ArticlePDF Available


  • Israel National Nature and Parks Authority
Yaniv Levy1, 3, Itzhak Aizenberg1, 2 & Noam Leader3
1 Israel Sea Turtle Rescue Center, Israel Nature & Parks Authority, Israel, email:
2 Hebrew University of Jerusalem, Koret School of Veterinary Medicine, Veterinary Teaching Hospital,
3 Ecology Dept., Science Division, Israel Nature & Parks Authority, Israel, email:
During the month of January 2019, 96 sea (marine) turtles were stranded along Israel's Mediterranean
coastline. 69 Loggerheads (Caretta caretta), 16 Green turtles (Chelonia mydas) and 11 unidentified sea
turtles were located. Only 30% (29) of the turtles were still alive when located, all suffering from serious
injuries, and were brought to the Israel Nature & Park Authority (INPA) Sea Turtle Rescue Center (STRC) for
medical treatment.
The large number of stranded turtles in January 2019 (Fig. 1), represents more than half (53%) of the mean
annual stranding events (182) of turtles during the years 2007 -2015. This also represents an alarming
nearly eight-fold increase in the number of stranded turtles located yearly in the month of January (Fig. 2).
On the 9th of January alone, the rescue center received 9 turtles in severe condition. This unusually high
number of turtles in a single day is the highest ever recorded since the establishment of the STRC 20 years
Figure 1: Daily number of sea turtles (Green and Loggerhead) strandings along Israel's coast during January
2019 (n=96).
Figure 2: Monthly mean dead and living stranded sea turtles during the years 2007-2015 (n=1,640)
All turtles documented (alive and dead) were located by civilians, rangers and beach employees who
reported to the local municipal hotline, INPA hotline, through social media or directly to STRC volunteers.
The information included location and usually a photograph. The compiled data was stored on the INPA's
designated computer network using the "Cybertracker" field data collection system.
The geographic distribution of stranded sea turtles along the coastline of Israel was relatively homogenous,
from Rosh HaNikra at the northern border of Israel all the way to Zikim in the south, bordering with the
Gaza Strip (Figure 3).
Medical triage, intensive care treatment, fluid and drug therapy were administrated to all sea turtles
hospitalized at the STRC. Radiological examinations (CT and X-Ray) were performed on survivors at the Kol
Hai veterinary clinic, Rehovot, by Dr. Itzhak Aizenberg. Post mortem was performed on seven turtles.
Tissue samples from Green turtles were taken for establishing the turtle origin using genetic analysis.
Three turtles had fishing hooks and one had fishing lines in their digestive system. Two others had trauma
to their carapace from boat propellers and another had suffered, most probably, a shark bite. During the
veterinarian diagnostics and treatments, ultra sounds, X-ray and emergency surgery were performed for
the extraction of hooks and fishing lines from the digestive system. Additionally, three of the examined
females had developed follicles, indicating their readiness for the reproduction season.
CT scans of live injured sea turtles revealed that 83% (19 of 23 examined) showed symptoms of soft tissue
trauma: pulmonary hemorrhage and accumulation of fluids in the middle ear (Fig. 4). Such symptoms are
consistent with shock-wave trauma, suggesting a fatal exposure to a yet undetermined strong impulsive
sound source, such as underwater explosions, on a significant level.
Figure 3: Green and Loggerhead sea turtle stranding locations along Israel's coastline. Red marks
Loggerhead; Green marks Green turtle; Light blue unidentified turtle.
Figure 4. CT scans showing symptoms of soft tissue trauma: hemorrhage in the lungs (bottom) or a
progressive infection and fluids in the inner ears (top picture): the left inner ear is filled with fluids, marked
in blue, and the right ear is half way filled, marked in purple). Photo Credit: Dr. Itzhak Aizenberg, Kol Hai
veterinary clinic, Rehovot.
Shock waves cause trauma to soft tissues at the linings of gas cavities. The most vulnerable organs in the
sea turtle, as in cetaceans, are the lungs and the inner ears (Aizenberg et al., 2013). These types of injuries
are known to occur from underwater explosions such as fishing with explosives or military actions (Viada et
al., 2008).
Similar stranding events, with identical clinical symptoms of soft tissue trauma (Aizenberg et al., 2013),
were previously documented by the INPA on a smaller scale in 2012 and 2015 (Fig. 5).
