Eyal Bigal

All Publications

• Bridging the gap in deep seafloor management: Ultra fine-scale ecological habitat characterization of large seascapes REMOTE SENSING IN ECOLOGY AND CONSERVATION Sorensen, O., van Rijn, I., Einbinder, S., Nativ, H., Scheinin, A., Zemah-Shamir, Z., Bigal, E., Livne, L., Tsemel, A., Bialik, O. M., Papeer, G., Tchernov, D., Makovsky, Y. 2025

  View details for DOI 10.1002/rse2.70002

  View details for Web of Science ID 001435263800001

• Shark shuffle: segregated co-occurrence of multiple dusky and sandbar lineages at a human-altered habitat in the eastern Mediterranean Sea. Scientific reports Bigal, E., Livne, L., Zemah-Shamir, Z., Levy, T., Shemesh, E., Tchernov, D., Scheinin, A. 2024; 14 (1): 19924

  Abstract

  Requiem sharks (genus Carcharhinus) have previously been reported to form large aggregations around marine infrastructures in the eastern Mediterranean Sea. While this behaviour may offer fitness advantages at the individual level, the implications of extended residency at human-altered habitats for population persistence have yet to be assessed. In this work, we investigated the phylogeographic and demographic composition of sharks near a coal-fired power and desalination station in Israel. Our aim was to infer habitat use and the mechanisms underlying the aggregation behaviour, and to highlight potential conservation impacts. We sampled, measured, and released 70 individuals between 2016 and 2022 to assess genetic variability within the cytochrome C oxidase I (COI) region and to analyse the aggregation's structure based on the sharks' size and sex distribution. In addition, we performed meristic counts on a reference specimen collected dead at another power station in Israel to supplement species identification using the abovementioned techniques. Our findings indicate size-based sex segregation of adult female dusky and male sandbar sharks (Carcharhinus obscurus and Carcharhinus plumbeus, respectively), with each species comprising two COI haplotypes. In the dusky shark, one haplotype corresponded to an Indo-Pacific lineage, and the other matched an Atlantic lineage. In the sandbar shark, we observed a haplotype previously sampled in the Mediterranean Sea, the Red Sea, the Northwest Indian Ocean, and South Africa, and another haplotype that was unique to our study site and genetically closer to the former than to sequences sampled in other ocean basins. This study provides the first indication of sympatric aggregation amongst phylogeographically distinct dusky and sandbar shark lineages, suggesting that human-altered habitats in the eastern Mediterranean Sea may influence the distribution of these species. Based on the observed segregation pattern, we conclude that the site does not function as a nursery, parturition, or mating area, and discuss other plausible explanations that warrant further research. Finally, we highlight important directions for future research and the implications of our findings for management and conservation.

  View details for DOI 10.1038/s41598-024-69460-x

  View details for PubMedID 39198577

  View details for PubMedCentralID 3596407

• Characterising a potential nearshore nursery ground for the blackchin guitarfish (<i>Glaucostegus cemiculus</i>) in Ma'agan Michael, Israel FRONTIERS IN MARINE SCIENCE Azrieli, B., Cohen, E., Livne, L., Ramon, D., Tsemel, A., Bigal, E., Shemesh, E., Zemah-Shamir, Z., Barash, A., Tchernov, D., Scheinin, A. 2024; 11

  View details for DOI 10.3389/fmars.2024.1391752

  View details for Web of Science ID 001268422500001

• First description of a Gammaherpesvirus in a common dolphin (<i>Delphinus delphis</i>) from the Eastern Mediterranean Sea VETERINARY RESEARCH COMMUNICATIONS Morick, D., Davidovich, N., Zemah-Shamir, Z., Kroin, Y., Bigal, E., Sierra, E., Segura-Gothlin, S., Wosnick, N., Hauser-Davis, R., Tchernov, D., Scheinin, A. P. 2023; 47 (4): 2253-2258

  Abstract

  In September 2020, a male common dolphin (Delphinus delphis) was found dead on a beach near Bat-Yam, Israel. A small, raised, well circumscribed penile lesion (i.e., mass) was identified and removed for histology and molecular characterizations. By histology, the penile mass presented focal keratinization of the squamous epithelium and a mild ballooning of acanthocytes in lower epithelium levels, as well as features compatible with viral plaques, and tested positive for a gammaherpesvirus through molecular characterization analyses. Tissue samples from the lungs, liver, and spleen, however, tested negative for herpesvirus infection. The gammaherpesvirus detected herein is similar to other isolates found in several areas worldwide in different cetacean species. This is the first reported case of gammaherpesvirus infection in dolphins from the eastern Mediterranean Sea, indicative of the need for long-term assessments to create viral infections databases in cetaceans, especially in a climate change context, which is likely to intensify infectious disease outbreaks in marine mammals in the future.

  View details for DOI 10.1007/s11259-023-10125-x

  View details for Web of Science ID 000972656400001

  View details for PubMedID 37088865

  View details for PubMedCentralID 5543654