Bao Yikang, Xu Peng
College of Oceanography and Ecological Science, Shanghai Ocean University, Shanghai 201306, China.
Biology (Basel). 2025 Feb 9;14(2):175. doi: 10.3390/biology14020175.
This study took Xiangshan Bay as an example to illustrate the variation characteristics of the physicochemical environments (temperature, salinity, light, nutrients, and currents) during one kelp cultivation cycle. The study was conducted from November 2020 to May 2021 through tracking down observations. Furthermore, the environmental factors were evaluated using suitability functions of kelp growth, aiming to provide references for promoting kelp cultivation in South China. We discussed the self-limiting effect of nutrients in the culture zone. The results showed that the average temperature, salinity, and light intensity during the cruises in Xiangshan Bay kelp farm were characterized by seasonal variations. Temperature was found to be the most critical environmental factor in determining the kelp cultivation window and hence the yield in Xiangshan Bay. The dissolved inorganic nitrogen (DIN) concentrations initially decreased and then increased, while the dissolved inorganic phosphorus (DIP) concentrations remained decreasing along with the kelp cultivation. The surface tide currents were dramatically attenuated by the suspended kelp cultivation, while the quasi-steady circulations which played a key role in nutrient supplementation for kelp cultivation were not weakened by the kelp cultivation. Among the cruises, the suitability indices' ranges for temperature, salinity, light, and nutrients were 0.02-0.94, 0.96-0.99, 0.97-1, 0.96-0.97 (DIN), and 0.92-0.95 (DIP), respectively. The results of the suitability functions demonstrated that the salinity and light conditions in Xiangshan Bay were very suitable for kelp cultivation and would not cause significant cultivation risks. Although the cultivated kelp could greatly absorb nutrients, the suitability index of nutrients remained adequate even during the late stage of cultivation, indicating the present kelp cultivation scale has not reached the carrying capacity of Xiangshan Bay and there is still much potential for development. To this end, further selective breeding of the thermal tolerance variety has become the key to improving the kelp cultivation performance in Xiangshan Bay. Meanwhile, the self-limiting effects in relation to nutrients are not significant in the Xiangshan Bay kelp farm, but it might be more significant in other kelp farms.
本研究以象山港为例，阐述了海带养殖一个周期内理化环境（温度、盐度、光照、营养盐和海流）的变化特征。该研究于2020年11月至2021年5月通过跟踪观测开展。此外，利用海带生长适宜度函数对环境因子进行评估，旨在为促进中国南方海带养殖提供参考。我们探讨了养殖区营养盐的自我限制效应。结果表明，象山港海带养殖场各航次期间的平均温度、盐度和光照强度呈现季节性变化。温度是决定象山港海带养殖窗口期进而产量的最关键环境因子。溶解无机氮（DIN）浓度先降低后升高，而溶解无机磷（DIP）浓度随着海带养殖持续下降。表层潮流因海带养殖而大幅衰减，而在海带养殖营养盐补充中起关键作用的准稳态环流并未因海带养殖而减弱。在各航次中，温度、盐度、光照和营养盐的适宜度指数范围分别为0.02 - 0.94、0.96 - 0.99、0.97 - 1、0.96 - 0.97（DIN）和0.92 - 0.95（DIP）。适宜度函数结果表明，象山港的盐度和光照条件非常适合海带养殖，不会造成显著养殖风险。尽管养殖海带能大量吸收营养盐，但即使在养殖后期营养盐适宜度指数仍充足，表明目前海带养殖规模尚未达到象山港的承载能力，仍有很大发展潜力。为此，进一步选育耐温品种已成为提高象山港海带养殖性能的关键。同时，象山港海带养殖场营养盐的自我限制效应不显著，但在其他海带养殖场可能更显著。
