This data release includes metadata and tabular data that documents lab and field trials testing the efficacy of carbon dioxide (CO2) gas diffused into water to manage invasive fish in anchialine pools. The data release also includes information documenting sensitivity, specificity, and accuracy of quantitative polymerase chain reaction (qPCR) assays to detect environmental DNA (eDNA) from tilapia (Oreochromis mosambicus), western mosquitofish (Gambusia affinis) and guppies (Poecilia reticulata). In total there are 11 datasets, 9 describing lab trials and 2 describing field trials. Lab data include 1) initial water conditions during pilot study, 2) behavioral response of fish to CO2 during pilot study, 3) survival of fish following exposure to CO2 during pilot study, 4) initial water conditions during full study, 5) behavioral response of fish to CO2 during full study, 6) survival of fish following exposure to CO2 during full study, 7) specificity of qPCR assays, 8) sensitivity of qPCR assays, and 9) accuracy of qPCR assays for detecting invasive fish from water samples collected from anchialine pools. Field data include 1) pH levels obtained in pools during treatment and 2) body lengths of fish removed during treatment. The lab work was conducted during 2019-2022 at the USGS Kilauea Field Station and field trials were conducted at Puuhonua o Honaunau National Historical Park and Kaloko-Honokohau National Historical Park during 2021-2022. NOTE: This data release was first posted on 06-09-2023, and is available from the author. The current data release (version 2.0) is a revision of that version, and was revised on 07-21-2023.