A study of the Planning and Management of Artificial Reefs’ Fishing Grounds in Tong-Yuan areas

• Main Authors: Lin, Da-Wei, 林大爲
• Other Authors: Ou, Ching-Hsiewn
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/09805732539625637203

碩士 === 國立臺灣海洋大學 === 環境生物與漁業科學學系 === 103 === Abstract 　　The purpose of this study is to elaborate the planning and management of Baixin and Tongxiao 2nd artificial reefs, which located at Tongxiao and Yuanli township in Miaoli county. And hope to help reach the sustainable fishery goal at Tong-Yuan areas in Miaoli county. The results are summarized as follows: 1.Before deploying the artificial reefs, we need a complete beforehand master plan, continuous later observation and the formulation of management regulation to ensure the sustainability of the fishing ground. The utilization management of the artificial reefs can be divided into three parts; time, space and behavior. To make sure the reef maintain its function properly and help gain experiences to refine future plans, we need to monitor and investigate the conditions of the reef (Such as buried in sand, drifting, damaged or covered by fishnets.) periodically after deployment. 2.The total catches at Tong-Yuan areas were 468.6 tons in 2013, and the output value reached 57,681 thousand NTD. Most of the catches were from coastal fishery, with gill net as main fishing method. The amount of boats and rafts was 406, and 90 percent of them were rafts. 3.The waters in Tong-Yuan areas have outstanding quality and hydrological condition, and because of its excellent primary productivity, the biodensity and richness are both considerably high. Furthermore, the biodiversity is also enhanced and can provide enough feed to the fishes. Therefore, it’s an ideal location for re-deployment of artificial reefs. 4.For deploying small artificial reefs at the bottom of the two reef areas mentioned above, there are concerns of subsidence problems. Deploying stacked or large steel reefs is recommended in the future. To prevent getting too close to terrigenous waters, the location of deployment should be at least 30 meters deep and west or northwest from the center of the reef areas. 5.The plans of artificial reef fishing ground including scale size, deployment and structure of the reefs. Detailed information of artificial reefs deployment in Taiwan can be found in Regulations Governing Deployment of Artificial Reefs or Other Fishery Constructions (2003); the purpose is to regulate the deployment of constructions that may protect or provide fishing grounds, or nourish marine resources. 6.Between 2010 and 2015, the total area of Baixin artificial reefs has increased from 4,500 m2 to 4,800 m2. The good integrity of the reefs and the increasing amount of periphyton showed an increase in biodiversity of this area, which has become an ideal fishing ground. It will bring positive effects on future works to expand the benefit of the fishing ground. 7.Between 2010 and 2015, the total area of Tongxiao 2nd artificial reefs has increased from 3,525 m2 to 5,925 m2. Although the integrity of the reefs shows no obvious damage, according to the results of the investigation in 2015; 70-75% of the utility pole reefs were found covered in fishnets, and the concrete reefs were also found covered in fishnets and even worse than they used to be. 8.In this study we recommend that the Baixin artificial reef area implement reefs on a 300 meters radius basis, and deploy one set (each set has 4 units) in the center and on each orientation of the outer ring. Each set are 300 meters apart, and each unit are 30 meters apart. There are 56 units of steel reefs in total, and hold around 6,776 m2 in total area. The volume is approximately 40,656 m3. The configuration of Tongxiao 2nd artificial reefs will be the same as Baixin artificial reefs but with 20 units of reefs, 2,420 m2 in total area and around 14,520 m3 in total volume. Baixin and Tongxiao artificial reef areas will have 76 units of reefs, 9,196 m2 in total area and 55,176 m3 in total volume. 9.The steel reef gathers the most abundant fish resources, the second is utility pole reef and the next is concrete reef. In other words, the fishery benefits from deploying a steel reef (500m3) is equal to 51 utility pole reefs or even 160 double layer concrete reefs (2.0m). For choosing steel reefs, the platform-like structure ones are not easy to be covered by fishnets, which are recommended in this study. The waste tires we used to hang on the steel reefs can now be replaced by the KK reefs, which are basically combined hollow concrete cylinders and have often been used by the Japanese. 10.Angling gear fishery is the main reason we plan to expand the area of artificial reefs deployment in this study. The designation of the main operation area of Baixin artificial reef area will be expanded outward from the center in a radius of 1,000 meters range, and the Tongxiao 2nd artificial reef area will be expanded from the center of the second quadrant in a radius of 300 meters range. 11.According to the current provisions, seine fishery is forbidden in the area of Baixin artificial reefs (ranged in a radius of 1,000 meters from the center) and Tongxiao 2nd artificial reefs (ranged in a radius of 300 meters from the center), and needs proper identification marks on fishing gears for accountability when found covered on reefs. If the nets were to fall or wrapped onto the reefs, the owner of the ship or the fisherman will either have to clean up the nets or pay for the cost. 12.For the gillnet fishery, there will be buffer zones to help the net hauling works, which are located outside Baixin artificial reef area (in a radius of 1,000-1,200 meters), and outside Tongxiao 2nd artificial reef area (from the center of the second quadrant, in a radius of 300-500 meters); as for bottom gillnet fishery. It is allowed to get close to the restricted areas for operation, but entering will not be allowed; although trawl-net fishery is already forbidden to operate within 3 nautical miles from the coast, we still need strict law enforcement to prevent trawlers from operating in the artificial reef area. Key words: Tong-Yuan areas, Baixin, Tongxiao 2nd, artificial reef, planning and management.