The Duke and Duchess of Cambridge talk with volunteers at beach clean up

The video tutorial begins with an introduction and apologies, followed by reassuring observations about crabs, emphasizing that they are not dead but just appear so. The discussion then shifts to the rarity of Thornbacks, a type of fish, and how they are not commonly found. The tutorial also covers a crossword puzzle related to identification and discovery processes. The video concludes with final remarks.

What does the speaker imply by stating 'you don't find them very often'?

What is the context of the word 'Crossword' in the conversation?