Catch rates of eastern school whiting fell 99% compared with control areas immediately after a marine seismic survey off south-eastern Australia, and the impact on whiting lasted at least 10 months (Knuckey et al., Marine Environmental Research 2026). Tiger flathead catches on the same 11,000 km² fishing ground dropped 75%, echoing the classic Barents Sea trial in which trawl catches of cod and haddock fell by about 50% once shooting started (Engås et al., Canadian Journal of Fisheries and Aquatic Sciences 1996). The sound behind those numbers carries a long way: airgun pulses have been recorded almost 4,000 km from the survey vessel (Nieukirk et al., Journal of the Acoustical Society of America 2012). This roundup takes the fisheries angle on seismic exploration; for shipping, sonar and ambient ocean noise in general, see our underwater acoustics and ocean sonar statistics. We aggregated data from NOAA Fisheries, the Federal Register, the Bureau of Ocean Energy Management (BOEM), PNAS, Nature Ecology & Evolution, Scientific Reports, the ICES Journal of Marine Science, the Canadian Journal of Fisheries and Aquatic Sciences, and more than a dozen other peer-reviewed studies.
TL;DR
- Eastern school whiting catch rates fell 99% and tiger flathead 75% versus control areas right after a survey (Knuckey et al., Marine Environmental Research 2026)
- Barents Sea trawl catches of cod and haddock dropped about 50% after shooting began, and about 70% inside the shooting area (Engås et al., CJFAS 1996)
- Rockfish hook-and-line catch per unit effort fell 52.4% during airgun emissions (Skalski et al., CJFAS 1992)
- Gillnet catches of Greenland halibut rose 132% during shooting, while longline catches of the same species fell 16% (Løkkeborg et al., CJFAS 2012)
- A survey over about 2,500 km² of seabed had no short-term or long-term effect on tropical demersal fish (Meekan et al., PNAS 2021)
- Airgun sounds were recorded almost 4,000 km from the survey vessel (Nieukirk et al., JASA 2012)
- A single small airgun still carried substantial energy up to 10 kHz at 1,300 m in shallow Danish water (Hermannsen et al., PLOS ONE 2015)
- Zooplankton mortality rose from 18% to 40-60% after air gun passes off Tasmania (McCauley et al., Nature Ecology & Evolution 2017, via Curtin University)
- Scallop mortality after four airgun passes reached 17.5% versus 3.6% in controls by day 120 (Day et al., PNAS 2017)
- Rock lobster balance impairment and statocyst damage persisted to 365 days after airgun exposure (Day et al., Proceedings of the Royal Society B 2019)
- A 100-day survey off Newfoundland and Labrador changed the abundance of none of the 5 most common groundfish species (Nguyen et al., Marine Pollution Bulletin 2025)
1. Airgun Source Levels and Array Size
A marine seismic survey is a ship towing an array of airguns: chambers that release compressed air every few seconds to send a sound pulse into the seabed, whose echoes map the rock layers below. What makes it different from most noise sources is persistence: a commercial survey fires one shot every 8 to 15 s, 24 hours a day, for weeks to months (Day et al., PNAS 2017), and the arrays proposed for the US Atlantic in 2018 had nominal source levels of up to 266 dB re 1 µPa zero-to-peak.
Read those numbers as engineering specifications, not as what a fish hears. A “source level” is back-calculated to 1 m from an idealised point source, and the four common metrics (zero-to-peak, peak-to-peak, rms and sound exposure level, or SEL, which adds up the energy of a pulse) are not interchangeable. In the 2018 Atlantic filings, the gap between zero-to-peak and rms was 23 dB for the Spectrum array (266 minus 243) but only 10 dB for the ION array (257 minus 247, with 36 airguns and 6,420 in³).
