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RESEARCH ARTICLE
Contents Vol 30(6)

Recent surveys of the sea otter (Enhydra lutris) population on Kuril Islands

Igor Popov https://orcid.org/0000-0002-2564-3294 A * and Anton Iurmanov B
+ Author Affiliations
- Author Affiliations

A Department of Applied Ecology, Faculty of Biology, St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia.

B K.A. Timiryazev Institute of Plant Physiology Russian Academy of Sciences, Street Botanicheskaya, 35, Moscow 127276, Russia. Email: yurmanov-anton.ya.ru@yandex.ru

* Correspondence to: i.y.popov@spbu.ru

Handling Editor: Mike Calver

Pacific Conservation Biology 30, PC24026 https://doi.org/10.1071/PC24026
Submitted: 3 April 2024  Accepted: 7 October 2024  Published: 24 October 2024

© 2024 The Author(s) (or their employer(s)). Published by CSIRO Publishing

Abstract

Context

Sea otters, an endangered species, require regular assessments of their distribution and abundance. These animals inhabit the coastal waters of the North Pacific, traversing from Japan through the Kurils, southern Kamchatka, Commander and Aleutian Islands, and the coasts of North America, to California. Although populations in America and the Commander Islands have been consistently monitored over recent decades, the same cannot be said for the Kuril Islands.

Aim

This study aims to estimate the state of sea otter populations on the Kuril Islands.

Methods

The study area encompassed a section of the Kuril archipelago, including Iturup, Urup, Broughton, Chirpoy, and Simushir Islands, surveyed from 2019 to 2023. Sea otters were counted along sections of the coastline, and published sources on other Kuril Islands were analysed.

Key results

There are several hundred sea otters within surveyed area, whereas in 1960–1980 ~2000 were reported. The total number of sea otters on the archipelago hardly exceeds 3000. The initial or normal number is not known, but the information on hunting indicates that it was much bigger. Up to the end of 19th century, at least ‘one thousand individuals’ had been harvested annually over several decades; this means that the total number was at least several tens of thousands.

Conclusions

Sea otter populations on the Kuril Islands are in decline, with poaching in the recent past identified as significant contributing factor in a part of the archipelago.

Implications

Urgent conservation measures are imperative to address the decline of sea otter populations.

Keywords: decline, kelp, killer whale, Kuril Islands, pelts, poaching, sea otter, trade.

References

Andersen Garcia M, Barre L, Simpkins M (2016) The ecological role of marine mammal killer whales in the North Pacific Ocean surrounding Alaska. Marine Mammal Commission, Bethesda, MD 20814.

Anon (2023) Sea otters spotted off Kiritappu Cape in Hokkaido. The Japan News. Available at https://japannews.yomiuri.co.jp/society/general-news/20230517-110112/

Belkin AN (1966) About current number and state of the sea otter population on Kuril islands. Izvestia TINRO 58, 3-13 [In Russian].
| Google Scholar |

Bodkin JL, Esslinger GG, Monson DH (2004) Foraging depths of sea otters and implications to coastal marine communities. Marine Mammal Science 20(2), 305-321.
| Crossref | Google Scholar |

Camp VL (2023) ‘A bibliography on the sea otter Enhydra lutris.’ 3rd edn. IUCN Otter Specialist Group Bulletin 40(D)), pp. 3–51.

Conrad PA, Miller MA, Kreuder C, James ER, Mazet J, Dabritz H, Jessup DA, Gulland F, Grigg ME (2005) Transmission of Toxoplasma: clues from the study of sea otters as sentinels of Toxoplasma gondii flow into the marine environment. International Journal for Parasitology 35(11-12), 1155-1168.
| Crossref | Google Scholar | PubMed |

Doroff AM, Estes JA, Tinker MT, Burn DM, Evans TJ (2003) Sea otter population declines in the Aleutian archipelago. Journal of Mammalogy 84(1), 55-64.
| Crossref | Google Scholar |

Doroff A, Burdin A, Larson S (2021) Enhydra lutris (errata version published in 2022). The IUCN red list of threatened species 2021: e.T7750A219377647. Available at https://dx.doi.org/10.2305/IUCN.UK.2021-3.RLTS.T7750A219377647.en [accessed 18 June 2024]

Ellis R (2004) ‘The empty ocean.’ (Island Press: Washington)

Estes JA, Tinker MT, Doroff AM, Burn DM (2005) Continuing sea otter population declines in the Aleutian archipelago. Marine Mammal Science 21, 169-172.
| Crossref | Google Scholar |

Fomin SV, Fedutin ID, Borisova EA, Meschersky IG, Filatova OA (2023) Sea otters (Enhydra lutris) found in the stomach of a stranded killer whale (Orcinus orca) in the Commander Islands, Western North Pacific. Aquatic Mammals 49(5), 462-467.
| Crossref | Google Scholar |

Foster E, Watson J, Lemay MA, Tinker MT, Estes JA, Piercey R, Henson L, Ritland C, Miscampbell A, Nichol L, Hessing-Lewis M, Salomon AK, Darimont CT (2021) Physical disturbance by recovering sea otter populations increases eelgrass genetic diversity. Science 374(6565), 333-336.
| Crossref | Google Scholar | PubMed |

International Otter Survival Fund (2014) The shocking facts of the illegal trade in otters. International Otter Survival Fund, Broadford, Isle of Skye, UK.

