Strain Elisabeth M A, Swearer Stephen E, Ambler India, Morris Rebecca L, Nickols Kerry J
Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, 7001, Australia.
Centre for Marine Socioecology, University of Tasmania, Hobart, TAS, 7053, Australia.
Sci Rep. 2024 Sep 27;14(1):22386. doi: 10.1038/s41598-024-72801-5.
Climate change is causing widespread impacts on seawater pH through ocean acidification (OA). Kelp forests, in some locations can buffer the effects of OA through photosynthesis. However, the factors influencing this variation remain poorly understood. To address this gap, we conducted a literature review and field deployments of pH and dissolved oxygen (DO) loggers within four habitats: intact kelp forest, moderate kelp cover, sparse kelp cover and barrens at one site in Port Phillip Bay, a wind-wave dominated coastal embayment in Victoria, Australia. Additionally, a wave logger was placed directly in front of the intact kelp forest and barrens habitats. Most studies reported that kelp increased seawater pH and DO during the day, compared to controls without kelp. This effect was more pronounced in densely populated forests, particularly in shallow, sheltered conditions. Our field study was broadly consistent with these observations, with intact kelp habitat having higher seawater pH than habitats with less kelp or barrens and higher seawater DO compared to barrens, particularly in the afternoon and during calmer wave conditions. Although kelp forests can provide local refuges to biota from OA, the benefits are variable through time and may be reduced by declines in kelp density and increased wave exposure.
气候变化正通过海洋酸化（OA）对海水pH值产生广泛影响。在某些地区，海带森林可以通过光合作用缓冲海洋酸化的影响。然而，影响这种变化的因素仍知之甚少。为了填补这一空白，我们进行了文献综述，并在澳大利亚维多利亚州菲利普港湾一个以风浪为主的沿海海湾的四个栖息地部署了pH值和溶解氧（DO）记录器，这四个栖息地分别是：完整的海带森林、中等海带覆盖度、稀疏海带覆盖度和裸地。此外，在完整的海带森林和裸地栖息地正前方放置了一个波浪记录仪。大多数研究报告称，与没有海带的对照组相比，海带在白天会提高海水的pH值和溶解氧。这种效应在海带密集的森林中更为明显，尤其是在浅水区和受庇护的环境中。我们的实地研究与这些观察结果大致一致，完整的海带栖息地的海水pH值高于海带较少或为裸地的栖息地，与裸地相比，海水溶解氧也更高，尤其是在下午和平静的波浪条件下。尽管海带森林可以为生物群提供局部的海洋酸化避难所，但这种益处会随时间变化，并且可能会因海带密度下降和波浪暴露增加而减少。
