Temporal changes in abundance of harbor porpoise (Phocoena phocoena) inhabiting the inland waters of Southeast Alaska

Dahlheim, Marilyn E.; Zerbini, Alexandre N.; Waite, Janice M.; Kennedy, Amy S.

doi:10.7755/fb.113.3.2

Cited by 5 publications

(10 citation statements)

References 20 publications

(49 reference statements)

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“…The nature and magnitude of incidental takes are currently unknown but may be significant in some fisheries for Pacific salmon ( Oncorhynchus spp.) and Pacific herring ( Clupea pallasi ) [ 6 ]. Line-transect abundance estimates from the inland waters of southeast Alaska indicated an overall decline in porpoise abundance in the mid-2000s.…”

Section: Introductionmentioning

confidence: 99%

“…Line-transect abundance estimates from the inland waters of southeast Alaska indicated an overall decline in porpoise abundance in the mid-2000s. Contrasting trends between the northern and southern regions of this study area suggest significant population structuring within the currently recognized southeast Alaska stock [ 6 ]. Concern for localized impact on undefined harbour porpoise stocks underscores the need for population genetic analyses to better define population structure; however, sample sizes generated by both strandings and fisheries by-catch are severely limited in key geographical areas, and efforts to supplement these sources with remotely collected tissue biopsies have proved extraordinarily challenging for these small, elusive cetaceans.…”

Section: Introductionmentioning

confidence: 99%

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Water, water everywhere: environmental DNA can unlock population structure in elusive marine species

et al. 2018

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Determining management units for natural populations is critical for effective conservation and management. However, collecting the requisite tissue samples for population genetic analyses remains the primary limiting factor for a number of marine species. The harbour porpoise (Phocoena phocoena), one of the smallest cetaceans in the Northern Hemisphere, is a primary example. These elusive, highly mobile small animals confound traditional approaches of collecting tissue samples for genetic analyses, yet their nearshore habitat makes them highly vulnerable to fisheries by-catch and the effects of habitat degradation. By exploiting the naturally shed cellular material in seawater and the power of next-generation sequencing, we develop a novel approach for generating population-specific mitochondrial sequence data from environmental DNA (eDNA) using surface seawater samples. Indications of significant genetic differentiation within a currently recognized management stock highlights the need for dedicated eDNA sampling throughout the population's range in southeast Alaska. This indirect sampling tactic for characterizing stock structure of small and endangered marine mammals has the potential to revolutionize population assessment for otherwise inaccessible marine taxa.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Water, water everywhere: environmental DNA can unlock population structure in elusive marine species

et al. 2018

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“…This citizen science study cost less than $10,000 for the mobile application revisions, field work equipment, and graduate student time; and it covered a spatial area that had only been surveyed several times in Southeast Alaska, yet had never been surveyed for all cetaceans, pinnipeds, and sea otter species [38][39][40][41]. While the Whale mAPP citizen science project received immense positive feedback and can provide inexpensive and potentially useful scientific data, it still has biases and constraints.…”

Section: Discussionmentioning

confidence: 99%

“…Overall, Southeast Alaska offers a potentially ideal location for collecting these data due to a high summer ship-based tourism [37] and marine mammal abundance [3,38,39]. Concurrently, long-term studies describing marine mammal distributions are resource intensive and therefore limited [38][39][40][41], making robust and reliable marine mammal data in this region valuable.…”

Section: Introductionmentioning

confidence: 99%

Obstacles and Opportunities of Using a Mobile App for Marine Mammal Research

Hann

Stelle

Szabo

et al. 2018

IJGI

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Abstract:This study investigates the use of a mobile application, Whale mAPP, as a citizen science tool for collecting marine mammal sighting data. In just over three months, 1261 marine mammal sightings were observed and recorded by 39 citizen scientists in Southeast Alaska. The resulting data, along with a preliminary and post-Whale mAPP questionnaires, were used to evaluate the tool's scientific, educational, and engagement feasibility. A comparison of Whale mAPP Steller sea lion distribution data to a scientific dataset were comparable (91% overlap) given a high enough sample size (n = 73) and dense spatial coverage. In addition, after using Whale mAPP for two weeks, citizen scientists improved their marine mammal identification skills and self-initiated further learning, representing preliminary steps in developing an engaging citizen science project. While the app experienced high initial enthusiasm, maintaining prolonged commitment represents one of the fundamental challenges for this project. Increasing participation with targeted recruitment and sustained communication will help combat the limitations of sample size and spatial coverage. Overall, this study emphasizes the importance of early evaluation of the educational and scientific outcomes of a citizen science project, so that limitations are recognized and reduced.

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“…Previous studies have demonstrated that localized harbor porpoise populations show variations in group sizes (Hobbs and Waite , Dahlheim et al . ), ranging patterns (Hobbs and Waite , Haelters et al . , Verfuß et al .…”

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confidence: 99%

Group characteristics, site fidelity, and photo‐identification of harbor porpoises,Phocoena phocoena, in Burrows Pass, Fidalgo Island, Washington

Elliser¹,

MacIver²,

Green

2017

Marine Mammal Science

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Little is known about harbor porpoises at the individual level or local group structure. Group characteristics, site fidelity, and photo‐identification of harbor porpoises were investigated off Fidalgo Island, Washington State. Harbor porpoise presence was affected by season and rip tide strength (Wald χ2 P < 0.04); calf presence was influenced by season and tide (Wald χ2 P < 0.0075). Average group size (2.32 ± 1.38, n = 266) was influenced by season, behavior, and calf presence (F7 = 9.71, P < 0.0001, R2 = 0.294). Fifty‐three individuals were identified using a matrix of primary, secondary, and confirmation markings that were stable over months/years. Over 35% were resighted in more than 1 mo (range 1–7, truexfalse¯ = 1.83); 15.1% were seen in more than 1 yr, suggesting some level of residency. Despite having higher effort, presence and group size were significantly lower in Summer. Variations in the significance of rip tide strength and tides relate to calf presence and support other findings that harbor porpoise population structure is complex and varies at small spatiotemporal scales and may also vary between populations and habitats. This study identifies variables affecting group characteristics and emphasizes the importance of research on local populations of harbor porpoises.

show abstract

Temporal changes in abundance of harbor porpoise (Phocoena phocoena) inhabiting the inland waters of Southeast Alaska

Cited by 5 publications

References 20 publications

Water, water everywhere: environmental DNA can unlock population structure in elusive marine species

Water, water everywhere: environmental DNA can unlock population structure in elusive marine species

Obstacles and Opportunities of Using a Mobile App for Marine Mammal Research

Group characteristics, site fidelity, and photo‐identification of harbor porpoises,Phocoena phocoena, in Burrows Pass, Fidalgo Island, Washington

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