Context

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, showed a new study. 

Key-highlights of the Study

• Kelp populations at equatorward-range edges are particularly vulnerable to climate change as these locations are undergoing warming at or beyond thermal tolerance thresholds.
• 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.
• Ecklonia radiata, the dominant and most widely distributed Laminarian kelp in the southern hemisphere, rapidly succumb to warmer temperatures in spring and summer when temperatures exceed 27 degrees Celsius.

What are Kelp Forests?

• Kelp forests are large brown algae that live in cool, relatively shallow waters close to the shore. They grow in dense groupings much like a forest on land.
• These underwater towers of kelp provide food and shelter for thousands of fish, invertebrates, and marine mammal species.
• Among the many mammals and birds that use kelp forests for protection or feeding are seals, sea lions, whales, sea otters, gulls, terns, snowy egrets, great blue herons, cormorants, and shore birds.
• These dense canopies of algae generally occur in cold, nutrient-rich waters. Because of their dependency upon light for photosynthesis, kelp forests form in shallow open waters and are rarely found deeper than 49-131 feet.
• In ideal conditions, kelp can grow up to 18 inches per day, and in stark contrast to the colorful and slow-growing corals, the giant kelp canopies tower above the ocean floor.
• Like trees in a forest, these giant algae provide food and shelter for many organisms.
• Also like a terrestrial forest, kelp forests experience seasonal changes.