Explore the vast range of titles available.

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.

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.

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.

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.

Humpback whale (Megaptera novaeangliae) mothers and their calves predominantly avoid social interactions with conspecifics. However, observations from East Australia indicate that mother–calf pairs occasionally associate with other mother–calf pairs. We investigated the prevalence, composition, and behaviour of multiple-mother-calf (multi-MC) groups in East Australia from 2009 to 2023. In 2009 and 2010, data were collected from two tropical breeding areas (Port Douglas and the Whitsunday Islands) and two coastal migratory locations (Hervey Bay and Eden). No multi-MC groups were detected in Port Douglas out of 15 calf groups observed. Only one (4%) of 23 calf groups encountered in the Whitsunday Islands was a multi-MC group. In Hervey Bay, seven (4%) multi-MC groups were recorded out of 180 calf groups; while in Eden, seven (11%) out of 63 calf groups were multi-MC groups. Between 2009 and 2023, 978 calf groups were encountered in Hervey Bay over 12 years, including 56 (6%) multi-MC groups; while 39 (13%) out of 293 calf groups encountered in Eden over six years were multi-MC groups. Multi-MC groups exhibited more social behaviours compared to single MC groups. Social behaviour was common in both Hervey Bay and Eden; however, groups in Hervey Bay displayed lower arousal behaviours, consistent with the area’s importance as a resting habitat for whales. We did not detect behavioural differences in multi-MC groups with or without escort whales. These findings suggest that humpback whale mothers may gradually socialise their calves by forming multi-MC groups, with an increasing prevalence along the southerly migration route as calves mature. While multi-MC groups have only been detected in Australia to date, it is possible that they occur elsewhere, particularly if social development is a key driver of the phenomenon. Our results enhance our understanding of humpback whale mother–calf sociality and highlight the importance of migration routes for calf social development.

In Maui Nui, Hawai'i, limited information is available regarding the impact of fisheries interactions on two island-associated populations of common bottlenose (Tursiops truncatus) and pantropical spotted (Stenella attenuata) dolphins. To quantify the number of individuals with evidence of fisheries interactions, this study examined images of bottlenose and spotted dolphins' dorsal fins, mouthlines, and bodies that were photographically identified during survey efforts from 1996 to 2020. Our results reveal that 27% of the 255 identified bottlenose dolphins and 13% of the 374 identified spotted dolphins displayed one or more fishery gear-related scars. These data suggest that fisheries interactions may pose a serious threat to the population of bottlenose dolphins and is a concern for spotted dolphins in Maui Nui, Hawai'i. Our methodology of reviewing above- and underwater footage for mouthline and body images increased scar-detection rates by 51 and 40% for bottlenose and spotted dolphins, respectively. We recommend that future surveys expand dorsal fin photo-identification efforts to collect additional above- and underwater images of animals' mouthlines and bodies when in the field. In conjunction with the apparent decline in the Maui Nui bottlenose dolphin population, our findings highlight the need for further investigation regarding the level of impact fisheries interactions have on the status of these populations.

The increase and diversification of vessel traffic worldwide has resulted in a variety of known disturbances to dolphins. As a remote island chain, the Hawaiian Islands rely heavily on the marine environment for transportation, recreation, and fishing that aggregates into significant levels of vessel traffic. Given the known presence of dolphins in this region, there is a gap in knowledge regarding the relative exposure risk that vessel traffic poses to island-associated dolphin populations in Hawai'i. This research identified the spatial distribution of pantropical spotted dolphins (Stenella attenuata) and common bottlenose dolphins (Tursiops trun-catus) and determined the extent of their overlap with various categories of vessel traffic in Maui Nui, Hawai'i. Species distribution was determined using kernel density estimates based on sighting data from 50 spotted dolphin sightings and 75 bottlenose dolphin sightings collected from 2013 to 2018. A combination of vessel GPS and Automatic Identification Systems (AIS) vessel tracks were used to quantify vessel traffic within the study area, resulting in 22,464 vessel tracks that were subsequently compiled into categories for analysis from 2014 to 2017. Risk of vessel exposure between vessels and dolphins, or co-occurrence, was determined by calculating the product of predicted dolphin density and predicted vessel density. Both species were exposed to vessel traffic risk over 100% of their distribution, but their highest exposure risk varied spatially, with high risk defined as > 0.25 on a normalized scale of low (0) to high (1) risk. The highest vessel exposure risk for spotted dolphins occurred in deeper, offshore waters, while the highest risk for bottlenose dolphins was in shallow, coastal waters. The vessel categories with the largest area of high risk to spotted dolphins were tour vessel and commercial fishing vessel traffic, while commercial transportation traffic had the highest exposure risk for bottlenose dolphins. This article provides baseline information for understanding the vulnerability of two island-associated dolphin populations to the threat of vessel traffic and highlights the differences in relative exposure risk based on species and vessel categories.

We examined the incidence of bent or collapsed dorsal fins of eight species of odontocetes observed in the nearshore waters of Maui Nui, Hawaii. Between 1995 and 2017, 1,312 distinctive individual odontocetes were photographically documented. Our photo-identification catalogs include 583 spinner dolphins (Stenella longirostris longirostris), 164 bottlenose dolphins (Tursiops truncatus), 132 short-finned pilot whales (Globicephala macrorhynchus), 253 pantropical spotted dolphins (Stenella attenuata), 82 false killer whales (Pseudorca crassidens), 70 melon-headed whales (Peponocephala electra), 15 pygmy killer whales (Feresa attenuata), and 13 rough-toothed dolphins (Steno bredanensis). Of these, two false killer whales (2.44% of catalog), two spinner dolphins (0.34% of catalog), and three pantropical spotted dolphins (1.19% of catalog) displayed major dorsal fin disfigurements. Both spinner dolphins and two of the spotted dolphins had multiple resights spanning several years, with one spotted dolphin having a 16-year span between resights. The two false killer whales with bent dorsal fins did not have any resights and were only sighted once throughout the study period. We also present the first progression of dorsal fin collapse after a significant injury to the leading edge of a spinner dolphin. Results from this research expand our knowledge on injuries to marine mammals and the survivorship of wild dolphins with dorsal fin injuries and contribute to the management of odontocetes in Hawaii, where interactions with fishing gear are a significant conservation issue.

In Maui Nui, Hawai'i, limited information is available regarding the impact of fisheries interactions on two island-associated populations of common bottlenose (Tursiops truncatus) and pantropical spotted (Stenella attenuata) dolphins. To quantify the number of individuals with evidence of fisheries interactions, this study examined images of bottlenose and spotted dolphins' dorsal fins, mouthlines, and bodies that were photographically identified during survey efforts from 1996 to 2020. Our results reveal that 27% of the 255 identified bottlenose dolphins and 13% of the 374 identified spotted dolphins displayed one or more fishery gear-related scars. These data suggest that fisheries interactions may pose a serious threat to the population of bottlenose dolphins and is a concern for spotted dolphins in Maui Nui, Hawai'i. Our methodology of reviewing above- and underwater footage for mouthline and body images increased scar-detection rates by 51 and 40% for bottlenose and spotted dolphins, respectively. We recommend that future surveys expand dorsal fin photo-identification efforts to collect additional above- and underwater images of animals' mouthlines and bodies when in the field. In conjunction with the apparent decline in the Maui Nui bottlenose dolphin population, our findings highlight the need for further investigation regarding the level of impact fisheries interactions have on the status of these populations.

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.