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Welcome to the U.S. Navy’s website for Surveillance Towed Array Sensor System (SURTASS) Low Frequency Active (LFA) Sonar
SURTASS LFA sonar is a long range surveillance sonar that is necessary for the U.S. Navy to meet its anti-submarine warfare and national security mission. SURTASS LFA sonar systems are operated onboard U.S. Navy surveillance ships to provide improved capability to detect quieter and harder-to-find foreign submarines at greater distances. These underwater sonar systems transmit low-frequency acoustic signals between 100 and 500 Hertz and include both active and passive components.
In 2019, the Department of the Navy, with the National Marine Fisheries Service (NMFS) as a cooperating agency, prepared a Supplemental Environmental Impact Statement/Supplemental Overseas Environmental Impact Statement (SEIS/SOEIS) for SURTASS LFA sonar in accordance with the National Environmental Policy Act and Executive Order 12114. The 2019 SEIS/SOEIS evaluated the potential environmental impacts associated with two training and testing action alternatives and a no-action alternative to the following resource areas: air quality, marine environment, biological, and economic resources. The 2019 Final SEIS/SOEIS is available for download here. After a 30-day public comment period, the Navy selected Alternative 2, the Preferred Action Alternative, which is documented in its Record of Decision.
In compliance with the Marine Mammal Protection Act (MMPA) and the Endangered Species Act (ESA), the Navy submitted applications to NMFS requesting authorizations to take marine mammals, sea turtles, and protected marine fishes incidental to the Navy’s training and testing activities using SURTASS LFA sonar. The Navy submitted an application for rulemaking and a letter of authorization (LOA) under the MMPA to take marine mammals incidental to the use of SURTASS LFA sonar for training and testing activities in the western and central North Pacific and eastern Indian oceans. The MMPA Final Rule and LOA were authorized and became effective on August 12, 2019. Additionally, the Navy submitted a Biological Evaluation to initiate Section 7 consultation under the ESA. In its ESA Biological Opinion on SURTASS LFA sonar, NMFS determined that the Navy’s planned use of SURTASS LFA sonar for training and testing activities is not likely to jeopardize the continued existence of threatened and endangered species under NMFS’s jurisdiction and is not likely to destroy or adversely modify designated critical habitat from August 2019 into the reasonably foreseeable future. The ESA 2019 Biological Opinion for SURTASS LFA sonar, which includes an Incidental Take Statement, was signed on July 30, 2019 and became effective on August 12, 2019.
Publications
- 2019-2020 Annual Report of SURTASS LFA Sonar Training and Testing Activities
- 2020 Annual Report of the SURTASS LFA sonar Marine Mammal Monitoring (M3) Program
- Federal Register publication of NMFS’s Final Rule.
- The 2019 to 2026 Letter of Authorization became effective on August 12, 2019.
- The 2019 to 2026 Biological Opinion-Incidental Take Statement for SURTASS LFA sonar was signed on July 30, 2019 and authorized on August 12, 2019.
- The Navy’s 2019 Record of Decision, selecting Alternative 2 (Preferred Alternative) of the FSEIS/SOEIS
- The Navy’s 2019 Final Supplemental Environmental Impact Statement/Supplemental Overseas Environmental Impact Statement (SEIS/SOEIS) for SURTASS LFA sonar
- Federal Register publication of NMFS’s Proposed Rule (comment period ends on April 1, 2019)
- Potential Marine Mammal Offshore Biologically Important Areas for SURTASS LFA Sonar: Marine Areas under Consideration
- Harbor Porpoise Desktop Study (February 28, 2019)
- The Navy’s 2018 Application for Rulemaking and a Letter of Authorization under the Marine Mammal Protection Act
- The U.S. Environmental Protection Agency (USEPA) published the notice of availability of the SURTASS LFA Draft SEIS/SOEIS on September 7, 2018 (83 FR 174: 45442) (EIS No. 20180203).
- The Navy’s 2018 Draft Supplemental Environmental Impact Statement/Supplemental Overseas Environmental Impact Statement (DSEIS/SOEIS) for Surveillance Towed Array Sensor System Low Frequency Active (SURTASS LFA) sonar.
- The 2017 National Defense Exemption (NDE) for continued SURTASS LFA sonar testing, training, and operations.
- The 2017 to 2022 Biological Opinion-Incidental Take Statement for SURTASS LFA sonar was signed and authorized 11 August 2017.
- The Navy’s 2017 Final Supplemental Environmental Impact Statement/Supplemental Environmental Overseas Impact Statement (SEIS/SOEIS) for Surveillance Towed Array Sensor System Low Frequency Active (SURTASS LFA) sonar.
- The U.S. Environmental Protection Agency (USEPA) published the notice of availability of the SURTASS LFA Final SEIS/SOEIS on July 7, 2017 (82 FR 129: 31597) (EIS No. 20170121).
- The Navy’s August 2016 Draft Supplemental Environmental Impact Statement/Supplemental Overseas Environmental Impact Statement (SEIS/SOEIS) for Employment of Surveillance Towed Array Sensor System Low Frequency Active (SURTASS LFA) Sonar.
- The U.S. Environmental Protection Agency (USEPA) published the notice of availability of the SURTASS LFA Draft SEIS/SOEIS on August 26, 2016 (81 FR 166).
- The Navy’s Notice of Intent (NOI) to prepare a Supplemental Environmental Impact Statement/Supplemental Overseas Environmental Impact Statement (SEIS/SOEIS) for Employment of Surveillance Towed Array Sensor System Low Frequency Active (SURTASS LFA) Sonar was published in the Federal Register (79 FR 37295) on June 5, 2015.