Marine Heat Waves (MHWs) are localized and temporary spikes in seawater temperature. While these climatic events are generally confined to specific regions, they are increasingly frequent worldwide. Thus, they exemplify the complex relationship between localized oceanic phenomena and planetary environmental troubles. Marine ecologists often inhabit the tension between their situated knowledge practices anchored in specific and idiosyncratic ecosystems and the planetary scale of ecological crises to do with oceanic environments. In this paper, I detail how marine ecologists in the Finnish Baltic Sea study MHWs through an in-situ underwater experiment. Expanding on recent STS debates on the issue of how situated knowledge practices can contribute to planetary ecological crises, I propose the analytic of “reliable speculation” to attend to the careful epistemic movements from situated experimental knowledge practice to planetary ecological concerns. The experiment’s in-situ design intentionally allows the Baltic Sea’s variability and unpredictability to affect the experimental process, making the Baltic not only a site of empirical research but a compelling place to think with and about the future of global oceans through reliable speculation: a mode of anticipating global ecological futures while remaining grounded in situated empirical practices.
Francesco Colona is an academic researcher based in the Netherlands. His research focuses on the production of visual data on public and private oceanographic vessels and their impact on ocean sciences research practices.