Understanding climate variability and change together with fishing activities through high-resolution scientific information and local observations can help implement and sustain improved coastal marine management strategies. Ethnographic data collected between 2010 and 2016 during previous studies with traditional handline fishers on South Africa's south coast suggest that fishers recently observed a deterioration in sea state and a reduction in sea days. Many fishers attributed this deterioration to increased climate variability. The fishers also suggested experiencing increased difficulty when leaving the nearshore through river mouths due to higher waves and stronger winds. The current study investigated these oceanic changes in terms of wave height variability and trends, using high resolution modelled wave data of the south coast for the period 1997–2013. Considering the fishers' perspectives, wave heights near their main launch sites during their main fishing season (austral summer) were focussed on. During the mid-to-late 2000s, a positive regime shift of summer nearshore wave heights occurred along the south coast and a statistically significant positive trend in summer nearshore wave heights occurred during the study period. These results support the local fishers’ observations suggesting that the sea state had been deteriorating, in terms of higher summer nearshore waves. While the magnitude of the observed change is not critical to small-boat fisheries in the area at present, it may contribute to the decrease in available sea days and hence, adds to the stressors in the commercial and small-scale sectors, further increasing their vulnerability to change.

中文翻译：

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对南非南部海岸的高分辨率模拟波高的分析表明最近海况恶化

通过高分辨率科学信息和当地观测了解气候变异和变化以及渔业活动，有助于实施和维持改进的沿海海洋管理战略。2010 年至 2016 年期间对南非南部海岸的传统手钓渔民进行的先前研究中收集的人种学数据表明，渔民最近观察到海况恶化和出海天数减少。许多渔民将这种恶化归因于气候变化的增加。渔民还表示，由于海浪和风力更大，在通过河口离开近岸时会遇到更大的困难。目前的研究调查了这些海洋变化的波高变化和趋势，使用 1997-2013 年期间南海岸的高分辨率建模波浪数据。考虑到渔民的观点，重点关注主要捕鱼季节（南半球夏季）期间主要发射场附近的海浪高度。2000 年代中后期，南海岸夏季近岸波高出现正态变化，研究期间夏季近岸波高出现统计上显着的正趋势。这些结果支持当地渔民的观察结果，表明海况在夏季近岸海浪升高方面一直在恶化。虽然观察到的变化幅度目前对该地区的小船渔业并不重要，但它可能导致可用海日减少，因此，