Figure 5. The number of live injured sea turtles diagnosed with soft tissue trauma between 2005-2019.
A mass stranding event, involving a large number of dead and seriously injured sea turtles, was detected
along the coastline of Israel during January 2019. Many of the injured turtles exhibited similar symptoms of
soft tissue trauma. The irregular numbers and type of injuries suggest a large-scale mortality event of sea
turtles in the Mediterranean Sea involving underwater blasting and the creation of underwater shock
There is an urgency to ascertain the possible cause leading to this incident, when and where in the
Mediterranean it had occurred, and whether this may pose a significant future risk for endangered
populations of the two threatened turtle species within the entire eastern Mediterranean. In particular, the
increased number of sea turtle strandings of both species has raised INPAs concerns regarding a potential
anthropogenic source originating within Israel's territorial waters or within Israel's Exclusive Economic Zone
The finding of three Green turtles among the 19 sea turtles diagnosed with soft tissue trauma (together
with 16 Loggerhead turtles), suggests focusing the search for an impact source in the eastern
Mediterranean Sea, as this encompasses the known habitat of this species in the Mediterranean Sea. While
Loggerhead turtles nest both in the central and eastern basins of the Mediterranean, Green turtles are
known to nest only in the eastern (Levantine) basin (Fig.6). Being mainly neritic-feeders, Green turtles
exhibit relatively localized inshore foraging grounds and a high degree of fidelity over extended time-scales
to nesting beaches, foraging grounds and migratory corridors, most of which are localized within the
Levantine basin (Broderick et al. 2007; Casale et al. 2018). This lends further support to a potential impact
source in relative proximity to Israel and its EEZ (between Egypt, Israel and Turkey; Fig. 6).
Figure 6. Main known migratory corridors for adult female Green turtles, Chelonia mydas, during
reproductive migrations from the breeding sites (yellow stars). Light green areas represent migratory
funnels in the open sea while darker strips represent paths along the coasts, typically in shallow water.
From Casale et al. (2018(. Area in light red marks suggested impact area.
We can only estimate at this stage that the impacted turtles were hurt during the last few days to weeks
prior to their discovery. We base this assumption on the relatively light decomposition state of turtle
carcasses found during this event and the high number of injured, yet living, turtles found. Furthermore,
because the pattern of turtle strandings during January exhibited several spikes (first peak on Jan. 9th,
second peak on January 17th), we cannot rule out that the impact source was a series of events, lasting for
several hours or days, as opposed to a single incident.
The available, yet limited data on Green turtle yearly distribution patterns within the eastern
Mediterranean suggests turtles spend the winter mainly in coastal feeding areas. Therefore, if shallow
water feeding areas attract aggregates of turtles, a localized blast event may be sufficient to explain the
numerical impact observed.
We do not know of any feeding area capable of attracting sea turtles in pelagic waters, yet the use of deep
water might be important as migratory corridors (Stokes et al, 2015). A substantial presence of sea turtles
within Israel's EEZ might thus occur, yet it is not expected to be in aggregated form. Hence, in this scenario,
only a moving blast source, capable of producing many underwater shock waves, while covering large
areas, may suffice to explain the large number of stranded sea turtles.
The Ministry of Environmental Protection has requested information from the Ministry of Defense and the
Ministry of Energy regarding any activity generating underwater blasts or loud level underwater impulse
noise during the mass sea turtle stranding event. Military operations, involving underwater blasts or
powerful underwater sonar, are most obvious candidates, yet at this time we have no knowledge of any
relevant (unclassified) military naval activity. Currently, the only public report is from the Ministry of Energy
stating that during the time in question, a 3D seismic air-gun survey for gas exploration was conducted in
two areas within Israel's EEZ, about 40 to 90 kilometers offshore.
It is important to note that during two major turtle stranding events involving soft tissue trauma (Fig. 5), in
2012 and during the current January 2019 event (but not in 2015), air-gun based seismic surveys for gas
exploration were carried out in the territorial waters off the Israeli coast (2012) or within Israel's EEZ
(2019). The temporal overlap between the current and past stranding events and seismic surveys has raised
the possibility of the involvement of these surveys in sea turtle mass stranding events.
