Information on the distribution of marine migratory species is lacking, and for a long time, these species have been overlooked in the designation of Marine Protected Areas (MPAs). This study ...analysed the home range of pygmy blue whales (PBWs) from western Australia to eastern Indonesia to be able to assess the overlap with current MPAs. In this study, data from 11 individual PBWs tagged in the Perth Canyon were used. Two home range methods, adaptive Local Convex Hull (a-LoCoH) and Brownian Bridge Movement Model (BBMM), were performed and compared to identify core use areas and connections between these areas (i.e., migration corridors). By assessing the relative properties and visually inspecting the home ranges, 90% BBMM (home range and migration corridor) and 50% BBMM (core use area) are chosen as the best results, because they cover the connected core-use areas to a large extent. The home ranges that were covered by current MPAs were only 2% in Indonesia and 16% in Australia. Important migration corridors without current protection are in the east Savu Sea, south of Timor Island, and wider Banda Sea. It is noteworthy that comparing methods is relevant to be able to choose the most suitable method for the data used and the goal of this study. The limited overlap between the calculated home ranges and the MPAs of the Indonesian waters articulates the importance of in-depth scientific studies to be able to evaluate, implement and develop marine conservation planning.
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.
The Wakatobi National Park (WNP) at the heart of Coral Triangle is an important area for cetaceans in Indonesia. Currently there is insufficient information on spatio-temporal occurrence patterns of ...cetaceans to inform effective conservation strategies. This study used platforms of opportunity from May 2004 to May 2012 as a cost-effective way to address this knowledge gap. A database was created of cetacean sightings per surveyed days at sea, allowing for an analysis of species diversity and habitat use around the islands. A total of 11 cetacean species were identified. Spinner and bottlenose dolphins were sighted most often, followed by melon-headed and sperm whales. Spinner dolphin showed a wide distribution in the area, whilst bottlenose dolphin and melon-headed whale occupied the waters between the main islands and south atolls. Sperm whales occurred mostly in waters to the north of the main islands and as melon-headed whales were mostly found in deep waters. Most cetacean sightings occurred in the zones designated for human use, indicating where potential conflicts might occur. No sightings were found in the Park core zone, indicating a mismatch between WNP design and the ecological needs of the cetaceans. A sub-sample of the data from dedicated fishing monitoring trips was used to derive a sighting frequency. Occurrence of both small and large cetaceans was highest during inter-monsoonal seasons, possibly related to an increase of prey availability due to seasonal upwelling and increase in survey activity. Inter-annual occurrence of cetaceans was variable, with no large cetaceans being sighted in 2010-2012, likely due to reduced survey efforts. In areas with limited resources for designated surveys, the use of platforms of opportunity can be a cost-effective tool to provide valuable data on cetacean occurrence. It helps identify potentially important areas as well as highlight where to direct designated research efforts. We discuss the implications of our findings for the conservation management of these cetaceans and give suggestions for improved marine park management.
The governance of marine conservation in Indonesia has been the subject of critique for decades. This paper elucidates and analyses the legal framework for marine mammal protection and current ...institutional arrangements, and reveals gaps and overlaps in the national legal and policy frameworks for marine mammal governance in the Archipelago. We reviewed available policies to assess the current regulation practices in the country's marine mammal protection. In total, five relevant international conventions, 28 Indonesian national regulations, and 16 provincial regulations on marine spatial planning were found. Progress on legal framework regarding marine mammal governance reveals three different phases: 1970s (species-centred approach), 1990s (site-based approach), and current (wider marine management approach). We summarized seven policies based on the following characteristics: species, site and other values. We identified functional overlap and unclear mandates as the main shortcomings of these regulations. Although marine mammal protection in Indonesia enjoys a set of regulations, the practical actions required by these regulations are still unclear. Protection gaps still exist, rendering conservation efforts less effective. The paper argues how an adequate and appropriate legal framework and institutional arrangements will ameliorate and strengthen marine mammal governance in Indonesia. We suggest some urgent-yet-lacking policies that should be added to the current regulations, including regulations on traditional whale hunting, the code of conduct for marine mammal watching tourism, standards for aquaria, and the legal basis for marine mammal stranding network and underwater noise pollution. We endorse the cetacean National Plan of Action for it is designed to enhance ecological and human-dimension research on cetaceans and address the detrimental effects of anthropogenic activities to the cetaceans. We suggest establishing a mechanism for cross-institutional coordination for more effective marine mammal protection in Indonesia. Becoming a full member of the Convention on the Conservation of Migratory Species of Wild Animals and International Whaling Commission will further strengthen the conservation management of marine mammals in Indonesia.