| Metric | Value | Source |
|---|---|---|
| Nominal source level, Spectrum Geo array (32 airguns, 4,920 in³) proposed for the US Atlantic | 266 dB re 1 µPa zero-to-peak, 272 dB peak-to-peak, 243 dB rms | NMFS, Atlantic Geophysical Survey IHAs, Federal Register 2018 |
| Back-calculated source level of a single small airgun (10 to 40 in³) in shallow Danish water | 212 to 221 dB re 1 µPa peak-to-peak; 186 to 192 dB re 1 µPa²s (SEL) | Hermannsen et al., PLOS ONE 2015 |
| Effective source level of the two 2,600 in³ arrays used in the North West Shelf experiment, Australia | 231 dB re 1 µPa at 1 m (mean square), 228 dB (SEL), 247 dB re 1 µPa·m (peak-to-peak); most energy below 100 Hz, with peaks at 10 and 50 Hz | Meekan et al., PNAS 2021 |
| Typical frequency band of seismic survey pulses | mostly 10 to 300 Hz | Carroll et al., Marine Pollution Bulletin 2016 |
| Intensity of seismic survey impulses | 230 dB rms or more | Nowacek et al., Frontiers in Ecology and the Environment 2015 |
| Firing pattern of a commercial survey | one shot every 8 to 15 s (every 20 to 30 m), array towed at about 3 to 4 km/h, 24 hours a day for weeks to months | Day et al., PNAS 2017 |
Context: for fisheries, the frequency band matters as much as the headline decibels. BOEM notes that fish sense sound through particle motion, a short-range cue, and that species with an air-filled swim bladder can also detect sound pressure, a cue that works over longer distances, so impacts on those species are expected to be more widespread (BOEM Study Profile GM-20-01b 2023).
2. How Far Airgun Sound Travels
Low-frequency pulses lose energy slowly, so a survey off one continent can be heard across an ocean basin. Autonomous hydrophones on the Mid-Atlantic Ridge recorded airgun sounds almost 4,000 km from the survey vessel, and at some sites airgun sounds were present on more than 80% of days per month for more than 12 consecutive months (Nieukirk et al., JASA 2012). Unlike the steady hum of shipping covered in our propeller cavitation and underwater noise statistics, this is a repeating impulse that can dominate a soundscape for months.
Close to the source, the picture is about “transmission loss”, the drop in level as sound spreads and is absorbed. In 15 m deep Danish water, a single small airgun lost about 18 dB per tenfold increase in distance, yet still carried substantial energy up to 10 kHz at 1,300 m (Hermannsen et al., PLOS ONE 2015). The practical consequence: for a small airgun, the common 500 m shut-down zone guards against temporary hearing loss, not against animals reacting.
| Metric | Value | Source |
|---|---|---|
| Farthest distance from the survey vessel at which airgun sounds were recorded, Mid-Atlantic Ridge, 1999 to 2009 | almost 4,000 km | Nieukirk et al., JASA 2012 |
| Persistence of airgun sounds at some Mid-Atlantic hydrophone sites | more than 80% of days per month for more than 12 consecutive months | Nieukirk et al., JASA 2012 |
| Transmission loss of a single small airgun in 15 m deep water, Aarhus Bay, Denmark | approximately 18 log(r); fitted slopes of 16 to 19 dB per tenfold increase in distance | Hermannsen et al., PLOS ONE 2015 |
| Highest frequency with substantial energy still present 1,300 m from a 10 to 40 in³ airgun | up to 10 kHz | Hermannsen et al., PLOS ONE 2015 |
| Estimated harbour porpoise reaction distance from one 40 in³ airgun, compared with the commonly used shut-down zone | several km versus 500 m | Hermannsen et al., PLOS ONE 2015 |
| Received level in a cod courtship experiment, and the distance from a conventional survey it mimics | up to about 165 dB re 1 µPa²s, similar to levels 5 to 35 km from a conventional survey | Rugtveit et al., Marine Pollution Bulletin 2026 |
| Drop in sound exposure level close to a two-airgun cluster (8.6 l total) | 221 dB re 1 µPa² s at 0 m versus 183 dB re 1 µPa² s at 25 m | Fields et al., ICES Journal of Marine Science 2019 |
| Field recordings in the North West Shelf experiment | about 70,000 airgun signals measured at 19 locations; ambient level 84 dB re 1 µPa | Meekan et al., PNAS 2021 |
Most recent available data for basin-scale propagation: Nieukirk et al., 2012, covering 1999 to 2009 recordings.
