Final answer:
Ocean acidification, caused by the absorption of CO2, impacts organisms like crabs, lobsters, and clams by compromising their ability to form shells, which ripples out into the entire food chain and affects coral reef ecosystems through coral bleaching. The correct answer is option 1.
Step-by-step explanation:
Acidification of the oceans is a process where the pH of ocean waters decreases, largely due to the absorption of excess carbon dioxide (CO2) from the atmosphere. This phenomenon has significant impacts on marine life, particularly for organisms that require calcium carbonate to form their shells and skeletons, such as crabs, lobsters, clams, corals, and certain plankton like pteropods. The acidification interferes with the availability of carbonate ions needed for the formation of aragonite, the mineral these organisms use to build their shells.
As ocean acidification progresses, these organisms may face difficulty in maintaining their shells, leading to their demise while still alive. This has a cascading effect on the food chain since many other species rely on these shell-building organisms for food. Additionally, ocean acidification, paired with rising temperatures, can lead to coral bleaching and the destruction of coral reef ecosystems, which serve as crucial habitats for a diverse range of marine life. These changes not only disrupt marine ecosystems but also have implications for human activities, as many people rely on these species for food and livelihood.