90 FR 56 pgs. 13582-13592 - Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to U.S. Coast Guard Construction in Florence, Oregon
Type: NOTICEVolume: 90Number: 56Pages: 13582 - 13592
Pages: 13582, 13583, 13584, 13585, 13586, 13587, 13588, 13589, 13590, 13591, 13592Docket number: [RTID 0648-XE693]
FR document: [FR Doc. 2025-04995 Filed 3-24-25; 8:45 am]
Agency: Commerce Department
Sub Agency: National Oceanic and Atmospheric Administration
Official PDF Version: PDF Version
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XE693]
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to U.S. Coast Guard Construction in Florence, Oregon
AGENCY:
National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.
ACTION:
Notice; issuance of an incidental harassment authorization.
SUMMARY:
In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued an Incidental Harassment Authorization (IHA) to the U.S. Coast Guard (USCG) to incidentally harass marine mammals during pile driving activities associated with Station Siuslaw River construction project in Florence, Oregon.
DATES:
The authorization is effective from November 1, 2025 through October 31, 2026.
ADDRESSES:
Electronic copies of the application and supporting documents, as well as a list of the references cited in this document, may be obtained online at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-coast-guards-station-siuslaw-river-construction-project. In case of problems accessing these documents, please call the contact listed below.
FOR FURTHER INFORMATION CONTACT:
Jenna Harlacher, Office of Protected Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the "take" of marine mammals, with certain exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq. ) direct the Secretary of Commerce (as delegated to NMFS) to allow, upon request, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are proposed or, if the taking is limited to harassment, a notice of a proposed IHA is provided to the public for review.
[top] Authorization for incidental takings shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for taking for subsistence uses (where relevant). Further, NMFS must prescribe the permissible methods of taking and other "means of effecting the least practicable adverse impact" on the affected species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and on the availability of the species or stocks for
Summary of Request
On October 26, 2023, NMFS received a request from the USCG for an IHA to take marine mammals incidental to pile driving activity associated with the Station Siuslaw River construction project in Florence, Oregon. Following NMFS' review of the application, we received a revised version of the application on April 18, 2024. After finalizing construction details, the USCG submitted revised versions on July 16, 2024 and October 16, 2024, followed by a final revised version on November 18, 2024, which was deemed adequate and complete on December 5, 2024. USCG's request is for take of harbor seal, California sea lion, Steller sea lion, and harbor porpoise by Level B harassment, and for harbor seal and harbor porpoise, Level A harassment. Neither USCG nor NMFS expect serious injury or mortality to result from this activity and, therefore, an IHA is appropriate.
Description of Activity
Overview
The USCG requested an IHA to correct shoreline erosion and replace the covered mooring and appurtenant structures at USCG Station Siuslaw River in Florence, Oregon (figure 1). This two-phased project entails both onshore and in-water construction activities including site preparation, demolition, shoreline stabilization measures, pile removal and installation, and overwater construction. Phase 1 includes onshore infrastructure improvements, sitework and shoreline stabilization, and phase 2 includes overwater and in-water construction including all pile install and removal.
The only part of the project that may result in Level A and Level B harassment of marine mammals, and further analyzed in this notice, are the in-water construction activities associated with vibratory and impact pile driving (phase 2). The USCG plans to remove 71 timber piles via vibratory driving and to install 79 total piles via vibratory and impact driving with an estimated 48 total days of pile removal and install. USCG plans to install 16-inch (in) (40.6 centimeters (cm)) to 20-in (50.8 cm) steel pipe piles, and/or 14-in (35.6 cm) H-piles for their new infrastructure. Pile driving will only occur within the Oregon Department of Fish and Wildlife (ODFW) approved in-water work window; however the IHA will have a 1-year period of effectiveness.
A detailed description of the planned construction project is provided in the Federal Register notice for the proposed IHA (90 FR 7082, January 21, 2025). Since that time, no changes have been made to the planned construction activities. Therefore, a detailed description is not provided here. Please refer to that Federal Register notice for the description of the specific activity.
Comments and Responses
A notice of NMFS' proposal to issue an IHA to USCG was published in the Federal Register on January 21, 2025 (90 FR 7082). That notice described, in detail, USCG's activities, the marine mammal species that may be affected by the activities, and the anticipated effects on marine mammals. In that notice, we requested public input on the request for authorization described therein, our analyses, the proposed authorization, and any other aspect of the notice of proposed IHA, and requested that interested persons submit relevant information, suggestions, and comments. This proposed notice was available for a 30-day public comment period. During the 30-day public comment period, NMFS did not receive any public comments.
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information regarding status and trends, distribution and habitat preferences, and behavior and life history of the potentially affected species. NMFS fully considered all of this information, and we refer the reader to these descriptions, instead of reprinting the information. Additional information regarding population trends and threats may be found in NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments ) and more general information about these species ( e.g., physical and behavioral descriptions) may be found on NMFS' website ( https://www.fisheries.noaa.gov/find-species ).
Table 1 lists all species or stocks for which take is expected and authorized for this activity and summarizes information related to the population or stock, including regulatory status under the MMPA and Endangered Species Act (ESA) and potential biological removal (PBR), where known. PBR is defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population (as described in NMFS' SARs). While no serious injury or mortality is anticipated or authorized here, PBR and annual serious injury and mortality (M/SI) from anthropogenic sources are included here as gross indicators of the status of the species or stocks and other threats.
