In some situations paua may never get to the minimum legal size (125mm) which could be caused by such things as a lack of food (food needs to brush past paua – paua do not go searching for food), stocking density (population), not enough aeration in the water (paua don’t move so the water passing through their gills needs to be carrying oxygen), the water is too warm for some of the year (the colder the water the bigger paua grow (the Chatham and Stewart Islands have the largest paua).

In some cases temporarily altering the minimum legal size (say down to 110mm) would allow a percentage of the paua population to be harvested while making more space and less demand on food available for the remaining paua. The result being that the remaining paua have a chance to grow.

Using Fish-downs as a management tool has not been used in New Zealand but is employed in other Abalone fisheries around the world.