Overfishing can<span> be defined as the catching of more fish from a single </span>population<span> ... Some commercially important stocks are in </span>such<span> a critical state that all fishing has .... than protecting the marine </span>environment<span> and conserving fish </span>populations<span>. .... Heavy fishing </span>pressures can change<span> the </span>genetic characteristics of a population<span>:.</span>