A good starting point would be to use Difco marine agar 2216 or a low nutrient agar (like Modified Marine Agar (0.005% (w/v) yeast extract, 0.05% (w/v) tryptone, 0.01% (w/v) β-glycerol phosphate disodium salt, pentahydrate, 3.33% (w/v) artificial sea salts—Instant Ocean Brand, 1.5% (w/v) agar, http://link.springer.com/article/10.1007/s10126-008-9154-1) as they require salt in the media to grow, usually Pseudoalteromonas spp. are fast growing bacteria (at least in my case) and I grow them at 28°C for one or two days, because their growth rate is extremely low to not present at 37°C.

Thank you for your response, I have used the aforementioned Difco marine agar and those plates appear to stimulating better growth, I have also noticed an increase in colonies by changing the incubation temperature to 28 degrees.