Wakamiko Proto-Caldera, a submarine volcano, is located at the bottom of the sea in the bay head area of Kagoshima Bay. In Kagoshima Bay, several species of fish with total mercury exceeding the provisional regulation value of 0.40 mg kg⁻¹ were found in the 1970s. The effects of mercury released from submarine volcanoes are suspected. However, the path from volcanic mercury to the broader ecosystem has not yet been clarified. In this study, as the first step to elucidate the impact of volcanic activity on the ecosystems of Kagoshima Bay, seasonal changes in the concentrations of dissolved gaseous mercury (DGM), Hg(II), filtered total mercury (FT-Hg), particulate mercury (P-Hg), and mercury in suspended particulate matter (Hg in SPM) in seawater of Kagoshima Bay were tracked every two months from Feb. 2014 to Dec. 2017. The dissolved total mercury (DT-Hg) concentration was calculated by summing the DGM and FT-Hg concentrations. The DT-Hg at the location in the caldera ranged from 0.09 to 6.83 ng L⁻¹ showing higher values in summer compared to winter, that is, in the stratified period. The P-Hg showed similar periodic variation as DT-Hg, and the highest Hg in SPM was 2.15 mg kg⁻¹, which is one order of magnitude higher than that observed at the reference site. The high mercury concentration in SPM suggests the accumulation of dissolved mercury discharged from volcanic activity on SPM. Since mercury loaded on SPM can be taken up by suspension feeders and enter the food chain, the Hg in SPM may be a key factor affecting Hg in fishes in Kagoshima Bay.

Wakamiko Proto-Caldera是一座海底火山，位于鹿儿岛湾湾头区的海底。在鹿儿岛湾，在 1970 年代发现了几种总汞含量超过暂定规定值 0.40 mg kg ^{-1的鱼类。}怀疑海底火山释放的汞的影响。然而，从火山汞到更广泛的生态系统的路径尚未明确。在这项研究中，作为阐明火山活动对鹿儿岛湾生态系统影响的第一步，溶解气态汞 (DGM)、Hg(II)、过滤总汞 (FT-Hg)、颗粒物浓度的季节性变化汞 (P-Hg) 和悬浮颗粒物中的汞从 2014 年 2 月到 2017 年 12 月，每两个月对鹿儿岛湾海水中的（SPM 中的汞）进行跟踪。溶解的总汞（DT-Hg）浓度通过将 DGM 和 FT-Hg 浓度相加计算得出。火山口位置的 DT-Hg 介于 0.09 至 6.83 ng L ^-1之间，与冬季（即分层期）相比，夏季值较高。P-Hg表现出与DT-Hg相似的周期性变化，SPM中最高Hg为2.15 mg kg ^-1，比在参考站点观察到的高一个数量级。SPM 中的高汞浓度表明火山活动排放的溶解汞在 SPM 上的积累。由于负载在 SPM 上的汞可以被悬浮喂食器吸收并进入食物链，因此 SPM 中的汞可能是影响鹿儿岛湾鱼类汞含量的关键因素。