| 英文摘要 |
This research is an extension of hydrological variation after 2008 Penghu winter fish kill event. Larvae fish community composition structure, intertidal zone creature, invertebrate, and fish around Penghu are collected and examined for building hydrological prediction model and for understand the impact of the event to economics. The SST satellite image collected during 1996 and 2010 shows that the winter of 2009 was a normal year but the year 2010 had an El Nino winter. The SST of 2009 and 2010 (Jan. to Feb.) was higher then the one for 2008 (Feb.) and the SST are relatively stable (20.48~23.9℃ during 2009, 18.45~22.39℃ during 2010). The SST shows that the water temperature was back to normal during 2009, and the winter water temperature was not affected by cold wave.
?The result of SCUBA diving survey found 130 species of 56 families in the echinoderms, mollusks, and crustaceans. This is not the first time of the chilling injury in the Penghu, and such event may more frequently occur because the degree of global warming is more serious, and the amplitude of global temperature is larger.
?Besides Penghu South Sea, all other regions in Penghu suffered tremendous loss in 2008. In last year, all suffered region recovered gradually and the fastest rate was at Mu-Tou-Yu, an islet. The highly affected east region, which showed low recovery, again in this year with fish species numbers even lower than the 2008 level at Niew-Yu. Overall, the results showed that species resilience is still inconsistent among islets. This phenomenon is probably related to whether the habitats have recovered, whether the amount of larval fish recruits are sufficient, and local ocean current and marine environmental changes.
?At present we have met some problems in dealing with the bounday conditions. First, we use idealized initional conditions to test the bounday conditions. The model seems to be able to simulate the similar features of the Kuroshio, Taiwan Warm Current, the Changjiang River plume, and the Tsushima Current, but the model blew up after a long-time integraion due to the continuous incease of the sea surface height. We think this is probably caused by the inflow and outflow moments and it induces that the mass is not conserved. Thus, we are still trying another kind of boundary condition to solve this problem.
?To conclude, the intertidal zone fishes are in the recovering stage after the winter event. However, the coral reef fish’s recovery rate varied between different island and waters which depend on the recovery rate of the habitat, amount of larvae fish, and whether or not the current and the environment are suitable for individuals to settlement. The recovery of fisheries is depending on different type of fisheries and time, which under different habitat environment, the species recovery rate are varied. This uncertainty might cause by short study time, lack of zooplankton, larvae fish, and other fishery type’s information and comparison form other water mass; thus the biomass for each species and environment variation cannot compared as a whole. It is recommended the continuing of investigate, monitor and build the database of biodiversity, biological resources and environmental information. In this way, a quick and certain estimate and react could be made once a dramatic fluctuation took place in the future. |
