Submarine springs near Izola, in the Northern Adriatic Sea, appear in funnel-shaped depressions and smell strongly of sulfur. Along the Mediterranean coast there are many submarine karst springs containing brackish or fresh water, but submarine sulfur springs are not particularly common. Three submarine sulfur springs and one terrestrial sulfur spring were investigated to better understand the water properties, water–rock interaction within the aquifer, and to explore the origin of the spring water. Groundwater and seawater samples were also collected for comparison. Based on the geological setting, physicochemical parameters, hydrogeochemical data, and stable isotope data (δ¹⁸O, δ²H, δ¹³C_DIC, δ³⁴S_SO4, δ¹⁸O_SO4), we can affirm that (1) the large concentration of seawater in the submarine springs samples is due to sampling challenges; (2) springs recharge from precipitation where confined karst aquifers outcrop; (3) deep water circulation is indicated; (4) redox conditions can provide a suitable environment for bacterial reduction of the marine or organic sulfate to the odorous H₂S; (5) geological data suggests that the coals beneath the alveolinic-nummulitic limestones are the source of sulfur. A multi-parameter and interdisciplinary approach has proven important in assessing submarine sulfur springs affected by seawater input.

北亚得里亚海伊佐拉附近的海底泉水呈漏斗状凹陷，散发着强烈的硫磺味。地中海沿岸有许多含有咸水或淡水的海底喀斯特泉水，但海底硫磺泉水并不特别常见。对三个海底硫磺泉和一个陆地硫磺泉进行了研究，以更好地了解含水层内的水性质、水-岩石相互作用，并探索泉水的来源。还收集了地下水和海水样品进行比较。根据地质背景、物理化学参数、水文地球化学数据和稳定同位素数据（δ ¹⁸ O、δ ² H、δ ¹³ C _DIC、δ ³⁴ S _SO4、δ ¹⁸ O _SO4），我们可以肯定：（1）海底泉水样本中的海水浓度是由于采样困难造成的； (2) 泉水从岩溶含水层露头处的降水补给； (3)指示深水循环； (4)氧化还原条件可以为细菌将海洋或有机硫酸盐还原成有气味的H ₂ S提供合适的环境； (5) 地质数据表明，泡铝石石灰岩下面的煤是硫的来源。事实证明，多参数和跨学科方法对于评估受海水输入影响的海底硫磺泉非常重要。