Spread of chemicals, particles, industrial, agricultural and residential waste, noise or the invasive organisms in the marine is the Marine Pollution. The Toxins bioaccumulate in Zooplankton and phytoplankton; and then get biomagnified in the ocean food chains. They cause Eutrophication, ocean acidification etc. leading to problems such as algal bloom, hypoxia and anoxia.
There are four main types of inputs of pollution into the ocean:
Direct discharge of waste into the oceans such as rivers
Runoff into the waters due to rain
Pollutants that are released from the atmosphere
Ship Pollution which includes many ways including the oil spills.
The London Convention or LC-72 has the formal title of “Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter“. This convention was signed in 1972 and entered into force in 1975. It has 78 parties. India is not a party to this convention.
This is a non-legally binding convention which covers the problem of deliberate disposal at sea of wastes or other matter from vessels, aircraft, and platforms. But it does not cover discharges from land-based sources such as pipes and outfalls, wastes generated incidental to normal operation of vessels, or placement of materials for purposes other than mere disposal, providing such disposal is not contrary to aims of the Convention.
One regional type of convention is Barcelona Convention, which covers the same problems in the Mediterranean sea.