3. Fish Catch Rates During and After Surveys
The newest field evidence is also the most severe. Using commercial Danish seine vessels in survey and control areas, Australian researchers measured a 99% drop in eastern school whiting catch rates and a 75% drop for tiger flathead immediately after a survey, and a logbook analysis confirmed a significant decline for whiting but not flathead (Knuckey et al., Marine Environmental Research 2026). A caveat the authors flag themselves: no randomized survey data existed from before the seismic work.
The older literature shows why fishers and regulators keep arguing. The Barents Sea trial found catch reductions 18 nautical miles from the shooting area (Engås et al., CJFAS 1996), but a Norwegian study 16 years later found gillnet catches went up, not down, while longline catches fell, which its authors attribute to fish becoming more active under airgun sound and feeding less (Løkkeborg et al., CJFAS 2012). The gear type, in other words, can flip the sign of the result.
| Metric | Value | Source |
|---|---|---|
| Catch rates immediately after a survey versus control areas, Danish seine, 11,000 km² ground in south-eastern Australia: eastern school whiting / tiger flathead | -99% / -75%; impact on whiting persisted at least 10 months | Knuckey et al., Marine Environmental Research 2026 |
| Average decline after shooting began, Barents Sea (40 × 40 nautical mile study area): trawl cod and haddock plus longline haddock / longline cod | about 50% by mass / 21% | Engås et al., CJFAS 1996 |
| Decline inside the 3 × 10 nautical mile shooting area: trawl (both species) and longline haddock / longline cod | about 70% / 45% | Engås et al., CJFAS 1996 |
| Farthest distance from the shooting area with reduced catches; recovery after shooting ended | 18 nautical miles; abundance not back to pre-shooting levels within 5 days | Engås et al., CJFAS 1996 |
| Rockfish hook-and-line catch per unit effort during emissions versus control trials, central California (single 1,639 cm³ airgun, 223 dB re 1 µPa source level) | -52.4% (90% CI: -27.9%, -76.9%); equivalent economic loss 49.8% | Skalski et al., CJFAS 1992 |
| Gillnet catches during shooting versus before shooting, Norway: redfish / Greenland halibut | +86% / +132% | Løkkeborg et al., CJFAS 2012 |
| Longline catches during shooting versus before shooting, Norway: Greenland halibut / haddock | -16% / -25% | Løkkeborg et al., CJFAS 2012 |
| Species with commercial catch rates significantly different from predictions, Gippsland Basin logbooks, 2012 to 2015 | 9 of 15 (authors attribute few of these to the survey) | Bruce et al., Marine Environmental Research 2018 |
Context: in the Barents Sea, the reduction was larger for big fish (over 60 cm) than for small ones. An earlier Norwegian study found cod catch rates near a survey returned to pre-shooting levels within about 12 hours (Løkkeborg and Soldal 1993, as summarized in BOEM Study Profile GM-20-01b 2023), a reminder of how much these results depend on site, species and exposure. Most recent available data for the Barents Sea and California trials: 1996 and 1992.
4. Fish Behaviour and the No-Effect Studies
Not every large experiment finds damage. On Australia’s North West Shelf, a survey over about 2,500 km² of seabed produced no short-term (days) or long-term (months) effects on the composition, abundance, size structure, behaviour or movement of demersal fish (Meekan et al., PNAS 2021). Off Newfoundland, a 100-day survey changed no groundfish abundance, though cod were slower to approach bait after loud days.
