DRIVEN LARVAL TRANSPORT ON SALEH BAY, SUMBAWA, INDONESIA *)

Transcription

1 BAROTROPIC TIDAL AND WIND-DRIVEN DRIVEN LARVAL TRANSPORT ON SALEH BAY, SUMBAWA, INDONESIA *) Widodo S. Pranowo 1), Yulia Herdiani 2) Ivonne M. Radjawane 3) 2), *) Presenting on WOM-12 APEC/MRC/OMISAR in Dalian, China, September 7-11, ) Center Research for Maritime Territories and Non-living Resources, Agency for Marine & Fisheries Research, Ministry of Marine Affairs & Fisheries The Republic of Indonesia. 2) Study Program of Oceanography, Faculty of Earth science & Mining Technology, Bandung Institute of Technology, Indonesia. 3) Laboratory of Oceanography, Department of Geophysics & Meteorology, Bandung Institute of Technology, Indonesia.

2 Map of Study Area

3 Background The transport of fish larvae related to its mechanism and behavior. The larvae migration is strongly affected by the ocean tide pattern because of the small swim speed (Baganti( Baganti,, 1997; Romimohtarto, et al., 2004). The transport of fish egg and fish larvae make an important role to determine the successful recruitment of fish stock. Saleh Bay is the one of area which have potential carrying capacity in recruitment of fish stock.

4 Scope & Purpose The scope of this study based on preliminary survey that found the highest capacity of puffer fish larvae in Saleh Bay. The purpose of this research is to describe a computer modeling study of tidal and wind- driven circulation and accompanying Canthigaster valentini (puffer) larval transport characteristics in the vicinity of Saleh Bay, Sumbawa Indonesia.

5 Preliminary Survey Results (1) Tidal elevation acquired by tide gauge in Saleh Bay February 2-8, Height (cm) Hours Highest = cm,, Lowest = -118 cm,, Tidal range = cm

6 Preliminary Survey Results (2) Water Quality Parameter Temp ( o C) Sal ( o / oo ) ph Visibiity (m) Nitrate (µg-at /lt) Phosphat (µg-at /lt) Oil spill & Waste None

7 Preliminary Survey Results (3) Canthigaster valentini fish larvae Local name: : Buntel valentini Distributions tions: tropical waters Ecology: Bay, Coral reef (1 55 m depth) Body Length: : 1.2 cm BL Larval swimming speed: 122 cm BL/second

8 Flowchart of Study Fish Larval Data: Dynamics & Preferences Modeling: 3DD Suite Software Model Input Data: Bathymetry, Tidal, Wind Results: Currents & Larval fish distribution Analyzing Conclusion = Tuning Parameters = Feed Back

9 3DD Suite Software model version 4.09 Developed d by: : ASR, Ltd. (Black, 2002) The 3DD Computational Marine and Freshwater Laboratory consists of a series of coupled numerical models to simulate physical and biological processes in marine and freshwater environments. The models are: 1. 3DD : 3-dimensional flows, short-wave and ocean/atmosphere heat transfer 2. POL3DD : 3-dimensional dispersal 3. WGEN : Estuary wave climate 4. WBEND : Refraction of monochromatic and spectral waves 5. 2DBEACH : Beach circulation and sediment transport 6. GENIUS : Sedimentation around coastal structures 7. Support Manager : Routines for preparation of input files, extraction of results from the model output file and for graphics. 8. PLOT3DD : Matlab graphical routines for plotting the model results are sophisticated and allow a broad range of output styles.

10 Flowchart of Modeling Input Data: Initial condition & Boundary condition 3DD Support Manager Data: Bathymetry, Tidal, Wind Model 3DD: Hydrodynamics 3D Barotropic Output: Currents & Sea levels POL3DD: Fish larval dispersal Data: Salinity, Temperature, Fish larval concentration Output: Distributions of fish larval PLOT3DD Graphics

11 Model Setup (1) Using basic equation for 3D hydrodynamics mode. Using basic equation for 3D hydrodynamics mode. Using an explicit finite difference scheme to solve the momentum and mass conservation equations with a second-order-accurate. Using Courant, Friedrich and Lewy condition or Courant Number (Cr) as limiting for the model time Step. Place discretisations using Cartesian coordinate for horizontal, and Layer model technique for vertical.

