other use of a national wildlife refuge that, based on sound professional judgment, will not materially interfere with or detract from the fulfillment of the National Wildlife Refuge System mission or [contradict] the purposes [for which] the [individual] refuge [was created].”  50 C.F.R. §29.21; 16 U.S.C. § 668ee(1).  Typically, each refuge manager is responsible for determining compatible uses within individual refuges.

Congress created the National Park Service (NPS) in 1916 with the enactment of the National Park Service Organic Act, originally codified at 16 U.S.C. §§1-4.  However, most of the NPS and many of the national historic preservation statutes, which once appeared in Title 16, are now found in new Title 54 of the Code, “National Park Service and Related programs” which was added to the Code in December 2014 by, Pub. L. 113-287.  Eighty-eight national parks are ocean, coastal or Great Lakes parks.  To facilitate administration of the National Park System, the Secretary of the Interior is authorized to carry out certain specified activities.  Among other things, 54 U.S.C. § 100902, authorizes the Secretary to grant rights-of-way to citizens, associations or corporations of the United States for public utility and for power and communication facilities upon a finding that the proposed rights-of-way are not incompatible with the public interest.  Policy guidance on such “special park uses” is contained in NPS Management Policies 2006 and in NPS Director’s Order #53: Special Park Uses.  See also Reference Manual 53: Special Park Uses.  A Special Use Permit is issued by a park superintendent to an individual or organization to allow the use of NPS-administered resources and to authorize activities involving access, construction, ground disturbance, or commercial vehicle use.  See 36 C.F.R. Parts 1-7.  These include activities affecting “[w]aters subject to the jurisdiction of the United States located within the boundaries of the National Park System, including navigable waters and areas within their ordinary reach . . . and without regard to the ownership of submerged lands, tidelands or lowlands.”  36 C.F.R. §1.2(a)(3).  Right-of-way permits which authorize such facilities as telephone lines, electric lines, telecommunications facilities, and water conduits on NPS lands are processed by each individual park and signed by a regional director.  SeeDirector’s Order 53, §6.  Regulations governing the issuance of rights-of-way are found in 36 C.F.R. Part 14.  Rights-of-way affecting wilderness areas in Alaska are governed by the Alaska National Interest Lands Conservation Act and its regulations.  See 43 C.F.R. Part 36.  A right-of-way permit is issued for a maximum term of 10 years.  It does not convey an interest in land and is subject to termination for cause or at the discretion of the regional director.


The Federal Energy Regulatory Commission (FERC) has some authority over undersea cables proposed to be laid on the U.S. continental shelf.  As described in an April 2009 Memorandum of Understanding between FERC and the Department of the Interior, FERC has authority to issue licenses under Part I of the Federal Power Act, 16 U.S.C. § 792-823a offsite link, and authority to issue exemptions from licensing under Sections 405 and 408 of the Public Utility Regulations Policy Act of 1978, 16 U.S.C. §§ 2705 offsite link2708, for the construction and operation of hydrokinetic projects on the OCS, such as wave power generation facilities. See Memorandum of Understanding between the U.S. Department of the Interior and the Federal Energy Regulatory Commission 1–2 (April 9, 2009).  This means that cable-laying related to such projects would fall, at least in part, under FERC’s purview; FERC would have authority to assess proposed cables’ potential environmental impacts in accordance with NEPA.  See id. The U.S. Army Corps of Engineers would likely be a cooperating agency, still ensuring compliance with NEPA, but focusing its review on impacts to navigation and national security.  See id.; see also Peter J. Schaumberg & Angela F. Colamaria, Siting Renewable Energy Projects on the Outer Continental Shelf: Spin, Baby, Spin!, 14 Roger Williams U. L. Rev. 624, 628–29 (2009) offsite link (discussing the evolution of regulatory authority over alternative energy projects on the U.S. outer continental shelf).