Underwater explosions create a strong and quick supersonic pressure wave (shock wave), which can cause
tissue damage and may be lethal to animals or humans in close proximity to the blast. However, pressure
pulses from air guns have longer rise times and are thus less likely than pressure waves from high
explosives to cause damage (Gordon et al. 2004). Accordingly, to date there is no evidence that seismic
pulses can cause acute physical damage such as the ones described in this event to marine mammals or sea
turtles (but see Meirelles et al. 2017). There is however, sufficient evidence that impulse noise from seismic
surveys poses a significant negative impact on both marine mammals and sea turtles which needs to be
addressed, ranging from temporary hearing loss to increased stress, behavioral changes and exclusion of
use of the noise affected area (Nelms et al. 2016; Popper et al. 2014).
The seismic survey in the Israeli EEZ in January 2019 was conducted in accordance with current regulations
regarding minimizing harm to cetaceans and sea turtles. The regulations were updated by the Ministry of
Energy, after consultation with the INPA, following the stranding event in 2012. The guidelines limit shallow
water seismic surveys (<300 m depth) during the sea turtle breeding season (March-October) and require
coordination with the INPA in water shallower than 120 m.
The current seismic survey in deep water employed standardized methods for seismic operations
worldwide, such as soft-start operation of air-guns (progressive increasing of the air-gun shots, in order to
avoid marine animals near the area of these activities), the use of daytime observers and Passive Acoustic
Monitoring (PAM, for detecting vocalizing cetaceans) and application of a shutdown-upon-sighting
protocol, throughout the operation. No sea turtles were documented in the vessel's sightings logs during
the survey.
Conclusions and Future directions
Our preliminary findings suggest that the mass stranding event of sea turtles along the coastline of Israel in
January 2019 was induced by a yet undetermined source of underwater blasts capable of creating
underwater shock waves, which resulted in large-scale mortality event of sea turtles in the Mediterranean
Sea, as observed in the clinical symptoms of soft tissue trauma.
Both Loggerhead and Green sea turtles are protected species by Israeli law, and both species are under
threat of extinction according to the IUCN Red Data Book (IUCN 2019). It is necessary therefore to
determine the possible cause of this turtle mortality event, and if found to be of an anthropogenic source,
to establish the necessary national and regional guidelines and practices (Popper et al., 2014), so as to
mitigate future negative effects of various levels of man-made underwater acoustic activity on sea turtles.
In a meeting held on February 12th, 2019, the Ministry of Environmental Protection, Ministry of Energy and
INPA agreed to summon an ad-hoc investigation, headed by the Ministry of Energy together with
environmental experts from the Ministry of Environmental Protection, INPA, Israel Oceanographic and
Limnological Research Institute (IOLR) and leading academic professionals. The Terms of References for the
investigative panel are listed in Appendix I. Conclusions and recommendations are expected by July 2019.
Aizenberg, I., King, R., Grundland, Y., Levy, Y. (2013). "Blast injury and sea turtles". Proceedings of the
International conference on diseases of zoo and wild animals 2013: May 8th - 11th, 2013, Vienna, Austria.
Leibniz Institute for Zoo and Wildlife Research.
Broderick, A. C., Coyne, M. S., Fuller, W. J., Glen, F., & Godley, B. J. (2007). Fidelity and over-wintering of sea
turtles. Proceedings of the Royal Society B, 274 (1617), 15338.
Casale, P., Broderick, AC., Camiñas, JA., Cardona, L., Carreras, C., Demetropoulos, A., Fuller, WJ., Godley,
BJ., Hochscheid, S., Kaska, Y., Lazar, B ., Margaritoulis, D., Panagopoulou, A ., Rees, AF., Tomas, J., Türkozan,
O. (2018). Mediterranean sea turtles: current knowledge and priorities for conservation and research.
Endangered Species Research, 36: 229267.
Gordon, J., Gillespie, D., Potter, J., Frantzis, A., Simmons, M., Swift, R. and Thompson, D. (2004). A
review of the effects of seismic surveys on marine mammals. Marine Technology Society Journal 37,
IUCN (2019). The IUCN Red List of Threatened Species. Version 2019-1.
Meirelles ACO, Silva CPN,, Amancio AC, Motta MRA, Carvalho VL. (2016). Unusual Dolphin standings during
an offshore seismic survey in Ceará Coast, northeastern Brazil. Proceedings XI Congress of the Latin
American Society of Specialists in Aquatic Mammals. Valparaíso, Chile.