12 Model Setup (2) The 3DD model grid is referenced in IJK coordinates

13 Model Setup (3) The staggered model grid. Parameters in the triangles have the same subscripts A schematic representation of the layered model techniques

14 Model Setting (1) North Open Boundary Depth (meter) 338 West Open Boundary 253,5 169 No 1 Layer thickness (top-down) in meter units , Horizontal grid: 129 x 111, x = y = 50 m No. 1 Scenario January (NW Monsoon) Wind speed (uniform & constant) 4 m/s Wind direction (uniform & constant) 6.2 degree July (SE Monsoon) 7.2 m/s 2.7 degree 10 50

15 Model Setting (2) No Parameters/Coeficients Value Units 1 Time step 0.4 second 2 First time step 1 second 3 Last time step second 4 Roughness length m 5 Effective depth 0.3 m 6 Drying height 0.05 m 7 Initial sea level 0 8 Latitude in the centre of the grid degree 9 Orientation of the grid relative to true north 0 degree 10 Horizontal eddy viscosity (uniform and constant) 1 11 Horizontal eddy viscosity multiplication factor 1 12 Number of horizontal eddy viscosity multiplying steps 1 13 Coastal slip 95 % 14 Non-linear term treatment 0-none; 4-third order 0 15 Barometric pressure 0 16 Vertical eddy viscosity type Mixing #1

16 Model Setting (3) No Parameter/Coefficient Value Unit No Parameter/Coefficient Value Unit 1 Model type Larvae 21 Surf-zone vertical eddy diffusivity 0.1 m2/s 2 Vertical mixing options Layered 22 Universal fish behavior 13 3 Layer orientation top down 23 Threshold current speed 0.1 m/s 4 Constant layer thickness 35 meter 24 Threshold duration 1 hour 5 Initial seed Threshold wave height Include horizontal advection yes 26 Day time surface layer thickness 5 m 7 8 Vertical velocity included Ambient background (magnitude) yes Night time surface layer thickness Start hour of simulation 10 9 m hour 9 Density inversion Positive 29 Advection probability (0,1) Model time step 60 Second 30 Seagrass release interval 60 steps Model duration Settlement period start hour Settlement period end hour Split steps Steps between releases Release duration Hour hour hour steps steps Swimming speed towards shallow water Wind boundary layer distance Depth where fish dive down to the seabed Fish swimming speed against current m/s m/s meter m/s 17 Horizontal Diffusion Constant 18 Longitudinal diffusion coefficient 10 m2/s 19 Lateral diffusion coefficient 1 m2/s 20 Vertical eddy diffusivity 0.01 m2/s

17 Map of verification site SALEH BAY Batahai Straits Skala: 0 km TG Saleh Straits T Legend: TG SL-4 Tide Gauge Fish Larval Source SL-4 T Verfication ORITIDE

18 Verification Results (1) Verification of Tide Elevation in Saleh Bay February 2-20, Height (m) Hours ORITIDE 3DD Simulation

19 Verification Results (2) Verification of Tide Elevation in Saleh Bay February 2-20, Height (m) Hours Tide gauge acquistion 3DD simulation ORITIDE prediction

20 Horizontal Current Pattern during Neap Tide ( FLOOD TO EBB ) ( EBB ) ( EBB TO FLOOD ) ( FLOOD )

21 Horizontal Current Pattern during Spring Tide (Northern Part ) j = 68 ( FLOOD TO EBB ) ( EBB ) j = 68 i = 36 ( EBB TO FLOOD ) ( FLOOD )

