Arabian Sea Whales at the 2024 IWC Scientific Committee Meeting

The 2024 IWC Scientific Committee Meeting took place in Bled, Slovenia from April 22nd to May 3rd, 2024. Representatives from ASWN participated in person and virtually to present both regional updates and results of research conducted at national or project levels. As in past years, the ASWN worked collectively to prepare an annual update for the Scientific Committee. This update included progress against ASWN objectives at the regional level, including coordination, communication and meetings, and contributions from most ASWN range countries with updates on their research, stakeholder engagement and management efforts for Arabian Sea humpback whales (ASHW) and other cetaceans in the region. The update highlighted the Extension of the Convention Migratory Species (CMS) Concerted Action for ASHW and the progress made by stakeholders in Oman towards a National Action Plan for ASHW and participation in the long-hoped-for regional Conservation Management Plan (CMP).  It also showcased the ways in which a wide range of stakeholders including national and international NGOs, government agencies, academic institutions and independent researchers are collaborating on cetacean research, conservation and management. 

The Committee expressed gratitude for the update and commended the ASWN members, the Oman Environment Authority, and other government officials and stakeholders for their efforts, collaborations, and scientific contributions over the past two decades. The Subcommittee acknowledged the growing support from ASHW range-country governments, particularly Oman and India, and noted Oman’s plan to form a cross-government committee to draft a national ASHW Action Plan and guide its participation in a regional CMP process. The Subcommittee welcomed the extension of the CMS Concerted Action and reiterated its support for the development of a joint CMS-IWC CMP for Arabian Sea humpback whales. It recommended the continued involvement of at least one range-country scientist in regional communications and coordination, emphasizing the need for a full-time CMP Coordination role once a CMP is approved.

Several documents and papers were presented by ASWN members at the meeting, including the following:

  1. SC/69B/CMP/05_Rev 1: summarized the activities and progress of the Arabian Sea Whale Network (ASWN) and its members since SC69A (see more details above).
  2. SC/69B/CMP/16Rev_1: provided an update on research conducted in Oman from 2023 to 2024, showcasing vessel-based studies funded by the Oman Environment Authority (EA) in the Gulf of Masirah in November, 2023.  The survey documented  multiple Arabian Sea humpback whales, Bryde’s whales, and humpback dolphin sightings. Drone imagery and biologging devices were employed to assess whale bioenergetics and behavior, and one whale was tagged with a transdermal satellite tag.The committee emphasized the importance of continued research activities in Oman, including fisheries and ship strike risk assessments, photo-id and genetic data collection, and updating abundance and trend models with recent data to inform conservation efforts and IUCN Red List assessments.
  3. SC/69B/CMP/12: provided a mark-recapture analysis of photo-ID records and genetic data from Omani waters (2000-2018). The analysis estimated the abundance and trend of Arabian Sea humpback whales (ASHWs). The photo-ID modeling was analyzed in relation to genetics, telemetry, acoustics, and strandings data that all support the  conclusion that the population in Oman’s waters likely declined from 2000 to 2018. The Committee welcomed the analysis, recognizing the importance of continued photo-ID data collection. However, the committee noted that the estimates provided in SC/69B/CMP/12 are provisional and likely to change with new data, and should not be cited before the completion of updated analyses.
  4. SC/69B/HIM/21: provided a bycatch risk assessment of ASHWs within their core home range (Gulf of Masirah Oman) through integration of satellite imagery to detect vessels and satellite telemetry data to define whale habitat. The high-risk bycatch score modeled for this area flag it as a priority concern to be addressed within a conservation management plan, whilst the method demonstrates potential to be applied across the broader part of the population’s range as a regional scale conservation management tool.
  5. SC/69B/ForInfo/54: reported on the results of a study funded by the IWC to conduct exploratory surveys for humpback whales along the western coast of India between 2016 and 2021, utilizing interview surveys, participatory informant networks (PIN), and Passive Acoustic Monitoring (PAM). This effort identified five hotspots where species have been reported offshore along the west coast of India. PAM off Netrani Island in Karnataka and Poovar in Kerala detected ASHW, blue whales, and an unidentified whale call. The sub-committee commended India’s passive acoustic monitoring efforts and recommended continued PAM implementation along the coasts of India and Oman, suggesting expansion to other areas of historical or potential ASHW distribution, including the Indus canyon region off the coast of Pakistan, with consideration for geopolitical challenges. Simultaneous deployments in different regions are encouraged to enable whale presence detection and song comparison.
  6. SC/69B/E/10: presented the first comprehensive review of cetacean stranding records in the United Arab Emirates (UAE), conducted using 125 opportunistic stranding records between 1989 and 2023, using a variety of sources. The Committee commended the strandings work in the UAE, which is an underrepresented region, and recommended (1) the continued collection of stranding information from the UAE; and (2) collaboration with partners in neighboring countries in order to obtain a better understanding of the extent and distribution of cetacean strandings in the region.
  7. SC/69B/SM/05: provided an update on collaborations to enhance conservation efforts for the Endangered Indian Ocean humpback dolphin (Sousa plumbea) by the Indian Ocean Humpback Dolphin Conservation Network (HuDoNet).
  8. SC/69B/SAN/03Rev2: provided an update on the Indian Ocean Cetacean Network (IndoCet), which focuses on cetacean research and conservation in the south-western Indian Ocean (SWIO). The Committee praised IndoCet’s accomplishments and urged continued efforts, recommending the development of a species action plan for Indian Ocean humpback dolphins through formal mechanisms like the CMS Concerted Action initiative or the IWC CMP process.
  9. SC/69B/HIM/03: provided guidelines on best practices for the disentanglement of free swimming small cetaceans. The Committee endorsed the guidelines in SC/69B/HIM/03 as Best Practices for the Disentanglement of Free-Swimming Small Cetaceans and recommended that they are made available through the IWC website and other dissemination channels.