Nelms, S. E., Piniak, W. E. D., Weir, C. R., & Godley, B. J. (2016). Seismic surveys and marine turtles: An
underestimated global threat? Biological Conservation 193, 49-65.
Popper, A.N., Hawkins, A.D., Fay, R.R., Mann, D., Bartol, S., Carlson, T., Coombs, S., Ellison, W.T., Gentry, R.,
Halvorsen, M.B., Løkkeborg, S., Rogers, P., Southall, B.L., Zeddies, D., Tavolga, W.N. (2014). "Sound
Exposure Guidelines for Fishes and Sea Turtles: A Technical Report prepared by ANSI-Accredited Standards
Committee S3/SC1 and registered with ANSI. ASA S3/SC1.4 TR-2014". Springer and ASA Press, Cham,
Stokes, K. L. K., Broderick, A. C. A., Canbolat, A. F., Candan, O., Fuller, W. J., Glen, F., Levy, Y., Rees, A. F.,
Rilov, G., Snape, R. T., Stott, I., Tchernov, D., Godley, B. J. (2015). Migratory corridors and foraging hotspots:
critical habitats identified for Mediterranean green turtles. Diversity and Distributions, 21(6): 665-674.
Viada, S. T., Hammer, R. M., Racca, R., Hannay, D., Thompson, M. J., Balcom, B. J., & Phillips, N. W. (2008).
Review of potential impacts to sea turtles from underwater explosive removal of offshore structures.
Environmental Impact Assessment Review, 28, 267285.
Subject: Terms of Reference (TOR) for investigative expert panel on the increase in the number of
injured sea turtles in January 2019.
Further to the meeting held on February 17, 2019, it was agreed that a professional team of experts
would be established to examine the sea turtle mass stranding event of January 2019. The team will
examine the possible causes of turtle injuries, including the circumstantial connection between the
seismic surveys and the impact to the turtles and other reasons. The team will be comprised of
representatives of the Ministries of Energy and Environmental Protection, INPA, IOLR, Haifa University
and other professionals as needed.
Topics for examination by the professional team:
1. Preparation of a review of the relevant literature:
1.1 Sources of energy and their intensity in seismic surveys. Spread of energy waves of seismic
surveys in water (sound waves and shock waves), intensities, and affected space.
1.2 Shockwave and hearing injuries in turtles and their possible causes.
1.3 The habitat and migration routes of sea turtles in the eastern Mediterranean Sea.
2. Detailed analysis of the January 2019 sea turtle stranding event (analysis for December 2018 -
February 2019):
2.1 Presentation of the strandings along the coastline through time, cross-section of ages and sex.
2.2 Analysis of turtle strandings along the Israeli coastline versus weather conditions, waves,
currents, survey timing.
2.3 Presentation of the pathological findings of the injured sea turtles.
3. Macro-analysis of sea turtle strandings during seismic surveys carried out in Israel's maritime area
during the last decade and in its vicinity (Egypt, Lebanon, Cyprus), weather conditions, naval
announcements to the mariners (closed areas) and other possible causes.
4.1. Reverse calculation of individual turtle stranding points (location and time) and correlation to
different source areas (seismic surveys or other areas such as closed military zones or fishing
activities in southern Israel).
4.2. Forward calculations from the survey points, according to the relevant dates and sea conditions
and the assessment of drifting of immobilized injured sea turtles without the ability to swim (if
there were turtles in the area where the survey was conducted where they could reach To be
decided according to the findings of section 1.1).
5. To examine existing means and R&D for early detection of turtles during seismic surveys.
6. Formulation of recommendations on new R&D aimed at reducing the existing information gaps on
Israel's maritime space.
7. Mapping in time and space of naval firing ranges or other activity in which explosives are used in
the maritime area to examine their possibility of being an additional source of damage to the
8. In accordance with the findings of the investigation, submitting appropriate recommendations to
reduce the harm to sea turtles.
... Recommendations for regulators to improve the safety of turtles, re the introduction of potentially harmful energy include: The real numbers of blast-injured individuals as inferred from the above table are most probably grossly underestimated since dead turtles, even recently dead, as a practice are not brought in for scanning, but must have contained many similarly injured animals. As detailed below, these are very high numbers compared to mean turtle stranding rates for these months during the last decade (range 8-16), making this event highly unusual (Levy et al., 2019 Figure 3). Three turtles had fishing hooks and one had fishing lines in their digestive system. ...
