Table_1_Density Decline in a Mediterranean Seahorse Population: Natural Fluctuations or New Emerging Threats?.XLSX

Illegal wildlife trade is considered one of the most serious threats to biodiversity worldwide, along with habitat loss/degradation and overfishing of wild stocks. Seahorses are considered at high risk as these fish represent an important component of traditional Chinese medicine but are also sold as curios and ornamental fish. On a worldwide level, illegal trade is controlled by numerous laws and regulations, but it seems to continue by assuming more dynamic routes. In the Mediterranean Sea, Hippocampus guttulatus formed one of the largest populations at Mar Piccolo di Taranto in South-Eastern Italy. During the routine monitoring of this population in 2016, a dramatic density decrease was observed. By using questionnaires and long-term datasets, the present study determined possible causes of this decline by investigating habitat changes, temperature trends and the existence of seahorse trafficking while also examining abundance trends during the last decade. The results indicated a sharp density decline starting from 2015, co-occurring with the period of high temperatures, while habitats remained almost constant. However, interviews with main stakeholders described both illegal and legal fishing activities as the main drivers for the declining seahorse density. Indeed, at one of the studied sites, which was under strict military control, seahorse abundance started to decline only after the intensification of fishing pressure in the basin. The study suggests that Mar Piccolo di Taranto could be one of the sources for international seahorse trade, thus highlighting the need for more intense and effective actions to prevent and combat illegal poaching, while threatened populations are requiring continuous and close monitoring. Due to unfavorable socio-economic conditions, a viable and thriving seahorse population at Mar Piccolo di Taranto could contribute to the revitalization of the coastal economy and the development of environmental awareness.

非法野生动物贸易与栖息地丧失/退化、野生种群过度捕捞一同被视为全球生物多样性面临的最严峻威胁之一。海马因作为传统中医药的重要组成部分，同时亦作为猎奇纪念品与观赏鱼进行售卖，因此被列为高风险物种。全球范围内，非法贸易虽受众多法律法规管控，但仍以愈发灵活多变的走私渠道持续存在。在地中海海域，意大利东南部塔兰托小海湾（Mar Piccolo di Taranto）的长吻海马（Hippocampus guttulatus）种群曾是该区域规模最大的种群之一。2016年对该种群开展常规监测期间，研究人员观测到其种群密度出现大幅下降。本研究通过问卷调研与长期数据集，结合对栖息地变化、温度趋势、海马非法贩运情况的调查，同时分析了近十年的种群丰度变化趋势，以明确此次种群下降的潜在成因。结果显示，种群密度自2015年起出现急剧下降，与高温时段重合，而栖息地环境几乎未发生显著变化。但对主要利益相关方的访谈结果显示，非法与合法捕捞活动均是海马种群密度下降的主要驱动因素。具体而言，在一处受严格军事管控的研究样地中，该区域的海马丰度仅在流域捕捞压力加剧后才出现下降。本研究表明，塔兰托小海湾可能是国际海马贸易的货源地之一，这凸显了需采取更有力、高效的行动来预防和打击非法偷猎，同时受威胁种群也需要开展持续且严密的监测。鉴于当前不利的社会经济状况，塔兰托小海湾内健康繁盛的海马种群有望助力沿海经济复苏与公众环保意识的提升。