Late Summer Distribution of Cetaceans near Barrow, Alaska: Results from Aerial Surveys Conducted During the Bowhead Whale Feeding Ecology Study, 2007–11

Shelden, Kim E. W.; Mocklin, Julie A.; Goetz, Kimberly T.; Rugh, David J.; Brattström, Linda Vate; Friday, Nancy A.

doi:10.7755/mfr.79.2.1

Cited by 4 publications

(5 citation statements)

References 12 publications

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“…It will also permit us to estimate survival and growth rates for young whales, which tend to have few markings. Under the old system, we were not able to reliably estimate survival and growth rates of juvenile (<13.0 m) whales because they were rarely considered marked and were rarely recaptured (Koski et al 1992;Zeh et al 2002;Shelden et al 2017).…”

Section: Discussionmentioning

confidence: 99%

A new scoring system for use in capture–recapture studies for bowhead whales photographed with drones

Koski

Young

2022

Drone Syst. Appl.

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Effective management of animal populations requires knowledge of life history parameters and estimates of population abundance. One method commonly used to estimate abundance is capture/recapture analyses of photographs. Small, relatively inexpensive, rotary-wing drones have become an effective platform for obtaining high-quality aerial photographs of whales. To conduct capture/recapture analyses the animal needs to be defined as marked or unmarked and the photographs must be of high quality. While a system for scoring quality and markedness has previously been developed for bowhead whales (Balaena mysticetus) (Rugh et al. 1998), a revised scoring system was needed to incorporate increased information in photographs taken by drones. We present a revised scoring system that enlarges two of the previously defined areas of the whale examined for markings and incorporates smaller markings into the definition of marked whales. We scored 30 whales using the previous criteria and the revised criteria developed in this paper. More whales were identified as marked (23%) and mark scores were higher for 30% of the zones scored using the new system. Increasing the number of marked whales during capture/recapture studies increases the precision of estimated parameters and permits us to make those estimates with smaller samples of photographs.

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Section: Discussionmentioning

confidence: 99%

A new scoring system for use in capture–recapture studies for bowhead whales photographed with drones

Koski

Young

2022

Drone Syst. Appl.

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“…The data set of interyear matches was comprised of whales that were photographed in at least two different years among 1985, 1986, 2003, 2004, 2005, and 2011. The fall 2011 surveys were conducted during the bowhead feeding study (BOWFEST) (Shelden and Mocklin ). Each of these matches enables us to assess whether a scar had been acquired in the interval between the two sightings.…”

Section: Methodsmentioning

confidence: 99%

Entanglement‐scar acquisition rates and scar frequency for Bering‐Chukchi‐Beaufort Seas bowhead whales using aerial photography

George

Tudor

Givens

et al. 2019

Marine Mammal Science

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The Bering‐Chukchi‐Beaufort Seas (BCBS) bowhead whale (Balaena mysticetus) has been considered at low‐risk for entanglement injuries and ship strikes because their range is mainly north of commercial fisheries; nevertheless, changes to their arctic habitat, including a longer open water period and declining sea ice, have resulted in increasing commercial activity and concern about fisheries interactions. We examined interyear matches (between 1985 and 2011) from a photo identification project and identified whales that had acquired entanglement injuries. We estimated the probability of a bowhead acquiring an entanglement injury using two statistical methods: interval censored survival analysis and a simple binomial model. Both methods give similar results, suggesting a 2.2% (95% CI: 1.1%–3.3%) annual probability of acquiring a scar. We also include an entanglement scar frequency analysis of aerial photographs from the 2011 spring and fall surveys near Point Barrow, Alaska, which suggest 12.4% of live bowheads show evidence of entanglement scarring. Entanglement rates for the BCBS bowhead stock are lower than many other large whale stocks, and abundance has increased over the past 35 yr; however, our findings indicate that fishing gear entanglement is a more serious concern for the BCBS bowhead whale population than previously thought.

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“…Prior to this report, only two humpback whale sightings had been documented near Pt. Barrow or in the Beaufort Sea in the literature (Hashagen et al, 2009; Shelden et al, 2017). The earliest sightings of which we are aware are from 2007 (Table 1).…”

Section: Figurementioning

confidence: 99%

“…Despite many hours of aerial survey effort during summer and early autumn months, there were relatively few sightings of humpbacks north of 71°N (Brower et al, 2018; Clarke et al, 2020; Shelden et al, 2017). Sightings made during boating activities near Pt.…”

Section: Figurementioning

confidence: 99%

“…Likewise, the nearshore region of Chukotka from the northern Bering into the Chukchi Sea has been proposed as a marine protected area for cetaceans based on recent gray and humpback sightings (Filatova et al, 2022). Despite many hours of aerial survey effort during summer and early autumn months, there were relatively few sightings of humpbacks north of 71 N (Brower et al, 2018;Clarke et al, 2020;Shelden et al, 2017). Sightings made during boating activities near Pt.…”

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Humpback whale sightings in northern Arctic Alaska

Stafford

George²,

Harcharek³

et al. 2023

Marine Mammal Science

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Late Summer Distribution of Cetaceans near Barrow, Alaska: Results from Aerial Surveys Conducted During the Bowhead Whale Feeding Ecology Study, 2007–11

Abstract: ABSTRACT-The aerial survey component of the Bowhead

Cited by 4 publications

References 12 publications

A new scoring system for use in capture–recapture studies for bowhead whales photographed with drones

A new scoring system for use in capture–recapture studies for bowhead whales photographed with drones

Entanglement‐scar acquisition rates and scar frequency for Bering‐Chukchi‐Beaufort Seas bowhead whales using aerial photography

Humpback whale sightings in northern Arctic Alaska

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