What do sirenes do during a hurricane/tsunami? What happens to their nursuries?
Sirenes are an Aquarian species that spends most of their time on or near shorelines, since their young can't breathe underwater. The young live in nursery pools on the beach, which are tended by their parents. Childless sirenes typically live further off-shore and spend more time in the water.
Most larger sirene settlements have built infrastructure to protect them from natural disasters. Dikes, flood walls, magic barriers, etc. However, freak accidents do happen sometimes and the infrastructure may fail.
In these cases, the sirenes are usually warned in advance that big waves are coming. They have a few choices depending on the situation:
A) Go deeper into the water, where there is less turbulence, and stay there until the disaster has passed. Childless sirenes usually take this route.
B) Go further inland. Sirenes with children who don't yet have gills must somehow get these children further inland. Since sirenes don't have legs, this can be nearly impossible without help from land-dwelling species. Most Great Kingdom governments are pretty good about protecting their sirene populations by rushing soldiers to the beaches before the disaster hits. Sirene parents surrender their young to the soldiers, and the soldiers take them to a safe location like a hospital or temporary camp until the disaster has passed. Afterwards the children are returned to their parents.
C) Alternatively to B, many sirene parents are taken inland with their children to ensure they have a caretaker, because not all cities have enough resources to care for them properly--especially if the disaster if affecting a large area. Those soldiers and medical staff will be stretched too thin in these cases. The parents and their children are both returned to the beach after the disaster has passed.
D) Abandon their young. Isolated or neglected sirene settlements may not receive help from land-dwelling communities, and this puts them in a heart-wrenching situation when disaster strikes. All they can do is tuck their young away somewhere on shore and hope they’re still there when things calm down. Thankfully, many of these communities have developed magic spells to combat this. Most commonly, the young are kept in magic air bubbles which are taken deep underwater with the parents until the disaster passes. There is only so much oxygen in these bubbles though, and this solution may fail if the disaster sticks around for too long.
Tragically, many sirenes still get killed or maimed in these freak events. High winds and turbulent waters can fling them into rocks, those who flee deeper into the water can be eaten by predators, and despite the kingdoms' best efforts, sometimes their young get lost in the chaos of the surrendering process.
On a positive note, sirene civilizations are very good at bouncing back after disasters like these. This is because sirenes don't really need shelter. All but the very youngest can survive without a roof over their heads just fine. They are resistant to very cold temperatures and obviously the rain is no bother to them.
While land-dwelling communities are scavenging scraps to put their houses back together, the sirenes just rebuild their community nursery pools and call it a day. They're a highly resilient species in these situations.