The Federal Communications Commission (FCC) has regulatory authority over the landing of submarine cables in the United States.   The FCC issues licenses for “any submarine cable directly or indirectly connecting the United States with any foreign country, or connecting one portion of the United States with any other portion thereof,” Cable Landing License Act of 1921, 47 U.S.C. § 34 offsite link.  The FCC also regulates the landing and operation of communications cables laid in U.S. coastal waters.  See Exec. Order No. 10,530, 19 Fed. Reg. 2709 (May 10, 1954) (granting FCC authority to exercise all authority vested in the President by 47 U.S.C. §§ 34-39, including the authority to issue, withhold or revoke licenses to land and operate submarine cables in the U.S. after obtaining approval of the Secretary of State.)  The FCC has adopted a categorical exclusion under NEPA for the construction of new submarine cable systems.  See 47 CFR §1.306, note 1see also In the Matter of Public Employees for Environmental Responsibility: Request for Amendment of the Commission’s Environmental Rules Regarding NEPA and NHPA, FCC 01-319 (Oct. 29, 2001) (denying petition for rulemaking asking the FCC to amend its environmental rules as applied to submarine cables to require an Environmental Assessment for all applications concerning submarine cables). However, FCC reserves the right to require the licensee to file an EA should it determine that the landing of the cable at a specific location or the construction of cable landing stations may significantly affected the environment.   47 C.F.R. § 1.767(g)(9).  The location of the cable system within the territorial waters of the U.S., its territories and possessions, and upon its shores shall be in conformity with plans approved by the Corps of Engineers.  47 C.F.R. 1.767(g)(2).  Before filing an application for a license to construct and operate a submarine cable system or to modify a previously approved cable system, applicants must determine whether they are required to certify that their proposed activities will comply with the enforceable policies of a coastal state’s approved coastal zone management plan.  47 C.F.R. 1.7167(a)(10).

Finally, the Antiquities Act offsite link, 54 U.S.C. §§ 320301-320303 (2018)   , gives the President authority to protect natural and cultural objects (and, thereby, restrict submarine cable-laying) through the designation of national monuments, id. § 431.  See also Admin. of Coral Reef Res. in the Nw. Hawaiian Islands, (Op. Att’y Gen. Sept. 15, 2000) (“[T]he authority the United States possesses under international law to protect the marine environment in the [exclusive economic zone (EEZ)], in combination with the overall amount of restraining and directing influence that the United States exerts in the EEZ . . . give[s] the United States sufficient ‘control’ over the EEZ for the President to invoke the Antiquities Act for the purposes of protecting the marine environment.”). Although this authority has largely been employed to protect terrestrial resources, President George W. Bush used it to designate the Papahanaumokuakea Marine National Monument on June 15, 2006. See Proclamation No. 8031, 71 Fed. Reg. 36,443 (June 26, 2006). The original Monument boundary, which extended approximately 50 nautical miles seaward from the shoreline of the Northwestern Hawaiian Islands, was further extended to 200 nautical miles from shore by Presidential Proclamation 9478 (August 25, 2016) offsite link.  Under the authority of the Antiquities Act, Presidents have also designated four other marine national monuments: the Marianas Trench Marine National Monumentthe Pacific Remote Islands Marine National Monumentthe Rose Atoll Marine National Monument; and the Northeast Canyons and Seamounts Marine National Monument.  The Pacific Remote Islands Marine National Monument was expanded by President Barack Obama on September 25, 2014, to include the waters and submerged lands of Jarvis and Wake Islands and Johnston Atoll that lie from the original Monument boundary to the seaward limit of the U.S. EEZ of the two islands and the atoll. See Proclamation No. 9173, 79 Fed. Reg. 58,645 (September 29, 2014).


Generally speaking, the environmental impacts of submarine cables are believed to be modest, although care must be taken during trenching and laying operations.  The greatest adverse impacts are most likely to occur during installation when there is increased vessel traffic and disturbance of the seafloor as cable trenches are excavated and the cables are laid.  Incorrect cable laying may also lead to significant damage to the marine environment. For an example of such damage from incorrectly laid submarine cables, see the Olympic Coast National Marine Sanctuary example below. 