The pattern across recent studies is that behaviour shifts more readily than abundance. That matters for fisheries because a fish that stops feeding or moves off the bottom for a few days is a lost catch, even if the population is untouched.
| Metric | Value | Source |
|---|---|---|
| Effect of a 5-day survey over about 2,500 km² on demersal fish composition, abundance, size, behaviour or movement, North West Shelf, Australia | no short-term (days) or long-term (months) effects | Meekan et al., PNAS 2021 |
| Sampling effort behind the North West Shelf result | 629 baited video deployments at 144 sites; 140 species recorded | Meekan et al., PNAS 2021 |
| Abundance change for the 5 most common groundfish species during a 100-day survey off Newfoundland and Labrador | none explained by seismic noise (323 baited videos of 5 hours each) | Nguyen et al., Marine Pollution Bulletin 2025 |
| Prior daily mean sound pressure level above which Atlantic cod arrived later at baited cameras | above 120 dB re 1 µPa² | Nguyen et al., Marine Pollution Bulletin 2025 |
| Scale of an American plaice tracking study during industry surveying (2024) | 297 fish tagged, 229 receivers, 68 survey days, control and impact sites more than 100 km apart | King et al., Marine Pollution Bulletin 2026 |
| Pelagic fish density at the onset of a seismic survey in Lake Geneva | decrease of more than 30% | Réalis-Doyelle et al., Scientific Reports 2025 |
| Stress hormone (cortisol) in juvenile roach scales, before shots versus during shots | 31 ± 0.7 versus 45 ± 0.3 U/mg (p < 0.05) | Réalis-Doyelle et al., Scientific Reports 2025 |
| Feeding herring schools as a 3D survey vessel approached from 27 km to 2 km over 6 hours, Vesterålen, Norway | no change in speed, direction or school size | Peña et al., ICES Journal of Marine Science 2013 |
Context: the Lake Geneva study is a freshwater case with a source level reported by the operator at 180 to 230 dB re 1 µPa, so it is a useful contrast rather than a direct model of an offshore survey. Most recent available data for the herring result: 2013.
5. Zooplankton and Invertebrate Impacts
The 2017 Tasmanian experiment changed the debate because it targeted the base of the food web. After air gun passes, zooplankton mortality rose from 18% to 40-60%, a two- to threefold increase in dead adult and larval animals, and sonar showed reduced zooplankton presence 15 minutes after a pass and a large gap 30 minutes after (McCauley et al., Nature Ecology & Evolution 2017, as summarized by Curtin University 2017).
Later work points to a smaller zone of harm. Around a full North Sea survey in 2022, wild copepod mortality never exceeded 35.9% (Scientific Reports 2025), and in a separate experiment caged copepods showed raised one-week mortality at 10 m from the airguns but not at 20 m (Fields et al., ICES Journal of Marine Science 2019). For shellfish the signal is about sublethal damage: lobsters lost the ability to right themselves because of injury to the statocyst, the small sensory organ lobsters use for balance (Day et al., Proceedings of the Royal Society B 2019).
| Metric | Value | Source |
|---|---|---|
| Zooplankton mortality after air gun passes versus before, Storm Bay, Tasmania | from 18% to 40-60% (two- to threefold increase in dead adult and larval zooplankton) | McCauley et al., Nature Ecology & Evolution 2017; Curtin University 2017 |
| Time until reduced zooplankton presence / a large gap in the zooplankton layer appeared on sonar | 15 minutes / 30 minutes after the air gun pass | Curtin University 2017 |
| Larval krill within the exposure range | all killed | McCauley et al., Nature Ecology & Evolution 2017 |
| Maximum immediate mortality of wild Calanus copepods around a 3,060 in³ North Sea survey (closest approach about 50 m, maximum SEL 182 dB re 1 µPa²s) | 35.9% | Scientific Reports 2025 (North Sea zooplankton study) |
| Mortality of cultured Calanus finmarchicus in submerged bags: immediate / up to 7 days after exposure | under 10% / under 30% | Scientific Reports 2025 (North Sea zooplankton study) |
| One-week Calanus mortality versus controls at 10 m / 20 m from the airguns | 9% higher / no significant difference (immediate effect only at 5 m or less) | Fields et al., ICES Journal of Marine Science 2019 |
| Scallop mortality at day 120, controls versus four airgun passes | 3.8% vs 14.8% (2013); 3.6% vs 17.5% (2014); natural wild mortality range 11-51% | Day et al., PNAS 2017 |
| Rock lobster righting time after exposure equal to a roughly 3,100 in³ array passing within 100 to 500 m | 157% longer than controls (experiment 1); impairment and statocyst damage persisted to 365 days | Day et al., Proceedings of the Royal Society B 2019 |
Context: the scallop study notes that the exposed mortality it measured stayed below the natural wild range, so its main finding is physiological stress (fewer blood cells, altered behaviour) rather than mass die-off. A Bass Strait scallop loss of 24,000 tons that the fishing industry linked to a survey is described in that paper as anecdotal. Most recent available data for scallops, lobsters and the Tasmanian zooplankton experiment: 2017 to 2019.
