Major threats to ocean ecosystems include:
- Dynamites devastate a whole ecosystem.
- Cyanide stuns target fish, but kills smaller organisms such as corals.
- Harvesting commercial fish such as bluefin tuna and Atlantic cod upsets complex symbiotic relationships.
- Inland pollution introduce sediments, toxins, and excess nutrients.
- Plastics and other debris can smother marine animals.
- Oil spills can be toxic to coastal ecosystems.