I've just made some graphics for sloped sections that should fit, if you want to configure them as fences. I included some non-animated gate pieces if you were thinking of configuring them as exhibit fences as well.
Let me know if you find they need any adjustment.
aviary-fence-extra-graphics.zip
When using APE I've found beached animations for the beluga. I guess they first planed to show aquatic animals struggling on land, but was scraped due to the game being family friendly
Here's a gif showing the animation
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