Marlins are popular with sport fishermen and favoured in the commercial fishery, for example for sashimi and sushi. They grow reasonably fast, but the little data that there are show that they are mostly overfishedOverfished:
A stock is overfished when the stock size has decreased so far that it can no longer produce a maximum sustainable yield. The size of the fish populations is insufficient to reproduce in the long term. .
When marlins are caught with fishing rods, the advantage is that undesired bycatch can be released back into the sea alive. Next to that they also don’t cause damage to the seabed.
Because marlins migrate far, international agreements for good management are necessary. The management of marlin is currently in hands of international tuna management commissions because there is much bycatch of marlin in the tuna fishery. In many areas catch data of marlin are missing and the management is not effective.