Oil at sea is cause by tanker ship accidents and illegal disposal of oil waste and byproducts from cargo ships. It destroys the insulating and water repellency ability of fur-bearing mammals and birds leading to death due to hypothermia. Ingesting oil when animals and birds try to clean themselves can poison them. Additionally, Fish and shellfish experience reduced growth, enlarged livers, changes in heart and respiration rates, fin erosion, and reproduction impairment when exposed to oil.
Fertilizer runoff and sewage disposals
80% of urban sewage discharged into the Mediterranean Sea is untreated. These extra nutrients cause flourishing alga blooms that deplete the dissolved oxygen in the water and suffocate marine life, leading to enormous dead zones.
Toxic pollution causes reductions in wildlife numbers, degrades ecosystem functions and threatens human health. Some of the known effects on marine animals include cancer, lesions, genetic and developmental deformities, behavior abnormalities, reproductive failures, and death.
Plastic poses a grave threat to marine life for a number of reasons, including: entanglement, ingestion and choking. A shockingly large percentage of marine animals, including birds, have traces of plastic within their bodies causing mortalities.