The effects of pollution on the population level is comparable in magnitude to the effects of fishing pressure , and considerable research has been done attempting to apply welldeveloped fishery models to predict the population effects of pollution . However, most models are extremely sensitive to changes in survival estimates of eggs and larvae, which are often difficult to estimate due to complex spatial and temporal dynamics of ichthyoplankton and to sampling problems , but may be more affected by pollution than adult fish . Furthermore, while most
models are capable of incorporating densitydependent factors, in practice they have not , and may thus be oflimited value to predict long-term effects
ofreduced recruitment to wild populations.