Fouling is a result of the accumulation of bacterial growth, algae and sessile invertebrates on both natural and manmade submerged surface. To combat fouling ships must constantly undergo cleaning up and maintenance processes. This work aimed to evaluate new biocide antifouling paints produced from marine algae, and study their suppressive effect on slime film forming bacteria. In addition, the effect of the leached components from these wood coated surfaces containing algae on the characteristics of the contact seawater medium was investigated compared with two commercial marine paints. To evaluate the suppressive effect of algae containing coatings, extraction of the new biocide antifouling paints were done by mixing different ingredients % of binder, pigment, filler, stabilizer and solvent. The obtained paints were durable, long lasting with no cracking formed before their incorporation with algae. The paint formulations were applied to wood panels and immersed in sterile glass beakers filled with seawater medium collected from the Eastern Harbour, Alexandria, Egypt. The physicochemical parameters (temperature, salinity, pH, dissolved oxygen and nutrient salts) of seawater samples around the tested panels' were measured after four weeks of immersion and the microbiological examination for the panels were measured after two and four weeks of immersion.Using of algae in the dry paint film leads to highest suppressive effect (%). The tested Ulva fasciata, Corallina mediterraneaand Codium Tomentosum were having the highest suppressive effect 100, 99.6 and 99.5%, respectively. These results matched with the characterization by gas chromatography-mass spectrophotometer (GC-MS) and Fourier transform infrared spectroscopy (FTIR).