Fisheries

A problem with recruitment is usually indicated by the absence, or very low density, of fish where they would normally be present.

Black petrels are relatively few in number and are sometimes caught on fishing lines and in nets. The effect of fishing-related deaths on the population is unknown.

Low recruitment could also be caused by widespread depletion of stocks

The movements of many juvenile native fish are often hindered by barriers to fish passage such as dams, weirs, falls, tide gates, culverts, screens and high water velocities. The New Zealand Fish Passage Guidelines sets out recommended practice for the design of instream infrastructure to provide for fish passage.