象山港海洋牧场建设与生物资源的增殖养护技术

通过生物资源生境营造、适宜性增殖物种筛选与应用、牧化物种增殖与采捕、效果评估和管理等技术的研究与运用,建立有效恢复生物资源、实现天然水域渔业生物资源产出功能最大化的象山港海洋牧场示范区。至今已建成由15个圆角六边形和1 000个台面框架型诱导礁组合而成的7个鱼礁群,面积25 hm~2,形成空方规模53 810 m~3;移植海带、坛紫菜和龙须菜等大型海藻,建成以浮式平面藻床为主的人工藻场80 hm~2。底播毛蚶、栉江珧等贝类2 000万粒;年放流大黄鱼、黑鲷、黄姑鱼、褐鲳鲉等鱼类苗种160万尾;中国明对虾、日本对虾等虾类1亿尾。调查结果显示,牧场示范区富营养化程度有所降低,初级与次级生产力明显提升,其中海藻年生物量约为18 000 kg/hm~2;海洋牧场的渔业资源养护效果良好,人工鱼礁投放19个月后,鱼礁区游泳动物群落的物种丰富度、总生物量和总丰度分别为对照区的1.32倍、2.04倍和1.49倍。

Marine ranching and fishery stock enhancement in the Xiangshan Bay

In order to establish a marine ranching demonstration area in the Xiangshan Bay for an effective restoration of biological resources and maximum output of fisheries resources in natural waters, habitat for biological resources was built, suitable proliferation species were screened and applied, ranchable species were multiplied and harvested, and a series of assessment and management techniques were applied. Seven groups of reefs consisting of 15 hexagons and 1 000 roundtable frame-type induction reefs were constructed with an area of 25 hm² and space of 53 810 m³. Large algae such as Laminaria japonica, Porphyra haitanensis and Gracilariopsis lemaneiformis were transplanted. Artificial ranch of 80 hm² for algae, floating plane algae beds as majority and three-dimensional floating algae beds as assistance, were built. Twenty million shellfish including Scapharca subcrenata and Atrina pectinata were cultured by bottom sowing;1.6 million fish such as Pseudosciaena crocea, Sparus macrocephlus, Nibea albiflora and Sebastiscus marmoratus were released annually; and ten million shrimps such as Fenneropenaeus chinensis, Marsupenaeus japonicas were released annually. Survey results show that the degree of eutrophication in ranch demonstration area has decreased, primary and secondary productivity improved significantly, with algae biomass 18 000 kg/hm². Fishery resources exhibited positive response to the marine ranching. Nineteen months after reef deployment, species richness, the total biomass and abundance of demersal nekton assemblage in the impact area were 1.32, 2.04 and 1.49 times higher, respectively, than those in the control areas.