•Indonesian marine mammal management policy adheres to most principles mentioned in five international conventions.•Marine mammal governance in Indonesia has developed in 3 phases: 1970s, 1990s, and current.•The guidance on incorporation of migratory paths in an MSP was implemented differently in the provincial regulations.•Unclear practical actions required by regulations and functional overlap were the main shortcomings of the legal framework.
Marine migratory species tend to be overlooked in marine spatial planning due to limited knowledge of their habitats and migration pathways, resulting in a disconnect between animal migration ecology ...and spatial management decision making. The aim of this study was to predict the migratory corridors, suitable habitats and use of marine reserves by pygmy blue whales and overlap with marine traffic. Firstly, based on available telemetry data, we analysed the home ranges, core-use areas and migratory corridors using Brownian Bridge Movement Models. Secondly, we predicted suitable habitat by modelling telemetry data against environmental predictors using Maximum Entropy modelling; and lastly we geometrically overlaid home ranges and suitable habitats with designated migration lanes, marine protected areas and marine traffic. Consistent movement of pygmy blue whales from Western Australia to the Banda and Molucca Seas in Indonesia demonstrated a high level of connectivity between the two regions. There is a discrepancy between the designated migration lanes for large whales in Indonesian marine spatial planning and migration routes suggested by this study. The home range analysis and habitat models revealed that large areas of the migration corridors, core-use, and suitable habitats are currently not protected, particularly along international waters and within the Banda and Molucca Seas. The results can aid marine conservation planning by delineating the important areas and areas with high marine traffic density to optimise migratory species protection.
•Consistent pygmy blue whale's movements have shown a high degree of Indo-Australia connectivity.•There was a spatial mismatch between areas important for pygmy blue whale and marine protected areas.•There is discrepancy between migration lanes for large whales in Indonesia and migration routes yielded from our study.•Areas important for pygmy blue whale overlap with some busiest shipping routes in the region.•Transboundary management is needed to protect areas important for pygmy blue whale.
This PhD thesis aimed to develop an approach to provide information to improve cetacean conservation management in Indonesia through suggestions for strengthening the governance and introduction of ...habitat-use-based spatial planning using complementary methods and underused data. We reviewed Indonesian marine mammal conservation governance, legal framework, institutional arrangement, and related policies. In the development of the legal framework regarding marine mammal governance, three different phases can be distinguished: 1970s following a species-centred approach, 1990s focusing on site-based approaches, and currently applying a wider marine management approach. There are currently 7 policies in place for marine mammal management in Indonesia. Some aspects of marine mammal conservations governance are missing, these include a legal basis regulating traditional whale hunting, a code of conduct for marine mammal tourism, standards for ex-situ conservation, and regulation of underwater noise pollution. Suggestions were provided to strengthen the current legal framework such as adapting institutional arrangements to remove functional overlaps and to solve unclear mandates and responsibility dualism. This study also suggests to reinforce international collaborations, including become a full member of the International Whaling Commission and ratify the Convention on the Conservation of Migratory Species of Wild Animals to further bolster Indonesian marine mammal conservation management. As current records of whale occurrence covering the whole of Indonesian waters are limited, this study employed historical whaling data (1761-1920) to model former seasonal distribution and habitat preferences of sperm whale. Two habitat modelling methods were used, Maximum Entropy (Maxent) and Generalised Additive Modelling (GAM). The models revealed that sperm whale occurrences were related to the distance to the coast, deep waters (-1,000 and -5,000 m isobaths) and submarine key features (trough and trench). The results indicate that in four areas in the eastern part of Indonesia, no seasonal differences occurred in sperm whale distribution, while noticeable seasonal differences were found in other areas. The predicted historical distributions were significantly larger than the current ones, another example of a shifting baseline caused by (historical) exploitation. Information on critical habitats and seasonal variability from this study can be used to direct future monitoring program, provides a baseline to assess present distribution of the species, and as an input for MPA and MSP establishment.To support national cetacean conservation and management planning with up-to-date information on cetacean spatial distribution and habitat preference, Maxent was used to model the distribution of 15 selected cetacean species in 7 ecoregions/seascapes in Indonesia using recent cetacean presence data (2000-2018) and topographic-oceanographic variables. The individual species habitat maps revealed a great heterogeneity in distribution among species and within species among different locations. This heterogeneity reflects an interrelated influence of topographic variables and oceanographic processes on the distribution of cetaceans. Areas rich in species were mainly related to coastal areas or insular-reef complexity, representing high productivity and upwelling-modified waters. The combined species habitat maps were overlaid with provincial MSP jurisdictions, MPAs, oil-gas contract areas, and marine traffic density to assess spatial overlaps. Although some suitable habitats are currently covered by MPAs, other important areas are not and instead overlap with oil-gas contract areas and marine traffic, indicating potentially high risks for cetaceans. The results provide priority areas for conservation and can be used as a basis for anthropogenic threat mitigation. Marine migratory species, including large cetaceans, tend to be overlooked in Indonesian MSP due to the limited knowledge of their habitats and migration pathways. Telemetry-based home range analysis and habitat modelling were performed to picture yet hardly considered parts of the pygmy blue whale’s (PBW) life cycle including migration. Based on available telemetry data (2009 and 2011), home ranges, core-use areas and migratory corridors were determined using Brownian Bridge Movement Modelling (BBMM). Further, habitat suitability was then predicted by modelling the telemetry data against known environmental predictors using Maxent. Home ranges differed in size and shape among individual PBWs. Shifts in SST and the presence of localised productivity along migration pathways are presumed to drive and support the PBW migration. A discrepancy was observed between the legally designated migration lanes for large whales in Indonesia and migration routes unveiled by this study. Clearly, large areas of migration corridors, core-use areas, and suitable habitats are currently not protected in mainly international waters and the Banda-Molucca Seas, an input for further conservation actions. Multi-national collaborations are encouraged for protecting cetacean key areas in the high seas .As a cost-effective alternative for the lacking systematic survey data in Wakatobi National Park (WNP) Indonesia, data from platforms of opportunity and incidental sighting data (2004-2012) were used to assess cetacean diversity, spatio-temporal occurrence patterns, habitat preferences, and to estimate sighting frequency. Of the 11 cetacean species identified, spinner and bottlenose dolphins were sighted most often, followed by melon-headed and sperm whales. Spatial occurrence patterns of these four most sighted species differed in relation to reef habitat types, park zoning system, and depth preference. Also the temporal occurrence patterns of these species differed seasonally, and the sighting frequency of cetaceans varied inter-annually. Interestingly, most cetacean sightings occurred in the WNP use-zones and nothing in the park core zone, suggesting a mismatch between park zoning design and the cetacean ecological needs. It is suggested to protect currently unprotected important cetacean habitats, and strictly regulate human activities in the current use zones in future WNP rezoning processes. This thesis demonstrates the use of multi-method and multi-dataset approaches to identify key governance aspects and acquire ecological data of cetaceans in under-studied tropical equatorial regions of Indonesia. Applying different methods and available datasets can complement each other and thereby strengthen the outcome of the research, especially for under-studied areas and for poorly known cetacean species. The study also added new knowledge about the cetacean spatial distribution, occurrence patterns, habitat use and preference, home range, migratory corridors, and about the status of under-studied cetacean populations and their relative abundance estimates. The findings from this thesis further stress the importance of refining key governance aspects and including previously ignored aspects of cetacean ecology and key areas into habitat-use-based spatial planning to optimise these migratory species conservation
