man: the crown of thorn is very poisonous. 1997, bali barat lose nearly 50% of coral life. we make, like, big expedition to remove them away from coral. alling: nono is known as one of the greatest naturalists in the northwest bali region. he's trained as a lawyer, but his life's work, his care, is for the environment. suparno: and we kill more than 700,000s of crown of thorns. dustan: i went to bali in 2011 and was awestruck by the reefs i saw. this is in the very base of the coral triangle. it's sort of the mother, if you will, of coral-reef biodiversity and of all marine biodiversity. and i've been going there annually since. and what this video depicts are the changes we saw before and after a very severe heating episode, caused in part by el nino and global warming. this is the sry of what happened to the reef in one year. so this is a hhy coral. we call it the monument coral. we have a temperature probe underneath that records the temperature of the sea water every 30 minutes. so we have very good temperature records from this part of the ocean. so this coral is probab

man: the crown of thorn is very poisonous. 1997, bali barat lose nearly 50% of coral life. and we make, like, big expedition to remove them away from coral. alling: nono is known as one of the greatest naturalists in the northwest bali region. he's trained as a lawyer, but his life's work, his care, is for the environment. suparno: and we kill more than 700,000s of crown of thorns. dustan: i went to bali in 2011 and was awestruck by the reefs i saw. this is in the very base of the coral triangle. it's sort of the mother, if you will, of coral-reef biodiversity and of all marine biodiversity. and i've been going there annually since. and what this video depicts are the changes we saw before and after a very severe heating episode, caused in part by el nino and global warming. this is the sry of what happened to the reef in one year. so this is a healthy coral. we call it the monument coral. we have a temperature probe underneath that records the temperature of the sea water every 30 minutes. so we have very good temperature records from this part of the ocean. so this coral i