Furthermore the following papers, originally prepared for and presented at the 19th Indian Ocean Tuna Commission Working Party on Ecosystems and Bycatch meeting in September 2023, were presented and discussed in the HIM subcommittee of the IWC Scientific Committee.

  1. IOTC-2023-WPEB19-27_rev1: provided a review of the scope of the Marine Mammal Protection Act Import Rule for IOTC Members, particularly for those with gillnet fisheries, and discussed potential synergies between the Rule and IOTC bycatch reporting and monitoring. This preliminary review was one part of an ongoing, broader analysis of unilateral and multilateral approaches to bycatch management in the Indian Ocean across multiple scales.
  2. IOTC-2023-WPEB19-28: this study focused on Pakistan’s drift gillnet fleet as a case study. The paper discussed existing data on catch and bycatch, the potential of satellite imagery and deep learning for fisheries management, and the methods, challenges, and insights gained. It served as a foundational study for similar analyses in the Indian Ocean and beyond to enhance understanding of data-poor fisheries.
  3. IOTC-2023-WPEB19-24_rev3: provided an ecological risk assessment of cetaceans to Indian Ocean tuna fisheries. This study highlighted the need to better quantify cetacean bycatch in Indian Ocean tuna fisheries, particularly in gillnet fisheries.

The Committee welcomed the ongoing and strengthening collaboration between the IWC BMI (Bycatch Mitigation Initiative) and the IOTC. 

Actions recommended for the ASW by the Scientific Committee at IWC-SC Meeting 2024

The SC highlighted the following priority actions to advance the conservation efforts for Arabian Sea humpback whales:

