“And it will come about that every living creature which swarms in every place where the two rivers come, will live, and there will be a very great quantity of fish. For these waters are come there, and the waters of the Sea will be healed, and everything will live wherever the river comes. And it will be that fishermen will stand by it. From Engedi even to Eneglaim will be a place for the spreading of nets. Their fish will be after their kinds, an extremely great quantity like the fish of the Great Sea.”
The river has now split into two rivers, so great is its flow, until it becomes a fresh water sea. It is continually growing. The picture is in direct contrast to that of Pharaoh (Ezekiel 29:3-5). There he was transplanted from the waters along with his fish, and all were cast into the wilderness and died for lack of water, victims of the scavengers. But here the wilderness becomes a great twofold river, and the fish multiply. And the waters heal wherever they go. The result is an abundance of life. In neither case is it to be taken pedantically literally.
The illustration of the fishermen is in order to emphasise the quantity of the fish, and God's provision for man. Whenever expert fishermen are found in quantities you can be sure that the fish are plentiful. We are not intended to apply the detail. The point is that abundant life has come where there was only aridity and death, and that what was once desert-like and ugly has become pleasant and beautiful, a new Paradise.
Engedi was an important oasis and fresh water spring west of the Dead Sea allotted to Judah at the conquest (Joshua 15:62), an oasis in a barren land. Now it would have become part of a large river-fed area where fish abounded, right up to Eneglaim (which would be another oasis, only mentioned here and otherwise unknown, possibly near Qumran).