Ismail ME, Fedutin ID, Ivkovich TV, Filatova OA (2023) Occurrence of killer whales Orcinus orca off the Commander Islands and Avacha Gulf from 2008–2021 and its relation to the sea otter Enhydra lutris population decline. Russian Journal of Theriology 22(1), 74-83.
| Crossref | Google Scholar |

Iurmanov AA, Popov IYu, Romanov MS (2022) Seagrasses at the islands Iturup and Urup of Kuril Archipelago. Geography, Environment, Sustainability 4(15), 39-43.
| Crossref | Google Scholar |

Johnson CK, Tinker MT, Estes JA, Conrad PA, Staedler M, Miller MA, Jessup DA, Mazet JAK (2009) Prey choice and habitat use drive sea otter pathogen exposure in a resource-limited coastal system. Proceedings of the National Academy of Sciences of the United States of America 106(7), 2242-2247.
| Crossref | Google Scholar | PubMed |

Kenyon KW (1969) The sea otter in the Eastern Pacific Ocean. North American Fauna 68, 1-352.
| Crossref | Google Scholar |

Klumov SK (1968) Artificial spread of the sea otters as a main method of restoration of their former habitat and increase in numbers. Oceanology VIII(5), 895-905 [In Russian].
| Google Scholar |

Kochnev AA, Litovka DI (2010) Sea otter (Enhydra lutris L.) at Chukotka. In ‘Marine mammals of the holarctic: collection of scientific papers after the sixth international conference’, 11–15 October 2010, Kaliningrad, Russia, pp. 278–280. (Kapros: Kaliningrad) Available at https://marmam.ru/upload/conf-documents/mm%D1%812010_full.pdf

Komedchikov N (2009) ‘Atlas of the Kuril Islands.’ (2009) (Russian Academy of Sсiences: Moscow, Vladivostok) [In Russian]

Kornev SI (2010) The present status of sea otter (Enhydra lutris L.) population in Russian part of areal. In ‘Issledovania vodnikh biologicheskikh resursov Kamchatki I severo-zapadnoy chasti Tikhogo okeana’. pp. 6–14. (Kamchatpress: Petropavlovsk-Kamchatskij) Available at https://cyberleninka.ru/article/n/sovremennoe-sostoyanie-populyatsiy-kalana-enhydra-lutris-l-v-rossiyskoy-chasti-areala [In Russian with the summary in English]

Kornev SI (2016) Marine mammals in the conditions of intensive economic exploitation of Kuril Islands; ways of their conservation. In ‘Sohranenie bioraznoobraziya Kamchatki i prilegayushchih morej’. pp. 382–387. (Kamchatpress: Petropavlovsk-Kamchatskij) Available at https://www.elibrary.ru/item.asp?id=28354536 [In Russian with the title in English]

Kornev SI (2020) Results of sea otters Enhydra lutris population counts in Kuril islands in 2020. . In ‘Sohranenie bioraznoobraziya Kamchatki i prilegayushchih morej’. pp. 293–297. (Kamchatpress: Petropavlovsk-Kamchatskij) Available at https://www.elibrary.ru/item.asp?id=44381450&selid=44743313 [In Russian with the title in English]

Kornev SI, Korneva SM (2006) Some criteria of assessment of condition and dynamics of population of sea otters (Enhydra lutris) in the Russian part of the range. Ecologiya 3, 190-198.
| Google Scholar |

Kornev SI, Truhin AM, Artyuhin YB, Purtov SY (2001) Rezul’taty ucheta morskih mlekopitayushchih na yuzhnoj Kamchatke i Kuril’skih ostrovah v iyune-avguste 2000 g. Results of census of marine mammals in the southern Kamchatka and Kuril islands in June-August 2000). In ‘Rezul’taty issledovaniya morskih mlekopitayushchih Dal’nego Vostoka v 1991–2000 gg’. pp. 191–204. (VNIRO: Moscow) [In Russian]

Kostenko VA, Nesterenko VA, Truhin AM (2004) Mlekopitayushchie Kuril’skogo arhipelaga. Dal’nauka, Vladivostok. Mammals of Kuril archipelago) [In Russian]

