If you intend to have birds give Guano then the place should be on land (because the last of your pictures looks like the seagulls are on open sea next to the Caravel).
If Guano becomes a yield as a fertilizer then that should be an Inca only thing at the start - europeans only started to harvest and export Guano to Europe after 1802 so after the games normal timeline from 1492 - 1792 so a "last era/age/technology advance" yield
https://en.wikipedia.org/wiki/Guano#History_of_human_use
And the yields of food should then be lowered if the use of guano would raise food production.
If Guano becomes a part of ammunition as part of gunpowder in the form of salpetre then not only birds should give guano but caves with bats too, e.g. in the american civil war the Confederates mined bat guano to produce gunpowder.
https://en.wikipedia.org/wiki/Guano#Bat_guano_2
If Guano becomes a yield as a fertilizer then that should be an Inca only thing at the start - europeans only started to harvest and export Guano to Europe after 1802 so after the games normal timeline from 1492 - 1792 so a "last era/age/technology advance" yield
https://en.wikipedia.org/wiki/Guano#History_of_human_use
And the yields of food should then be lowered if the use of guano would raise food production.
If Guano becomes a part of ammunition as part of gunpowder in the form of salpetre then not only birds should give guano but caves with bats too, e.g. in the american civil war the Confederates mined bat guano to produce gunpowder.
https://en.wikipedia.org/wiki/Guano#Bat_guano_2