| 英文摘要 |
Abstract of "Study on the Environment Essential Fish Habitat in the the Water around Taiwan": 1. "Study on marine biodiversity and sustainable fishery utilization in the" : Pen-Chia Yu, Mian-Hua Yu, and Hua-Ping Yu are the three islands locating in the waters of northern Taiwan, which are formed due to plate movement between Eurasia and Philippine plats. There is the regions where the Kuroshio Current and China Coastal Current interactive with shelf topographic features. This is thus result in a varied fisheries and oceanic conditions with oceanic fronts, upwelling, and eddies. Therefore, this study attempts to contribute the data base of biodiversity, fishing activities, and environmental information. It would be the important reference for considering sustainable utilization of fish and the fishery management such as the closing zone and period for policy of marine protect area around these three islands. The results of sea surface temperature (SST) images showed the seasonal variations around the three islands, the SST was lower than 18°C in wintertime and increased to 23°C in spring. The fishing methods of Taiwanese seine, torch light net, trawling and pole and lines boots also showed the seasonal variations, and the fish compositions of demersal longline fishery were mainly dominated in demersal fish species. The results of VDR analysis showed that setting the marine protected area around 3 nautical miles of the three islands would affect the fisheries of longline, pole and lines boots and gill net. The biodiversity analysis showed the longline and trawling fisheries had highest diversity index in wintertime and springtime, respectively. The data of zooplankton was carried out in four cruises from 2011 to 2013, the most dominant specie was copepod. Copepod contributed 55.35%, 57.38%, 54.69% and 43.24% to the total abundance of zooplankton, respectively. The relationships of zooplankton assemblage between stations could be divided into 3 groups by Cluster Analysis. And the result indicated that zooplankton has seasonal change obviously. The abundance of larval fish were 2019.636±4115.356 ind./1000m3 in summertime higher than spring (272.532±196.5 ind./1000m3). Total numbers of 9816 larvae were collected from 48 stations. The most dominant families in spring and summer were Scombridae and Carangidae, and in autumn and winter were Myctophidae and Gonostomatidae, respectively. All the stations could be divided into three groups by the cluster analysis. It suggested that the temporal distribution of larval fish in autumn and winter were similar, but different from spring and summer. 2. "Evaluations on fishery effectiveness of artificial reefs and the feasibility of new-site establishment" : The yearly project was launched by the Fisheries Agency to evaluate the effectiveness of recently-installed steel-frame reefs at 6 artificial reef (AR) sites, namely, Bu-dai (Chiayi County), Lun-wei (Changhua County), Chi-lai-bi (Hualien County), Tan-shui (New Taipei City), Yie-liu (New Taipei City) and Jia-ding IV (Kaohsiung City), and one protective reef (PR) site at Wang-gong (Changhua County). Also included were feasibility studies on 3 to-be-decided new sites, including one off Lun-wei of Changhua County, another off Yunlin County, and the other off Bu-dai of Chiayi County. AR sites at Lun-wei and Lu-kang in Changhua County, Bu-dai in Chiayi County, and a sunk boat in Yunlin County were assigned as reference sites separately for the above three new-site candidates. In this year we have successfully collected information on the present status of above 10 AR sites through totally 32 scuba dives. The observed ARs, which remained mostly intact, were located in depths of 16.9~51.0 m. A total of 51,262 individuals of 139 fish species in 79 genera from 40 families were observed. The total biomass of the fish was estimated to be 1,825,730 g. In average, 46,814 g of fish biomass occurred at each reef unit/set. The highest biomass, i.e., 144 kg in average, occurred in Chi-lai-bi site. The next was Wang-gong PR site (108 kg). The standing stocks were in the range of 24~35 kg at Lun-wei and Yie-liu, and 24~35 kg at Tan-shui and Jia-ding IV. The lowest biomass was found at Bu-dai (7.4 kg). It is noted that all the steel-frame reefs surveyed in this year were emplaced after 2010. The fauna of fouling organisms was relatively small, indicating that developments of the ecosystems on AR were still in the early stage. More diverse fouling organisms would be forthcoming. Till then, more fishes would come and settle, thereby to enhance the fishery resources in these regions. Among the new-site candidates, the reference site for Lun-wei was rich in the fishery resource. However, the water depth (50.2m) of the new site was relatively deep for AR deployment. Alternatively, a site in the eastward with the depth of 30~40m would be more appropriate for this purpose. The reference site off Yunlin was poor in the fishery resource. Yet the local fishermen claimed that they had caught well, and requested earnestly AR installation in this new site. According to the topological data, this was a site suitable for AR emplacement. However, as strong currents prevailed, it might not be easy for fishes to stay in the reef area. Considering the rarity of AR in this region, tentative AR emplacements are suggested to provide further data for final decision making. With an average of 5 kg of fish biomass in the A-type steel-frame reefs near the Bu-Dai site, the fishery resource was relatively poor too. Similarly, harvests were claimed by fishermen angling at this AR area. In view of their eagerness to support the new site establishment, and the rarity of ARs so far emplaced in this neighborhood, the recommendation of a wider scale of AR emplacement is made for this site. As high as 40~50% of net coverage was found on A-type steel-frame reefs at Bu-dai AR site. Net removal is need for this site. The sunk boat used as a reference in the new site evaluation for Yunlin County was not located in an official AR area. However, this reef was rich in fishery resources, yet impaired from 80% of net coverage. Net removal is recommended for this boat reef. In electric pole reefs I ＆ II in Wang-gong PR site, 80% and 30% of net coverage occurred. Net removal is needed at this site to ensure a sustainable use of the AR. 3. "The survey of primary production and upwelling fishery resources on upwelling zone in surrounding water of Taiwan" : 本計畫為科技保密計畫，故不引入相關資訊，請另參照細部計畫期末報告紙本。 4. "Effects of climate change on the fragile and important fishery resources in the surrounding waters of Taiwan" : Theinterannual and seasonal variations of the sea surface temperature anomaly (SSTA) and the upwelling area in the Taiwan straits were studied using remotesatellite data between 2000 and 2013. It was revealed that while the SSTA wasrelatively low lead to the upwelling area expanded in summer-autumn, whichaffected the abundance (in terms of the CPUE) of Uroteuthis chinensis locatedin the waters surrounding the Peng Hu islands. Good correspondence was observedbetween the variation of the upwelling area and the CPUE of U. chinensis over alarge extent around the Peng Hu islands. Furthermore, the ocean environment ofthe Taiwan straits showed a dramatic change between normal conditions, El Niño and La Niña events during 2008 and 2010. The upwelling area and the CPUE of U.chinensis during La Niña were markedly greater compared to during the El Niño event. Analysis of the environmental variations of the Taiwan strait inassociation with the CPUE of U. chinensis suggested that in years when the SSTAwas relatively lower (2000~2001, 2010~2012 ), the upwelling area was larger,causing the CPUE of U. chinensis to increase. This could be the reason that alarge increase in upwelling causes the SST to decrease, leading to an increasein the available U. chinensis for feeding and their aggregation. |
