A Case of Natural Killer Whale (Orcinus orca) Entrapment in Northern Norway: From Assessment to Rescue

Jourdain, Eve; Karoliussen, Richard; Curé, Charlotte; Massenet, Mathilde; Barrett‐Lennard, Lance G.; Ellis, Graeme M.

doi:10.1578/am.45.1.2019.14

Cited by 3 publications

(8 citation statements)

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“…The other five interventions used a variety of methods and combinations thereof to drive the entrapped killer whales back to open waters (Table 4). Vessels were used as observation platforms and to deploy equipment in all cases, but flotillas of vessels (described in Jourdain et al, 2019) were used to herd and guide the whales out of the entrapment site only in two of these five interventions (Cases #7, 17; Table 4; Figure 5). "Hukilaus, " consisting of a long surface line interspersed at intervals with weighted, vertical lines (modified from Figure 15 in Norris and Dohl, 1980) were successfully used in two other cases (Cases #15, 19; Table 4; Figure 6; Supplementary Video 4).…”

Section: Intervention Methodsmentioning

confidence: 99%

“…Killer whales temporarily stopped or attempted to turn around at sections of the channel where there was significant narrowing, faster currents, rising shallows, and kelp beds (Bain, 1995, EJ unpublished data; Supplementary Video 4). For two interventions (Cases #17,19), the whales were constantly monitored for their behavior state and positions from the flight monitor of an aerial drone, to verify a calm and grouped state, and to adjust the progression of the operation (described in Jourdain et al, 2019).…”

Section: Intervention Methodsmentioning

confidence: 99%

“…In some cases, kelp beds presented an apparent physical or acoustic block to open waters (e.g., Case #7). Furthermore, the only two observations of killer whales attempting to exit the entrapment site on their own only at slack tide (Case #17, see Jourdain et al, 2019) suggested that currents in the constricted channel may also play a role in impeding the movements of entrapped killer whales. Decreasing water level in the channel overtime owing to tidal fluctuations may have, in some cases, further constrained the whales' willingness or even ability (e.g., Case #19) to leave site (Figure 3; Supplementary Video 4).…”

Section: Why Do Killer Whales Become Entrapped?mentioning

confidence: 99%

“…Second, behavior patterns should be monitored for signs of entrapment, including for lone individuals in unrestricted areas (Category 3). Behavioral signs of entrapment include strong preference for certain parts of the entrapment site (Bain, 1995;Jourdain et al, 2019), atypical behavior (e.g., stereotyped pacing back and forth in a small area, long periods spent motionless at the surface, see Figure 4), lack of feeding activity (most cases) and possible intermittent production of loud repeated calls as an apparent attempt to connect with conspecifics (Kuczaj et al, 2015;Jourdain et al, 2019) (Table 4). If there is evidence for entrapment, monitoring should further aim at detecting any signs of nutritional stress or impaired health.…”

Section: Management Of Killer Whale Entrapmentsmentioning

confidence: 99%

“…As means to guide the whales back to open waters, a coordinated line of boats (Figure 5) with intermittent banging of metal hollow pipes held in the water (Bain, 1995), a "hukilau" (modified from Figure 15 in Norris and Dohl, 1980;Figure 6; Supplementary Video 4) and/or underwater playbacks of killer whale calls (Jourdain et al, 2019) may be used (Table 4). Although all three methods have proved effective, they may be more or less appropriate in different situations.…”

Section: Management Of Killer Whale Entrapmentsmentioning

confidence: 99%

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Natural Entrapments of Killer Whales (Orcinus orca): A Review of Cases and Assessment of Intervention Techniques

Jourdain¹,

Barrett‐Lennard

Ellis

et al. 2021

Front. Conserv. Sci.

