Explanation:

A recent study showed that Kelp forests — underwater ecosystems formed in shallow water by the dense growth of several different species known as kelps — are declining because of climate change. Kelp populations at equatorward-range edges are particularly vulnerable to climate change as these locations are undergoing warming at or beyond thermal tolerance thresholds, the study published in the journal Nature. Due to this, the unique adaptive or evolutionary genetic diversity that the rear-edge populations (populations in warm, low-latitudes) may contain is also under threat due to rapid warming. x Kelp Forests are underwater ecosystems formed in shallow water by the dense growth of several different species known as kelps. Though they look very much like plants, kelps are actually extremely large brown algae. Some species can reach heights (underwater) of 45 m, and under ideal physical conditions, kelp can grow 45 cm in a single day. As a result of this incredible growth, kelp forests can develop very quickly in areas where they did not previously exist. Hence, statement 1 is not correct. x Kelp thrives in cold, nutrient-rich waters. Because kelp attaches to the seafloor and eventually grows to the water’s surface and relies on sunlight to generate food and energy, kelp forests are always coastal and require shallow, relatively clear water. Generally speaking, kelps live further from the tropics than coral reefs, mangrove forests, and warm-water seagrass beds, so kelp forests do not overlap with those systems. Like those systems, though, kelp forests provide important three-dimensional, underwater habitat that is home to hundreds or thousands of species of invertebrates, fishes, and other algae. Some species aggregate and spawn in kelp forests or utilize these areas as juvenile nursery habitats. Large predatory species of sharks and marine mammals are known to hunt in the long corridors that form in kelp forests between rows of individual plants. Hence, statement 2 is not correct. x Kelp forests comprise one of the ocean’s most diverse ecosystems. Many fish species use kelp forests as nurseries for their young, while seabirds and marine mammals like sea lions, sea otters and even gray whales use them as shelter from predators and storms. x Sea urchins can destroy entire kelp forests at a rate of 30 feet (9 m) per month by moving in herds. Sea otters play a key role in stabilizing sea urchin populations so that kelp forests may thrive x Giant kelp is harvested from kelp forests and used as a binding agent in products like ice cream, cereal, ranch dressing, yogurt, toothpaste, lotion and more. Hence, Statement 3 is correct.