Rewriting the history of an extinction—was a population of Steller's sea cows ( Hydrodamalis gigas ) at St Lawrence Island also driven to extinction?

Abstract

The Kommandorskiye Islands population of Steller's sea cow (Hydrodamalis gigas) was extirpated ca 1768 CE. Until now, Steller's sea cow was thought to be restricted in historic times to Bering and Copper Islands, Russia, with other records in the last millennium from the western Aleutian Islands. However, Steller's sea cow bone has been obtained by the authors from St Lawrence Island, Alaska, which is significantly further north. Bone identity was verified using analysis of mitochondrial DNA. 800-920 CE). The samples date from close to the beginning of the mediaeval warm period, which could indicate that the population at St Lawrence Island was driven to extinction by climate change. A warming of the climate in the area may have changed the availability of kelp; alternatively or in addition, the animals may have been driven to extinction by the expansion of the Inuit from the Bering Strait region, possibly due to opening waterways, maybe following bowhead whales (Balaena mysticetus), or searching for iron and copper. This study provides evidence for a previously unknown population of sea cows in the North Pacific within the past 1000 years and a second Steller's sea cow extirpation event in recent history.

Pleistocene fossils from Japan show that the recently extinct Spectacled Cormorant (Phalacrocorax perspicillatus) was a relict

“…Interestingly, the relict pattern of P. perspicillatus parallels that of another large marine vertebrate, Hydrodamalis gigas (Steller's sea cow), in the North Pacific. The sea cow was once thought to have had been restricted to the Commander Islands and western Aleutian Islands before it was driven to extinction in the 18th century by overexploitation (Mattioli andDomning 2006, Domning et al 2007), although there is a Holocene subfossil record from St. Lawrence Island in the Bering Sea (Crerar et al 2014). Fossils of this species are also known from the upper Pleistocene of California (Jones 1967) and at least 2 middle Pleistocene localities in Japan (Shinohara et al 1985, Furusawa andKohno 1994), indicating that the species has undergone a range contraction since the Pleistocene.…”

Illegal Trade of Marine Mammal Bone Exposed: Simple Test Identifies Bones of “Mermaid Ivory” or Steller's Sea Cow (Hydrodamalis gigas)

“…This was expected from such a small section of DNA. Only six of the bones have been examined using radiocarbon data to suggest an origin for the bones other than Bering Island (Crerar et al, 2014). Four more samples were examined in 2016 and were all consistent with having come from St. Lawrence Island (unpublished).…”

“…The bone samples were purported to come from St. Lawrence Island, which was verified for a sub-set of samples via referral to shipping manifests. Radioisotope analysis identified the St. Lawrence bone as coming from a population distinct from Bering Island samples (Crerar et al, 2014). A sample with provenance as coming from Bering Island was used as a positive control for the test.…”

The dilemma of trade samples and the importance of museum vouchers—caveats from a study on the extinction of Steller's sea cow: a comment on Crerar et al. (2014)

“…Crerar et al [ 1 ] recently argued that a population of Steller's sea cows ( Hydrodamalis gigas ) persisted on St Lawrence Island (SLI), Alaska, well into historical time. If true, then Steller's sea cows were hunted to extinction in multiple places at different times in the past millennium [ 2 ].…”

“…If true, then Steller's sea cows were hunted to extinction in multiple places at different times in the past millennium [ 2 ]. We wish to highlight several serious issues with the data and practices that Crerar et al [ 1 ] used to support their findings. Specifically, these concerns focus on the lack of voucher specimens and the source material (trade specimens) because they depart from accepted practices in natural history research.…”