Pollution

Pollution By: Conor Johnston



Over 80% of marine pollution comes from land -based activities. The pollution that comes frrom these categories oil, fertilizers, solid garbage, sewage, toxic chemicals. Oil spills only realease 12% of pollutants into the ocean but when oil comes from industrial runoff it comes out to 36%. Fertilizer runoff from farms and lawns can cause extra extra nutrients to enter the ocean and cause eutophication. Eutophication flourishes algal blooms which depletes oxygen which suffocates marine life. Also all waste that is not properly packaged can reach the sea. Plastic bags decompose very slowly and if consumed by marine life such as dolphins or whales suffocate them.

In many parts of the world sewage lays untreated. Sewage discharged into Mediterranean Sea reaches 80% and all of it is untreated. Sewage again can cause eutrophication which leads to human diseases and beach closures. All marine life from plankton to polar bears can be affected by man made chemicals. For centuries toxic chemicals were deliberately being dumped in the ocean. All land generated waste was dumped because the ocean became a conveniant dumping zone. The waste continued to be dumped until the 1970s which when all waste from radioactive waste and chemical weopons could be dumped. The dumping continued untill it was banned by the London Dumping Convention in 1972, and a amended treaty in 1996 which furter resricts what could be dumped into the sea.

People assumed that all chemicals could be safely dispersed in the huge ocean however that is not the case. The chemicals actually become more concentrated as they enter the foodchain. The small animals at the bottom of the food chain absorb the chemicals and as they feed they do not break down as easy and concentrate in their bodies and become worse and effect higher members of the food chain.