[top] Marine mammal abundance estimates presented in this document represent the total number of individuals that make up a given stock or the total number estimated within a particular study or survey area. NMFS' stock abundance estimates for most species represent the total estimate of individuals within the geographic area, if known, that comprises that stock. For some species, this geographic area may extend beyond U.S. waters. All managed stocks in this region are assessed in NMFS' U.S. Pacific Marine Mammal SARs. All values presented in table 1 are the most recent available at the time of publication (including from the draft 2023 SARs) and are available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.
| Common name | Scientific name | Stock | ESA/ MMPA status; strategic (Y/N)? 2 | Stock abundance (CV, N min , most recent abundance survey)? 3 | PBR | Annual M/SI? 4 |
|---|---|---|---|---|---|---|
| Odontoceti (toothed whales, dolphins, and porpoises) | ||||||
| Family Phocoenidae (porpoises): | ||||||
| Harbor Porpoise | Phocoena phocoena | Central Oregon? 5 | -, -, N | 7,492 (0.421, 5,332, 2022) | 53 | 0 |
| Order Carnivora-Pinnipedia | ||||||
| Family Otariidae (eared seals and sea lions): | ||||||
| CA Sea Lion | Zalophus californianus | U.S | -, -, N | 257,606 (N/A, 233,515, 2014) | 14,011 | >321 |
| Steller Sea Lion? 6 | Eumetopias jubatus | Eastern | -, -, N | 36,308 (N/A, 36,308, 2022) | 2,178 | 93.2 |
| Family Phocidae (earless seals): | ||||||
| Harbor Seal | Phoca vitulina | OR/WA Coastal | -, -, N | UNK (UNK, UNK, 1999) | UND | 10.6 |
| 1 ?Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy ( https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)). | ||||||
| 2 ?Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is automatically designated under the MMPA as depleted and as a strategic stock. | ||||||
| 3 ?NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region. CV is coefficient of variation; N min is the minimum estimate of stock abundance. | ||||||
| 4 ?These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated with estimated mortality due to commercial fisheries is presented in some cases. | ||||||
| 5 New stock in 2023 SARs. | ||||||
| 6 N est is best estimate of counts, which have not been corrected for animals at sea during abundance surveys. Estimates provided are for the United States only. | ||||||
All species that could potentially occur in the project areas are included in section 3 of the IHA application on page 12. While killer whales ( Orcinus orca ), humpback whales ( Megaptera novaeangliae ), and gray whales ( Eschrichtius robustus ) have been sighted off the Oregon coast, the USCG's project is located in the Siuslaw River where these species do not occur. Therefore, the temporal and/or spatial occurrence of these species is such that take is not expected to occur, and they are not discussed further beyond the explanation provided here and in the USCG's application. For more details on the species that are likely to occur near the project area and may be taken by USCG's activities, see sections 3 and 4 of USCG's IHA application, the SARs, and NMFS' website.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals underwater, and exposure to anthropogenic sound can have deleterious effects. To appropriately assess the potential effects of exposure to sound, it is necessary to understand the frequency ranges marine mammals are able to hear. Not all marine mammal species have equal hearing capabilities ( e.g., Richardson et al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. (2007, 2019) recommended that marine mammals be divided into hearing groups based on directly measured (behavioral or auditory evoked potential techniques) or estimated hearing ranges (behavioral response data, anatomical modeling, etc. ). Generalized hearing ranges were chosen based on the ~65 decibel (dB) threshold from composite audiograms, previous analyses in NMFS (2018), and/or data from Southall et al. (2007) and Southall et al. (2019). We note that the names of two hearing groups and the generalized hearing ranges of all marine mammal hearing groups have been recently updated (NMFS, 2024) as reflected below in table 2.
| Hearing group | Generalized hearing range?* |
|---|---|
| Low-frequency (LF) cetaceans (baleen whales) | 7 Hz to 36 kHz. |
| High-frequency (HF) cetaceans (dolphins, toothed whales, beaked whales, bottlenose whales) | 150 Hz to 160 kHz. |
| Very High-frequency (VHF) cetaceans (true porpoises, Kogia, river dolphins, Cephalorhynchid, Lagenorhynchus cruciger & L. australis ) | 200 Hz to 165 kHz. |
| Phocid pinnipeds (PW) (underwater) (true seals) | 40 Hz to 90 kHz. |
| Otariid pinnipeds (OW) (underwater) (sea lions and fur seals) | 60 Hz to 68 kHz. |
| *?Represents the generalized hearing range for the entire group as a composite ( i.e., all species within the group), where individual species' hearing ranges may not be as broad. Generalized hearing range chosen based on ~65 dB threshold from composite audiogram, previous analysis in NMFS 2018, and/or data from Southall et al. 2007; Southall et al. 2019. Additionally, animals are able to detect very loud sounds above and below that "generalized" hearing range. | |
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For more detail concerning these groups and associated frequency ranges, please see NMFS (2024) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their Habitat
The effects of underwater noise from USCG's construction activities have the potential to result in harassment of marine mammals in the vicinity of the project area. The notice of proposed IHA (90 FR 7082, January 21, 2025) included a discussion of the effects of anthropogenic noise on marine mammals and the potential effects of underwater noise from the USCG's pile driving activities on marine mammals and their habitat. That information and analysis is referenced in the notice and is not repeated here; please refer to the notice of the proposed IHA (90 FR 7082, January 21, 2025).
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes authorized through the IHA, which will inform NMFS' consideration of "small numbers," the negligible impact determinations, and impacts on subsistence uses.
Harassment is the only type of take expected to result from these activities. Except with respect to certain activities not pertinent here, section 3(18) of the MMPA defines "harassment" as any act of pursuit, torment, or annoyance, which (i) has the potential to injure a marine mammal or marine mammal stock in the wild (Level A harassment); or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering (Level B harassment).
Authorized takes will primarily be by Level B harassment, as use of the acoustic sources ( i.e., pile driving) has the potential to result in disruption of behavioral patterns for individual marine mammals. There is also some potential for auditory injury (Level A harassment) to result, primarily for very high frequency species and phocids because predicted auditory injury zones are larger than for high-frequency species and otariids. Auditory injury is unlikely to occur for high-frequency species and otariids. The mitigation and monitoring measures are expected to minimize the severity of the taking to the extent practicable. As described previously, no serious injury or mortality is anticipated authorized for this activity. Below we describe how the take numbers are estimated.
