Bowhead Research Articles

Unraveling the Genetic Legacy of Commercial Whaling and Population Dynamics in Arctic Bowhead Whales and Narwhals.

Assessing genetic structure and diversity in wildlife is particularly important in the context of climate change. The Arctic is rapidly warming, and endemic species must adapt quickly or face significant threats to persistence. Bowhead whales (Balaena mysticetus) and narwhals (Monodon monoceros) are two long-lived Arctic species with similar habitat requirements and are often seen together in the Canadian Arctic. Although their ranges overlap extensively, bowhead whales experienced significantly greater commercial whaling mortality than narwhals over several centuries. The similar habitat requirements but different harvest histories of these two species provide an opportunity to examine present-day genetic diversity and the demographic and genetic consequences of commercial whaling. We whole-genome resequenced contemporary Canadian Arctic bowhead whales and narwhals to delineate population structure and reconstruct demographic history. We found higher genetic diversity in bowhead whales compared to narwhals. However, bowhead whale effective population size sharply declined contemporaneously with the intense commercial whaling period. Narwhals, in contrast, exhibited recent growth in effective population size, likely reflecting exposure to limited opportunistic commercial harvest. Bowhead whales will likely continue to experience significant genetic drift in the future, leading to the erosion of genetic diversity. In contrast, narwhals do not seem to be at imminent risk of losing their current levels of genetic variation due to their long-term low effective population size and lack of evidence for a recent decline. This work highlights the importance of considering population trajectories in addition to genetic diversity when assessing the genetics of populations for conservation and management purposes.

Identification of Key Habitats of Bowhead and Blue Whales in the OSPAR Area of the North-East Atlantic—A Modelling Approach towards Effective Conservation

Effective protection of highly mobile and data-poor species constitutes a great challenge amid growing ocean exploitation and use. Blue whales and bowhead whales in the North-East Atlantic face several threats, such as climate change, ship strikes, pollution, and entanglement in fishing gear. Consequently, the OSPAR (“Oslo-Paris Convention for the Protection of the Marine Environment of the North-East Atlantic”) Commission recognised their need for protection and included them on the OSPAR List of Threatened and/or Declining Species. Two actions to protect these endangered species that OSPAR Contracting Parties have agreed on are (i) identifying areas that play an essential role in the species’ life cycle—subsequently called key habitats, and (ii) ensuring that those key habitats are covered by OSPAR marine protected areas (MPAs). In addition, OSPAR has committed to expanding its network of MPAs and other effective area-based conservation measures by 2030 to cover at least 30% of the OSPAR maritime area (termed the 30 × 30 target) from today’s approx. 11%. In this paper, we present the results of modelling key habitats for the bowhead and blue whales in the North-East Atlantic, including Arctic waters. Due to the sparse data situation for these species, we apply presence-only modelling methods. As this method can, in principle, produce somewhat biased results, we recommend that systematic, regular surveys on these species in Arctic waters be significantly intensified for future analyses to overcome the data paucity and allow using presence–absence/count data modelling approaches. Key habitats of blue whales were identified between Iceland and Svalbard, extending to the Azores. For bowhead whales, key habitats were identified in the Fram Strait. However, our findings show that only 11.8% of blue whale key habitats and 4.1% of bowhead whale key habitats are currently covered by OSPAR MPAs. To protect 30% of key habitats for these species in the most efficient way, our analyses suggest that suitable areas to designate new OSPAR MPAs are located around the Azores for blue whales and in the Fram Strait for bowhead whales. With these additional MPAs, OSPAR would substantially improve the protection of the two endangered species and, at the same time, progress towards its 30 × 30 target.

Food chain without giants: modelling the trophic impact of bowhead whaling on little auk populations in the Atlantic Arctic.

In the Atlantic Arctic, bowhead whales (Balaena mysticetus) were nearly exterminated by European whalers between the seventeenth and nineteenth centuries. The collapse of the East Greenland-Svalbard-Barents Sea population, from an estimated 50 000 to a few hundred individuals, drastically reduced predation on mesozooplankton. Here, we tested the hypothesis that this event strongly favoured the demography of the little auk (Alle alle), a zooplanktivorous feeder competitor of bowhead whales and the most abundant seabird in the Arctic. To estimate the effect of bowhead whaling on little auk abundance, we modelled the trophic niche overlap between the two species using deterministic simulations of mesozooplankton spatial distribution. We estimated that bowhead whaling could have led to a 70% increase in northeast Atlantic Arctic little auk populations, from 2.8 to 4.8 million breeding pairs. While corresponding to a major population increase, this is far less than predicted by previous studies. Our study illustrates how a trophic shift can result from the near extirpation of a marine megafauna species, and the methodological framework we developed opens up new opportunities for marine trophic modelling.

