Populations of managed species can be kept in check by harvest. Which two factors are required for harvest management to be effective on a sustainable basis?
 1) Effective means of extraction e.g. using purse seine nets for fish
 2) Human compliance to the rules e.g. quotas
 3) Accurate data on population numbers/density growth rates
 4) Deregulation of fishing and hunting areas i.e. keep it open to all