  1. Continued involvement of at least one range-country scientist in regional communications and coordination, noting the need for a full-time CMP coordination role.
  2. Continuation of fisheries and ship strike risk assessments and work with stakeholders to develop mitigation measures for threats within the most important known habitat for Arabian Sea humpback whales, the Gulf of Masirah and Offshore waters IMMA.
  3. Continuation of collection of photo-ID and genetic data from Arabian Sea humpback whales. If possible, the sampling should be expanded to encompass wider temporal (and possibly spatial) coverage to increase sample sizes for updated abundance and trend modeling.
  4. Use of data collected from 2019 onwards to update models of abundance and trends, and to update the visual health assessment conducted by Minton et al. (2022).
  5. Formal review of the abundance estimates presented in SC/69B/CMP/12rev1 (or an update thereof) by the IWC’s ASI/ASG, and publication in a peer-reviewed journal.
  6. Continuation of passive acoustic monitoring off the coasts of India and Oman and implementation in other areas of historical or potential Arabian Sea humpback whale distribution.
  7. Completion the genetic analyses to provide clarity on the taxonomic status of ASHW.
  8. Organization of an in-person workshop in Oman to progress the development of a CMP.

The IWC Scientifc Committee report and its annexes can be downloaded here.

The Environment Society of Oman celebrates the graduates of a year-long Cetacean Research and Conservation Capacity Building programme

On Friday, October 5th, 2023, the Environment Society of Oman celebrated the achievement of four early-career Omani scientists who completed a year-long long capacity building programme on cetacean research and conservation.  The programme, previously funded by HSBC Oman and now by Sohar International Bank, started in September 2022 with a series of classroom style components, delivered through a combination of online and in-person elements including lectures, questions and answers and group exercises. Half-day long modules focused on topics including general cetacean biology and ecology, cetaceans in Oman, cetacean research methodology, protocols for boat-based research in Oman, and a module titled ‘beyond research – engaging stakeholders in conservation’.

Participants also took part in boat-based surveys in the Muscat area and the Gulf of Masirah, where they had a chance to complement their classroom learning with hands-on experience in data collection protocols, photo-identification, data downloading and archiving, and mapping and data analysis.   On Thursday, October 5th, participants presented the results of their final projects, which required them to apply their experience in a very practical way.  Final projects included the drafting and design of a ‘glossy’ survey report for funders, geospatial analysis of the November 2022 Gulf of Masirah survey data, the design of a month-long social media campaign to raise awareness of cetaceans and their conservation needs in Oman, and the design and implementation of a systematic cetacean survey in Musandam.  

All four candidates did an excellent job of presenting their project results to ESO management and the sponsor. The programme will continue with some more Muscat-based survey training.  It will be great to see what this inspiring new generation of cetacean scientists and advocates do next.

ASWN members participate in a regional meeting showcasing new tools for marine conservation

The Global Biodiversity Initiative Project (GOBI) hosted a meeting in Oman on October 2-4th, 2023 with the theme of ‘New tools to support ocean conservation, planning and sustainable use in the northwest Indian Ocean’.  A number of ASWN members participated, representing organizations from Oman, Pakistan, and India.  

The workshop highlighted a suite of new tools developed under the GOBI-IKI Project, including:

The meeting also included presentations from regional participants, who described ongoing projects to protect marine biodiversity in Oman, India, Sri Lanka, Pakistan, the Seychelles, and Mauritius. These presentations included a focus on Arabian Sea humpback whales, and the work that the Environment Society of Oman, WCS India, WWF Pakistan and the University of Karachi, and the ASWN are doing to better understand the population and to work towards a regional Conservation Management Plan for this Endangered population.  

The meeting provided an excellent opportunity for a few ASWN members to reconnect in person, and to welcome new members from WCS India and WWF Pakistan.  It also provided inspiration to and raise funds to bring the wider network together in person.  Watch this space!

Iran’s reporting network yields valuable records of Bryde’s whales

Bryde’s whales (Balaenoptera edeni) sighting

In recent news from the region, two baleen whales were spotted by fishermen; Mr. Meysam Sajadi Far and Amir Jamshidiat from Kangan, at two different locations in the Persian* Gulf on the 20th and 21st of June 2023. The fishermen shared photos and videos of the sightings with ASWN members, Plan4theLand, who, in turn, shared photos with ASWN members with particular expertise in identifying baleen whales. It was agreed that the whales are very likely to be Bryde’s whales (Balaenoptera edeni) based upon some discernible features and elimination of other candidate species.