Submarine cables are predominantly laid in one of two ways: buried or not buried.  Industry, industry watch groups, and regulatory bodies acknowledge that, when placed in waters more than 2,000 meters in depth, cables are generally not buried.  They are simply laid across the ocean floor. This is because, at such depths, cables are significantly less susceptible to potentially harmful interactions with living marine resources. In waters of less than 2,000 meters in depth, cables are generally buried 0.6-1.5 meters beneath the substrate. This is usually conducted using a water jet plow towed along the desired cable path. Burial protects the surrounding environment from potential cable movement resulting from currents and prevents potentially harmful interactions with, or damage caused by, the cable. See Sargasso Sea Alliance, The Relationship Between Submarine Cables and the Marine Environment offsite link, pg. 181; Oregon Fishermen’s Cable Committee, Agreement Between and Among the Oregon Fishermen’s Undersea Cable Committee, Inc., MFS Globenet, Inc. and WCI Cable, Inc. offsite link, pg. 4; Marine Insight, How Undersea Cables are Laid by Cable Ships offsite link; and Kingfisher Information Service - Offshore Renewable & Cable Awareness Project, Cable Burial offsite link). 

Environmental assessments (EAs) can be an invaluable tool in avoiding or minimizing any adverse environmental impacts associated with submarine cable installations. Burial and laying, though relatively short-lived activities, can be disruptive to the area and ecosystem in which they are carried out. Assessing the local substrate and flora and fauna composition before installation may help to ensure that environmentally sensitive or fragile areas and organisms are avoided or not harmed. One regional body, the Commission of the Oslo/Paris Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR Commission offsite link)   has prepared an Assessment of the Environmental Impact of Cables (2009) and developed non-binding Guidelines on Best Environmental Practice (BEP) in Cable Laying and Operating (2009) for minimization of potential environmental harm associated with cable installation. The key components of these Guidelines are to (1) avoid protected and environmentally sensitive or valuable areas; (2) use the shortest possible length; (3) bundle existing cables and pipelines where safe; and (4) minimize cable-cable and cable-pipeline crossings. 

Once in place—if correctly laid—submarine cables have thus far not been shown to have a significant adverse effect on the surrounding marine environment as they are generally immobile once placed and coated with a layer of polyethylene, which is inert in seawater.  Submarine communications cables produce no emissions, while the heat and electromagnetic fields (EMFs) emitted by submarine power cables have not been shown to have a demonstrably adverse impact on surrounding marine environments and organisms. 

A number of environmental assessments, Findings of No Environmental Impact (FONSIs) and other studies have been conducted concerning the actual and potential impacts of submarine cables on the marine environments. Governments and private entities sometimes carry out these investigations prior to the commencement of submarine cable installation.  Below is an illustrative list of these studies and their findings. Note that the listing here of assessments is without prejudice to any view or position that has or may be taken by the NOAA Office of General Counsel, NOAA or the U.S. Department of Commerce with respect to them. 

Tuen Mun: In 2000, Hutchison Global Crossing Limited prepared an EIA on a proposed submarine cable project between Tuen Mun and Chek Lap Kok in Hong Kong.  Potential installation and operational impacts were deemed “negligible.”  The EIA found that installation would only produce short-term disruptions and the cable’s operation would not introduce anything foreign into the marine environment. 

Underwater Fiber Optic Cables near St. Croix, U.S. Virgin Islands: On March 9, 2000, the U.S. Department of Justice settled an environmental lawsuit against AT&T, a subsidiary, and two contractors related to the installation of underwater fiber optic cables near St. Croix, U.S. Virgin Islands.  The agreement required AT&T and the two contractors to pay $1.8 million in civil penalties for alleged Clean Water Act and River and Harbors Act violations in connection with the installation of underwater fiber optic cables that run to and from St. Croix.  The violations involved the unlawful release of large amounts of drilling lubricants during that installation.  Although AT&T had a federal permit to drill and to install the fiber optic cables, the permit did not authorize the discharge of drilling mud into the ocean.  The defendants were supposed to contain the drilling mud within the hole being drilled and recapture it for proper disposal.   According to one account, the drilling mud covered and killed conch and other aquatic organisms and smothered large areas of seagrass and coral. Jamie Bate, More Drilling Mud Found in Butler Bay, Caribbean Business News.

