Final answer:
In the provided sentence, 'swarms of visitors and immigrants' is the subject, 'strain' is the transitive verb, and 'the island's resources' is the direct object being acted upon by the verb.
Step-by-step explanation:
To identify the transitive verb and its direct object, let's examine the sentence: 'The economy of Easter Island, a territory of Chile, depends on tourism, but swarms of visitors and immigrants strain the island's resources.' The subject of the sentence is 'swarms of visitors and immigrants', the transitive verb is 'strain', and the direct object is 'the island's resources'.
Remember that a transitive verb is an action verb that requires one or more objects to receive the action. Here, 'strain' is the verb that requires an object, which in this case, is 'the island's resources'. No indirect object is present in this sentence.