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"Stack, Stephanie H."
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New northernmost distribution records of the Eastern South Pacific southern right whale (Eubalaena australis), including the first cases from Ecuador and northern Peru
by
Buchan, Susannah J.
,
Van Waerebeek, Koen
,
Uceda-Vega, Piero
in
Animals
,
Aquatic mammals
,
Biological monitoring
2024
The Eastern South Pacific Right Whale (SRW) ( Eubalaena australis ) population has gained interest due to its Critically Endangered conservation status. So far, this population has been confirmed only along the coasts of Chile (18°20’S to 56°30’S) and from southern to central Peru (17°38’S to 12°11’S). Recent records have extended the species’ known range, highlighting its geographic distribution, now reaching 1500 km north. Here, we report six recent records, consisting of five sightings and one stranding, that expand the documented range to northern Ecuador (0.6°N). The northern extension of the population may be associated with the unusual three-year-long cold phase (La Niña) of the El Niño Southern Oscillation (ENSO) in the eastern South Pacific, population expansion, movement and re-distribution of the species, increased monitoring effort, or a combination of these factors. These observations raise hope for the Critically Endangered SRW population, as the occurrence of mother-calf pairs may indicate a potential for population recovery. Nevertheless, these findings intensify concerns for what is still the least abundant SRW population, underscoring the urgency for more targeted research and conservation measures.
Journal Article
Rapid weight loss in free ranging pygmy killer whales (Feresa attenuata) and the implications for anthropogenic disturbance of odontocetes
2021
Understanding the impacts of foraging disruptions to odontocete body condition is fundamental to quantifying biological effects of human disturbance and environmental changes on cetacean populations. Here, reductions in body volume of free-ranging pygmy killer whales (
Feresa attenuata
) were calculated using repeated measurements of the same individuals obtained through Unoccupied Aerial System (UAS)-photogrammetry during a prolonged disruption in foraging activity arising from a 21-day stranding event. Stranded individuals were used to verify UAS-derived volume and length estimates through 3D-imaging, water displacement, and post-mortem measurements. We show that (a) UAS estimates of length were within 1.5% of actual body length and UAS volume estimates were within 10–13% of actual volume, (b) foraging disruption resulted in a daily decrease of 2% of total body mass/day, and (c) pygmy killer whales can lose up to 27% of their total body weight within 17 days. These findings highlight the use of UAS as a promising new method to remotely monitor changes in body condition and animal health, which can be used to determine the potential effects of anthropogenic disturbance and environmental change on free-ranging odontocetes.
Journal Article
The impact of the anthropause caused by the COVID-19 pandemic on beach debris accumulation in Maui, Hawaiʻi
by
Beato, Elizabeth
,
Machernis, Abigail F.
,
Currie, Jens J.
in
704/172
,
704/172/4081
,
Accumulation
2023
The COVID-19 pandemic and subsequent travel restrictions led to a considerable reduction in tourism and human activity on Maui, presenting a unique opportunity to study debris accumulation on local beaches during changing levels of human activities. Standardized daily debris accumulation surveys were completed at two beach sites in Maui, Hawai ‘i before (2017) as well as throughout the initial year of the pandemic (2020–2021) and allowed for the assessment of pandemic-related restrictions on marine debris accumulation trends. Throughout the pandemic, reduced beach use due to higher lockdown levels had significant impacts on debris accumulation at both sites, but only one of the two sites experienced a significant decrease (~ 90% reduction) in debris accumulation rates when compared to the same months in 2017. Daily accumulation rates across two sites increased from an average of 16 items/100 m during peak lockdown levels to 43 items/100 m when restrictions eased. The observed fluctuations in debris accumulation rates, driven by changes in tourism and travel restrictions during the COVID-19 pandemic emphasize the importance of proactive measures to protect the natural environment, including source reduction and effective legislation for waste prevention. By addressing both local and remote sources of debris and focusing on reducing waste at its source, it is possible to mitigate the impacts of debris accumulation on coastal environments and marine life in Hawaiʻi.
Journal Article
The Impact of Vessels on Humpback Whale Behavior: The Benefit of Added Whale Watching Guidelines
by
Machernis, Abigail F.
,
Currie, Jens J.
,
Stack, Stephanie H.
in
Additives
,
Animal behavior
,
Anthropogenic factors
2021
The concurrent increase in marine tourism and vessel traffic around the world highlights the need for developing responsible whale watching guidelines. To determine the impact of vessel presence on humpback whale behaviors in Maui Nui, a land-based study was conducted from 2015 to 2018 in Maui, Hawai'i. Theodolite tracks were used to summarize humpback whale swim speed, respiration rate, dive time, and path directness to determine the potential impacts of various types of vessel presence on whale behavior. Vessel presence, proximity, and approach type in conjunction with biological parameters were used in a generalized additive modeling framework to explain changes in whale behaviors. The results presented here show increases in swim speed, respiration rate, and path directness in conjunction with decreasing dive times, which has been shown to be an energetically demanding avoidance strategy. These observations, in conjunction with increasing awareness on the implication of non-lethal effects of human disturbance and changing oceanic environments on humpback whales, highlights the need for a pre-cautionary approach to management. Stricter guidelines on whale watching will limit the level of disturbance to individual humpback whales in Hawai'i and ensure they maintain the fitness required to compensate for varying ecological and anthropogenic conditions.