6. Regulatory Exposure Thresholds
US rules translate all of this into a handful of decibel lines. For fish, NMFS treats 206 dB re 1 µPa peak as the onset of physical injury from impulsive sources such as airguns, with cumulative SEL limits that depend on fish size (NMFS Summary of Recommended Acoustic Thresholds 2025). These fish values were set in 2008 as interim criteria for impact pile driving, derived from explosive and airgun studies, apply to all fish species alike, and the agency describes its thresholds as recommendations, not binding rules.
Field experiments give a sense of real exposures: lobsters held 10 to 12 m deep under a small airgun received up to 213 dB peak-to-peak, although a peak-to-peak reading is not directly comparable with the zero-to-peak level the fish threshold uses. Marine mammals get species-group thresholds that were last revised in the 2024 technical guidance, and the same peak-and-SEL structure appears in offshore wind permitting, covered in our offshore wind pile driving and bubble curtain statistics.
| Metric | Value | Source |
|---|---|---|
| Onset of physical injury in fish, impulsive sources such as airguns (peak level) | 206 dB re 1 µPa | NMFS Summary of Recommended Acoustic Thresholds 2025 |
| Onset of physical injury in fish, cumulative SEL over 12 hours: fish of 2 g or more / fish under 2 g | 187 / 183 dB re 1 µPa²s | NMFS Summary of Recommended Acoustic Thresholds 2025 |
| Informal level for behavioural disturbance in fish | 150 dB rms | NMFS Summary of Recommended Acoustic Thresholds 2025 |
| Behavioural disturbance threshold for marine mammals, non-explosive impulsive sources | 160 dB rms | NMFS Summary of Recommended Acoustic Thresholds 2025 |
| Maximum received levels at rock lobster pots in the Tasmanian airgun experiments | 209 to 213 dB re 1 µPa peak-to-peak; 186 to 191 dB re 1 µPa²·s single-shot SEL | Day et al., Proceedings of the Royal Society B 2019 |
| Maximum received single-shot SEL at scallops, 45 in³ versus 150 in³ airgun | 181 versus 188 dB re 1 µPa²·s | Day et al., PNAS 2017 |
Context: the fish SEL limits are cumulative over 12 hours, while the scallop and lobster rows above are single-shot values. Summed over all shots, the lobsters’ maximum cumulative SEL reached 192 to 195 dB re 1 µPa²·s, above the 187 dB injury line for fish of 2 g or more.
7. Survey Volume, Permits and Research Effort
The scale of planned survey effort explains why fisheries groups push back. In late 2018, five companies received federal authorizations to survey the US Atlantic with airguns, with planned survey lines totalling 141,128 km, the sum of the five filed plans (13,062 + 13,766 + 58,300 + 27,330 + 28,670 km). In the Gulf, the paperwork is continuous: 81 Letters of Authorization are listed as expired under the previous Gulf of America regulations (NOAA Fisheries, Issued Letters of Authorization 2026).
Research effort, by contrast, is thin. A 2023 systematic review found only 31 field studies on wild animals that met its criteria, and just 6 of them on fish (Affatati and Camerlenghi, Frontiers in Marine Science 2023). BOEM’s own study profile admits its analyses “relied on research with limited applicability”.