Flow-Induced Vibration Analysis by Simulating a High-Speed Train Pantograph

This paper investigates the aerodynamic behavior and dynamic characteristics of high-speed train pantographs under various operating conditions using advanced aerodynamic simulations and dynamic analyses. The simulations show significant fluctuations in aerodynamic loads during tunnel entry and exit, heavily influenced by train speed and pantograph position (raised/lowered). Modal simulations reveal distinct low-frequency vibrations in pantographs, significantly impacted by external aerodynamic forces. Importantly, the lowered position exposes the pantograph to upward aerodynamic forces, leading to increased bow-net contact force and off-line rate, ultimately compromising current collection stability. Both maximum contact force and off-line rate further increase with higher train speeds. To improve pantograph design, the paper proposes adjustments to the airbag’s equivalent spring stiffness and the bow head’s density. These modifications aim to mitigate contact force and enhance the stability and reliability of pantographs at high speeds. This research offers theoretical and practical insights, aiding in the design, optimization, and refinement of future pantograph systems.

Seasonal and diurnal marine mammal presence in the proposed marine protected area of Southampton Island, Hudson Bay, Nunavut as revealed by passive acoustic monitoring

Marine protected areas contribute to mitigating the effects of human activities on marine ecosystems. The waters of Southampton Island, Nunavut, Canada are under consideration to become a marine protected area, but baseline information of marine mammal presence and habitat use is lacking. This study represents the first passive acoustic monitoring of marine mammals in this area, with data collected in 2018 and 2019. Bioacoustics analyses and generalized linear models were used to investigate species seasonal and temporal vocalization trends; infer behavior and habitat use from vocal cues; and explore vocal activity correlation with sea ice. Over a diel period, bearded seals ( Erignathus barbatus (Erxleben, 1777)) and walruses ( Odobenus rosmarus (Linnaeus, 1758)) were found to increase their vocal activity at night, whereas belugas ( Delphinapterus leucas (Pallas, 1776)) mainly vocalized during daytime. Seasonally, bearded seals were recorded only during their breeding season at sea ice break-up, while walruses vocalized consistently throughout the open-water period outside their breeding season. Beluga vocal trends suggest their use of the area as a migratory corridor during sea ice break-up and freeze-up. Finally, bowhead whales ( Balaena mysticetus Linnaeus, 1758) were recorded later than expected, concurrently with the onset of their mating vocal displays during the fall migration at sea ice freeze-up.

Baleen whale microsatellite panel for individual identification and parentage assignment in Mysticeti

Highly polymorphic single tandem repeat loci (STR, also known as microsatellite loci) remain a familiar, cost efficient class of genetic markers in genetic studies in ecology, behavior and conservation. Here we characterize a new, universal set of ten STR loci in seven species of baleen whales, optimized for PCR amplification in two multiplex reactions along with a Y chromosome marker for sex determination. The optimized, universal set of STR loci provides a convenient starting point for new genetic studies in baleen whales aimed at identifying individuals and populations. Data from the new STR loci were combined with genotypes from previously published STR loci to assess the power to assign parentage using paternity exclusion in four species: fin whale (Balaenoptera physalus), humpback whale (Megaptera novaeangliae), blue whale (B. musculus) and bowhead whale (Balaena mysticetus). Our results suggest that parentage studies should always be accompanied by a power analysis in order to ascertain that each individual specific study is based upon data with sufficient power to assign parentage with statistical rigor.