For acoustic impacts, generally speaking, we estimate take by considering: (1) acoustic criteria above which NMFS believes the best available science indicates marine mammals will likely be behaviorally harassed or incur some degree of auditory injury; (2) the area or volume of water that will be ensonified above these levels in a day; (3) the density or occurrence of marine mammals within these ensonified areas; and, (4) the number of days of activities. We note that while these factors can contribute to a basic calculation to provide an initial prediction of potential takes, additional information that can qualitatively inform take estimates is also sometimes available ( e.g., previous monitoring results or average group size). Below, we describe the factors considered here in more detail and present the take estimates.
Acoustic Criteria
NMFS recommends the use of acoustic criteria that identify the received level of underwater sound above which exposed marine mammals will be reasonably expected to be behaviorally harassed (equated to Level B harassment) or to incur auditory injury of some degree (equated to Level A harassment). We note that the criteria for auditory injury, as well as the names of two hearing groups, have been recently updated (NMFS 2024) as reflected below in the Level A Harassmen t section.
Level B Harassment -Though significantly driven by received level, the onset of behavioral disturbance from anthropogenic noise exposure is also informed to varying degrees by other factors related to the source or exposure context ( e.g., frequency, predictability, duty cycle, duration of the exposure, signal-to-noise ratio, distance to the source), the environment ( e.g., bathymetry, other noises in the area, predators in the area), and the receiving animals (hearing, motivation, experience, demography, life stage, depth) and can be difficult to predict ( e.g., Southall et al., 2007, 2021; Ellison et al., 2012). Based on what the available science indicates and the practical need to use a threshold based on a metric that is both predictable and measurable for most activities, NMFS typically uses a generalized acoustic threshold based on received level to estimate the onset of behavioral harassment. NMFS generally predicts that marine mammals are likely to be behaviorally harassed in a manner considered to be Level B harassment when exposed to underwater anthropogenic noise above root-mean-squared pressure received levels (RMS SPL) of 120 dB (referenced to 1 µPa) for continuous ( e.g., vibratory pile driving, drilling) and above RMS SPL 160 dB re 1 µPa for non-explosive impulsive ( e.g., seismic airguns) or intermittent ( e.g., scientific sonar) sources. Generally speaking, Level B harassment take estimates based on these behavioral harassment thresholds are expected to include any likely takes by temporary threshold shift (TTS) as, in most cases, the likelihood of TTS occurs at distances from the source less than those at which behavioral harassment is likely. TTS of a sufficient degree can manifest as behavioral harassment, as reduced hearing sensitivity and the potential reduced opportunities to detect important signals (conspecific communication, predators, prey) may result in changes in behavior patterns that would not otherwise occur.
USCG's planned activity includes the use of continuous (vibratory pile driving) and impulsive (impact pile driving) sources, and therefore the RMS SPL thresholds of 120 and 160 dB re 1 µPa are applicable.
Level A Harassment -NMFS' Updated Technical Guidance for Assessing the Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 3.0) (Updated Technical Guidance, 2024) identifies dual criteria to assess auditory injury (Level A harassment) to five different underwater marine mammal groups (based on hearing sensitivity) as a result of exposure to noise from two different types of sources (impulsive or non-impulsive). USCG's planned activity includes the use of impulsive (impact pile driving) and non-impulsive (vibratory pile driving) sources.
[top] The 2024 Updated Technical Guidance criteria include both updated thresholds and updated weighting functions for each hearing group. The thresholds are provided in table 3 below. The references, analysis, and methodology used in the development of the criteria are described in NMFS' 2024 Updated Technical Guidance, which may be accessed at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance-other-acoustic-tools.
| Hearing group | Auditory injury onset acoustic thresholds?* (received level) | Impulsive | Non-impulsive |
|---|---|---|---|
| Low-Frequency (LF) Cetaceans | Cell 1: L pk,flat : 222 dB; L E,LF,24h : 183 dB | Cell 2: L E,LF,24h : 197 dB. | |
| High-Frequency (HF) Cetaceans | Cell 3: L pk,flat : 230 dB; L E,HF,24h : 193 dB | Cell 4: L E,HF,24h : 201 dB. | |
| Very High-Frequency (VHF) Cetaceans | Cell 5: L pk,flat : 202 dB; L E,VHF,24h : 159 dB | Cell 6: L E,VHF,24h : 181 dB. | |
| Phocid Pinnipeds (PW) (Underwater) | Cell 7: L pk,flat : 223 dB; L E,PW,24h : 183 dB | Cell 8: L E,PW,24h : 195 dB. | |
| Otariid Pinnipeds (OW) (Underwater) | Cell 9 L pk,flat : 230 dB; L E,OW,24h : 185 dB | Cell 10: L E,OW,24h : 199 dB. | |
| *?Dual metric criteria for impulsive sounds: Use whichever criteria results in the larger isopleth for calculating auditory injury onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level criteria associated with impulsive sounds, the PK SPL criteria are recommended for consideration for non-impulsive sources. | |||
| Note: Peak sound pressure level ( L p,0-pk ) has a reference value of 1 µPa, and weighted cumulative sound exposure level ( L E,p ) has a reference value of 1 µPa 2 s. In this Table, criteria are abbreviated to be more reflective of International Organization for Standardization standards (ISO 2017; ISO 2020). The subscript "flat" is being included to indicate peak sound pressure are flat weighted or unweighted within the generalized hearing range of marine mammals underwater ( i.e., 7 Hz to 165 kHz). The subscript associated with cumulative sound exposure level criteria indicates the designated marine mammal auditory weighting function (LF, HF, and VHF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours. The weighted cumulative sound exposure level criteria could be exceeded in a multitude of ways ( i.e., varying exposure levels and durations, duty cycle). When possible, it is valuable for action proponents to indicate the conditions under which these criteria will be exceeded. | |||
Ensonified Area
Here, we describe operational and environmental parameters of the activity that are used in estimating the area ensonified above the acoustic thresholds, including source levels and transmission loss coefficient.