| Metric | Value | Source |
|---|---|---|
| Companies granted Atlantic incidental harassment authorizations for airgun surveys (one year each) and their combined planned survey lines | 5 companies; 141,128 km in total | NMFS, Atlantic Geophysical Survey IHAs, Federal Register 2018 |
| Area of marine seismic surveys along Brazil’s coast in a two-decade dataset | about 800,000 km² | Reis-Filho et al., Marine Environmental Research 2026 |
| Field studies on wild animals meeting a systematic review’s criteria: total / mammals / invertebrates / fish / birds | 31 / 16 / 8 / 6 / 1 | Affatati and Camerlenghi, Frontiers in Marine Science 2023 |
| BOEM cooperative study on airgun effects on Gulf reef fish: budget / performance period | $260,000 / FY 2021 to 2024 | BOEM Environmental Studies Program, Study Profile GM-20-01b 2023 |
| Planned design of the BOEM reef fish study: adult fish to tag / lead time before the survey / receiver recording life | at least 50 / at least 30 days / about six months | BOEM Environmental Studies Program, Study Profile GM-20-01b 2023 |
Context: an authorization is not a completed survey. The 2018 IHAs cover only the incidental take of marine mammals, so the line totals describe planned effort, not kilometres actually shot. Most recent available data for Atlantic plans: 2018.
Summary: Marine Seismic Airgun Surveys by the Numbers
| Metric | Value | Source |
|---|---|---|
| Eastern school whiting catch rate after a survey versus control areas | -99% | Knuckey et al., Marine Environmental Research 2026 |
| Tiger flathead catch rate after a survey versus control areas | -75% | Knuckey et al., Marine Environmental Research 2026 |
| Barents Sea trawl catches of cod and haddock after shooting began | about -50% (about -70% inside the shooting area) | Engås et al., CJFAS 1996 |
| Rockfish hook-and-line catch per unit effort during emissions | -52.4% | Skalski et al., CJFAS 1992 |
| Gillnet catch of Greenland halibut during shooting | +132% | Løkkeborg et al., CJFAS 2012 |
| Demersal fish effects in a 2,500 km² experiment | none detected (days or months) | Meekan et al., PNAS 2021 |
| Groundfish species whose abundance changed during a 100-day Newfoundland survey | none of the 5 most common | Nguyen et al., Marine Pollution Bulletin 2025 |
| Pelagic fish density at survey onset, Lake Geneva | more than 30% lower | Réalis-Doyelle et al., Scientific Reports 2025 |
| Farthest recorded airgun sound from its source | almost 4,000 km | Nieukirk et al., JASA 2012 |
| Energy still present 1,300 m from a small airgun | up to 10 kHz | Hermannsen et al., PLOS ONE 2015 |
| Zooplankton mortality after air gun passes, Tasmania | from 18% to 40-60% | McCauley et al., Nature Ecology & Evolution 2017; Curtin University 2017 |
| Maximum wild copepod mortality around a North Sea survey | 35.9% | Scientific Reports 2025 (North Sea zooplankton study) |
| Scallop mortality at day 120, four passes versus control | 17.5% vs 3.6% (2014) | Day et al., PNAS 2017 |
| Lobster balance impairment after exposure | persisted to 365 days | Day et al., Proceedings of the Royal Society B 2019 |
| Fish injury onset, peak level | 206 dB re 1 µPa | NMFS Summary of Recommended Acoustic Thresholds 2025 |
| One-week copepod mortality 10 m from airguns versus controls | 9% higher | Fields et al., ICES Journal of Marine Science 2019 |
| Field studies on wild animals in a 2023 systematic review / of which on fish | 31 / 6 | Affatati and Camerlenghi, Frontiers in Marine Science 2023 |
Methodology and Sources
- Knuckey et al., Seismic acquisition causes substantial decrease in catch rates of commercially-important fish, Marine Environmental Research 2026
- Engås et al., Effects of seismic shooting on local abundance and catch rates of cod and haddock, Canadian Journal of Fisheries and Aquatic Sciences 1996
- Skalski et al., Effects of sounds from a geophysical survey device on catch-per-unit-effort in a hook-and-line fishery for rockfish, CJFAS 1992
- Løkkeborg et al., Sounds from seismic air guns: gear- and species-specific effects on catch rates and fish distribution, CJFAS 2012
- Bruce et al., Quantifying fish behaviour and commercial catch rates in relation to a marine seismic survey, Marine Environmental Research 2018
