but there have been none since nets were introduced in 1952. A more recent comparison shows that in South Africa there were three shark attacks, none fatal, at protected beaches in KwaZulu-Natal between 1990 and 2011, while there were 20 fatal attacks in the same period at unprotected beaches in the Eastern and Western Cape Provinces. However, the net program in New South Wales has been called "outdated and ineffective" by environmental groups; they argue that shark nets do not protect swimmers. 65% of shark attacks in New South Wales occurred at netted beaches. Environmental impact Shark nets result in incidence of bycatch, including threatened and endangered species like sea turtles, dugongs, dolphins and whales. In Queensland in the 2011/12 summer season there were 700 sharks caught, 290 above 4 metres in shark nets and drum lines. In New South Wales, the meshing averages one humpback whale every two years; the whale is almost always released alive. In Queensland in 2015, the bycatch included one bottlenose and seven common dolphin (one released alive), 11 catfish, eight cow-nose rays, nine eagle rays, 13 loggerhead turtles, five manta rays (all but one survived), eight shovelnose rays, three toadfish, four tuna, and a white spotted eagle, which was safely released. New South Wales and Queensland also utilize acoustic pingers attached to the nets to reduce bycatch of dolphins, whales and other marine mammals. Use of the pingers has been shown to significantly reduce marine mammal bycatch. The current net program in New South Wales has been described as being "extremely destructive" to marine life. Between September 2017 and April 2018, more than 403 animals perished in the nets in New South Wales, including 10 critically endangered grey nurse sharks, 7 dolphins, 7 green sea turtles and 14 great white sharks. Between 1950 and 2008, 352 tiger sharks and 577 great white sharks died in the nets in New South Wales — also during this period, a total of 15,135 marine animals perished in the nets. More than 5,000 marine turtles have been caught on the nets. The New South Wales government prohibits people from rescuing entangled animals — this prohibition has been called "heartless and cruel". In a 30-year period, more than 33,000 sharks have perished in KwaZulu-Natal's shark net program. During the same 30-year period, 2,211 turtles, 8,448 rays, and 2,310 dolphins died in KwaZulu-Natal's shark net program. Animal welfare groups note