My sample was collected from the Pacific Ocean but the date was not recorded and I only know the year in which it was sampled was sometime in 2010 - how do I report this?

The minimum requirement is the name of the ocean/sea (or country) of the collection event and date to the nearest year. In this case, as you know the ocean and the year of collection, there is no reason that you can not share these metadata. You would report:

• geo_loc_name (or /country) = Pacific Ocean
• collection_date = 2010