Almost ot the fishes growth up, and spawn in a habitation. For example, common carp (cyprinus carpio L). Common carp growths up in freshwater, also spawns there. Another sample, pope, the bigest fish. Pope growths up in the sea, and also spawns there.
But not by the eel. It lives in two habitation. Eel growths up in the rivers, but it doesn’t spawns there. Eel migrates to the deep sea to spawn. After spawning, broodstock deads. When larva, eel doesn’t live in the sea. But it will reback to the rivers, and adult there.
To see eel lifely, it can be supposed where fishing ground is. Broodstocks crowns in mouth of river, before migrating to the sea. Also by the glass eels, they crowns there, before going to reaches of rivers.
So, where fishing ground of glass eels are ? Of course, mouth of river that face to the deep sea. Another as fishing ground, mouth of river also used as adaft place, after migrate to the deep sea, or after migrate to reaches of river. When adaft to both of water, glass eels condition are very weak.
Although mouth of rivers are fishing ground of eels, but don’t mout of river suit for eels. Naturaly, eel always look for place safe for their life. In the field indicate, that glass eels doesn’t like mouth of river by high waves, but they liker slow waves. Logically, because glass ees still weak. They can’t live in high waves.
For example, Pelabuhan Ratu, a gulf of South Sukabumi, West Java, Indonesia. The beach face to Hindia Ocean, waves is very high. Mouth of Cimandiri River the end there. There, eels found in high populations. Because, waves is slowly. Hindian Ocean waves blocked by the ground.
Another sample is Sagara Anakan Mouth River, a beach in South Cilacap, Central Java. Sagara Anakan River ended there. Sagara Anakan isn’t gulf, but glass eels found in high populations. Why ? Because, waves is slowly. Hindia Ocean waves blocked by Nusa Kambangan Inland.
Differ by glass eels, mouth of rivers by high waves aren’t problem for consumtios, and broodstock. They can live every where, in slow waves or high waves. Because, both of them are very strong. Even, broodstock can challenge waves when migrate to the deep sea.