How can I prevent monsters from producing at sea?

Monsters will come from the sea
How can I ban

And I would like to ask, how to limit the number of monster generation

R30:
MobType: z1,z2,z5,sk1,sk2,sk3,c1,si1,si2,si3,en1,en2
Worlds: lda30
Chance: 1
Priority: 1
Action: replace
UseWorldScaling: true
R30-1:
MobType: z3,z4,sk4,c2,c3,si4,en3,en4
Worlds: lda30
Chance: 0.3
Priority: 1
Action: replace
UseWorldScaling: true