Renfro Bobbie, Chadwick Nanette E
Department of Biological Sciences, 101 Rouse Life Sciences Building, Auburn University, Auburn, Alabama, United States of America.
PLoS One. 2017 Sep 5;12(9):e0184175. doi: 10.1371/journal.pone.0184175. eCollection 2017.
Chronic anthropogenic disturbances on coral reefs in the form of overfishing and pollution can shift benthic community composition away from stony corals and toward macroalgae. The use of reefs for recreational snorkeling and diving potentially can lead to similar ecological impacts if not well-managed, but impacts of snorkeling on benthic organisms are not well understood. We quantified variation in benthic community structure along a gradient of snorkeling frequency in an intensively-visited portion of the Mesoamerican Barrier Reef. We determined rates of snorkeling in 6 water sections and rates of beach visitation in 4 adjacent land sections at Akumal Bay, Mexico. For each in-water section at 1-3 m depth, we also assessed the percent cover of benthic organisms including taxa of stony corals and macroalgae. Rates of recreational snorkeling varied from low in the southwestern to very high (>1000 snorkelers d-1) in the northeastern sections of the bay. Stony coral cover decreased and macroalgal cover increased significantly with levels of snorkeling, while trends varied among taxa for other organisms such as gorgonians, fire corals, and sea urchins. We conclude that benthic organisms appear to exhibit taxon-specific variation with levels of recreational snorkeling. To prevent further degradation, we recommend limitation of snorkeler visitation rates, coupled with visitor education and in-water guides to reduce reef-damaging behaviors by snorkelers in high-use areas. These types of management activities, integrated with reef monitoring and subsequent readjustment of management, have the potential to reverse the damage potentially inflicted on coral reefs by the expansion of reef-based recreational snorkeling.
过度捕捞和污染等形式的长期人为干扰会使珊瑚礁的底栖生物群落组成从石珊瑚转向大型藻类。如果管理不善，将珊瑚礁用于休闲浮潜和潜水可能会导致类似的生态影响，但浮潜对底栖生物的影响尚未得到充分了解。我们在中美洲堡礁游客密集的区域，沿着浮潜频率梯度对底栖生物群落结构的变化进行了量化。我们确定了墨西哥阿库马尔湾6个水域的浮潜率和4个相邻陆域的海滩访问率。对于每个1 - 3米深的水域，我们还评估了底栖生物的覆盖百分比，包括石珊瑚和大型藻类的分类群。休闲浮潜率在海湾西南部较低，在东北部则非常高（>1000名浮潜者/天）。随着浮潜水平的提高，石珊瑚覆盖面积显著减少，大型藻类覆盖面积显著增加，而对于其他生物，如柳珊瑚、火珊瑚和海胆等分类群，其趋势各不相同。我们得出结论，底栖生物似乎随着休闲浮潜水平呈现出分类群特异性变化。为防止进一步退化，我们建议限制浮潜者的访问率，同时开展游客教育并配备水中导游，以减少高使用区域浮潜者对珊瑚礁造成破坏的行为。这些类型的管理活动，与珊瑚礁监测及后续管理调整相结合，有可能扭转基于珊瑚礁的休闲浮潜扩张可能对珊瑚礁造成的破坏。
