I'm not reffing this just yet, but I want to say that
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Well, from the current looks of it, Darkamber had her Politoed in the shallows of the water while your Roselia was on the shoreline. So I'd assume that Lotad would be around there too. If I'm correct, most Lotad stay around the shallows (anime, an episode where Ash, Brock, and May see a bunch of Lotad and collect berries as well).
I'm sure that it is based on prevalence of certain natural elements rather than what truly exists around. However, I will give you brownie points because technically there are plenty of rocks under the water, so I wouldn't be surprised if it were to work. So at this point, though, based on the strange way that NP is defined, I'll see what Deck Knight has to say about this attack.Nature Power: The Pokemon draws upon the natural elements present to use an attack it couldn’t normally use. A dirt terrain or sandy environment will produce Earthquake. An artificial environment with no natural elements will produce Tri Attack. Rocky terrain, a cave, or mountainous area will produce Rock Slide. A mostly grassy arena or field will produce Seed Bomb. A watery environment will produce Hydro Pump. A prevalence of snow will produce Blizzard.
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Well, from the current looks of it, Darkamber had her Politoed in the shallows of the water while your Roselia was on the shoreline. So I'd assume that Lotad would be around there too. If I'm correct, most Lotad stay around the shallows (anime, an episode where Ash, Brock, and May see a bunch of Lotad and collect berries as well).