Exposure of satellite tagged bowhead whales (Balaena mysticetus) to transiting vessels in the Eastern Canadian Arctic

AbstractClimate change poses new challenges to Arctic marine mammals, with increasing vessel traffic and associated underwater noise pollution emerging as significant threats. The bowhead whale (Balaena mysticetus), an endemic Arctic cetacean, faces these new threats. The Eastern Canada‐West Greenland (ECWG) bowhead whale population migrates through areas with the highest levels of vessel traffic in the Canadian Arctic. Here, we document the spatial and temporal overlap between 36 satellite‐tagged ECWG bowhead whales and vessels equipped with Automatic Identification System (AIS) transponders during 2012–2017. We report 1,145 instances where vessels were within 125 km of a tagged whale, with 306 occurrences within distances ≤50 km. Overlap between vessels and tagged bowhead whales was quantified monthly within years to investigate individual whale encounter rates. Results indicate that ECWG bowhead whales encounter the majority (79%) of vessels annually during August–October, with the highest number of encounters (42%) observed in September. Encounter rates ranged from 0.25 to 0.51 vessels encountered per day per whale during August–October compared to <0.07 vessels per day in all other months in this study. To better inform conservation strategies, further research is required to assess bowhead whale behavioral responses relative to distance from vessels.

Automated approach for recovering modal components in shallow waters.

This paper proposes a fully automated method for recovering modal components from a signal in shallow waters. The scenario involves an unknown source emitting low-frequency sound waves in a shallow water environment, and a single hydrophone recording the signal. The proposed automated algorithm is based on the warping method to separate each modal component in the time-frequency space. However, instead of manually choosing a single arrival time for extraction, the method performs successive extractions with automated time selection based on an explicit quality factor. Modal component separation is achieved through a watershed algorithm, streamlining the process and eliminating the need for manual intervention. The proposed method is tested on experimental data of a right whale gunshot, a combustive sound source, and a bowhead whale upsweep, demonstrating its effectiveness in real-world scenarios.

Abstract 4890: In silico study of enzymes involved in heparan sulfate catabolic process in cancer resistant mammals

Abstract Some mammals such as elephants, bats, whales, and blind mole rats (Spalax) are resistant to cancer. One of the cancer protective mechanisms present in such species includes a reduced degradation of heparan sulfate (HS), an important component of the extracellular matrix (ECM), present in Spalax. Such effect occurs due to a splicing variant of heparanase, called variant 36, that lacks enzymatic activity. Consequently, both HS and ECM are very stable in Spalax’s tissues. If HS is stabilized, in cancer resistant mammals, due to the decrease of heparanase or other enzymes involved in HS catabolic process is unknown. We studied total of 9 enzymes (HPSE2, GusB, IDUA, IDS, NAGLU, SGSH, GNS, Sulf-2, HGSNAT) that regulate HS catabolism and homologs in 9 mammals. Multiple sequence alignments were done by MEGA to identify substitutions present in cancer resistant species in comparison with cancer susceptible animals. Such amino acid variants were further analyzed and both their energy stability and their functional effects were predicted by using online in silico tools including MAESTROweb, Condel, PANTHER, REVEL, and CADD. Finally, homologs with deleterious predicted variants were modelled with SWISSMODEL and their 3D structures were analyzed with Pymol and ChimeraX to identify structural features likely related to its loss of function. We found two loss of function missense variants, K264Q and W626L, in Alpha-L-iduronidase (IDUA) of Spalax. In addition, most of Brandt's bat enzymes and the N-sulphoglucosamine sulphohydrolase (SGSH) of the bowhead whale were very energy destabilizing enzymes with positive and higher ΔΔG values compared to human homologs. In the other hand, although some catalytic residues in the study enzymes are conserved in cancer resistant animals, their spatial arrangement and conformation in the 3D structure are different compared to human homologs, including E182 of IDUA which is one of the catalytic residues. In general, the secondary structure is conserved across the 9 enzymes studied but some differences were observed in cancer resistant animals including one of the beta strands near the catalytic domain in human and mice IDUA that appears as a loop in Spalax. In summary, HS stabilization could raise in cancer resistant mammals through the existence of lack of enzymatic activity not only in heparanase but also in other enzymes that participate in HS catabolic process, via a set of loss of function variants and changes in secondary and tertiary structure as well as a reduction of energy stabilization. More interestingly, such mechanism could be present in other cancer resistant mammals such as bats and bowhead whales. This study demonstrates that computational approaches are useful to study biological mechanisms of cancer resistance present in some mammals. This knowledge could be translated to humans and HS catabolic process could offer a new source of therapeutic anticancer targets. Citation Format: Fabrizio Oliveri Payet, Claudia Machicado Rivero. In silico study of enzymes involved in heparan sulfate catabolic process in cancer resistant mammals [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4890.

