Mae LLYW.CYMRU yn defnyddio cwcis sy'n hanfodol i'r safle weithio. Defnyddir cwcis nad ydynt yn hanfodol hefyd i deilwra a gwella gwasanaethau. Trwy barhau i ddefnyddio'r safle, rydych yn cytuno ein bod ni'n defnyddio cwcis.
Diffiniad: The rate of fishing above which the recruitment to the exploitable stock becomes significantly reduced. This is characterized by a greatly reduced spawning stock, a decreasing proportion of older fish in the catch, and generally very low recruitment year after year. May lead to stock collapse if prolonged and combined with poor environmental conditions.