Indonesia harbours a high diversity of cetaceans, yet effective conservation is hampered by a lack of knowledge about cetacean spatial distribution and habitat preferences. This study aimed to ...address this knowledge gap at an adequate resolution to support national cetacean conservation and management planning. Maximum Entropy (Maxent) modelling was used to map the distribution of 15 selected cetacean species in seven areas within Indonesian waters using recent cetacean presence datasets as well as environmental predictors (topographic and oceanographic variables). We then combined the individual species suitable habitat maps and overlaid them with provincial marine spatial planning (MSP) jurisdictions, marine protected areas (MPAs), oil and gas contract areas, and marine traffic density. Our results reflect a great heterogeneity in distribution among species and within species among different locations. This heterogeneity reflects an interrelated influence of topographic variables and oceanographic processes on the distribution of cetacean species. Bathymetry, distance to- coast and the −200m isobaths, and chlorophyll-a concentration and sea surface temperature were important variables influencing distribution of most species in many regions. Areas rich in species were mainly related to coastal areas or insular-reef complexity, representing high productivity and upwelling-modified waters. Although some important suitable habitats currently fall within MPAs, other areas are not and overlap with oil and gas exploration activities and marine traffic, indicating potentially high risk areas for cetaceans. The results of this study can support national cetacean conservation and management planning, and be used to reduce or avoid adverse anthropogenic threats. We advise to consider currently unprotected suitable cetacean habitats in MPA and MSP development.
•We address knowledge gaps on cetacean distribution and habitat preferences in Indonesia.•Highly suitable cetacean habitats were highlighted as priority areas for future spatial conservation.•The study is a basis for assessing the overlap between cetacean habitats, conservation areas, and anthropogenic threats.•Additional cetacean protection measures can be extended through MPA and MSP development.
Aim
This study is the first in Indonesia to assess historical sperm whale (Physeter macrocephalus) seasonal distributions by combining historical whaling data with environmental factors associated ...with sperm whale habitat preferences. As current records of whale occurrence covering the whole of Indonesian waters are incomplete, we used historical whaling data summarized by Charles Haskins Townsend in 1935 to model its potential distribution for each season.
Location
Indonesian waters (92‐143E, 9N‐14S).
Taxa
Sperm whale (P. macrocephalus).
Methods
We used a presence‐only habitat model – Maximum Entropy (Maxent) –, and a presence–pseudo‐absence method – generalized additive model (GAM) – with nine submerged topographic variables to predict historical seasonal distributions.
Results
Both Maxent and GAM predict similar potential distribution which align closely with the whaling data. The results indicate that in four areas in the eastern part of Indonesia, no seasonal differences occurred in sperm whale distribution, while noticeable seasonal differences were indicated in other areas. The key parameters that characterize sperm whale habitat in both models were distance to coast, distance to −1,000 and −5,000 m isobaths, and submarine key features such as trough and trench.
Main conclusions
The historical catch data of this species can be used to describe the historical species distribution and provide a baseline to assess present distribution, prioritize current research and monitoring and recommend future data collection. Our models also predict distributions that are significantly larger than the ones occupied by sperm whales nowadays, another example of a shifting baseline. Our study demonstrates the benefits of incorporating historical whaling data into habitat models for ecological investigation and to inform conservation efforts for cetaceans.
While occurrences of Omura's and melon-headed whales, both listed as protected species in Indonesia, have been reported in various parts of the country, knowledge of both species in Raja Ampat, West ...Papua, has remained extremely limited. Although Raja Ampat lies within Bird's Head Seascape, one of the highest marine biodiversity regions globally, cetaceans have rarely been considered in conservation plans due to limited research efforts. Here, Sahri et al provide a more systematic descriptions of both species based on the photographs and drone footage they recently collected in Raja Ampat and update the Raja Ampat cetacean species list.
Abstract
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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