A statistical acoustics approach for estimating population-scale bowhead whale migration speed and direction.

Bowhead whales vocalize during their annual fall migration from the Beaufort Sea to the Bering Sea, but the calling rates of individual animals are so low that tracking an individual trajectory is impractical using passive acoustic methods. However, the travel speed and direction of the migrating population can be inferred on a statistical basis by cross-correlating time sequences of call density measured at two locations spaced several kilometers apart. By using the triangulation abilities of a set of vector sensors deployed offshore the Alaskan North Slope between 2008 and 2014, call density time sequences were generated from 1-km wide and 40-km tall rectangular "zones" that were separated by distances ranging from 3.5 to 15 km. The cross-covariances between the two sequences generate a peak corresponding to the average time it takes for whales to travel between the zones. Consistent westward travel speeds of ∼5 km/h were obtained from four different locations on 6 of the 7 years of the study, independent of whether the zones were separated by 3.5, 7, or 15 km. Some sites, however, also revealed a less prominent eastern movement of whales, and shifts in migration speed were occasionally detectable over week-long time scales.

Basin‐Wide Shift in Bowhead Whale Migration in the Pacific Arctic

AbstractIn a rapidly changing Arctic, multiple lines of evidence suggest that bowhead whale migration is changing. To explore these changes further, we used passive acoustic data to examine bowhead whale presence in the western Beaufort Sea (12 years) and Chukchi Plateau (11 years) spanning 2008 to 2022. Departure from the western Beaufort Sea shifted 45 days later over the 12‐year period. Summer presence increased at both sites, suggesting feeding areas within the Chukchi Sea are becoming more favorable. Likewise, findings from the Bering Strait suggest that some whales are remaining north of the Bering Strait for the winter instead of in the Bering Sea. These Pacific Arctic‐wide changes to migration have occurred over only one decade. Questions remain about prey availability in the Chukchi Sea, implications of migratory changes, such as a northward shift in the core overwintering area, and impact to communities south of the Bering Strait.

On the edges of extinction: Indigenous whaling governance, the 1977 “bowhead controversy” and its legacy

Abstract In its nearly 80-year history, the International Whaling Commission (IWC) has shifted from a “whalers club” to an international governance body chiefly focused on the protection and conservation of global cetacean populations. Drawing on recent scholarship on extinction and its entanglements, this article compares two addresses given by whalers at IWC meetings 40 years apart to problematise the way whaling and its relation to extinction is conceptualised in international environmental governance. Guided by practice-oriented document analysis and recent theorisation of extinction as an entangled process, this article analyses the personal stakeholder testimonies from two different representatives of the North Slope whalers of Northern Alaska to the IWC – one in relation to the 1977 Alaska bowhead whaling controversy and the other in the context of the 2018 negotiations over streamlining Aboriginal Subsistence Whaling management and supporting greater flexibility and Indigenous autonomy. By comparing these two statements from very different points of history for the IWC and the governance of Indigenous whaling, this article illustrates some of the ongoing struggles for environmental governance to recognise extinction as a complex, multifaceted process that reverberates throughout human and more-than-human communities.

Mechanisms of Cancer-Resistant Mammals

Cancer is a medical disorder when a few of the body’s cells multiply uncontrollably and extend in a considerable amount of time. Researchers are trying everything to find a solution for cancer. This review is mainly focused on elephants, bowhead whales, naked mole rats and their inner mechanisms, which make them resistant to cancer. Statistically, larger animals such as elephants have much more cells then human, which means that they ought to have more cases of cancer, but there is an inner mechanism, which works in these animals and makes them cancer resistant. Elephants possess unique p53 genes with 20 copies, while people only have one. If cells are severely damaged, the p53 genes instructs the cells to be destroyed due to potential cancer risk. This process appeared to cause them to activate the LIF6 gene, and that leads to apoptosis of shattered cells. Bowhead whales are able to repair double-strand breaks more accurately and more efficiently. Bowhead whales are less likely than humans to create removals when repairing mismatched DNA termini. Naked mole rat cells are immune to cancer as they are more susceptible to early and firsthand suppression, which is a mechanism that prevents tumors from forming. Unfortunately, humans are still clueless about how to transfer the cancer preventing methods which exist in these three magical organisms into human. Hopefully, with the rapid development of technology and advances in the biomedical field, one day scientists will be able to put these theories into practice.

