Why is marine life in danger? What are the current threats to marine life?
Mainly because of pollution.
Any pollution in the ocean disrupts ecosystems.
Little things like pieces of fishing nets can get caught on coral then get pulled by currents and break off chunks of it. The coral helps provide shelter for fish and without that predators will eat more fish than they normally would which could unbalance the prey to predator ratio.
Sea turtles think plastic bags are jelly fish and choke on them when they try to eat them.
Oil that gets leaked into the ocean pollutes the water and prevents algae from getting sunlight and fish from getting the oxygen normally trapped in water.
People as a whole create problems too because people hunt creatures like shellfish, salmon, sharks, and other creatures that we eat. Since our population is growing the demands for those types of food increase so more of those creatures die, upsetting the ecosystem.