近海中上层柔性浮鱼礁设计与应用

Design and application of offshore middle-upper-layer flexible floating reefs

当前我国海洋牧场建设、栖息地改造主要通过底层鱼礁进行,从产生营养物质上升流、饵料场和产卵场及生物链的角度未充分利用整个水体空间,导致效能不能发挥到最佳。为解决这一问题,针对我国东海近海海域海况和生物特性研发了能与底层人工鱼礁协同工作的中上层浮鱼礁。从改善流场、自身体积保持等角度设计了四层网格式柔性浮式鱼礁,进行了浮力、重力及抗浪流能力的校核计算,确定了锚系技术方案及水下效果监控方法。在象山港海洋牧场进行了布放,实际效果测试表明所设计的浮鱼礁可以有效改善区域流场,在最高潮和最低潮时均可保持竖直方向的拉伸状态,最大潮流速度时倾斜角度不超过20度,现场多批次调查及水下视频监控效果显示所研发的鱼礁能够与底层鱼礁协同工作,投放2个月后有鱼类稳定地出现在浮鱼礁周围,取得了良好的效果。

Currently,the main way to construct marine ranching and reform habitat is to build up underlying reefs,however the whole ocean water space can＇t be fully used in these aspects,such as generating upwelling of nutrient substance,bait field,spawning ground and biological chain,which do not maximize its efficiency.To solve this problem,based on sea conditions and biological characteristics in offshore waters in the East China Sea,a kind of upper-middle-class floating reef is developed that can cooperate with bottom reefs.Proceed from improving flow field and keeping volume unchanged,the flexible floating reef with four layers frame was designed,then its buoyancy force,gravity and capability of resisting waves were calibrated and calculated. The technical scheme of anchor system and the method of monitoring its applying effect underwater were determined. Three reefs were placed in marine ranching of Xiangshan Bay to test their practical effect.The test results show that the designed reef can effectively improve the regional flow field. It can keep tensile state in axial and has a tilt less than 20 degree in strong tidal current. The data from several investigations and video monitoring system show that the upper-middle-class flexible floating reefs can cooperate with the bottom reefs. Some fish appeared stably around after the floating reefs were placed for 2 months. The effect is satisfactory.