1. Impact of aquacultures on the marine ecosystem: modelling benthic carbon loading over variable depth Marko Jusup, Sunčana Geček and Tarzan Legović Ruđer Bošković Institute, Bijenička cesta 54, Zagreb, Croatia marko.jusup@irb.hr, suncana@irb.hr, legovic@irb.hr marko.jusup@irb.hrsuncana@irb.hrlegovic@irb.hr

2. Tuna fishfarm near island Kudica, Adriatic SeaThunnus thyunnusMaena smaris (location Fulija)Pinna pectinata & Astropecten aurantiacus (location Kluda)Eupagurus prideaux & Adamsia paliata (location Veli Drvenik)Remnants of Mytilus galloprovicialis (location Veli Drvenik)Tuna fishfarm near island Fulija, Adriatic Sea Photos courtesy of Donat Petricioli, Oikon d.o.o.

3. Random Displacement Model with gravitational settling: Advection-diffusion equation: Random Displacement Model:

4. Test case #1: Schematic view of bathymetry and BCL (in gC/m 2 day)

5. Test case #2: Schematic view of bathymetry and BCL (in gC/m 2 day)

6. Test case #3: Schematic view of bathymetry and BCL (in gC/m 2 day)

7. Test case #4: Schematic view of bathymetry and BCL (in gC/m 2 day)

8. Test case #5: Schematic view of bathymetry and BCL (in gC/m 2 day)

9. Thank you for your attention! Conclusion: Approximating the realistic bathymetry with the uniform bottom can lead to serious error. It is possible to: predict wrong shape of the maximum deposition region, miscalculate its area, give incorrect value and location of the maximum BCL, fail to estimate the total area exposed to particulate waste.