Caption: Locations of two Bryde’s whale sightings reported by fishers to ASWN Partners in Iran, Plan4theLand.

Sightings of Bryde’s whales are fairly common throughout the Northern Indian Ocean, including in the Persian* Gulf. ASWN members have reported many sightings over the years, and the ASWN Google Group email list has proven a good forum for sharing these sightings and confirming species’ identifications. The region hosts two 2 genetically recognized, but poorly studied subspecies of Bryde’s whale: the larger, offshore form, Balaenoptera edeni brydei, and the smaller, coastal form, Balaenoptera edeni edeni (Kershaw et al. 2013). Furthermore, researchers are always on the lookout for the more rarely documented Omura’s whale (Balaenotera omura) (Cerchio et al. 2019), which is similar in general size and warm-water range, and is known to occur in the region, based on a confirmed stranding record from Qeshm, Iran (Ranjbar et al. 2016). In the recent observations of these two baleen whales, photographic evidence clearly indicates that they are not Omura’s whales, leaving Bryde’s whale as the most likely alternative since other small to medium size balaenopterid (rorquals) whales are absent from the Gulf.

Reports from fishing communities and recreational vessels or other ‘citizen scientists’ are very helpful in learning more about the distribution of these whales in the region. This information plays a vital role in regional research and conservation efforts. During the 2023 IWC Scientific Committee meeting, the Committee discussed the importance of further investigations to better understand the drivers of the distribution and relative abundance of Bryde’s whales in the Arabian region.

Recent acoustic data from southern oman (Cerchio et al. 2023) indicated the consistent presence throughout the year of a vocalisation likely to be from Bryde’s whale, and the results of boat-based surveys (Minton et al. 2023) reflected an inverse relationship between detections of Bryde’s whales and humpback whales, with authors speculating that both species’ relative abundance may vary in relation to oceanographic conditions that favour one type of prey over another. There were several recommendations to continue this work and, when possible, combine observational and acoustic datasets within the Arabian Sea to advance our understanding of whale habitat use and distribution in the region. The sub-committee recommended regional collaboration to continue to collect information, and to conduct more dedicated research to better address the status of this species. The ASWN hopes to foster this regional collaboration and to support members in their efforts to foster effective reporting networks that will facilitate the contribution of more valuable sightings like this most recent one from Iran.

Cited Literature

  • Cerchio, S., Willson, A., Cholewiak, D., Sackett, M., Al Harthi, S., Baldwin, R., Collins, T., Minton, G., Sarrouf Willson, M., 2023. Acoustic monitoring for baleen whale vocalizations off southern Oman, 2020 to 2022. Document presented to the Scientific Committee of the International Whaling Commission SC/69A/CMP/12/Rev1, 18.
  • Cerchio S, Yamada TK and Brownell RL Jr (2019) Global Distribution of Omura’s Whales (Balaenoptera omurai) and Assessment of Range-Wide Threats. Front. Mar. Sci. 6:67. doi: 10.3389/fmars.2019.00067
  • Kershaw, F., Leslie, M.S., Collins, T., Mansur, R.M., Smith, B.D., Minton, G., Baldwin, R., LeDuc, R.G., Anderson, R.C., Brownell, R.L., 2013. Population differentiation of 2 forms of Bryde’s Whales in the Indian and Pacific Oceans. Journal of Heredity 104, 755-764.
  • Minton, G., Willson, A., Christiansen, F., Al Jabri, A., Al Lawati, R., Al Aamri, A., Baldwin, R., Collins, T., Cerchio, S., Willson, M.S., 2023. Cetacean surveys in Oman November 2019- November 2022. Docment presented to the Scientific Committee of the International Whaling Commission SC/69A/CMP/07, 19.
  • Ranjbar, S., Dakhteh, S. M. H., and Van Waerebeek, K. (2016). Omura’s whale Balaenoptera omurai stranding on Qeshm Island, Iran, Persian Gulf: further evidence for a wide (sub)tropical distribution. J. Mar. Biol. Oceanogr. 5:3. doi: 10.4172/2324-8661.1000161
*also known as the Arabian Gulf in many ASHW range countries
Lake Bled, Slovenia

Arabian Sea Whales at the 2023 IWC Scientific Committee Meeting

This year the annual IWC Scientific Committee (SC) meeting was held in Bled, Slovenia between the 24th April and the 6th May 2023. A few ASWN members had the opportunity to attend the meeting in person or virtually, including Gianna Minton, Andrew Willson, Sal Cerchio, Tim Collins, Aida al Jabri and Moazzam Khan. 

