It's based on the number of fish you pull out of the ocean, not the time spent. You can't actually start off collecting coconuts as that needs L2 Farming, but as it only needs 1500 points you can get it pretty quickly. Collecting only coconuts without any fishing would put off the onset of the algae until after you were forced to go back to fishing by running out of coconuts. That's assuming you haven't developed any other method of farming. It's your decision as to the best strategy, though ...
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To err is human; to arr is pirate.