TERRITORIAL SEA                       895

an extension of sovereignty by coastal states in order to prevent
depletion of the fish stocks. Effective conservation can be achieved
consistently with present territorial limits and without affecting the
international character of the high seas. In recognition of this fact,
the fisheries Proclamation, as indicated above, contemplates the for'-
mulation by the United States of appropriate conservation regula-
tions either unilaterally or jointly with other states, depending upon
whether the United States has a sole or a joint interest in the particular
high seas fishery to be conserved. Examples of joint undertakings in
this regard are the halibut and salmon conservation treaties between
the United States and Canada, the tuna investigatory conventions
between the United States and Mexico and Costa Rica, and the North-
west Atlantic Fisheries Convention which was signed on behalf of the
United States and nine other countries, including Norway.
  The Officer in Charge is authorized, in his discretion, to communi-
cate the contents of this instruction on an informal basis to the official
who put these questions to the Embassy.