Prey consumption of bowhead whales in West Greenland estimated from drone measurements of body size and condition

Prey consumption of bowhead whales in West Greenland estimated from drone measurements of body size and condition

An Automatic Deep Learning Bowhead Whale Whistle Recognizing Method Based on Adaptive SWT: Applying to the Beaufort Sea

The bowhead whale is a vital component of the maritime environment. Using deep learning techniques to recognize bowhead whales accurately and efficiently is crucial for their protection. Marine acoustic remote sensing technology is currently an important method to recognize bowhead whales. Adaptive SWT is used to extract the acoustic features of bowhead whales. The CNN-LSTM deep learning model was constructed to recognize bowhead whale voices. Compared to STFT, the adaptive SWT used in this study raises the SCR for the stationary and nonstationary bowhead whale whistles by 88.20% and 92.05%, respectively. Ten-fold cross-validation yields an average recognition accuracy of 92.85%. The method efficiency of this work was further confirmed by the consistency found in the Beaufort Sea recognition results and the fisheries ecological study. The research results in this paper help promote the application of marine acoustic remote sensing technology and the conservation of bowhead whales.

Pilot study: decoding the skin microbiome of bowhead (Balaena mysticetus) and killer whales (Orcinus orca) in Nunavut, Canada

Given the increasing challenges that Arctic cetaceans face, it is critical to investigate novel methods for assessing their health. Skin microbiomes have emerged as a promising method of detecting health issues that can help guide conservation efforts for free-ranging cetaceans. This study characterized the skin microbiome of 17 bowhead (BW) and 2 killer whales (KW). Fifty-six amplicon sequence variants were identified exclusively from cetacean samples, 20 belonged to BW, 13 to KW, and 23 to BW and KW. We identified bacteria from the genera Tenacibaculum and Psychrobacter, which have been previously described as bacteria that play a role in the health of cetaceans. In addition, in the healthy bowhead whale (H-BW) samples, we identified Clostridium sensu stricto 1 and 7, Carnobacterium spp., and Yersinia spp. which are of concern because these bacteria are opportunistic pathogens. Stranded BW had a less diverse microbiome than H-BW and had pathogens, including Aeromonas species and Streptococcus agalactia. Opportunistic pathogens of the genera Moritella (previously Vibrio spp.), Shewanella, Psychrilyobacter, and Legionella were discovered in KW. Due to their predator–prey relationships, the findings of this pilot study support the importance of keeping a close eye on the bowhead and killer whale populations in the Arctic.

Reproductive parameters of Bering‐Chukchi‐Beaufort Seas bowhead whales

AbstractData from Bering‐Chukchi‐Beaufort Seas bowhead whales (Balaena mysticetus), harvested during 1973–2021 by aboriginal subsistence hunters, were used to estimate reproductive parameters: length at sexual maturity (LSM), age at sexual maturity (ASM), pregnancy rate (PR), and calving interval. Sexual maturity (N = 187 females) was determined from the presence/absence of corpora in the ovaries, or a fetus. Using sampling bias‐corrected logistic regression, LSM was estimated at 13.5 m, 95% CI [13.0, 13.8]. There was a downward trend in LSM over time, statistically significant with one method but marginal with another. A growth model translated this estimate to an ASM estimate of 23.5 years, 95% CI [20.4, 26.7]. Pregnancy rate was determined from mature females (N = 125), and from a subset limited to certain autumn‐caught whales (n = 37) to reduce bias. The PR was estimated at 0.46 globally, 95% CI [0.36, 0.55] and 0.38 for the autumn sample, 95% CI [0.20, 0.51]. Both estimated PRs are consistent with a 3‐year calving interval, because the larger estimate includes two cohorts of pregnant whales harvested in spring, and bowhead whale gestation is longer than 12 months. These analyses represent the most conclusive empirical estimates of ASM, LSM, and PR for this bowhead whale stock from the largest available data sets to date.

