Ratings are in for the first night of Shark Week, one of Discovery’s highest-profile annual programming events. The week of shark-related programming got off to a strong start Sunday night, with 3.3 million viewers tuning in for its first hour, when it aired “Great White Invasion,” reports EW.com’s Inside TV blog.

"What’s really impressive about this is that this week marks the 24th year Discovery has aired Shark Week and it’s still going strong," the story notes.

Nevertheless, the opening block was down slightly in viewership from last year, the piece adds. Andy Samberg of "Saturday Night Live" is this year’s host.