Journal Article
The Behavioural Impacts of Commercial Swimming With Whale Tours on Humpback Whales (Megaptera novaeangliae) in Hervey Bay, Australia
by
Machernis, Abigail F.
,
Stack, Stephanie H.
,
Currie, Jens J.
in
Adaptive management
,
Animal behavior
,
anthropogenic impacts
2021
Swim-with-whale tourism has expanded across several countries globally, with humpback whales ( Megaptera novaeangliae ) being the most commonly targeted species of baleen whale. Behavioural responses from humpback whales to swim-with-whale tours have been reported, however, responses are likely context-dependent. In 2014, swimming with humpback whales began in Hervey Bay, Queensland, Australia, an important resting ground and migratory stopover for humpback whales. The behavioural responses of humpback whales to this swim-with-whale industry have not been examined in Queensland, preventing informed management of this industry. The aims of this study were to: (1) examine short-term behavioural responses in whales before, during , and after swim-with-whale tours, and (2) investigate behavioural responses of whales throughout swim-with-whale tours compared to whale watch tours. Data were collected on board a commercial vessel, where before, during and after data were collected during swim-with-whale tours (250 h) and whale watch tours (150 h). Within the swim-with-whale tours, behavioural changes were detected before, during , and after the vessel approached and placed swimmers in the water on a mermaid line, with the majority of significant changes occurring in the during and after phases. The number of direction changes made by the whales was highest when swimmers were in the water and the whales did not resume undisturbed behaviour after the swimmers exited the water. There was a 50% reduction in the proportion of time that whales spent resting during swim-tours compared to during whale watch tours. In both tour types, the time spent engaging in various behaviours was impacted by the distance between the vessel and the whale(s). These results support the conclusion that the behaviour of humpback whales in Hervey Bay was altered in response to swim-with-whale tourism. As humpback whales are capital breeders with limited energy reserves, reducing disturbance to them is of high importance for their continued population recovery and for the sustainability of the marine tourism industry. In Australia, where swim-with-whale tourism is becoming more established, robust education and enforcement programs, combined with continued monitoring of population dynamics through scientific research, are needed to minimise impacts to the population and guide adaptive management strategies.
Journal Article
Tourism informing conservation: The distribution of four dolphin species varies with calf presence and increases their vulnerability to vessel traffic in the four‐island region of Maui, Hawai‘i
by
Self, Holly
,
Stack, Stephanie H.
,
Currie, Jens J.
in
Animal reproduction
,
Anthropogenic factors
,
Aquatic mammals
2021
We need reliable information about the spatial and temporal distribution of mobile species to effectively manage anthropogenic impacts to which they are exposed. Yet, we often cannot sustain dedicated annual surveys and data obtained from platforms of opportunity offer an alternative avenue to understand where these species spend time. Four odontocete species that occur in the four‐island region of Maui, Hawai'i, USA, are vulnerable to a range of human activities, but there is a lack of information regarding their distribution. We therefore do not know the extent of the risk these activities present for the conservation of these species (bottlenose dolphins, spinner dolphins, Pantropical spotted dolphins and false killer whales). We used a cross‐validated maximum entropy (MaxEnt) occupancy model to estimate the distribution of these four species in an area extensively observed from platforms of opportunity (PoP). We then determined in a similar fashion whether the calves of those species were more likely to be observed in particular areas and whether distribution changed with season. Maxent models relying on local environmental variables described dolphin observations well (AUC > 0.7). Their distribution differed for all species when calves were present, indicating that different environmental variables describe area use for schools with calves present. The number of sighting events of all species varied significantly with season. Bottlenose dolphins and false killer whales were more prevalent in winter, while spotted and spinner dolphins were more prevalent in summer. We show that an overlap in the distribution of dolphin schools with calves and vessel traffic in the region could result in collision and chronic stress risks. This suggests a need for specific regulations for mitigating anthropogenic influences, such as acoustic disturbance or chronic energetic disturbance from vessel traffic. This elevated risk associated with vessel traffic is likely of conservation concern in this region for the endangered population of false killer whales and for spinner dolphins. We used data collected by tour operators in Maui to show that schools of false killer whales and spinner dolphins with calves in the region spend time where there is a lot of vessel traffic. We discuss the conservation implications of these findings.
