The major direct effects of man on seal populations are caused by hunting. Subsistence hunting using traditional methods has a long history and generally resulted in a balance between the hunters and the seals. More recently commercial hunting, using sophisticated methods, has reduced many seal stocks to low levels. In some cases no balance was achieved and either the seals or the industry became extinct. Minor direct effects of man on seals include sport hunting and the destruction of seals for fisheries protection. These are generally of local importance only. Indirect effects may be either detrimental or beneficial to seal stocks. Detrimental effects include fishing operations which may result in the unintentional destruction of seals or compete with seals for available limited fish stocks, habitat destruction, pollution, and anthropogenic disturbance. Beneficial indirect effects include increase of available food stocks resulting from the reduction of another predator, increase of available breeding habitat as a result of human population shifts, and changes in ethical attitudes to seals.