At some resorts , turtle tourism ranges from structured offerings -LRB- at the Marriott CasaMagna in Puerto Vallarta , Mexico , a marine biologist monitors the beach , moves eggs to an on-site nursery and organizes evening hatchling releases -RRB- to more laid-back encounters -LRB- the owner of 3 Rivers , an environmentally friendly lodge on the island of Dominica in the West Indies , offers to wake up guests and rush them down to the beach in the middle of the night if he gets word that a nesting female has appeared -RRB- .