Common dolphins (Delphinus delphis) in Israel: Unique dynamics of a critically endangered population

Yaly Mevorach, Aviad Scheinin, Ori Galili, Nina Luisa Santostasi, Dan Tchernov

Research output: Contribution to journalArticlepeer-review

Abstract

The most eastern population of common dolphins (Delphinus delphis) in the Mediterranean Sea inhabits the southern coastal waters of Israel. They are mainly observed in the shallow waters off Ashdod and Ashkelon, between the 15-30 m isobaths, with no reported observations north or west of this area. These dolphins were observed and studied year-round between 2016-2021 using boat-based surveys and photo identification methods. Common dolphins were encountered and photographed 43 times during the study period, resulting in 2,851 identifications of 25 distinctive mature individuals and 12 calves. Most individuals (62%) were sighted over multiple years, with high yearly and monthly sighting rates, indicating long-term site fidelity and residency. Closed population mark-recapture models estimated a total abundance of 25 (95% CI 24 – 37) individuals in 2016 that declined to only 15 (95% CI 15 – 15) individuals in 2021. Social network analysis described these remaining individuals as one closed and well-associated social unit. Survival probabilities for this population appeared lower than those of other delphinid populations. The decrease in their abundance, coupled with their apparent isolation level, qualifies the local population for a re-assessment of their conservation status. This study first describes the Israeli local population of common dolphins, their dynamics and an assessment of their status based on the IUCN Red List framework.

Original languageEnglish
Article number916950
JournalFrontiers in Marine Science
Volume9
DOIs
StatePublished - 17 Nov 2022

Bibliographical note

Funding Information:
This study was funded by the Morris Kahn Marine Research Station, the department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, as part of a long-term monitoring study of the cetacean species along the Israeli coastline and by the Ministry of Energy in Israel. Additionally, this research was partly funded by the Prince Albert II of Monaco Foundation (grant No. 2241) as part of the ACCOBAMS Survey Initiative (ASI), coordinated by the Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS). Yaly Mevorach was supported by an M.Sc grant by the University of Haifa.

Publisher Copyright:
Copyright © 2022 Mevorach, Scheinin, Galili, Santostasi and Tchernov.

Keywords

  • abundance
  • common dolphins
  • conservation status
  • delphinus delphis
  • extinction risk
  • IUCN red list
  • mark-recapture
  • social structure

ASJC Scopus subject areas

  • Oceanography
  • Global and Planetary Change
  • Aquatic Science
  • Water Science and Technology
  • Environmental Science (miscellaneous)
  • Ocean Engineering

Fingerprint

Dive into the research topics of 'Common dolphins (Delphinus delphis) in Israel: Unique dynamics of a critically endangered population'. Together they form a unique fingerprint.

Cite this