This is the only Bond film that has a shark
That really had no reason to have a shark.
The Thunderball and Live and Let Die novels had sharks in them so it made sense for the films to.
For Your Eyes Only and Licence To Kill both featured scenes from the Live and Let Die novel that had sharks so it made sense for sharks to be in those films also.
But in TSWLM it seems they just threw a shark in to bank off of the popularity of Jaws which came out two years earlier.