When you register to participate in a meeting, the checkbox "Receive email alerts" provides an opportunity to choose if you would like to receive an email whenever a document is posted or updated.

If you would like to update the setting for receiving email alerts, login to the WCPFC website, navigate to the meeting you would like to change and click on the button "Notify me via email" as shown in the screenshot below. Turn it on to receive emails, off to stop receiving emails.