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Identifying mortality sources and mitigation solutions is crucial in species management and conservation. In killer whales (Orcinus orca), mortality events may pose a serious concern for the conservation of small discrete populations, especially if they involve entire groups. This study investigated 19 incidents involving 116 killer whales from a minimum of five populations becoming naturally entrapped in inshore areas of the North Pacific (n = 12) and North Atlantic (n = 7) oceans between 1949 and 2019. Here, we aim to provide an assessment of possible causal factors, lethality and human responses to these events. Site characteristics and group size identified three categories of entrapments. In Category 1, nine cases involved small groups of killer whales (median = 5, range: 1–9) at sites characterized by severe geographic and food constraints. Four cases in Category 2 included larger groups (median= 14, range: 6–19) and entrapment sites with no obvious geographic constraints but at which man-made structures could have acted as deterrents. Five cases assigned to Category 3 involved lone, often young individuals settling in a restricted home range and engaging in interactions with people and boats. Overall, all or some of the killer whales swam out on their own after a mean of 36 d of entrapment (range: 1–172, SD = 51, n = 9 cases), died of nutritional/physiological stress after 58 d (range: 42–90, SD = 21, n = 3 cases) or of injury after ~5 years of daily interactions with boat traffic (n = 1 case). Indication of the killer whales' declining condition or being at risk of injury, and of poor habitat quality, led to the decision to intervene in seven cases where a variety of methods were used to guide or relocate remaining individuals back to open waters after 39 d (SD = 51, range = 8–150). Monitoring protocols, which aided in identifying entrapment situations, and intervention methods which enhanced the health and survival of entrapped killer whales, are discussed.

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Section: Intervention Methodsmentioning

confidence: 99%

Section: Intervention Methodsmentioning

confidence: 99%

Section: Why Do Killer Whales Become Entrapped?mentioning

confidence: 99%

Section: Management Of Killer Whale Entrapmentsmentioning

confidence: 99%

Section: Management Of Killer Whale Entrapmentsmentioning

confidence: 99%

See 3 more Smart Citations

Natural Entrapments of Killer Whales (Orcinus orca): A Review of Cases and Assessment of Intervention Techniques

Jourdain¹,

Barrett‐Lennard

Ellis

et al. 2021

Front. Conserv. Sci.

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Killer Whale Orcinus orca (Linnaeus, 1758)

Samarra

Esteban

2021

Handbook of the Mammals of Europe

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The Self-Stranding Behavior of a Killer Whale (Orcinus orca) in Inner Danish Waters and Considerations concerning Human Interference in Live Strandings

Alstrup

Thøstesen²,

Hansen

et al. 2023

Animals

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The rescue attempts of stranded whales and euthanasia considerations must include condition assessments of the individual involved, but this is challenged by our insufficient knowledge about the health statuses of these whales. Here, we describe three separate strandings of a young male killer whale (Orcinus orca) in shallow Danish waters during 2021–2022. During the first two stranding events, the whale exhibited remarkable behavior and, after refloating attempts and several kilometers of swimming, it returned to shallow water. This suggests that it actively chose to be in this shallow water, perhaps to ensure free airways and respiration. During the last stranding, it stayed in shallow water for 30 days, during which, euthanasia was considered due to its seemingly worsened condition, including a collapsed dorsal fin. However, suddenly, the whale swam away and, a year later, he was seen alive, confirming that euthanasia would have been the wrong decision. This case raises an important question as to when and under what circumstances active human interventions, such as refloating attempts, should be launched and when euthanasia should be carried out. Every stranding is unique and decisions should be based on thorough considerations of the animal’s health and the chance of a successful rescue.

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A Case of Natural Killer Whale (Orcinus orca) Entrapment in Northern Norway: From Assessment to Rescue

Cited by 3 publications

References 0 publications

Natural Entrapments of Killer Whales (Orcinus orca): A Review of Cases and Assessment of Intervention Techniques

Natural Entrapments of Killer Whales (Orcinus orca): A Review of Cases and Assessment of Intervention Techniques

Killer Whale Orcinus orca (Linnaeus, 1758)

The Self-Stranding Behavior of a Killer Whale (Orcinus orca) in Inner Danish Waters and Considerations concerning Human Interference in Live Strandings

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