Pioneer Seamount: In 2003, researchers from the Monterey Bay Aquarium Research Institute, NOAA’s Monterey Bay National Marine Sanctuary and NOAA’s Office of Oceanic and Atmospheric Research conducted a survey and study of the Pioneer Seamount Submarine Cable, approximately two-thirds of which is lies within the Monterey Bay National Marine Sanctuary. The study found that portions of the cable were suspended between rocky outcroppings. The constant movement of the cable by ocean currents caused incisions and damage to the rocks. It also snagged passing sea objects, including large amounts of floating kelp, which became intertwined with the cable. 

Olympic Coast National Marine Sanctuary: In 2005, NOAA and the U.S. Army Corps of Engineers conducted an environmental assessment of a pair of trans-Pacific submarine fiber optic cables running through the Olympic Coast National Marine Sanctuary from Mukilteo, Washington to Japan.  See 70 Fed. Reg. 59032 (Oct. 11, 2005)“Remediation for the Pacific Crossing-1 North and East Submarine Fiber Optic Cables in the Olympic Coast National Marine Sanctuary” (Nov. 4, 2005).  The environmental assessment found that substantial portions of the cable were improperly installed, resulting in portions of the cable being buried at an insufficient depth, being completely unburied, or being suspended above the seafloor.  NOAA concluded that this improper installation caused persistent damage to sanctuary resources, posed a potentially serious safety risk to fishers employed in bottom contact fisheries, and limited access of Native American tribal fishers to portions of their treaty-reserved fishing grounds.  Additional potential environmental impacts NOAA identified included ghost fishing—whereby unburied cable portions ensnare fishing equipment and these, in turn, ensnare marine animals—and marine animal entanglement in unburied cables lengths.  Pursuant to a Settlement Agreement dated Nov. 4, 2005, the cable owners agreed to recover and re-lay the cables in the Sanctuary, an effort that was completed in late summer 2006.  See Olympic Coast National Marine Sanctuary: Condition Report 2008 (Sept. 2008), at 16Ken Weiner & Seth Davis, Olympic Re-Lay: Innovative Techniques in Cable Projects with Regulatory and Environmental Dimensions, in 37 Submarine Telecoms Forum, 26-31 (March 2008) offsite link.  In connection with the 2005 Settlement Agreement, Olympic Coast National Marine Sanctuary issued Pacific Crossing a permit authorizing the recovery and reinstallation of the two submarine cables.  Among the terms and conditions imposed by the permit to ensure protection of sanctuary resources was a requirement that Pacific Crossing purchase a general liability insurance in the amount of $1 million per occurrence and $2 million general aggregate limit against any claims arising out of activities conducted under the permit, including damages and response costs resulting from injury to, destruction of, or loss of sanctuary resources. 

Australia-Hawaii Fiber Optic Cable System: In 2007, AMEC Earth & Environmental, Inc. prepared an environmental assessment of the installation of one submarine fiber optic cable connecting existing telecommunications infrastructure in Keawa’ula, O’ahu and Sydney, Australia.  Potential short-term impacts on marine biological resources included noise from the cable ship, potential for collision with project ships, contact with the cable, and damage to coral during cable placement, but were found to not be significant due to the cable-laying ship’s slow pace and predictable route.  Further, the study found no adverse impacts on marine species or habitats in the area, as the cable is non-polluting.

Cape Wind: In 2008, NMFS evaluated the impact of a project proposal to construct and operate 130 wind turbine generators in Nantucket Sound on essential fish habitat and fishery resources.  NMFS found that the proposed project affected a portion of the Nantucket Sound designated as EFH for 18 federally managed species and made recommendations to avoid or minimize impact. The final EIS was a comprehensive 800-page study that addressed multiple project alternatives and was released in 2012. Potential installation impacts were deemed temporary and minimal, including increased turbidity, suspended sediment levels, flora and fauna destruction, and habitat loss and modification. Thermal and EMF emissions from the cable were predicted to have only a negligible impact on the surrounding marine environment. Ultimately, however, the Cape Wind project did not go forward. 