Kurilgeo News (2021) http://kurilgeo.ru/?news (accessed 24 November 2021) [In Russian]

Kuzin AE, Maminov MK, Perlov AS (1984) Chislennost’ lastonogih i kalana na Kuril’skih ostrovah. In ‘Morskie mlekopitayushchie Dal’nego Vostoka’. pp. 54–72. (TINRO: Vladivostok). Number of pinnipeds and sea otters in Kuril islands) [In Russian]

Linnik EV (2023) Results of population surveys of Enhydra lutris (Mustelidae, Carnivora) in the territory of the Kurilsky nature reserve and the small Kurils federal sanctuary (The Russian Far East). Trudy Mordovskogo Gosudarstvennogo Zapovednika im. P. G. Smidovish 33, 129-144 Available at https://cyberleninka.ru/article/n/rezultaty-uchetov-chislennosti-enhydra-lutris-mustelidae-carnivora-na-territorii-zapovednika-kurilskiy-i-zakaznika-federalnogo [In Russian with summary in English].
| Google Scholar |

Mamaev EG (2018) Present status of the sea otter (Enhydra lutris L.) population on the Commander Islands. In ‘Marine mammals of the holarctic, Vol. 2’. pp. 32–39. (Marine Mammal Council: Moscow)

Miller MA, Moriarty ME, Duignan PJ, Zabka TS, Dodd E, Batac FI, Young C, Reed A, Harris MD, Greenwald K, Kudela RM, Murray MJ, Gulland FMD, Miller PE, Hayashi K, Gunther-Harrington CT, Tinker MT, Toy-Choutka S (2021) Clinical signs and pathology associated with domoic acid toxicosis in southern sea otters (Enhydra lutris nereis). Frontiers in Marine Science 8, 585501.
| Crossref | Google Scholar |

Nevedomskaya IA (2017) Kurilsky kalan (Enhydra lutris) v zapovednike “Kurilsky” i zakaznike “Malye Kurily”. Kuril sea otter (Enhydra lutris) in the nature reserve “Kurilsky” and wildlife sanctuary “Malye Kurily”). Mordovsky Zapovednik 12, 18-20 Available at https://cyberleninka.ru/article/n/kurilskiy-kalan-enhydra-lutris-v-zapovednike-kurilskiy-i-zakaznike-malye-kurily [In Russian].
| Google Scholar |

Nikolaev AM (1958) Materialy po biologii kalana ostrova Urup (Data on biology of the sea otter of Urup Island). Soobshcheniya Sahalinskogo Kompleksnogo Nauchnoissledovatel’skogo Instituta 6, 171-184 [In Russian].
| Google Scholar |

Nikolaev AM (1968) Sea otter of Kuril islands – biology and commercial use. Abstract of PhD thesis, Voronezh, Russia. Voronezhsky Gosudarstvenny Universitet. [In Russian]

Nikolaev AM (1969) Voprosy ohrany i rasseleniya kalanov na ostrovah Kuril’skoj gryady. About protection and spread of sea otters over Kuril islands. In ‘Morskiye mlekopitayushie’. (Ed. VA Arseniev) pp. 102–105. (Nauka: Moscow) [In Russian]

Nikulin VS, Vertyankin VV, Fomin VV (2008) Sea otters (Enhydra lutris L.) of Commander Islands (brief story of development of population for 1957–2007). In ‘Research of water biological resources of Kamchatka and of the northwest part of Pacific Ocean: Selected Papers, Vol. 10’. (Ed. YP Diyakow) pp. 90–108. (KamchatNIRO: Petropavlovsk Kamchatskiy). [In Russian with summary in English]

Ovsyanikova EN, Altukhov AA, Carswell LP, Kenner MC (2020) Sea otter (Enhydra lutris) abundance assessment for the Kuril Island population in Far Eastern Russia. Marine Mammal Science 36, 1001-1009.
| Crossref | Google Scholar |

Papworth SK, Rist J, Coad L, Milner-Gulland EJ (2009) Evidence for shifting baseline syndrome in conservation. Conservation Letters 2, 93-100.
| Crossref | Google Scholar |

Pauly D (1995) Anecdotes and the shifting baseline syndrome of fisheries. Trends in Ecology & Evolution 10, 430.
| Crossref | Google Scholar | PubMed |

Popov I, Scopin A (2021) The historical and contemporary status of the sea otter Enhydra lutris population on Urup Island, southern Kuril Islands. Oryx 55(4), 529-534.
| Crossref | Google Scholar |

Raymond WW, Tinker MT, Kissling ML, Benter B, Gill VA, Eckert GL (2019) Location-specific factors influence patterns and effects of subsistence sea otter harvest in Southeast Alaska. Ecosphere 10(9), e02874.
| Crossref | Google Scholar |

