When scientists examined the whales' stomachs', they found proof that the whales died from a poison produced by algae, but the whales themselves had not eaten the algae. What do you think the scientists found in the whales’ stomachs?

Explanation:

Its stomach was filled eith 30 plastic bags, and many smaller pieces of plastic. ... The whale was emaciated, and scientists believe that the plastic had gathered in such an amount in its stomach that it had created a plug, stopping the digestive process.

The cause of death appears to be starvation, though that's under investigation. Many of the stranded whales in 2019 have been malnourished, said David Weller, a research wildlife biologist with NOAA's Southwest Fisheries Science Center in La Jolla, California.

It's because whales do not naturally chew and swallow they suck in their food.

Explanation:

so basically they swallow plastic and other man-made projects that might contain algae.

sodium i think the chemical element of atomic number 11, a soft silver-white reactive metal of the alkali metal group.