A recent study has confirmed commercial fishing is endangering common dolphin populations in the Mediterranean. The culprit is bottom trawling - the main type of commercial fishing in Israel and targets codfish, red mullet and sole.

Bottom trawling involves dragging a large fishing net through the water, close to the sea bed to trap various species of fish. Data from the Department of Fisheries in Israel's Ministry of Agriculture shows that over the years the amount of fish caught through this method is vastly depleting and indicates that these particular fish populations dropped between the years 1949 and 2006. Scientists carried out the research to see if this decline in fish was causing direct harm to the dolphins so they examined the contents of the stomachs of 26 dolphins that had either stranded or were killed in nets. The dolphins' stomachs contained mainly non-commercialised fish, suggesting that they do not compete directly with the trawlers, and that the commercial fishing does not directly affect the dolphins' nutrition. Over 3,000 kilometres of Israel's central coast and 232 marine surveys were studied to examine the behaviour of the dolphins as a result of trawling and after carrying out the research on the live dolphins that frequent the area, it was a very different finding.

Many of the dolphins were observed around the boats and it was discovered this was because the dolphins were feeding on other fish species that swim around the vessels which is a huge concern as it's this activity that is killing the dolphins. They mammals are being caught in the actual nets as they dragged along in the ocean. It's obviously not known if the dolphins are aware of the dangers to them but seem to be left with little choice due to their need to search for food around the trawlers due to the scarcity of other food sources. Lactating female dolphins require larger quantities of food than usual, and despite the risk for their calves that swim by their side, female dolphins have been observed significantly more frequently around the trawlers, possibly indicating that they could not obtain enough fish in other areas.

At present the common dolphin populations are stable and thought to number approx 350, researchers have identified over 100 dolphins with 40 of the same mammals being seen regularly.