Sadly, this how these places get poached again as there is nobody to watch illegal fishing boats. The number of dive boats had been stritcly regulated around Guadalupe for years and often had scientists onboardVoir plus to study the sharks. It did not create any issue for the marine life.
A poor decision made by someone sitting in an office, having no clue of what is happening on the field and ignoring scientific advice.

Great white cage diving hotstpot Isla Guadalupe has been permanently closed to tourism by the Mexican Government.

Isla Guadalupe permanently closed to shark diving