Arabian Sea Humpback Whales (ASHW) were identified as a priority candidate for a Conservation Management Plan (CMP) in 2010. During this year’s meeting the IWC SC congratulated  the significant progress that has been made towards the development of a joint CMS-IWC CMP for ASHWs despite the current obstacles. The efforts of Arabian Sea Whale Network members were acknowledged by the Committee members as essential to creating the framework to develop a CMP. The Committee commended stakeholders in Oman for hosting a workshop focusing on Conservation Management of  ASHW at national and regional levels, and further reiterated the importance of regional collaboration. 

A number of documents and papers were presented by ASWN members at the meeting including the following: 

  • The annual ASWN Progress Report (SC/69A/CMP/04Rev1): featured contributions from several ASWN members, including updates on both regional-level activities and  projects, sightings and stranding reports, and capacity building conducted at local and national levels throughout the region. The report highlighted the lack of  sightings of ASHWs in the Arabian Gulf in past years despite the increased observation and reporting efforts. The sub-committee on CMS encouraged both, the work of the ASWN, and continued progress towards developing and implementing a regional CMP.
  • Cetacean Surveys in Oman (SC/69A/CMP/07): Findings surveys conducted between November 2019 and November 2022 further reinforced the need for continued monitoring of species of whales’ relative abundance, distribution and health in relation to changing oceanographic conditions in the Arabian Sea.
  • Sightings of whales in the Northern Arabian Sea along the coast of Pakistan in 2022 and 2023 (SC/69A /CMP/05): reports on the past year’s results of  the WWF Pakistan crew-based observer programme, which still includes some humpback whale sightings despite a lack of funding for the captains that share sightings data.
  • Variation in songs of Arabian Sea humpback whales (SC/69A/CMP/10): indicates continued isolation of ASHW from other Indian Ocean humpback whale populations, a slow rate of song change in the Arabian Sea, and connectivity between Oman and India.
  • Acoustic monitoring for baleen whale vocalizations off southern Oman from 2020 to 2022 (SC/69A/CMP/12): reported frequent detections of blue whale songs from NWIO and CIO populations; indicating the two populations’ range overlap in southern Oman.
  • Geospatial analysis of ASHW habitat preference and ship strike risk assessment (SC/69A/HIM/07): presented a ship strike risk analysis and a suggestion  that routing vessels 40 nm further offshore from the current shipping lane off the Arabian Sea coast of Oman would reduce ship trike risk by as much as 88%.
  • A note on humpback whales (Megaptera novaeangliae) in the central Indian Ocean (SC/69A/ForInfo/33): described a bimodal pattern of occurrence of humpback whales in the CIO using information collated from various sources, including social media and a citizen science project.
  • Arabian Sea Humpback Whale (Megaptera novaeangliae) Singing Activity off Netrani Island, India (SC/69A/ForInfo/52 ): describes humpback whale song recorded by a passive acoustic recorder moored off of southern India.
  • Remote and non-invasive quantification of ‘Tattoo Skin Disease-Like’ dermatopathy in endangered Arabian Sea humpback whales using drone photography (SC/69A/ForInfo/68): Drone aerial photography was used as a complementary approach to images obtained during boat-based surveys to identify and quantify TSD-L lesions.
  • A report from the ASHW Biotelemetry ICG (SC/69A/SMP26):  described discussions related to the risks and potential value of continuing satellite tagging to address the key data gaps following previous tagging  studies.  The document includes recommendations to adopt rigorous tagging protocols following best practices that were endorsed by the committee. 