Full-text available
2 This report was prepared subsequent to a major sea turtle stranding event along the coast of Israel during the 2018-19 winter. The Ministry of Energy, together with the Israel Nature and Parks Authority and the Ministry of Environmental Protection established a multidisciplinary expert team to investigate the possible causes of this event. Acknowledgements: We would like to thank the following colleagues for productive discussions of this report:
Full-text available
The available information regarding the 2 sea turtle species breeding in the Mediterranean (loggerhead turtle Caretta caretta and green turtle Chelonia mydas) is reviewed, including biometrics and morphology, identification of breeding and foraging areas, ecology and behaviour, abundance and trends, population structure and dynamics, anthropogenic threats and conservation measures. Although a large body of knowledge has been generated, research efforts have been inconsistently allocated across geographic areas, species and topics. Significant gaps still exist, ranging from the most fundamental aspects, such as the distribution of major nesting sites and the total number of clutches laid annually in the region, to more specific topics like age at maturity, survival rates and behavioural ecology, especially for certain areas (e.g. south-eastern Mediterranean). These gaps are particularly marked for the green turtle. The recent positive trends of nest counts at some nesting sites may be the result of the cessation of past exploitation and decades of conservation measures on land, both in the form of national regulations and of continued active protection of clutches. Therefore, the current status should be considered as dependent on such ongoing conservation efforts. Mitigation of incidental catch in fisheries, the main anthropogenic threat at sea, is still in its infancy. From the analysis of the present status a comprehensive list of re search and conservation priorities is proposed.
Full-text available
Seismic surveys are widely used in marine geophysical oil and gas exploration, employing airguns to produce sound-waves capable of penetrating the sea floor. In recent years, concerns have been raised over the biological impacts of this activity, particularly for marine mammals. While exploration occurs in the waters of at least fifty countries where marine turtles are present, the degree of threat posed by seismic surveys is almost entirely unknown. To investigate this issue, a mixed-methods approach involving a systematic review, policy comparison and stakeholder analysis was employed and recommendations for future research were identified. This study found that turtles have been largely neglected both in terms of research and their inclusion in mitigation policies. Few studies have investigated the potential for seismic surveys to cause behavioural changes or physical damage, indicating a crucial knowledge gap. Possible ramifications for turtles include exclusion from critical habitats, damage to hearing and entanglement in seismic survey equipment. Despite this, the policy comparison revealed that only three countries worldwide currently include turtles in their seismic mitigation guidelines and very few of the measures they specify are based on scientific evidence or proven effectiveness. Opinions obtained from stakeholder groups further highlight the urgent need for directed, in-depth empirical research to better inform and develop appropriate mitigation strategies. As seismic surveying is becoming increasingly widespread and frequent, it is important and timely that we evaluate the extent to which marine turtles, a taxon of global conservation concern, may be affected.
AimLevels of sea turtle bycatch in the Mediterranean are thought to be unsustainable. We provide a comprehensive overview of adult green turtle (Chelonia mydas) distribution during nesting, migration and foraging phases, highlighting transitory as well as residential areas of high use to facilitate adequate protection for this long-lived, migratory species.LocationMediterranean Sea.Methods Thirty-four females were satellite tracked from breeding grounds in the four countries with major nesting (Cyprus, Turkey, Israel and Syria) for a total of 8521 (mean: 251) tracking days in a collaborative effort to summarize the most comprehensive set of distribution data thus far assembled for this species in the Mediterranean.ResultsTen foraging grounds are identified, with two major hotspots in Libya accounting for >50% of turtles tracked to conclusive endpoints. The coastlines of Egypt and Libya contain high densities of migrating turtles following the nesting season, particularly July-September, and likely also pre-nesting (April-June). A high-use seasonal pelagic corridor running south-west from Turkey and Cyprus to Egypt is also evident, used by >50% of all tracked turtles.Main conclusionsBycatch levels and mortality rates for the key foraging areas and high-density seasonal pathways identified here are largely unknown and should be investigated as a priority. We recommend that the Gulf of Sirte in Libya be explored as a potential biodiversity hotspot and considered for proposal as a marine protected area (MPA). Green turtle fidelity to nesting beaches, foraging areas and migratory pathways renders them vulnerable to localized threats but enables targeted mitigation measures and protection.
