Department of Earth, Environment and Life Science, University of Genoa, Genoa, Italy.
Department of Earth, Environment and Life Science, University of Genoa, Genoa, Italy; National Biodiversity Future Center (NBFC), Palermo, Italy.
Mar Environ Res. 2024 Jun;198:106537. doi: 10.1016/j.marenvres.2024.106537. Epub 2024 May 1.
Marine macroalgal forests are facing unprecedented challenges worldwide due to the accelerating impacts of climate change. These ecosystems play a crucial role in supporting biodiversity, coastal ecosystem functions and services, and are indeed object of several conservation and restoration measures. The Mediterranean Sea is warming faster than the oceans and thermal anomalies are occurring with increasing intensity, frequency and duration. Along the Mediterranean coasts, Cystoseira sensu lato species are the main representatives of macroalgal forests and their decline has been widely documented. Some relevant achievements in the implementation of ecological restoration have been obtained, but rising temperatures and the occurrence of thermal anomalies increasingly threaten the success of these restoration attempts. In the summer of 2022, ex-situ restoration actions of Ericaria amentacea were carried out by collecting fertile material from three donor sites of the Italian coasts along a latitudinal gradient, during the period of sexual maturity (June/July). Noteworthy during the summer of 2022, anomalous thermal conditions were recorded at the donor sites, with sea surface temperatures exceeding the climatological mean up to 4.3 °C and heatwaves lasting up to 78 days. Our results suggest that these thermal anomalies may have affected the culture of the embryos in both the pre- and post-zygotic phases, resulting in significantly low culture efficiency at the three donor sites. The reproductive structures showed some abnormalities, fertilization of eggs was lower and embryo growth was slower, resulting in lower percent cover of seedlings on the tiles and lower survival rate. The observations underscore the vulnerability of Mediterranean algal forests to global change and highlight additional challenges for their restoration due to the increasing frequency and severity of thermal anomalies, emphasizing the need for adaptive strategies and a comprehensive understanding of the species in a changing climate. Marine forest restoration requires long lasting projects, to allow for long-term monitoring and better understanding the biology of the species and for mitigating stochastic events that can cause the temporary failure of efforts.
由于气候变化的加速影响，海洋大型藻类森林正面临前所未有的挑战。这些生态系统在支持生物多样性、沿海生态系统功能和服务方面发挥着关键作用，实际上是几项保护和恢复措施的对象。地中海的升温速度比海洋快，热异常的发生强度、频率和持续时间都在增加。在地中海沿岸，广义的马尾藻属（Cystoseira sensu lato）物种是大型藻类森林的主要代表，它们的衰退已被广泛记录。在实施生态恢复方面已经取得了一些相关成就，但不断上升的温度和热异常的发生越来越威胁到这些恢复尝试的成功。2022 年夏季，在性成熟期间（6/7 月），从意大利沿海的三个捐赠点收集有性繁殖材料，对 Ericaria amentacea 进行了异地恢复行动。在 2022 年夏季，值得注意的是，捐赠点记录到异常热条件，海面温度比气候平均值高出 4.3°C，热浪持续长达 78 天。我们的研究结果表明，这些热异常可能影响了胚胎在合子前和合子后阶段的培养，导致三个捐赠点的培养效率显著降低。生殖结构显示出一些异常，卵子受精率较低，胚胎生长较慢，导致瓦片上幼苗的覆盖率较低，存活率较低。这些观察结果强调了地中海藻类森林对全球变化的脆弱性，并突出了由于热异常的频率和严重程度增加，对其恢复的额外挑战，强调了适应策略的必要性以及在不断变化的气候中对物种的全面了解。海洋森林恢复需要长期项目，以便进行长期监测，更好地了解物种生物学，并减轻可能导致努力暂时失败的随机事件。