Honotua: In 2009, Alcatel-Lucent Submarine Networks prepared a draft environmental assessment of the installation of a submarine fiber optic cable connecting an existing cable station and onshore telecommunications infrastructure at Spencer Beach, Hawai’i to infrastructure on the island of Tahiti, French Polynesia.  The assessment found that the cable route was designed to stay within an area of existing cables, avoiding disturbance to the reef and no adverse impact on the natural contours of the project area or coastal processes.

Ghana and Nigeria offsite link: In 2009, the African Development Bank prepared an environmental and social impact assessment regarding a subsea telecommunications cable along the Atlantic coast of West Africa. The Project had the potential for impacts during the pre-installation and installation phases only and not during operation or decommissioning. A detailed impact assessment was carried out for four potential impact areas:  habitats and flora;  fauna;  coastal processes and water quality; and  human health and safety. The proposed cable was predicted to impact only a small amount of common and widespread habitat, and the extent of the impact would be local and short in duration. The disturbance on fauna was considered temporary with the potential for vessel strikes as well as increases in noise from the pre-installation and installation vessels. The assessment also found that the installation of the cable may result in a temporary disturbance of coastal processes such as longshore sediment transport and beach erosion/accretion. Water quality impacts were also considered a possibility due to release of wastewater from vessels or due to disturbance of sediments and the resulting increased turbidity. There was also the potential for impacts on human health and safety due to accidents and unplanned events such as collision of project vessels with fishing boats and nets or other vessels.

Hawaii Interisland Renewable Energy Program: In 2010, AECOM Earth & Environmental, Inc. prepared an evaluation of the environmental impacts of a proposed wind energy generation, transmission, and delivery program on Maui County Islands and the City and County of Honolulu.  The marine cable installation and related shore crossings might affect coral reef and other sensitive coastal resources, as well as turtle and monk seal activities in the area.  The placement of power cables on the ocean floor could cause temporarily increased turbidity, noise, disturbance, habitat loss, habitat damage, and, in certain cases, long-term habitat change due to the introduction of artificial substrate.  The assessment found that these impacts are generally limited to the near proximity of the cable routes and, with the exception of long-term habitat alteration, are temporary.  

Rhode Island Ocean Special Area Management Plan offsite link: In 2010, the Rhode Island Coastal Resources Management Council (CRMC) adopted the Rhode Island Ocean Special Area Management Plan (Ocean SAMP). The Ocean SAMP is a set of comprehensive regulations outlining Rhode Island's process for ensuring the management and protection of the ocean resources within the Ocean SAMP study area. The Ocean SAMP study area refers to the approximately 1,467 square miles over portions of Block Island Sound, Rhode Island Sound, and the Atlantic Ocean to which the CRMC applies the regulations adopted in the SAMP. The CRMC selected these parts of the ocean as the study area because the natural and human activities that take place in these offshore waters have a reasonably foreseeable effect on the people of Rhode Island, and conversely, human activities also affect the study area's ecosystem. The CRMC developed the Ocean SAMP over the course of two years with the input of a wide variety of stakeholders--resource users, researchers, environmental and civic organizations, and local, state, and federal government agencies. On July 22, 2011, NOAA approved incorporation of the Ocean SAMP into the state's federally approved coastal management program under the Coastal Zone Management Act on July 22, 2011. 

Rhode Island’s Ocean SAMP addresses submarine cables, and the language it uses is codified in the Rhode Island Administrative Code.  The Ocean SAMP discusses the possibility of habitat destruction resulting from the cable-laying process. It notes that there could be temporary habitat destruction through plowing trenches for cable placement, and permanent habitat destruction if the top layers of sediment are replaced with new material during the cable-laying process or if the cables are not sufficiently buried within the substrate.  The Ocean SAMP indicates that the effects of submarine cable laying depend on the grain size of sediments, hydrodynamics, and turbidity of the area, and on the species and habitats present. Disturbance to the seabed during cable laying may also result from anchor and chain damage from the installation barge, as the barge will have to anchor repeatedly along the length of the cable route. In addition to cable laying, cable repair or decommissioning can affect benthic habitats. Other variables mentioned in the Ocean SAMP that impact the extent of the impacts from cable activities are the depth of the water and whether the environment is homogenous. 

