Research Bias in Long-Term Monitoring of Antarctic Nearshore Marine and Terrestrial Biota.

Long-term observations are essential for ecological research, providing insights into species and ecosystem variability, processes, and responses to change. In a time of rapid global change, ecosystem modification, and emerging threats, such long-term monitoring (LTM) is increasingly important. Antarctica is experiencing an unprecedented change that is potentially challenging for its uniquely adapted flora and fauna. This review synthesizes LTM studies of Antarctic nearshore and terrestrial biota, examining monitored species, sites, biological parameters, and environmental factors. LTM of Antarctic biota was limited (< 140 studies) and strongly biased toward charismatic megafauna (> 60% focused on penguins and marine mammals). More than half of the studies spanned > 10 years, ~80% exceeded 5 years, and ~60% included environmental data to inform biological trends. Inconsistencies in methodologies were noted, which limit the capacity for cross-study comparisons. Changes in local and regional species' abundances, distributions, and/or functions were reported for many of the biota groups examined. LTM efforts were concentrated along the West Antarctic Peninsula, with notable gaps across East Antarctica, reflecting the varied accessibility across the continent. Based on the limitations and gaps identified in this review, we recommend LTM of Antarctic nearshore and terrestrial ecosystems should expand to include understudied key ecosystems and locations, use harmonized protocols to ensure data are comparable, and integrate environmental monitoring at biologically relevant scales. Establishing sentinel sites and facilitating international collaboration and data sharing would be a powerful approach to circum-Antarctic monitoring. LTM is essential not only for documenting and predicting ecological responses in Antarctica but also for informing global understanding of ecosystem resilience under climate change-providing critical data for conservation, management, and policy in a rapidly transforming world.