The purpose of this study was to collect and synthesize existing information relevant to the explosive removal of offshore structures (EROS) in aquatic environments. Data sources were organized and summarized by topic — explosive removal methods, physics of underwater explosions, sea turtle resources, documented impacts to sea turtles, and mitigation of effects. Information was gathered via electronic database searches and literature source review. Bulk explosive charges are the most commonly used technique in EROS. While the physical principles of underwater detonations and the propagation of pressure and acoustic waves are well understood, there are significant gaps in the application of this knowledge. Impacts to sea turtles from explosive removal operations may range from non-injurious effects (e.g. acoustic annoyance; mild tactile detection or physical discomfort) to varying levels of injury (i.e. non-lethal and lethal injuries). Very little information exists regarding the impacts of underwater explosions on sea turtles. Effects of explosions on turtles often must be inferred from documented effects to other vertebrates with lungs or other gas-containing organs, such as mammals and most fishes. However, a cautious approach should be used when determining impacts to sea turtles based on extrapolations from other vertebrates. The discovery of beached sea turtles and bottlenose dolphins following an explosive platform removal event in 1986 prompted the initiation of formal consultation between the U.S. Department of the Interior, Minerals Management Service (MMS) and the National Marine Fisheries Service (NMFS), authorized through the Endangered Species Act Section 7, to determine a mechanism to minimize potential impacts to listed species. The initial consultation resulted in a requirement for oil and gas companies to obtain a permit (through separate consultations on a case-by-case basis) prior to using explosives in Federal waters. Because many offshore structure removal operations are similar, a “generic” Incidental Take Statement was established by the NMFS that describes requirements to protect sea turtles when an operator's individual charge weights did not exceed 50 lb (23 kg). Requirements associated with the Incidental Take Permit were revised in 2003 and 2006 to accommodate advances in explosive charge technologies, removals of structures in deeper waters, and adequate protection of deep water marine mammal species in Gulf of Mexico waters. Generally, these requirements include pre- and post-detonation visual monitoring using standard surface and aerial survey methods for sea turtles and marine mammals, and, in some scenarios, passive acoustic survey methods for marine mammals within a specified radius from an offshore structure. The survey program has been successful in mitigating impacts to sea turtles associated with EROS. However, even with these protective measures in place, there have been observations of sea turtles affected by explosive platform removals.
While fidelity to breeding sites is well demonstrated in marine turtles, emerging knowledge of migratory routes and key foraging sites is of limited conservation value unless levels of fidelity can be established. We tracked green (Chelonia mydas, n=10) and loggerhead (Caretta caretta, n=10) turtles during their post-nesting migration from the island of Cyprus to their foraging grounds. After intervals of 2-5 years, five of these females were recaptured at the nesting beach and tracked for a second migration. All five used highly similar migratory routes to return to the same foraging and over-wintering areas. None of the females visited other foraging habitats over the study period (units lasted on average 305 days; maximum, 1356 days), moving only to deeper waters during the winter months where they demonstrated extremely long resting dives of up to 10.2h (the longest breath-holding dive recorded for a marine vertebrate). High levels of fidelity and the relatively discrete nature of the home ranges demonstrate that protection of key migratory pathways, foraging and over-wintering sites can serve as an important tool for the future conservation of marine turtles.
The IUCN Red List of Threatened Species
  • Iucn
IUCN (2019). The IUCN Red List of Threatened Species. Version 2019-1.
Unusual Dolphin standings during an offshore seismic survey in Ceará Coast, northeastern Brazil. Proceedings XI Congress of the Latin American Society of Specialists in Aquatic Mammals
  • Aco Meirelles
  • Cpn Silva
  • A C Amancio
  • Mra Motta
  • V L Carvalho
Meirelles ACO, Silva CPN,, Amancio AC, Motta MRA, Carvalho VL. (2016). Unusual Dolphin standings during an offshore seismic survey in Ceará Coast, northeastern Brazil. Proceedings XI Congress of the Latin American Society of Specialists in Aquatic Mammals. Valparaíso, Chile.
A review of the effects of seismic surveys on marine mammals
  • J Gordon
  • D Gillespie
  • J Potter
  • A Frantzis
  • M Simmons
  • R Swift
  • D Thompson
Gordon, J., Gillespie, D., Potter, J., Frantzis, A., Simmons, M., Swift, R. and Thompson, D. (2004). A review of the effects of seismic surveys on marine mammals. Marine Technology Society Journal 37, 16-34.