The USCG opted to perform its own acoustic modeling for the Level A and Level B harassment isopleths using dBSea, a software developed by Marshall Day Acoustics for the modeling of underwater sound propagation in a variety of environments. Use of this model allowed USCG to incorporate site-specific information, therefore providing more accurate results than other more generalized tools. dBSea was also used in a previous construction project by the USCG (88 FR 77985, November 11, 2023). NMFS has reviewed USCG's modeling and determined that it is acceptable for use here.
Marshall Day Acoustics built the model by importing bathymetry data and placing noise sources in the environment. Each source can consist of equipment chosen from either the standard or the user-defined databases. Noise mitigation methods may also be included. The user has control over the seabed and water properties including sound speed profile, temperature, salinity, and current. To examine results in more detail, the model allows users to plot noise levels in cross sections, or extract a detailed spectrum at any point in the calculation area. USCG calculated noise levels to the deepest depth within the project area.
USCG derived representative acoustic modeling scenarios based on descriptions of the expected construction activities through consultations between the USCG project design and engineering teams. The team modeled activities that are expected to result in take of marine mammals ( i.e., in-water pile driving and removal) at a location with characteristics representative of the project site. The USCG modeled the full range of potential water depths in the project area at a single representative location. As described in the Detailed Description of the Specified Activity section of the notice of the proposed IHA (90 FR 7082, January 21, 2025), USCG may install a variety of pile types and sizes, and the exact pile sizes have not yet been determined. However, in an effort to avoid underestimating potential impacts to marine mammals, USCG conducted its analysis using the maximum possible pile size for each project use. Table 4 lists the sound source levels for each activity that USCG incorporated into the model. Table 5 shows the model-estimated Level A and Level B harassment isopleths for the planned activities. Please refer to the Acoustic Assessment included in USCG's IHA application for additional details on the modeling principles and assumptions and a summary of construction and operational scenarios included in the underwater acoustic modeling analysis.
| Pile driving method | Pile type and size | db RMS | dB peak | db SEL | Reference |
|---|---|---|---|---|---|
| Impact installation | Steel pipe pile 24-in | 194 | 207 | 178 | Caltrans 2020. |
| H-pile | 178 | 200 | 166 | Caltrans 2020. | |
| Vibratory installation | Steel pipe pile 24-in | 165 | Caltrans 2020. | ||
| Vibratory removal | Timber | 162 | Caltrans 2020. | ||
| Note: dB peak = peak sound level; rms = root mean square; SEL = sound exposure level. | |||||
| *?All sound levels are referenced at 10 m. | |||||
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| Size and type | Level A isopleth (m) | VHF | Phocids | Otariids | Level B isopleth (m) |
|---|---|---|---|---|---|
| Vibratory Installation and Removal | |||||
| 24-in steel pipe pile installation | 58 | 39 | 17 | 1,117 | |
| Timber removal | 16 | 14 | 1,106 | ||
| Impact Installation | |||||
| 24-in steel pipe pile | 335 | 256 | 95 | 717 | |
| H-pile | 96 | 35 | 18 | 110 | |
Marine Mammal Occurrence and Take Calculation and Estimation
In this section, we provide information about the occurrence of marine mammals, including density or other relevant information which will inform the take calculations and describe how the information provided is synthesized to produce a quantitative estimate of the take that is reasonably likely to occur and authorized. The USCG uses marine mammal species densities from the Pacific Navy Marine Species Density Database to estimate take for marine mammals. This database incorporates analyzed literature and research for marine mammal density estimates per season for regions throughout the United States, and the USCG based their take estimates on regionally available population density estimates and site-specific knowledge. Although this database provides densities for all species present in the action area, the densities are based on offshore abundance and not directly relevant to occurrence within in the Siuslaw River. Following careful review of the analysis presented by the USCG in its application, including marine mammal occurrence data, NMFS has determined that different information inputs than those selected by the USCG, represent the best available scientific information for marine mammal abundance in the action area. These selections are discussed in greater detail below.
For all species, the numbers of individuals are based on average group sizes from Bates et al. (2023) that described marine mammal occurrences near Coos Bay, Oregon in 2014 and 2015. While Coos Bay is south of the action area, this area is more representative of the action area within the Siuslaw River than the offshore data in the application. We derived potential take estimates from the average group sizes recorded over the specified period in Bates et al. (2023) and used the occurrences of these sightings during the surveys, along with sightings in OBIS-SEAMAP around the action area, to estimate our sighing rates in the project vicinity (table 6).
| Species | Average group size | Sighting rate for action area |
|---|---|---|
| California sea lion | 1.4 | Group every other day. |
| Steller sea lion | 1.8 | Group every other day. |
| Harbor seal | 1 | 2 groups/day. |
| Harbor porpoise | 1.3 | Group every other day. |
To calculate the total estimated takes by Level B harassment, we multiplied the estimated days of activity by the associated average group size and sighting rate for each species (table 6). There is also some potential for take by Level A harassment of harbor seal and harbor porpoise during impact pile driving due to the largest zones of each species being greater than the shutdown zones and because of the cryptic nature and assumed lower detectability of these species.