Journal Article
Tending the sick: Observations of epimeletic behavior in humpback whales towards conspecifics during entanglement events
by
Cartwright, Rachel
,
Bejder, Lars
,
Pack, Adam A.
in
Animals
,
Anthropogenic factors
,
Aquatic mammals
2025
Anthropogenic impacts on marine systems are increasing in frequency, geographic range and severity. While changes in climate will likely lead to the greatest impacts at the system-level, for marine megafauna, entanglement in marine debris also constitutes a pernicious threat. For baleen whales, in regions where high productivity and prolific fisheries overlap, entanglement is emerging as a component of their life history: In some of these regions, entanglement comprises the leading cause of serious injury and mortality. Additionally, up to 80% of whales carry scars indicative of entanglement, and associated declines in long-term health are reducing fecundity. Here, we describe behavioral traits seen in humpback whales during entanglement incidents. Specifically, we focus on reports of humpback whales that have remained in association with entangled whales during these incidents and apply the term “companion whales” in reference to these whales. Reports reviewed include a detailed account of a recent incident observed in Hawaiian waters, a compilation of 62 accounts of similar behavior extracted from 414 reports of entanglement events provided by regional entanglement response networks, and a series of six reports associated with whaling activities. The similarities between the current behavior of companion whales and behaviors observed during whaling activities suggest that this may be an example of behavioral plasticity, underscoring the expanding behavioral repertoire exhibited by baleen whales, and highlighting their potential resilience as they respond to the changing marine environment.
Journal Article
New northernmost distribution records of the Eastern South Pacific southern right whale
by
Buchan, Susannah J
,
García-Cegarra, Ana M
,
Van Waerebeek, Koen
in
Biological monitoring
,
Cetacea
,
Diseases
2024
The Eastern South Pacific Right Whale (SRW) (Eubalaena australis) population has gained interest due to its Critically Endangered conservation status. So far, this population has been confirmed only along the coasts of Chile (18°20'S to 56°30'S) and from southern to central Peru (17°38'S to 12°11'S). Recent records have extended the species' known range, highlighting its geographic distribution, now reaching 1500 km north. Here, we report six recent records, consisting of five sightings and one stranding, that expand the documented range to northern Ecuador (0.6°N). The northern extension of the population may be associated with the unusual three-year-long cold phase (La Niña) of the El Niño Southern Oscillation (ENSO) in the eastern South Pacific, population expansion, movement and re-distribution of the species, increased monitoring effort, or a combination of these factors. These observations raise hope for the Critically Endangered SRW population, as the occurrence of mother-calf pairs may indicate a potential for population recovery. Nevertheless, these findings intensify concerns for what is still the least abundant SRW population, underscoring the urgency for more targeted research and conservation measures.
Journal Article
Conservation and Education Through Ecotourism: Using Citizen Science to Monitor Cetaceans in the Four-Island Region of Maui, Hawaii
by
Currie, Jens J.
,
Stack, Stephanie H.
,
Kaufman, Gregory D.
in
Aquatic mammals
,
Cetaceans
,
Data collection
2025
Pacific Whale Foundation (PWF) Eco-Adventures operates a fleet of nine ecotour vessels in Maui, Hawaii and has used these vessels as an opportunistic research platform since 2010. The researchers at PWF have utilized ecotour vessels as a platform of opportunity (PoP) to collect photo-ID
data, through a program called Researcher-on-Board (ROB) and for the development of an application to log cetacean sightings, called Whale and Dolphin Tracker (WDT). In this article we compare the amount of data collected using these two methods and contrast to systematic research surveys
taking place in the same location and same time period to demonstrate the value of citizen science. Both the ROB and WDT programs have been shown to be cost-effective alternatives to surveys aboard dedicated research vessels, with the additional benefit of having tour operations contribute
directly to the management and monitoring of marine mammals.
Journal Article
Identifying spinner dolphin Stenella longirostris longirostris movement and behavioral patterns to inform conservation strategies in Maui Nui, Hawai'i
2020
Spinner dolphins Stenella longirostris longirostris in Hawai'i exhibit a predictable diurnal behavioral pattern which makes them vulnerable to human disturbance: feeding at night in offshore waters and resting during daytime in bays. There is concern that human activity, such as swimming with and viewing wild dolphins from vessels, is altering their natural behavioral patterns and preventing them from having adequate rest. In light of this, state and federal management agencies are proposing enhanced protection measures. Research on spinner dolphins has largely focused off Hawai'i Island and there are insufficient data from Maui Nui (Maui, Lāna'i, Kaho'olawe, and Moloka'i) to inform appropriate management measures for the genetically distinct stock that resides around these islands. Using location data from 316 encounters between 1996 and 2019, we identified 2 hotspots for spinner dolphins within the region, located along west Maui and south Lāna'i. The predominant behavior observed was traveling, and there was little resting behavior documented throughout the study period, with no resting behavior observed along the coastline of Maui. Our findings revealed that spinner dolphins use a wide variety of available habitat in Maui Nui and were observed resting both near the shore of Lāna'i and in the channels between islands. Based upon these findings, the proposed lone area for closure in south Maui is inadequate for providing protection to spinner dolphins during resting hours, and we propose that the identified hotspots be considered as additional sites for closures, in addition to an approach limit for vessels transiting Maui Nui.
Journal Article