Hoffman and Swinburne Islands, built from landfill for quarantine purposes, exist now as heron nesting colonies in The New York Harbor. These islands will disappear by 2100 due to erosion, sea level rise, and storm surges. The Black Crowned Night Heron is the most endangered by this loss of nesting habitat, predicted to be locally extinct by 2035. Human intervention on these sites will result in the premature loss of these nesting colonies. The project deploys ephemeral and permanent infrastructure to mitigate the loss of the islands history, the birds habitat, and produce knowledge to reposition future interventions via 2 research outposts that programmatically and materially expire at the same time the heron leaves the site, and a permanent eco concrete archive that will accumulate physical artifacts and measure sea level rise by reimagining the nilometer, an ancient egyptian building typology, on site.