Most of the Arabian Peninsula is unsuited to agriculture, making irrigation and land reclamation projects essential. The narrow coastal plain and isolated oases, amounting to less than 1% of the land area, are used to cultivate grains, coffee and tropical fruits. Goat, sheep, and camel husbandry is widespread elsewhere throughout the rest of the Peninsula. Some areas have a summer humid tropical monsoon climate, in particular the Dhofar and Al Mahrah areas of Oman and Yemen. These areas allow for large scale coconut plantations. Much of Yemen has a tropical monsoon rain influenced mountain climate. The plains usually have either a tropical or subtropical arid desert climate or arid steppe climate. The sea surrounding the Arabian Peninsula is generally tropical sea with a very rich tropical sea life and some of the world's largest, undestroyed and most pristine coral reefs. In addition, the organisms living in symbiosis with the Red Sea coral, the protozoa and zooxanthellae, have a unique hot weather adaptation to sudden rise (and fall) in sea water temperature. Hence, these coral reefs are not affected by coral bleaching caused by rise in temperature as elsewhere in the indopacific coral sea. The reefs are also unaffected by mass tourism and diving or other large scale human interference. However, some reefs were destroyed in the Persian Gulf, mostly caused by phosphate water pollution and resultant increase in algae growth as well as oil pollution from ships and pipeline leakage.