PERAN PENDIDIKAN AGAMA ISLAM FORMAL DAN NON FORMAL DALAM MENINGKATKAN AKHLAKUL KARIMAH

Islamic religious education plays a very important role in the formation of a person's morals. And education, especially morals and morals, must be given from an early age to foster children's spiritual and physical growth, both spiritual, motoric, emotional, social and shape children's characteristics into good ones. It is not only in educational institutions that the family plays an important role in educating children, the main thing is in forming their characteristics properly and correctly.There are three forms of educational institutions currently developing in our country, namely formal, non-formal and informal. Formal educational institutions are educational institutions whose curriculum is created and managed by the government from pre-school level to university level. Then non-formal educational institutions are educational institutions whose curriculum is created and managed by the community, including Islamic boarding school or diniyah educational institutions. Meanwhile, informal education is education that is built or organized by the family and environment only for education without structure and does not require permission from the government.This article discusses the role of formal and non-formal Islamic religious education in improving morals. There are still students whose morals are not good, especially morals towards teachers. Researchers want to improve good morals towards teachers in order to gain useful knowledge and blessings. This research uses descriptive qualitative using data analysis techniques in the form of observation where the researcher takes qualitative primary data sources obtained from teachers of morals and aqidah. In this research the data source is secondary. The first research is that a student must obey the teacher by getting used to it when the teacher speaks or walks, the students bow their heads while giving respect with a bowed head gesture. To produce results such as when in class students or students must enter the class first to greet and prepare the place for the incoming teacher. The second is the teacher's guidance to students, namely using concrete story methods such as studying and giving sermons and this must also be used as an example by the teacher, so that from this method students who previously behaved badly can become good so that they can be applied in society. Third, if there are students or students who are difficult to manage, namely by using the approach of providing advice and motivation so that a student has good morals, it cannot be denied that stubborn students can occur due to internal factors such as lack of love for parents, then it will be fun for the teacher to talk to the student. Thank God, in this way students can change from bad morals to good morals..

Estimating abundance of Eastern Canada-West Greenland bowhead whales using genetic mark-recapture analyses

The Eastern Canada-West Greenland (EC-WG) bowhead whale (Balaena mysticetus) population is widely distributed across the eastern Canadian Arctic and across Baffin Bay to the western coast of Greenland. Their vast distribution makes obtaining population estimates via aerial surveys difficult, as coverage over their entire range is not possible. Genetic mark recapture analyses address this issue, as biopsy samples can be collected at various locales across the EC-WG bowhead whale population’s distribution and microsatellites can be analyzed to identify unique individuals. EC-WG bowhead whales were subject to intense commercial whaling pressure between the early 1700 s and early 1900 s, after which a moratorium on commercial whaling was put in place in 1915. We used available genetic samples from EC-WG bowhead whales in mark recapture models to estimate population abundance from 2012 to 2021 to gain insight on population dynamics ∼100 years post commercial whaling. The preferred model, using a Jolly-Seber structure, estimated the total abundance as 5173 individuals (CI: 3436–7788). Since the cessation of commercial whaling, the population has been thought to be rebounding, which is reflected by gradually increasing abundance estimates, from the low hundreds in the 1970 s and 1980 s, to ∼6000 in the early 2000 s, but our present estimate suggests population abundance may be plateauing well below the pre-commercial whaling carrying capacity estimate. This population estimate for EC-WG bowhead whales is required to update the population dynamics for conservation efforts.

First filter feeding in the Early Triassic: cranial morphological convergence between Hupehsuchus and baleen whales

Modern baleen whales are unique as large-sized filter feeders, but their roles were replicated much earlier by diverse marine reptiles of the Mesozoic. Here, we investigate convergence in skull morphology between modern baleen whales and one of the earliest marine reptiles, the basal ichthyosauromorph Hupehsuchus nanchangensis, from the Early Triassic, a time of rapid recovery of life following profound mass extinction. Two new specimens reveal the skull morphology especially in dorsal view. The snout of Hupehsuchus is highly convergent with modern baleen whales, as shown in a morphometric analysis including 130 modern aquatic amniotes. Convergences in the snout include the unfused upper jaw, specialized intermediate space in the divided premaxilla and grooves around the labial margin. Hupehsuchus had enlarged its buccal cavity to enable efficient filter feeding and probably used soft tissues like baleen to expel the water from the oral cavity. Coordinated with the rigid trunk and pachyostotic ribs suggests low speeds of aquatic locomotion, Hupehsuchus probably employed continuous ram filter feeding as in extant bowhead and right whales. The Early Triassic palaeoenvironment of a restrictive lagoon with low productivity drove Hupehsuchus to feed on zooplankton, which facilitated ecosystem recovery in the Nanzhang-Yuan’an Fauna at the beginning of the Mesozoic.