Arctic Pack Ice Habitat Restoration Via Induced Rafting

This study details proposed interventions of rafted pack ice disturbance corridors to sustain carrying capacity for minimum viable populations of ice-obligate and -associated species to avert extinction from climate change (Fig. 1). This includes marine mammals, seabirds, fishes, and micro- to macrofauna and flora within and around the pack ice, water column, and benthic species to which they are trophically and biogeochemically linked (Fig. 2). Pack ice is characterized as a seasonal translucent aquifer permitting ice algae primary production providing most of the diets of ringed seals, walrus, Arctic cod and polar bears via intervening trophic levels. A case is considered at Hanna Shoal – currently limited to 2 m ice and a source of walrus mass haulouts due to ice loss. A proposed icebreaker-mounted rafting device operating January–May is explored, producing 26,000 km of corridor, 770 km² of rafted ice (12 Manhattans; 1.3 × 10⁹ m³), 6.8 × 10⁸ m³ ‘channel’ ice, and 4.7 × 10⁸ m³ flooded ice, with average ice thickening rate volumetrically equivalent to 1,400 pumps depositing flooded ice on natural ice assuming 150 m radii and 10 cm/day. Ice towing tank prototypes, FE ice models, and focal species behaviors are analyzed, along with a moored version of the device. Rafting is presented as ecologically preferable by favoring natural microstructure, macrostructure, hydrology, melting resistance, succession, and through internalization of bottom ice communities, potentially extending the amount, range and duration of their flux to the benthos during melting, which may be critical for many species. By winter’s end, rafted ice may reach 2.5–4 m (4 m approaching multiyear status), and a second device lagging the first may produce 3.7–6 m. Based on these findings, guidelines are presented within a seascape ecology and ice mechanics framework, noting that interventions targeting only thickness, albedo or other global climate model criteria, may still risk pack ice ecological collapse.