22 Current Profile at Grid i = 36 during Spring Tide Flood to Ebb Ebb to Flood

23 Current Profile at Grid j = 68 during Spring Tide Flood to Ebb Ebb to Flood

24 Horizontal Current Pattern during Spring Tide (Southern Part ) ( FLOOD TO EBB ) ( EBB ) ( EBB TO FLOOD ) ( FLOOD )

25 Horizontal Current Pattern during Spring Tide Condition in Northwest Monsoon (Northern Part ) j = 68 ( EBB TO FLOOD ) ( FLOOD ) j = 68 i = 36 ( FLOOD TO EBB ) ( EBB )

26 Current Profile at Grid i = 36 during Spring Tide Condition in Northwest Monsoon Ebb to Flood Flood to Ebb

27 Current Profile at Grid j = 686 during Spring Tide Condition in Northwest Monsoon Ebb to Flood Flood to Ebb

28 Horizontal Current Pattern during Spring Tide Condition in Northwest Monsoon (Southern Part ) ( EBB TO FLOOD ) ( FLOOD ) ( FLOOD TO EBB ) ( EBB )

29 Horizontal Current Pattern during Neap Tide Condition in Northwest Monsoon (Northern Part ) ( EBB TO FLOOD ) ( FLOOD ) ( FLOOD TO EBB ) ( EBB )

30 Horizontal Current Pattern during Neap Tide Condition in Northwest Monsoon (Southern Part ) ( EBB TO FLOOD ) ( FLOOD ) ( FLOOD TO EBB ) ( EBB )

31 Horizontal Current Pattern during Neap Tide Condition in Southeast Monsoon (Northern Part ) ( EBB TO FLOOD ) ( FLOOD ) ( FLOOD TO EBB ) ( EBB )

32 Horizontal Current Pattern during Neap Tide Condition in Southeast Monsoon (Southern Part ) ( EBB TO FLOOD ) ( FLOOD ) ( FLOOD TO EBB ) ( EBB )

33 Horizontal Current Pattern during Spring Tide Condition in Southeast Monsoon (Northern Part ) j = 68 ( EBB TO FLOOD ) ( FLOOD ) j = 68 i = 36 ( FLOOD TO EBB ) ( EBB )

34 Current Profile at Grid i = 36 during Spring Tide Condition in Southeast Monsoon Ebb to Flood Flood to Ebb

35 Current Profile at Grid j = 686 during Spring Tide Condition in Southeast Monsoon Ebb to Flood Flood to Ebb

36 Horizontal Current Pattern during Spring Tide Condition in Southeast Monsoon (Southern Part ) ( EBB TO FLOOD ) ( FLOOD ) ( FLOOD TO EBB ) ( FLOOD )

37 Dispersal Larval Results ( AFTER 6 HOURS ) ( AFTER 9 HOURS ) ( AFTER 12 HOURS ) ( AFTER 15 HOURS )

38 Conclusion Remarks Tidal elevation produced by the 3DD Barotropic Hydrodynamical model is in a good agreement with the ORITIDE results, but moderately good with the observation results. The current entered the Saleh Bay dominated by the current originated from Batahai Strait. The current pattern in the north part of the bay is more complicated compared with the southern part. Because of the narrow wide of bay mouth in north part of the bay, so the water exchange between bay water and outside bay is limited. The transport dispersal of Canthigaster valentini agrees with the current pattern circulation.

39 Acknowledgment This research funded by Indonesian National Budget Fund (APBN) for The Agency for Marine & Fisheries Research, Ministry of Marine Affairs & Fisheries. We would like to thank to Dr. Agus Supangat (Deputy Director of Non- living Resources) and Dr. Safri Burhanuddin (Director of Center Research for Maritime Teritorries & Non-living Resources), Dr. Aryo Hanggono (Director of SEACORM), APEC Secretariat,, and also gratefully thank to Sumbawa Carrying Capacity Team.

40 Thank You 1) 2), 3) 1),

41 intermezzo ARGO FLOATS TYPE: PROVOR Checking/adjusting mission parameters, ensuring correct operation of components and testing satellite transmissions for 5 KORDI s Floats in CSIRO Marine Labs, Hobart, July 27 31, 2004.