1. Biofiltration of fish farm effluents in Crete- the role of macroalgae in nutrient stripping Amsterdam, 29-30/1/03 Institute of Marine Biology of Crete Manolis Tsapakis, Eugenia Apostolaki, Vivi Pitta, Ioannis Karakassis

2. 1.When should we deploy the filters 2.When should we replace the filters 3.How many filters should we deploy … in order to remove the maximal amount of N & P and fine particles from the system. Objectives - Strategy

3. Filters standing and sampling

4. Biotic succession on Biofilters

6. Sampling of mesocosms

7. Dissolve oxygen July Experiment Sept. Experiment Nov.Experiment

8. Ammonia trends

9. Phosphate Trends

10. Oxygen fluxes: Two months biofilters DAY NIGHT

11. NH 4 fluxes: Two months biofilters DAY NIGHT

12. PO 4 fluxes: Two months biofilters DAY NIGHT

13. Oxygen fluxes during the night experiment vs water temperature

14. NH 4 fluxes during the day experiment vs Solar irradiation

15. Mass Balance of Nitogen in Sitia fish farm Fish Biomass: ~1000tn Feed per Day: 1000kg Nitrogen (8%): 80kg Released as NH 4 (~20%): 16 kg Released as total dissolve N (60%): 48kg Released as fine particulate matter (4-6%): 3.2-4.8kg Then The estimated consumption of dissolve NH4 during a day of a two month Biofilter is approximately 1.3 mg N

16. During the day the biofilters uptake dissolve inorganic nutrients (N, P) & fine particulate matter and release oxygenDuring the day the biofilters uptake dissolve inorganic nutrients (N, P) & fine particulate matter and release oxygen The uptake rate of dissolve N is depending from the solar irradiationThe uptake rate of dissolve N is depending from the solar irradiation During the night the biofilters consume fine particulate matter and release NH 4 and PO 4.. In addition, they consume oxygenDuring the night the biofilters consume fine particulate matter and release NH 4 and PO 4.. In addition, they consume oxygen Conclusions

17. New design Do you think that the micro bioassay experiment in large scale could be a good biofiletr?Do you think that the micro bioassay experiment in large scale could be a good biofiletr? What to you think if we fill the dialysis bag with high density phytoplankton?What to you think if we fill the dialysis bag with high density phytoplankton? The product may can be used by the fish farm hatchery.The product may can be used by the fish farm hatchery. Dialysis Bag High density phytoplacton