Editing Atlantic Ocean (section)

== Environmental conditions ==
The Atlantic absorbs heat and carbon dioxide from the atmosphere. Rising water temperatures change the distribution of marine organisms and can reduce the amount of oxygen dissolved in seawater. Carbon dioxide reacts with seawater and lowers its pH, making it harder for corals and shell-forming organisms to produce calcium carbonate structures.

Thermal expansion and melting land ice contribute to rising sea levels. Higher water levels increase coastal flooding during storms and allow waves to reach farther inland. Low-lying coasts around the Caribbean, Gulf of Mexico and northern South America are particularly exposed to storm surges. Coastal erosion also threatens settlements and infrastructure where beaches or wetlands cannot move inland.

Plastic waste is carried by rivers and coastal currents into the ocean. Larger items gradually break into smaller particles that can be consumed by marine animals. Oil spills damage coastal habitats and may remain in sediment after visible surface oil has dispersed. Agricultural nutrients entering through rivers can cause excessive plankton growth, followed by oxygen depletion when the organic material decomposes.

Fishing pressure has reduced some Atlantic fish populations. Nets and longlines also capture animals that were not the intended target. Management agreements regulate catch limits for species that move across national waters, but enforcement remains difficult in the open ocean.