Here's why:
* Diet: Seals are adapted to eat fish, squid, krill, and other larger marine animals.
* Size: Diatoms are too small for seals to filter out of the water or effectively consume.
* Food chain: Diatoms are a crucial part of the marine food web, providing food for smaller organisms like zooplankton. These zooplankton are then consumed by larger fish and eventually by seals.
So, while seals don't directly eat diatoms, they indirectly benefit from them through the complex food chain that starts with these tiny algae.