Shelton AO, Harvey CJ, Samhouri JF, Andrews KS, Feist BE, Frick KE, Tolimieri N, Williams GD, Antrim LD, Berry HD (2018) From the predictable to the unexpected: kelp forest and benthic invertebrate community dynamics following decades of sea otter expansion. Oecologia 188(4), 1105-1119.
| Crossref | Google Scholar | PubMed |

Shin F (2014) About the Kuril Islands in the mid-Meiji 30s. Development of the ocean fishing industry. Bulletin of Niigata University – Faculty of Education 7(2), 297-317.
| Google Scholar |

Shitikov AM (1971) Influence of the trophic factor on the distribution of sea otters on the middle and northern Kuril Islands. Works of VNIRO-TINRO Marine Mammals 80, 227-239.
| Google Scholar |

Short FT, Polidoro B, Livingstone SR, Carpenter KE, Bandeira S, Bujang JS, Calumpong HP, Carruthers TJB, Coles RG, Dennison WC, Erftemeijer PLA, Fortes MD, Freeman AS, Jagtap TG, Kamal AHM, Kendrick GA, Judson Kenworthy W, La Nafie YA, Nasution IM, Orth RJ, Prathep A, Sanciangco JC, Tussenbroek Bv, Vergara SG, Waycott M, Zieman JC (2011) Extinction risk assessment of the world’s seagrass species. Biological Conservation 144, 1961-1971.
| Crossref | Google Scholar |

Shubin VO (1987) Report on the field archeological studies in Aleutka bay of Urup island in 1986. Archive of the Sakhalin museum, Yuzhno-Sakhalinsk. [In Russian]

Shubin VO (2007) Report on the field archeological studies on Kuril islands in 2006. Archive of the Sakhalin museum, Yuzhno-Sakhalinsk. [In Russian]

Shulezhko TS, Permyakov PA, Ryazanov SD, Burkanov VN (2018) Bigg’s Killer Whales (Orcinus orca) in the Kuril Islands. Aquatic Mammals 44(3), 267-278.
| Crossref | Google Scholar |

Snow HJ (1897) ‘Notes on the Kuril Islands.’ (John Murray: London)

Snow HJ (1910) ‘In forbidden seas.’ (Edward Arnold: London)

Soga M, Gaston KJ (2018) Shifting baseline syndrome: causes, consequences, and implications. Frontiers in Ecology and the Environment 16, 222-230.
| Crossref | Google Scholar |

Springer AM, Estes JA, van Vliet GB, Williams TM, Doak DF, Danner EM, Forney KA, Pfister B (2003) Sequential megafaunal collapse in the North Pacific Ocean: an ongoing legacy of industrial whaling? Proceedings of the National Academy of Sciences of the United States of America 100, 12223-12228.
| Crossref | Google Scholar | PubMed |

Tezuka K (2009) Ainu sea otter hunting from the perspective of Sino-Japanese trade. Senri Ethnological Studies 72, 117-131.
| Google Scholar |

Thomas NJ, Cole RA (1996) The risk of disease and threats to the wild population. Endangered Species Update 13(12), 23-27.
| Google Scholar |

Tinker MT, Hatfield BB, Harris MD, Ames JA (2016) Dramatic increase in sea otter mortality from white sharks in California. Marine Mammal Science 32(1), 309-326.
| Crossref | Google Scholar |

Tinker MT, Bodkin JL, Bowen L, Ballachey B, Bentall G, Burdin A, Coletti H, Esslinger G, Hatfield BB, Kenner MC, Kloecker K, Konar B, Miles AK, Monson DH, Murray MJ, Weitzman BP, Estes JA (2021) Sea otter population collapse in southwest Alaska: assessing ecological covariates, consequences, and causal factors. Ecological Monographs 91(4), e01472.
| Crossref | Google Scholar |

Voronov VG (1964) Kalany na Kurilah. Sea otters on Kurils. Ohota i ohotnich’e hozyajstvo 1, 10-11 [In Russian].
| Google Scholar |

Voronov VG (1974) ‘Mammals of the Kuril Island’s.’ (Nauka: Leningrad). [In Russian]

Voronov VG, Nikolaev AM, Pereleshin SD (1956) Kalan ostrova Urup. Sea otter of Urup Island. Soobsheniya Sakhalinskogo Kompleksnogo Nauchno-Issledovatel’skogo Instituta 4, 53-730 [In Russian].
| Google Scholar |

Yongdan L (2018) Precious skin the rise and fall of the otter fur trade in Tibet. Inner Asia 20(2), 177-198.
| Crossref | Google Scholar |