Trophodynamic of phytoplankton-zooplankton as determination of fish larvae survival at Lagoon of Pulau Pari, Seribu Island
Trofodinamik Fitoplankton-Zooplankton sebagai Penentu Kelangsungan Hidup Larva Ikan di Laguna Pulau Pari Kepulauan Seribu
View/ Open
Date
2012Author
Puspasari, Reny
Damar, Ario
Kamal, M. Mukhlis
T.F.Lumban Batu, Djamar
Wiadnyana, Ngurah Nyoman
Metadata
Show full item recordAbstract
Fish larvae utilize planktonic organisms as a food. Their Feeding success is determined by the dynamic of biomass and structure composition of phytoplankton and zooplankton population. The work is aimed to investigate the dynamic of biomass and composition of planktonic organisms and their relationship to the environmental conditions and also to determine the growth and development of fish larvae. The measurement of physical, chemical and biological parameters was conducted periodically at 5 stations. Grazing experiments were conducted to predict the growth and grazing rate of planktonic organisms such as nanophytoplankton, microphytoplankton, microzooplancton, mesozooplankton and fish larvae in many combinations of organism. Results show that environment condition of Pulau Pari lagoon was good and could support the survival of marine biota. Phytoplankton biomass was largely composed by size fraction of < 20 μm in the amount of 82,10 – 93,40 % from total chlorophyll-a concentration. Phytoplakton size fraction of ≥ 20 μm, was dominated by Bacillariophyceae genus Skeletonema and Chaetoceros. Zooplankton biomass was largely composed by size fraction < 200 μm (microzooplankton) in the amount of 63,90 % from total zooplankton biomass. Zooplankton was dominated by Class Crustacea, sub Class Copepod for microzooplankton and sub Class Malacostraca for mesozooplankton. Fish larvae were dominated by family Pomacentridae, Aulostomidae, Blenniidae, Engraulidae dan Pinguipedidae. The fish larvae in pre flexion stage development consisted of 62,985 from total larval abundance. The peaks of fish larvae biomass occurred in July and October, might indicate the larval production seasons. The dynamic of fish larvae biomass in July was in a “match” condition with that of other planktonic organisms, resulting a growth and development especially Blenniidae. While in October was in a “mismatch” condition this is probably due to food limitation. All of the planktonic organisms were influenced by the environment condition although there was no significant correlation among them. Grazing experiment shows that nanophytoplankton was the main prey of microzooplankton while microphytoplankton is the main prey of mesozooplankton. Fish larvae graze all components of planktonic organisms however the most abundance prey found in the stomach of fish larvae was microzooplankton. Allover of this study suggest that to support the ecological function of Pulau Pari lagoon as a spawning and nursery grounds, environment management would be needed to conserve natural habitat in the lagoon by rehabilitation of coral reef and seagrass ecosystems.
Collections
- DT - Fisheries [725]