They’d seen all the animals a diver would expect to see in a kelp forest, such as garibaldi fish and kelp bass. But the only signs of the big brown algae were a few loose floating pieces and some ...

Their prehensile tails grip seafloor holdfasts to prevent drifting and link during courtship. Sizes range from tiny, like a lima bean, to over a foot in length. Seahorses prefer calm, shallow ...

But the only signs of the big brown algae were a few loose floating pieces and some decaying holdfasts on rocks near the shore — a sign that kelp had been there in the recent past, but no longer.

A giant sea bass swims amid kelp at the Aquarium of the Pacific in Long Beach. Kelp is highly sensitive to environmental changes. Fluctuations in temperature, light availability, nutrients and ...