June 2025

Oceanography | Vol. 38, No. 2

52

FEATURE ARTICLE

EXPLORING CLIMATE CHANGE, GEOPOLITICS, MARINE

ARCHEOLOGY, AND ECOLOGY IN THE ARCTIC OCEAN THROUGH

WOOD-BORING BIVALVES

By Jørgen Berge, Torkild Bakken, Kristin Heggland, Jon-Arne Sneli, Øyvind Ødegård, Mats Ingulstad,

Terje Thun, and Geir Johnsen

BACKGROUND

In 1652, a young Siberian larch sprouted somewhere along the

Yenisei region in Siberia (Figure 1). Almost 250 years later, in

1904, that tree died. Then, in 2016, it ended up in a bottom trawl

in the Arctic Archipelago of Svalbard. In order to reach Svalbard,

the log must have been captured by sea ice in the Kara Sea and

transported by the Transpolar Drift (TPD) across the Arctic

Ocean before it was released and eventually sank in Rijpfjorden

at 80°N. When it was brought up on the deck of the research

vessel and examined by scientists, the log was heavily infested

with living specimens of the wood-boring bivalve Xyloredo nooi.

Shipworms and other wood-boring mollusks have never before

been reported from the High Arctic. This is, however, not only

a story about a piece of wood drifting across the Arctic Ocean

and the first report of Arctic wood-boring mollusks. It also tells

a story about the connection between climate and environmen­

tal conditions, and the history of human activity in Svalbard, the

influence of the European timber industry and the Soviet Union

planned economy, Arctic resource extraction during the last

400 years, and preservation of marine archeological artifacts—

and it reveals significant gaps in knowledge concerning Arctic

benthic fauna. The latter has strong implications for contem­

porary geopolitical issues in the region, including the ongoing

debate regarding deep-sea mining.

MATERIALS AND METHODS

During two research cruises on R/V Helmer Hanssen funded by

The University of Tromsø – The Arctic University of Norway

(UiT), pieces of wood infested with wood-boring mollusks

were trapped and collected in the bottom trawl (Campelen

1800 bottom trawl) at two locations on Svalbard. In January

2016, a 7 m long log that was partly buried in anoxic sedi­

ment was collected in Rijpfjorden, located on the northern side

of Nordaustlandet, Svalbard. (80°17'40.44''N, 22°18'0.07''E) at

250 m depth. A second piece of infested wood was collected on

June 26, 2019, on the west coast of Svalbard in Smeerenburgfjord

at 215 m depth.

Wood-boring mollusks collected from the wood were

brought back to the laboratory and identified following origi­

nal descriptions of Xyloredo species (Turner, 1972). The col­

lected specimens were found to comply with the description

of X. ingolfia and deposited in the collections at the Norwegian

University of Science and Technology Museum in Trondheim

(NTNU-VM 82062-82067; Bakken et  al., 2024). In order to

undertake a thorough taxonomical identification, type speci­

mens (paratypes) of X. ingolfia were borrowed from the Natural

History Museum of Denmark in Copenhagen (NHMD-76456).

The newly collected mollusks were similar to the type spec­

imens in proportion of valves and in the sub-rectangular and

ABSTRACT. We present the first record of a wood-boring, deep-sea mollusk belonging to the genus Xyloredo from the high Arctic.

Wood-boring mollusks of the genus Teredo have previously sporadically been documented in the Arctic, but only in shallow waters

strongly affected by relative warm Atlantic waters. Our finding not only identifies a new and until now unknown member of the

Arctic marine bottom fauna but also points to the fact that historical shipwrecks in the region may not be as well preserved as we

thought. Further, this study demonstrates how the natural and cultural histories of the Arctic are deeply intertwined, necessitating

interdisciplinary approaches to uncover connections and insights across domains that might otherwise remain obscure. Specifically,

we demonstrate how the discovery of wood-boring mollusks, inside a Siberian larch that sprouted in the Yenisei region in 1652 and

recovered in a bottom trawl offshore Svalbard, is directly linked to the Transpolar Drift. Analyzing how a tree ends up in a Svalbard

fjord more than 100 years after its death in 1904 also provides insights into how the logging industry in Siberia has significantly influ­

enced human presence on and the history of Svalbard. Without extensive logging in Siberia, far less driftwood would have reached

Svalbard during the last 100 years. Hence, there would have been fewer wood falls to attract the wood-eating bivalves in its ecosys­

tem, and as driftwood has been an important resource for firewood and building materials, Svalbard’s human history would most

likely have been different.