Seychelles offsite link: In 2010, the African Development Bank Group prepared an EIA regarding a submarine cable project in Seychelles. The potential installation impacts of habitat and organism disturbance and increased turbidity and suspended sediment levels were shown to be likely, but not of significant effect. Ship sewage and other discharges, however, were likely to increase during installation and predicted to possibly increase bacteria levels and introduce invasive species. Artificial EMFs were unlikely to occur given that the project involved a telecommunications cable. 

Tonga and Fiji offsite link: In August 2010, Tonga Cable Limited prepared an environmental assessment of a subsea cable from Tonga to Fiji that traverses over 800 km of ecologically sensitive, and seismically, volcanically and tectonically active seabed. No impacts were found that with appropriate mitigation could not be eliminated, or reduced to low or negligible levels. The cable was found to pass through an area of seagrass that would be disturbed when a trench is dug in order to bury the cable. The low-intensity seismic activities involved in this project could potentially alter the behavior of cetaceans. 

Tanzania offsite link: In 2010, iXSurvey prepared an environmental and social impact assessment study of a 2,000 km subsea cable that was to be installed and run from Seychelles to landing sites in Mombasa, Kenya, and Dar es Salaam or Zanzibar, Tanzania. A detailed impact assessment was carried out for three potential impact areas: habitats, fauna and flora; human health and safety; and the Menai Bay Conservation Area. Potential impacts were determined to be moderate or minor and to be negligible following application of mitigation measures. Construction activities were determined to result in some negative environmental impacts during route clearance and cable laying, particularly to benthic biota along the survey route. However, any disturbance would occur over a very short duration, and natural recovery would readily occur. More specifically, the pre-laying grapple run was predicted to have negative impacts via a small amount of turbidity and through physical contact mortality or injury to marine organisms. Also, cable laying could do damage through increased turbidity, release of contaminants, and alteration of sediments.

Southwest Alaska: In 2011, United Resource Services prepared an EIA addressing submarine cable installation in Southwest Alaska. The potential installation impacts of increased turbidity, suspended sediment, and habitat loss and disturbance were deemed to be localized, temporary, and minimal. Harm caused to marine animals because of the presence of the cable was found to be unlikely. 

Soule River offsite link: In 2013, Soule River, LLC carried out an EIA as part of an application to install a submarine cable along the Soule River in Alaska, including in marine areas. Installation impacts such as increased turbidity, suspended sediment levels, noise levels, and habitat disturbance were predicted to be short-term and minimal. The cable was also found unlikely to interfere with fish passage and breeding activity.  

Exxon Mobil Offshore Power Distribution System:  In 2014, BOEM prepared and environmental assessment and made a Finding of No Significant Impact in relation to ExxonMobil’s proposed Offshore Power Distribution System Project to replace two existing power cables, recover one cable in federal waters and install new electrical equipment for the replacement power cables, offshore of Santa Barbara County, CA.

Barber’s Point: In 2014, the Naval Undersea Warfare Center Division prepared an environmental assessment of the installation and operation of a fixed surface ship radiated noise measurement system, which would include the installation of an undersea data transmission cable off the coast of N n kuli, O’ahu.  Installation of the cable could affect smaller, less mobile invertebrates, but larger, more mobile organisms would not be harmed, as they are capable of avoiding the cable as it installed.  The cable will be manually installed by divers, thereby avoiding contact with live coral.

Guantanamo Bay: In 2015, the U.S. Defense Information Systems Agency performed an environmental assessment of the installation of a submarine fiber optic cable connecting the Defense Information System Network at Guantanamo Bay, Cuba to a similar network in Miami, Florida.  The assessment determined that the project would cause no significant impact to the environment because past similar projects had only minor, localized, and transient effects on the environment.  SeeEnvironmental Assessment: Guantanamo Bay to Dania Beach Submarine
Fiber Optic Cable System (January 28, 2015).