[top] Based on the relative proportion of the area expected to be ensonified above the Level A harassment threshold for phocids from impact pile driving (approximately 0.14 square kilometers (km 2 )) to the area ensonified above the Level B harassment threshold (0.59 km 2 for impact pile driving), we estimated that of the total number of harbor seals that may be located within the greater Level B harassment zone, approximately 24 percent will enter the smaller Level A harassment zone (256 m) and stay in the zone long enough to incur auditory injury. Thus, we assume that 24 percent of the total estimated takes of harbor seals (96 individuals; see table 7) will be by Level A harassment. Therefore, we are authorizing 23 takes of harbor seals by Level A harassment and 73 takes by Level B harassment (table 7). Take by Level A harassment for harbor porpoise was calculated in the same way as for harbor seals. For otarriids, we are not authorizing take by Level A harassment as the shutdown zones are much larger than the Level A harassment zones for most activities, and the likely occurrence of otariids in the action area is much lower than for harbor porpoise and harbor seals.
| Species | Stock | Take by Level A harassment | Take by Level B harassment | Total take | Percent of stock taken |
|---|---|---|---|---|---|
| California sea lion | U.S | 0 | 34 | 34 | <0.1 |
| Steller sea lion | Eastern | 0 | 43 | 43 | 0.1 |
| Harbor seal | Oregon/Washington Coast | 23 | 73 | 96 | 0.4 |
| Harbor porpoise | Central Oregon | 11 | 20 | 31 | 0.4 |
Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods of taking pursuant to the activity, and other means of effecting the least practicable impact on the species or stock and its habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance, and on the availability of the species or stock for taking for certain subsistence uses (latter not applicable for this action). NMFS regulations require applicants for incidental take authorizations to include information about the availability and feasibility (economic and technological) of equipment, methods, and manner of conducting the activity or other means of effecting the least practicable adverse impact upon the affected species or stocks, and their habitat (50 CFR 216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to ensure the least practicable adverse impact on species or stocks and their habitat, as well as subsistence uses where applicable, NMFS considers two primary factors:
1. The manner in which, and the degree to which, the successful implementation of the measure(s) is expected to reduce impacts to marine mammals, marine mammal species or stocks, and their habitat. This considers the nature of the potential adverse impact being mitigated (likelihood, scope, range). It further considers the likelihood that the measure will be effective if implemented (probability of accomplishing the mitigating result if implemented as planned), the likelihood of effective implementation (probability implemented as planned), and;
2. The practicability of the measures for applicant implementation, which may consider such things as cost, and impact on operations.
USCG must ensure that construction supervisors and crews, the monitoring team, and relevant USCG staff are trained prior to the start of all pile driving activity, so that responsibilities, communication procedures, monitoring protocols, and operational procedures are clearly understood. New personnel joining during the project must be trained prior to commencing work.
Pre- and Post-Activity Monitoring
• Monitoring must take place from 30 minutes prior to initiation of pile driving activity ( i.e., pre-clearance monitoring) through 30 minutes post-completion of pile driving activity; and
• Pre-start clearance monitoring must be conducted during periods of visibility sufficient for the lead protected species observer (PSO) to determine that the shutdown zones indicated in table 8 are clear of marine mammals. Pile driving may commence following 30 minutes of observation when the determination is made that the shutdown zones are clear of marine mammals.
Soft Start
USCG must use soft start techniques when impact pile driving. Soft start requires contractors to provide an initial set of three strikes at reduced energy, followed by a 30 second waiting period, then two subsequent reduced-energy strike sets. A soft start must be implemented at the start of each day's impact pile driving and at any time following cessation of impact pile driving for a period of 30 minutes or longer.
Shutdown Zones
USCG will establish shutdown zones for all pile driving activities. The purpose of a shutdown zone is generally to define an area within which shutdown of the activity will occur upon sighting of a marine mammal (or in anticipation of an animal entering the defined area).
If a marine mammal is observed entering or within the shutdown zones indicated in table 8, pile driving must be delayed or halted. For in-water heavy machinery activities other than pile driving, if a marine mammal comes within 10 m, work must stop and vessels must reduce speed to the minimum level required to maintain steerage and safe working conditions. A 10 m shutdown zone will also serve to protect marine mammals from physical interactions with project vessels during pile driving and other construction activities, such as barge positioning or drilling. If an activity is delayed or halted due to the presence of a marine mammal, the activity may not commence or resume until either the animal has voluntarily exited and been visually confirmed beyond the shutdown zone indicated in table 8 or 15 minutes have passed without re-detection of the animal. Construction activities must be halted upon observation of a species for which incidental take is not authorized or a species for which incidental take has been authorized but the authorized number of takes has been met entering or within the harassment zone.
All marine mammals will be monitored in the Level B harassment zones and throughout the area as far as visual monitoring can take place. If a marine mammal enters the Level B harassment zone, in-water activities will continue and the animal's presence within the estimated harassment zone will be documented.
USCG will also establish shutdown zones for all marine mammals for which take has not been authorized or for which incidental take has been authorized but the authorized number of takes has been met. These zones are equivalent to the Level B harassment zones for each activity. If a marine mammal species for which take is not authorized by this IHA enters the shutdown zone, all in-water activities will cease until the animal leaves the zone or has not been observed for at least 15 minutes, and USCG will notify NMFS about the species and precautions taken. Pile driving will proceed if the non-IHA species is observed to leave the Level B harassment zone or if 15 minutes have passed since the last observation.
[top] If shutdown and/or clearance procedures will result in an imminent safety concern, as determined by USCG or its designated officials, the in-water activity will be allowed to continue until the safety concern has been addressed, and the animal will be continuously monitored.
| Activity | Minimum shutdown zone (m) | VHF cetaceans | Phocid | Otariid | Level B harassment zone (m) |
|---|---|---|---|---|---|
| Vibratory Removal | 20 | 20 | 10 | 1,110 | |
| Vibratory Installation | 60 | 40 | 20 | 1,120 | |
| Impact Installation | 200 | 100 | 100 | 720 |
Protected Species Observers
The placement of PSOs during all construction activities (described in the Monitoring and Reporting section) will ensure that the entire shutdown zone is visible. Should environmental conditions deteriorate such that the entire shutdown zone will not be visible ( e.g., fog, heavy rain), pile driving will be delayed until the PSO is confident marine mammals within the shutdown zone could be detected.
