The first sentence is right. The subject, sharks, is plural. Therefore, the verb, have is also plural.
For the same reason, have is the correct verb in your second sentence.
The sharks (has, have) added to its popularity since I was there. Have
Sharks (have, has) interested me for a long time. Has
Could someone please tell me if I have the correct helping verb for the above sentences?
2 answers
yup