Huge graves will be dug on a Coromandel beach on North Island of New Zealand Tuesday after more than 50 whales beached themselves and died despite frantic efforts to save them. (China Daily/Reuters)

(China Daily/Reuters)

(China Daily/Reuters)

    WELLINGTON, Nov. 30 (Xinhuanet) -- Huge graves will be dug on a Coromandel beach on North Island of New Zealand Tuesday after more than 50 whales beached themselves and died despite frantic efforts to save them.

    The 73 pilot whales became stranded at Opoutere beach north of Whangamata on Sunday and as of early Tuesday only about 20 had survived with half of those also expected to die, according to New Zealand Press Association on Tuesday.

    The whales were only discovered Monday morning. The Department of Conservation sent a large team to the north end of the beach and were joined by about 50 volunteers.

    The largest of the whales was six meters long and rescuers said they faced a difficult job because the whales had been on the beach for hours.

    It is not known what made the whales go ashore in the largest whale stranding on the Coromandel for a decade. But rescuers believe the 73 whales may have been chasing food when they stranded on Beach.

    A digger channeled water around the stranded whales and dug a channel to float 18 of them out to sea.

    Rescuers were battling to save last three pilot whales while the digger began digging huge graves on the beach to bury the 50 dead whales, which ranged from four to six meters in length. Enditem