The USCG must employ PSOs and establish monitoring locations as described in the application and the IHA. PSOs will monitor the full shutdown zones and the Level B harassment zones to the extent practicable. Monitoring zones provide utility for observing by establishing monitoring protocols for areas adjacent to the shutdown zones. Monitoring zones enable observers to be aware of and communicate the presence of marine mammals in the project areas outside the shutdown zones and thus prepare for a potential cessation of activity should the animal enter the shutdown zone.
Bubble Curtain
A bubble curtain must be employed during all impact pile installation. The bubble curtain must be deployed in a manner guaranteed to distribute air bubbles around 100 percent of the piling perimeter for the full depth of the water column. The lowest bubble ring must be in contact with the mudline for the full circumference of the ring. The weights attached to the bottom ring must ensure 100 percent mudline contact. No parts of the ring or other objects may prevent full mudline contact. Air flow to the bubblers must be balanced around the circumference of the pile.
Based on our evaluation of USCG's measures, as well as other measures considered by NMFS, NMFS has determined that the mitigation measures provide the means effecting the least practicable impact on the affected species or stocks and their habitat, paying particular attention to rookeries, mating grounds, and areas of similar significance.
Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of the MMPA states that NMFS must set forth requirements pertaining to the monitoring and reporting of such taking. The MMPA implementing regulations at 50 CFR 216.104(a)(13) indicate that requests for authorizations must include the suggested means of accomplishing the necessary monitoring and reporting that will result in increased knowledge of the species and of the level of taking or impacts on populations of marine mammals that are expected to be present while conducting the activities. Effective reporting is critical both to compliance as well as ensuring that the most value is obtained from the required monitoring.
Monitoring and reporting requirements prescribed by NMFS should contribute to improved understanding of one or more of the following:
• Occurrence of marine mammal species or stocks in the area in which take is anticipated ( e.g., presence, abundance, distribution, density);
• Nature, scope, or context of likely marine mammal exposure to potential stressors/impacts (individual or cumulative, acute or chronic), through better understanding of: (1) action or environment ( e.g., source characterization, propagation, ambient noise); (2) affected species ( e.g., life history, dive patterns); (3) co-occurrence of marine mammal species with the activity; or (4) biological or behavioral context of exposure ( e.g., age, calving or feeding areas);
• Individual marine mammal responses (behavioral or physiological) to acoustic stressors (acute, chronic, or cumulative), other stressors, or cumulative impacts from multiple stressors;
• How anticipated responses to stressors impact either: (1) long-term fitness and survival of individual marine mammals; or (2) populations, species, or stocks;
• Effects on marine mammal habitat ( e.g., marine mammal prey species, acoustic habitat, or other important physical components of marine mammal habitat); and,
• Mitigation and monitoring effectiveness.
Visual Monitoring
Marine mammal monitoring must be conducted in accordance with the conditions in this section and the IHA. Marine mammal monitoring during pile driving activities must be conducted by PSOs meeting the following requirements:
• PSOs must be independent of the activity contractor (for example, employed by a subcontractor) and have no other assigned tasks during monitoring periods;
• At least one PSO must have prior experience performing the duties of a PSO during construction activity pursuant to a NMFS-issued incidental take authorization;
• Other PSOs may substitute relevant experience, education (degree in biological science or related field), or training for prior experience performing the duties of a PSO during construction activity pursuant to a NMFS-issued incidental take authorization; and,
• Where a team of three or more PSOs is required, a lead observer or monitoring coordinator will be designated. The lead observer will be required to have prior experience performing the duties of a PSO during construction activities pursuant to a NMFS-issued incidental take authorization.
PSOs must have the following additional qualifications:
• Ability to conduct field observations and collect data according to assigned protocols;
• Experience or training in the field identification of marine mammals, including the identification of behaviors;
• Sufficient training, orientation, or experience with the construction operation to provide for personal safety during observations;
[top] • Writing skills sufficient to prepare a report of observations including but not limited to the number and species of marine mammals observed; dates and times when in-water construction activities were conducted; dates, times
• Ability to communicate orally, by radio or in person, with project personnel to provide real-time information on marine mammals observed in the area as necessary.
USCG must assign a minimum of two PSOs to monitor during pile driving. One PSO must be stationed at the pile driving site, and the second PSO must be stationed at the best practicable location for monitoring the Level A and Level B harassment zones. Possible PSOs locations include the staging barges, on shore at the project site, or at the entrance to the commercial dock area. All PSOs will have access to high-quality binoculars, range finders to monitor distances, and a compass to record bearing to animals as well as radios or cells phones for maintaining contact with work crews.
Monitoring will be conducted 30 minutes before, during, and 30 minutes after all in water construction activities. In addition, PSOs will record all incidents of marine mammal occurrence, regardless of distance from activity, and will document any behavioral reactions in concert with distance from piles being driven or removed. Pile driving activities include the time to install or remove a single pile or series of piles, as long as the time elapsed between uses of the pile driving equipment is no more than 30 minutes.
USCG shall conduct briefings between construction supervisors and crews, PSOs, USCG staff prior to the start of all pile driving activities and when new personnel join the work. These briefings must explain responsibilities, communication procedures, marine mammal monitoring protocol, and operational procedures.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS within 90 days after the completion of pile driving and removal activities, or 60 days prior to a requested date of issuance from any future IHAs for projects at the same location, whichever comes first. The report will include an overall description of work completed, a narrative regarding marine mammal sightings, and associated PSO data sheets.
