There are two types of important seaweeds in the intertidal zone, one is the green algae, locally known as "green seaweed", and the other is red algae, locally known as "long-leaf laver (Porphyra dentate)". Wild lavers in Penghu have wide and thick thallus, very nutritious. Whenever the northeast monsoon sets in, wild lavers grow on unmanned island or scars that are far from artificial pollution; with low temperature and weakened sunlight, the climate is just perfect for growing laver, thus giving Penghu laver the most unique flavor.

Lavers grown on north sea unmanned island requires "fishery harvest right", which is collectively by all villager nearby; collective harvest usually takes place two to three times maximum in a year, first time around December on the lunar calendar. One month after laver matures again, the second harvest will take place, which is also a good opportunity to experience fishing for seaweed. When harvesting, short sticks or scrapers must be on hand, along with a basket drains water; when the tide is rising, walk in against the current, apply a little force in stirring the water with one hand, and you should be able to collect laver, and experience the fun of fishing for seaweed.