Decline of Dolphin species

The common dolphin (Delphinus delphis) was an abundant cetacean species in some areas of the Eastern Mediterranean, particularly in the Ionian Sea. What are the factors that have caused the decline of this species? Based on scientific papers (including the last reading assignment you had), why do you think the common dolphin was more susceptible to decline than other species of cetaceans from this region, such as the bottlenose dolphin? You need to make sure you review a number of scientific papers to find the answer to this question!
Between 20 and 25 lines (not sentences)
Use only scientific papers as references (up to 4)
Please be specific on the reasons, mention examples, don’t be too general or too vague