Specifically, the report must include:
• Dates and times (begin and end) of all marine mammal monitoring;
• Construction activities occurring during each daily observation period, including the number and type of piles driven or removed and by what method ( i.e., impact) and the total equipment duration for vibratory removal for each pile or total number of strikes for each pile (impact driving);
• PSO locations during marine mammal monitoring;
• Environmental conditions during monitoring periods (at beginning and end of PSO shift and whenever conditions change significantly), including Beaufort sea state and any other relevant weather conditions including cloud cover, fog, sun glare, and overall visibility to the horizon, and estimated observable distance;
• Upon observation of a marine mammal, the following information: (1) Name of PSO who sighted the animal(s) and PSO location and activity at the time of sighting; (2) Time of sighting; (3) Identification of the animal(s) ( e.g., genus/species, lowest possible taxonomic level, or unidentifiable), PSO confidence in identification, and the composition of the group if there is a mix of species; (4) Distance and bearing of each marine mammal observed relative to the pile being driven for each sightings (if pile driving was occurring at time of sighting); (5) Estimated number of animals (min/max/best estimate); (6) Estimated number of animals by cohort (adults, juveniles, neonates, group composition, sex class, etc. ); (7) Animal's closest point of approach and estimated time spent within the harassment zone; (8) Description of any marine mammal behavioral observations ( e.g., observed behaviors such as feeding or traveling), including an assessment of behavioral responses thought to have resulted from the activity ( e.g., no response or changes in behavioral state such as ceasing feeding, changing direction, flushing, or breaching);
• Number of marine mammals detected within the harassment zones and shutdown zones; by species; and,
• Detailed information about any implementation of any mitigation triggered ( e.g., shutdowns and delays), a description of specific actions that ensured, and resulting changes in behavior of the animal(s), if any.
If no comments are received from NMFS within 30 days, the draft final report will constitute the final report. If comments are received, a final report addressing NMFS comments must be submitted within 30 days after receipt of comments.
Reporting Injured or Dead Marine Mammals
In the event that personnel involved in the construction activities discover an injured or dead marine mammal, the USCG must immediately cease the specified activities and report the incident to the Office of Protected Resources (OPR) ( PR.ITP.MonitoringReports@noaa.gov ), NMFS and to the West Coast Regional Stranding Coordinator as soon as feasible. If the death or injury was clearly caused by the specified activity, USCG must immediately cease the specified activities until NMFS is able to review the circumstances of the incident and determine what, if any, additional measures are appropriate to ensure compliance with the terms of the IHA. The USCG must not resume their activities until notified by NMFS. The report must include the following information:
• Time, date, and location (latitude/longitude) of the first discovery (and updated location information if known and applicable);
• Species identification (if known) or description of the animal(s) involved;
• Condition of the animal(s) (including carcass condition if the animal is dead);
• Observed behaviors of the animal(s), if alive;
• If available, photographs or video footage of the animal(s); and,
• General circumstances under which the animal was discovered.
Negligible Impact Analysis and Determination
[top] NMFS has defined negligible impact as an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival (50 CFR 216.103). A negligible impact finding is based on the lack of likely adverse effects on annual rates of recruitment or survival ( i.e., population-level effects). An estimate of the number of takes alone is not enough information on which to base an impact determination. In addition to considering estimates of the number of marine mammals that might be "taken" through harassment, NMFS considers other factors, such as the likely nature of any impacts or responses ( e.g., intensity, duration), the context of any impacts or responses ( e.g., critical reproductive time or location, foraging impacts affecting energetics), as well as effects on habitat, and the likely effectiveness of the mitigation. We also assess the number, intensity, and context of estimated takes by evaluating this information relative to population status. Consistent with the 1989 preamble for NMFS' implementing regulations (54 FR 40338, September 29, 1989), the impacts from other past and
To avoid repetition, our analysis applies to all species listed in table 1 for which take could occur, given that NMFS expects the anticipated effects of the planned pile driving and removal on different marine mammal stocks to be similar in nature. Where there are meaningful differences between species or stocks, or groups of species, in anticipated individual responses to activities, impact of expected take on the population due to differences in population status, or impacts on habitat, NMFS has identified species-specific factors to inform the analysis.
Pile driving activities associated with the USCG construction project have the potential to disturb or displace marine mammals. Specifically, the project activities may result in take, in the form of Level A and Level B harassment, from underwater sounds generated from pile driving and removal. Potential takes could occur if individuals are present in the ensonified zone when these activities are underway.
The takes by Level B harassment will be due to potential behavioral disturbance and TTS. Takes by Level A harassment will be due to auditory injury. No serious injury or mortality is expected, even in the absence of required mitigation measures, given the nature of the activities. The potential for harassment will be further minimized through the construction method and the implementation of the planned mitigation measures (see Mitigation section). Take by Level A harassment is authorized for harbor seals and harbor porpoise to account for the possibility that an animal could enter a Level A harassment zone prior to detection, and remain within that zone for a duration long enough to incur auditory injury before being observed and the USCG shutting down pile driving activity. The Level A harassment zones identified in table 6 are based upon an animal's exposure to pile driving of up to three of the largest steel piles per day. Given the short duration to vibratory or impact drive each pile and breaks between pile installations (to reset equipment and move piles into place), an animal will have to remain within the area estimated to be ensonified above the Level A harassment threshold for multiple hours. This is highly unlikely given marine mammal movement in the area. The number of takes by Level A harassment authorized is very low for both marine mammal species. Any take by Level A harassment is expected to arise from, at most, a small degree of auditory injury, i.e., minor degradation (likely only a few dB) of hearing capabilities within regions of hearing that align most completely with the energy produced by vibratory and impact pile driving ( i.e., the low-frequency region below 2 kHz), not severe hearing impairment or impairment within the ranges of greatest hearing sensitivity. Animals will need to be exposed to higher levels and/or longer duration than are expected to occur here in order to incur any more than a small degree of auditory injury. Due to the small degree anticipated, any auditory injury incurred will not be expected to affect the reproductive success or survival of any individuals, much less result in adverse impacts on the species or stock.
Additionally, some subset of the individuals that are behaviorally harassed could also simultaneously incur some small degree of TTS for a short duration of time. However, since the hearing sensitivity of individuals that incur TTS is expected to recover completely within minutes to hours, it is unlikely that the brief hearing impairment will affect the individual's long-term ability to forage and communicate with conspecifics, and will therefore not likely impact reproduction or survival of any individual marine mammal, let alone adversely affect rates of recruitment or survival of the species or stock.
