Potential Use of Saline Groundwater for Inland Aquaculture Based on Hydrological and Fisheries Insights: Case of Hokkaido, Japan

This study evaluated the potential use of saline groundwater for inland aquaculture in Hokkaido, Japan, by assessing hydrological characteristics such as the spatial distribution and depth of saline groundwater and the suitability of water quality for aquaculture purposes. For this study, data were collected and analyzed from groundwater surveys conducted and published by public institutions in Japan over the past 60 years. Consequently, 244 saline groundwater sources were extracted for this study. The characteristics of saline groundwater were classified into two types based on well depth. Saline groundwater shallower than 500 m is situated in coastal lowlands and has low salinity (<18.2: one‐third of seawater). Depth deeper than 500 m is situated both on the coast and inland, and has high salinity ranging from 18.2 to 35.9 (seawater). Fisheries insights showed that the temperature of saline groundwater at depths shallower than 500 m and the salinity of saline groundwater at depths greater than 500 m were suitable for inland aquaculture. Although other water quality parameters, such as nitrogen, iron, and manganese, fail to meet the strict quality standards for aquaculture, saline groundwater could be used for aquaculture purposes after appropriate water treatment. This study emphasizes that integrating saline groundwater into aquaculture systems could offer a sustainable alternative to marine‐based aquaculture, mitigating environmental risks and supporting fisheries impacted by global warming.