Fishing on the high seas is, although not totally lawless, is subject to a mish mash of different regulatory organisations. There is a move for the UN to start a Conservation Treaty for the High Seas. This would be
a new international effort hoping to stem the tide of illegal and under-regulated fishing and otherwise protect the ocean from a range of threats, to benefit everyone.
To state that the UK can will only be able to legally fish within our own fishing grounds is simply not true.