Elemental patterns in antarctic limpet shells indicate size and geographic differences based on gull pellet assemblages

Seabirds play a key role in connecting different parts of Antarctic ecosystems, yet the biogeochemical consequences of their interactions with marine invertebrates are not well understood. This study examines Nacella concinna shells recovered from kelp gull (Larus dominicanus) pellets across ten Antarctic islands, investigating how interactions between seabirds and limpets record elemental signatures shaped by organismal traits and environmental conditions. By analysing the levels of various elements (calcium, magnesium, sodium, phosphorus, manganese, iron, zinc, copper, cobalt, aluminium, nickel, tin and beryllium), we demonstrate that gull pellets provide a unique and underutilised record of marine-terrestrial nutrient transfer. This approach reveals how seabirds redistribute elements from coastal benthic habitats to terrestrial deposition sites, offering new insights into nutrient cycling and ecological connectivity in extreme polar environments. The elemental patterns in the shells reflect a combination of intrinsic and extrinsic factors. Shell size, used as a proxy for age, strongly influenced the concentrations of Mg, P, Mn, Be and Zn, indicating that there are age-related physiological controls on biomineralisation. Geographic location also modulated elemental composition, with elements such as copper and tin (Sn) showing pronounced spatial variability. This suggests that local environmental conditions shape elemental uptake prior to ingestion by gulls. The combined sensitivity of Mg, P, Sn and Ni to both size and geography highlights their potential as reliable indicators of ecological variability and environmental change across Antarctic islands. This study provides a novel framework for understanding how biological processes mediate nutrient redistribution in polar ecosystems by capturing the biogeochemical imprint of seabird-limpet interactions. Gull pellets are revealed to be not only biological remnants, but also focal points of elemental deposition and integrative records of marine-terrestrial linkages. These findings enhance our comprehension of ecosystem resilience in the swiftly evolving Antarctic region, emphasising the significance of seabird-mediated pathways in shaping nutrient dynamics and habitat functionality.