Behavioral responses of marine mammals to pile driving in the Siuslaw River are expected to be mild, short term, and temporary. Marine mammals within the Level B harassment zones may not show any visual cues they are disturbed by activities or they could become alert, avoid the area, leave the area, or display other mild responses that are not observable, such as changes in vocalization patterns. Given that pile driving will occur for only a portion of the project's duration, any harassment will be temporary. Additionally, many of the species present in region will only be present temporarily based on seasonal patterns or during transit between other habitats. These temporarily present species will be exposed to even smaller periods of noise-generating activity, further decreasing the impacts.
Any impacts on marine mammal prey that will occur during USCG's planned activity will have, at most, short-term effects on foraging of individual marine mammals, and likely no effect on the populations of marine mammals as a whole. Indirect effects on marine mammal prey during the construction are expected to be minor, and these effects are unlikely to cause substantial effects on marine mammals at the individual level, with no expected effect on annual rates of recruitment or survival.
For all species and stocks, take will occur within a limited, confined area (adjacent to the project site) of the stock's range, and, there are no known biologically important areas (BIAs) near the project area that will be impacted by USCG's activities. While harbor seal is the species most likely to occur within the immediate project area, the nearest haulout is outside of the ensonified areas. There are known haulout sites for harbor seals near the project area including across the river and upriver from the action area, the closest being 400 m from the project area. Although, the most recent survey taken of this area was in 2014. There are no other haulouts in the immediate project vicinity; the next closest haulout is 129 km away.
In addition, it is unlikely that minor noise effects in a small, localized area of habitat will have any effect on the reproduction or survival of any individuals, much less the stocks' annual rates of recruitment or survival. In combination, we believe that these factors, as well as the available body of evidence from other similar activities, demonstrate that the potential effects of the specified activities would have only minor, short-term effects on individuals. The specified activities are not expected to impact rates of recruitment or survival and would therefore not result in population-level impacts.
In summary and as described above, the following factors primarily support our determination that the impacts resulting from this activity are not expected to adversely affect any of the species or stocks through effects on annual rates of recruitment or survival:
• No serious injury or mortality is anticipated or authorized;
• Take by Level A harassment is authorized for harbor seal and harbor porpoise only and will be very small amounts and of a low degree;
• For all species and stocks, the Siuslaw River is a very small and peripheral part of their range;
[top] • The intensity of anticipated takes by Level B harassment is relatively low for all stocks. Level B harassment will be primarily in the form of behavioral disturbance, resulting in avoidance of the project areas around where impact or vibratory pile driving is occurring, with some low-level TTS that may limit the detection of acoustic cues for
• Effects on species that serve as prey for marine mammals from the activities are expected to be short-term and, therefore, any associated impacts on marine mammal feeding are not expected to result in significant or long-term consequences for individuals, or to accrue to adverse impacts on their populations;
• The project area does not overlap any areas of known important habitat for marine mammals;
• The ensonified areas are very small relative to the overall habitat ranges of all species and stocks; and,
• The lack of anticipated significant or long-term negative effects to marine mammal habitat.
Based on the analysis contained herein of the likely effects of the specified activity on marine mammals and their habitat, and taking into consideration the implementation of the monitoring and mitigation measures, NMFS finds that the total marine mammal take from the planned activities will have a negligible impact on all affected marine mammal species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for specified activities other than military readiness activities. The MMPA does not define small numbers and so, in practice, where estimated numbers are available, NMFS compares the number of individuals taken to the most appropriate estimation of abundance of the relevant species or stock in our determination of whether an authorization is limited to small numbers of marine mammals. When the predicted number of individuals to be taken is fewer than one-third of the species or stock abundance, the take is considered to be of small numbers. Additionally, other qualitative factors may be considered in the analysis, such as the temporal or spatial scale of the activities. For all species, the take is below one third of the population for all marine mammal stocks (table 7).
Based on the analysis contained herein of the planned activity (including the mitigation and monitoring measures) and the anticipated take of marine mammals, NMFS finds that small numbers of marine mammals will be taken relative to the population size of the affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine mammal stocks or species implicated by this action. Therefore, NMFS has determined that the total taking of affected species or stocks will not have an unmitigable adverse impact on the availability of such species or stocks for taking for subsistence purposes.
Endangered Species Act
Section 7(a)(2) of the ESA of 1973 (16 U.S.C. 1531 et seq. ) requires that each Federal agency insure 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 designated critical habitat. To ensure ESA compliance for the issuance of IHAs, NMFS consults internally whenever we authorize take for endangered or threatened species.
No incidental take of ESA-listed species is authorized or expected to result from this activity. Therefore, NMFS has determined that formal consultation under section 7 of the ESA is not required for this action.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA; 42 U.S.C. 4321 et seq. ) and NOAA Administrative Order (NAO) 216-6A, NMFS must review our proposed action ( i.e., the issuance of an IHA) with respect to potential impacts on the human environment.
This action is consistent with categories of activities identified in Categorical Exclusion B4 (IHAs with no anticipated serious injury or mortality) of the Companion Manual for NAO 216-6A, which do not individually or cumulatively have the potential for significant impacts on the quality of the human environment and for which we have not identified any extraordinary circumstances that would preclude this categorical exclusion. Accordingly, NMFS has determined that the issuance of the IHA qualifies to be categorically excluded from further NEPA review.
Authorization
NMFS has issued an IHA to the USCG for the potential harassment of small numbers of four marine mammal species incidental to the Station Siuslaw River Construction Project in Florence, Oregon, that includes the previously explained mitigation, monitoring and reporting requirements.
Dated: March 19, 2025.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine Fisheries Service.
[FR Doc. 2025-04995 Filed 3-24-25; 8:45 am]
BILLING CODE 3510-22-P