Telemetry-based home range and habitat modelling reveals that the majority of areas important for pygmy blue whales are currently unprotected

Sahri, Achmad; Jak, Charlotte; Putra, Mochamad Iqbal Herwata; Murk, Albertinka J.; Andrews‐Goff, Virginia; Double, Michael C.; Lammeren, Ron J. van

doi:10.1016/j.biocon.2022.109594

Cited by 11 publications

(6 citation statements)

References 65 publications

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“…Cetaceans are species that are hard to study because they are highly mobile animals and mostly being underwater [62,63]. Most information on cetacean occurrences elsewhere, including in Indonesia come from the animals being at the water surface or from deceased bodies that have washed ashore.…”

Section: Discussionmentioning

confidence: 99%

Predicting cetacean habitats beyond surveyed regions in Indonesian waters: species distribution model transferability may not always be preferable

Sahri,

Maters,

Putra

et al. 2023

IOP Conf. Ser.: Earth Environ. Sci.

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Understanding the distribution of cetaceans in Indonesian waters is imperative for their conservation management, however such information is lacking for the country. Our study predicted the species distributions of two cetacean species (common bottlenose dolphin and sperm whale) beyond the surveyed regions in Indonesian Exclusive Economic Zone (EEZ). This was done by using a combination of presence-only data, randomly generated pseudo-absences and environmental predictors variables within the Biomod2 framework in R. Ten potential predictor variables were identified, of which five were selected after correlation tests. Local Random Forest models were built to the extent of four small study regions, and later projected to the whole Indonesian EEZ. The common bottlenose dolphin local models showed preference for areas close to the coast and shallower waters. Sperm whale local predictions were located further into the open waters and at deeper waters. The extrapolated predictions into the Indonesian EEZ, however, showed some unexpected results. The high occurrences for common bottlenose dolphins were not only located close to the islands, but also more into open waters. In contrast, sperm whale distributions have high occurrences near coastal areas and in the vicinity of islands than in the open oceans. This information suggested that the transferability of species distribution models may not always be preferable, because provide low accuracy. Sighting data, choices of variables and model settings influenced the outcome of the extrapolated models. Despite the unpreferable of the extrapolations, the results are still beneficial for cetacean conservation purposes, since the study was able to identify potential habitats in unsurveyed regions.

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Section: Discussionmentioning

confidence: 99%

Predicting cetacean habitats beyond surveyed regions in Indonesian waters: species distribution model transferability may not always be preferable

Sahri,

Maters,

Putra

et al. 2023

IOP Conf. Ser.: Earth Environ. Sci.

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“…Its global threatened statuses require dedicated effort to establish conservation measures; however, its oceanic habitat hinders data collection and the coordination between stakeholders and governments. Conservation measures should include not only the core-used areas where social groups spend most of their time, exhibiting higher degrees of philopatry, but also the corridors used by males during their migrations between feeding and breeding grounds (Gero et al, 2014;Sahri et al, 2022). Remote islands such as the ones in Macaronesia provide an excellent location for studying this marine predator and/or the effects of anthropogenic threats, but surveillance of the open ocean is paramount since only a small part of the population approaches the islands regularly.…”

Section: Discussionmentioning

confidence: 99%

Unraveling site fidelity and residency patterns of sperm whales in the insular oceanic waters of Macaronesia

Ferreira

Steiner²,

Martín

et al. 2022

Front. Mar. Sci.

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Knowledge of the distribution and residency of pelagic marine megafauna, particularly deep-diving species, is scarce due to their high mobility over difficult-to-access oceanic areas and long periods underwater. However, the threatened status of many of these species, such as the sperm whale Physeter macrocephalus, increases the need to obtain quantitative data to support conservation measures. In the warm temperate waters of Macaronesia (Eastern North Atlantic), sperm whales occur year-round in a set of island systems (the Azores, Madeira, and the Canaries), mainly in social groups of females and juveniles with the occasional visits of mature males. Although it is known that they perform inter-archipelago movements, information on site fidelity and residency times is still scarce. Here, based on photographic-identification data, site fidelity and residency times of sperm whales were estimated for subareas of the Azores and the Madeira archipelagos, with a preliminary assessment for a subarea of the Canaries. The Azores and Madeira subareas presented similar proportions of individuals with recaptures (~25%), mainly inter-annual, while in the subarea of the Canaries, only <10% of the individuals were recaptured. Standardized Site Fidelity Indexes showed very low values (<0.01) for both the Azores and Madeira subareas. Lagged identification rates based on models including emigration and reimmigration estimated that an average of 44.8 individuals (SE=4.9) spent 12.9 days (SE=1.5) in the Azores before leaving for 99.1 days (SE=12.5), while 8.4 individuals (SE=16.1) spent 0.8 day (SE=6.6) in Madeira before leaving for 8.6 days (SE=6.9), with a very low mortality rate. This study i) indicates a degree of residency of about ¼ of the identified individuals for the Azores and Madeira subareas and ii) supports that these oceanic archipelagos constitute an important habitat for a Vulnerable species in the Atlantic. Moreover, it also highlights the importance of combining data from opportunistic and dedicated surveys and joint national and international efforts toward the conservation of marine megafauna.

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“…Generally speaking, with the exception of East Kalimantan, we have no baseline data on cetacean population dynamics and residency in the country. The general residency and migratory pattern of cetaceans in the country are not yet well studied, but there are emerging patterns of migratory cetaceans (e.g., the pygmy blue whales Balaenoptera musculus brevicauda that migrate between Banda Sea and Australia, [43,44], and Mustika et al's unpublished data]) and some areas with year-round residency (e.g., the spinner dolphins Stenella longirostris north of Bali [45]).…”

Section: Discussionmentioning

confidence: 99%

When and Where Did They Strand? The Spatio-Temporal Hotspot Patterns of Cetacean Stranding Events in Indonesia

Mustika

High

Putra

et al. 2022

Oceans

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Analyses of the spatial and temporal patterns of 26 years of stranding events (1995–2011 and 2012–2021, n = 568) in Indonesia were conducted to improve the country’s stranding response. The Emerging Hot Spot Analysis was used to obtain the spatial and temporal hotspot patterns. A total of 92.4% events were single stranding, while the remaining were of mass stranding events. More stranding events were recorded between 2012 and 2021 in more dispersed locations compared to the previous period. Within the constraints of our sampling limitations, East Kalimantan and Bali were single stranding hotspots and consecutive hotspots. East Java and Sabu-Raijua in East Nusa Tenggara were mass stranding hotspots. Temporally, Raja Ampat (West Papua) experienced a significant increase in case numbers. The presence of active NGOs, individuals or government agencies in some locations might have inflated the numbers of reported cases compared to areas with less active institutions and/or individuals. However, our results still give a good understanding of the progression of Indonesia’s stranding responses and good guidance of resource allocation for the stranding network. Several locations in Indonesia that need more efforts (e.g., more training workshops on rescue and necropsies) have been identified in this paper. Suggestions to improve data collection (including georeferencing tips) have also been included.

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Telemetry-based home range and habitat modelling reveals that the majority of areas important for pygmy blue whales are currently unprotected

Cited by 11 publications

References 65 publications

Predicting cetacean habitats beyond surveyed regions in Indonesian waters: species distribution model transferability may not always be preferable

Predicting cetacean habitats beyond surveyed regions in Indonesian waters: species distribution model transferability may not always be preferable

Unraveling site fidelity and residency patterns of sperm whales in the insular oceanic waters of Macaronesia

When and Where Did They Strand? The Spatio-Temporal Hotspot Patterns of Cetacean Stranding Events in Indonesia

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