Mandatory auditor rotation is designed to address a potential conflict of interest between a public company and its auditor. Because an auditor is hired and paid by the public company it audits the auditor's desire to maintain a good relationship with its client could conflict with its duty to rigorously question the client's financial statements.
I hope for your help to explore and protect the wild ocean in ways that will restore the health and in so doing secure hope for humankind. Health to the ocean means health for us.