Global activities involving the collection of marine biodiversity information have provided a large amount of biological observation records that cover various spatiotemporal areas. To predict biological responses or distribution changes in response to environmental changes by using these observation records, it is essential to analyze not only the current marine physicochemical environmental conditions but also the past conditions when the organisms were observed. We developed a new function to estimate the past marine environmental conditions for the observation records in our marine biodiversity database (Biological Information System for Marine Life: BISMaL) and examine whether the database can reliably estimate thermal habitats for both benthic and planktonic marine organisms. For the benthic squat lobster Shinkaia crosnieri, the estimated and observed in situ temperatures were similar to each other. For the planktonic chaetognaths Krohnitta pacifica and K. subtilis, the estimated temperatures showed clear seasonal changes specific to their distribution areas. These results indicated that BISMaL can reliably provide past habitat conditions regardless of planktonic or benthic lifestyles. BISMaL, which provides both biological observations and estimated past environmental conditions through web services, could lower the barrier to data access and use and make data-driven science available not only for data scientists but also for various marine scientists, such as taxonomists, ecologists and field scientists. Database URL: https://www.godac.jamstec.go.jp/bismal/e/.
