There are no less than FIVE fishing spots, possibly more. There are two small swampy ponds you mentioned, underground at the border of 8 and 9, facing each other. There is the outdoor ocean at the top right edge of Area 9. There is a tiny pond in an underground ultra-icy cave in area 8 where BOTH the Endemic and Piscine researchers occasionally appear, and there is a vast lake right next to the abandoned ship in Shipwreck Camp.
There are no less than FIVE fishing spots, possibly more. There are two small swampy ponds you mentioned, underground at the border of 8 and 9, facing each other. There is the outdoor ocean at the top right edge of Area 9. There is a tiny pond in an underground ultra-icy cave in area 8 where BOTH the Endemic and Piscine researchers occasionally appear, and there is a vast lake right next to the abandoned ship in Shipwreck Camp.