These pollutants can have a serious effect on water sources by depleting oxygen levels , stunting the growth of plants and even suffocating fish -- as in the Gulf of Mexico `` Dead Zone . '' Agricultural pollution has a caused a ' Dead Zone ' in the Gulf of Mexico . Globally the number of Dead Zones has doubled every decade since the 1970 's . The drive to increase biofuel production could increase pollution in rivers and seas . Water use rose 40 percent in the Philippines between 2000 and 2005 .
Agricultural pollution has a caused a ' Dead Zone ' in the Gulf of Mexico . Globally the number of Dead Zones has doubled every decade since the 1970 's . The drive to increase biofuel production could increase pollution in rivers and seas . Water use rose 40 percent in the Philippines between 2000 and 2005 .