For example, increased nutrients such as phosphorus and nitrogen in the water caused an algae bloom to form. This algae bloom can then produce a toxin that poisons sea animals. One example of this is in the Pacific coast, where dolphins, whales, and sea lions were found poisoned due to consuming fish that were contaminated by this. Algae blooms can also threaten sources of food for humans, such as by contaminating shellfish. 

Another side effect is the increased levels of carbon in the ocean, this causes bicarbonate ions to form instead of calcium carbonate, which requires carbonate ions. As a result of this, animals that build shells and coral cannot properly survive, and their shells will be much weaker than normal. Furthermore, temperatures rising will also cause coral to bleach, which kills them if its not reversed quickly.