- Meekan et al., A large-scale experiment finds no evidence that a seismic survey impacts a demersal fish fauna, PNAS 2021
- Nguyen et al., Examining the effect of intensive seismic surveys on abundance and behaviour of groundfish species, Marine Pollution Bulletin 2025
- King et al., Evaluating the impact of seismic surveying on American plaice movement using acoustic telemetry, Marine Pollution Bulletin 2026
- Rugtveit et al., The effect of seismic shooting on the courtship behaviour of cod, Marine Pollution Bulletin 2026
- Réalis-Doyelle et al., The effect of seismic air gun shots on physiology and behaviour of fish lake communities, Scientific Reports 2025
- Peña et al., Feeding herring schools do not react to seismic air gun surveys, ICES Journal of Marine Science 2013
- McCauley et al., Widely used marine seismic survey air gun operations negatively impact zooplankton, Nature Ecology & Evolution 2017
- Curtin University, news release on the Tasmanian zooplankton study, 2017
- Zooplankton mortality and distribution around a seismic survey, Scientific Reports 2025
- Fields et al., Airgun blasts used in marine seismic surveys have limited effects on mortality, and no sublethal effects on behaviour or gene expression, in the copepod Calanus finmarchicus, ICES Journal of Marine Science 2019
- Day et al., Exposure to seismic air gun signals causes physiological harm and alters behavior in the scallop Pecten fumatus, PNAS 2017
- Day et al., Seismic air guns damage rock lobster mechanosensory organs and impair righting reflex, Proceedings of the Royal Society B 2019
- Nieukirk et al., Sounds from airguns and fin whales recorded in the mid-Atlantic Ocean, 1999-2009, Journal of the Acoustical Society of America 2012
- Hermannsen et al., Characteristics and propagation of airgun pulses in shallow water, PLOS ONE 2015
- Carroll et al., A critical review of the potential impacts of marine seismic surveys on fish and invertebrates, Marine Pollution Bulletin 2016
- Nowacek et al., Marine seismic surveys and ocean noise: time for coordinated and prudent planning, Frontiers in Ecology and the Environment 2015
- NMFS, Summary of Recommended Endangered Species Act Acoustic Thresholds (Marine Mammals, Fishes, and Sea Turtles), September 2025
- NOAA Fisheries, Marine Mammal Acoustic Technical Guidance and Other Acoustic Tools
- NMFS, Taking Marine Mammals Incidental to Geophysical Surveys in the Atlantic Ocean, Federal Register, December 7, 2018
- NOAA Fisheries, Issued Letters of Authorization, expired Gulf of America regulations
- Reis-Filho et al., Neglected impacts and modeling uncertainties of seismic surveys on fish and fisheries, Marine Environmental Research 2026
- Affatati and Camerlenghi, Effects of marine seismic surveys on free-ranging fauna: a systematic literature review, Frontiers in Marine Science 2023
- BOEM Environmental Studies Program, Study Profile GM-20-01b, Assessing the Impact of Seismic Airguns on Commercially and Recreationally-important Fish, revised 2023
- Data watch: Several cornerstone results are old (Skalski 1992, Engås 1996, Nieukirk 2012) and are flagged as most recent available data in the text. The Tasmanian zooplankton figures (18% to 40-60%) come from Curtin University’s summary of McCauley et al.; the 2025 North Sea authors describe McCauley’s in situ mortality as roughly 45% and their own as considerably lower, but their highest value (35.9%) was recorded about 6 km from the source. Fields et al. 2019 report 183 dB re 1 µPa² s at 25 m in their Results and 186 dB in their Discussion; we use the Results value. Knuckey et al. 2026 had no randomized pre-survey data, and Bruce et al. 2018 attribute few of their 9 significant catch changes to the survey itself. The Gulf count of 81 expired Letters of Authorization comes from a live listing that changes as letters expire or are added. BOEM’s GM-20-01b final report was due in October 2024, but its study profile lists no completed publications, and the federal marine mammal thresholds may be revised once minke whale hearing data are published.
Last updated: October 25, 2026. We update this roundup quarterly, and the next refresh is expected when NOAA Fisheries posts the 2025-2026 summary monitoring report for Gulf of America geophysical surveys.