Samoa offsite link: In 2015, the Samoan Ministry of Communication and Information Technology prepared an initial environmental examination of a submarine cable system connecting Samoa to more efficient regional and global communications infrastructure via Fiji. The terrestrial environmental and social impacts associated with the proposal were deemed minor since no vegetation needed to be cleared and some existing cable connection infrastructure was used. Overall, potential environmental impacts arising from the project are limited. The work could have two impacts on cetaceans: 1) acoustic effect of ocean sonar survey on marine mammals, and 2) entanglement in the cable by deep-diving cetaceans such as the sperm whale. To prevent damage to coral communities, the plan was to float the cable in and have it placed around the corals by divers working with a marine specialist. 

Wind Energy Research Activities, Offshore Virginia:  In 2015, BOEM issued a Finding of No Significant Impact in connection with the Virginia Offshore Wind Technology Advancement Project.  The project would consist of two wind turbine generators, a generator interconnecting submarine cable, a submarine transmission cable, and an onshore interconnection cable that would connect the project with existing infrastructure in the City of Virginia Beach, VA.

Quintillion Subsea Project:  In August 2016, NMFS issued a Final Environmental Assessment for the issuance of an Incidental Harassment Authorization for the take of marine mammals by harassment incidental to the Alaska Phase of the Quintillion Subsea Projects in the U.S. Arctic Ocean.

Hawaiki Submarine Cable: In 2016, GHD prepared an environmental assessment of a submarine cable spanning across the Pacific Ocean directly connecting the USA and Australia with landings in Portland, USA; Sydney, Australia; Mangawhai Heads, New Zealand; and Tafuna, American Samoa. Potential impacts from the project include noise disturbance from horizontal directional drilling; chemical and physical impacts to shoreline and benthic habitats through the unplanned release of hydrocarbons, environmentally hazardous chemicals, and other pollutants; and physical disturbance from plowing, water jetting activities, and vessel anchoring. However, the risk of all these potential impacts was found to be minimal with the prescribed management measures. 

Fiji Connectivity Project offsite link In September 2016. the Final EIA was completed for a submarine connectivity project linking Fiji to Samoa. The assessment identified some low to moderate risks to whales, dolphins and turtles associated with vessel movements, some coral reef disturbance and benthic community disruption, as well as minor disturbance to birds.

Lake Erie Connector Project  In October 2016, the U.S. Department of Energy and the U.S. Army Corps of Engineers released an Environmental Assessment associated with a proposal to lay a cable between Haldimand County, Ontario and Erie County, Pennsylvania. The EA indicated there would be a potential effect on fish behavior from the magnetic fields of the submerged cables, some displacement of lakebed food sources for lake sturgeon, and minimal effects on the eastern sand darter and cisco. The assessment also identified two known underwater archaeological sites within a mile of the cable and coordinated with the appropriate agencies to reduce potential harm to them. 

Fundy Isles Submarine Cables Replacement Project offsite link: In January 2018, the Government of New Brunswick, Canada issued an Environmental Impact Assessment for a proposal to install two new electrical transmission cables to connect New Brunswick and Deer Island. The survey found that the negative effects of disturbing sediment would be short-lived and could diminish in a matter of hours. 

Sixth Power Project Caye Caulker Submarine Cable In February 2019, a final Environmental and Social Impact Assessment was submitted to the Belize Department of Energy for review of a project to connect Ambergris Caye to provide electricity to Caye Caulker, Belize. The study concluded that there would be minimally adverse and negligible impacts on marine and terrestrial flora and fauna. The study noted that the largest disturbances would be the noise and lights of construction, some minimal mangrove clearing, and localized sediment disturbance. However, the study indicated that there was a potential of collisions of marine mammals (especially the Antillean Manatee) with vessels and designated this potential impact to be moderate.


NOAA Resources

Other Resources

Kraus, Christopher, and Lionel Carter, A Bibliography of Submarine Communication Cables (2018)

Moulding, Alison L., Evaluation of Past Coastal Construction Project Monitoring in Southeast Florida and Recommendations to Improve Future Monitoring. Nova Southeastern University Oceanographic Center, June 2011 (recommending post-installation cable monitoring for longer time periods where cables are not fixed to the seafloor because of the potential for continual impact to coral colonies)

Last updated July 8, 2019