Actions recommended for the ASW by the Scientific Committee at IWC-SC Meeting 2023

Discussion of the body of work presented led the IWC Scientific Committee to draw the following conclusions and recommendations:

Excerpt from  Annex F ,  page 18-19 – recommendations for Arabian Sea humpback whales

The sub-committee applauded the stakeholder engagement workshop held in Oman to advance ASHW conservation and the potential benefits of a CMP. 

Noting that a) in 2008 the population of ASHW was estimated at 82 individuals, and that since then SC has repeatedly expressed concern about the urgent need for conservation management interventions; b) detection of ASHW song during the breeding season declined from 59% of monitored hours in 2011-12 to 2% in the 2021/2022 season, and that sightings of ASHW in formerly core habitat have become sporadic, coinciding with sea surface temperature anomalies which are at or above an upper threshold for ASHW; c) a weakening of the northwest Indian Ocean monsoon is causing deoxygenation and denitrification of surface waters, which is negatively influencing ecosystem productivity including sardines, an important ASHW prey; d) a 35% regional increase in the volume of vessel traffic between 2008 and 2018 has increased the risk of ship strike within ASHW core habitat; and e) two thirds of animals observed in the western Arabian Sea have scarring associated with fisheries interactions:

The committee commended efforts fostered by authorities to study the ASHW population and expressed deep concern for the population based on its current status and the degrading condition of its habitat, strongly reiterated that the Arabian Sea humpback whales are priority candidates for a CMP, and welcomed efforts to encourage range states to develop a joint CMS-IWC CMP. The sub-committee strongly recommended the following actions as a matter of absolute urgency throughout the ASHW range:

  1. produce a synthesis of ASHW distribution, identification of important habitats and potential threats throughout its range, and use these to develop marine spatial management plans across the region to mitigate impacts in high-risk areas with a focus on both commercial and artisanal fisheries interactions, and impacts from commercial shipping and ship strike risk assessments using multi-species and dynamic species distribution modelling approaches;
  2. support the continuation of the crew-based observer programme in Pakistan (SC/69A/CMP/05), and, where possible, replicate this approach throughout the region especially in areas where systematic cetacean surveys are not feasible;
  3. continue the use of UAVs to assess body condition in conjunction with other metrics to assess seasonal and annual variation and to evaluate health, scarring, and foraging success and that photographic data collected in Oman from 2019-2022 is used to conduct an updated visual health assessment using the same methodology as used by Minton et al. (2022);
  4. conduct continuous and simultaneous passive acoustic monitoring in ASHW identified habitat in both the western Arabian Sea (different parts of Oman’s waters, Socotra and the Gulf of Aden) and eastern Arabian Sea (Pakistan, India, Sri Lanka and the Maldives) to: (a) describe and assess changes in spatiotemporal distribution throughout the Arabian Sea and (b) use song structure variation as an indicator of movements of individuals, potential sub-structure within the population, and monitor for future mixing with other populations;
  5. conduct further satellite telemetry studies specifically aimed at filling important data gaps in the temporal distribution and sex composition of existing data, including assessing movement behaviour of individuals during the periods February and June to October, and increasing the sample size of females;
  6. collate and analyse stranding data throughout the suspected ASHW range to better understand trends in whale distribution and mortality;
  7. complete genetic analyses of the Megaptera indica type specimen in comparison with genetic samples from Oman in order to clarify the taxonomic status of ASHW; and
  8. regularly update abundance and trend estimates with the most recently available photographic mark-recapture data.

Furthermore, the subcommittee noted that the lack of funding for dedicated coordination of the network was potentially hindering progress toward a CMP, and recommended that funding be sought to support coordination and capacity building opportunities for a range country scientist to take on this role.  The subcommittee also discussed stranding records of Bryde’s whales from Pakistan and UAE. Given the limited information on Bryde’s whales in the region the committee recommended regional collaboration to conduct more dedicated research to better address the status of the species across the region. 

The complete report of the 2023 IWC-SC Meeting can be found here.