Kelp forests

In News: Kelp forests are declining because of climate change as per the study published in the journal Nature 2023

• Kelp populations at equatorward-range edges are particularly vulnerable to climate change as these locations are undergoing warming at or beyond thermal tolerance thresholds

Kelp forests

• Kelp are large brown algae
• These are underwater ecosystems found in cool, nutrient rich, shallow waters that are close to the shore
• Many organisms use the thick blades as a safe shelter for their young from predators or even rough storms.
• Some kelp species can measure up to 150 feet (45 m) long. If living in ideal physical conditions, kelp can grow 18 inches (45 cm) a day.
• 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.
• Ecklonia radiata is the dominant and most widely distributed Laminarian kelp in the southern hemisphere
• New populations were found in shallower and cooler winter months with temperatures around 20°C
• Kelp can sometimes persist at lower latitudes, aided by cool water upwelling or in deep-water refugia where they are protected by thermocline (the transition layer between the warmer mixed water at the surface and the cooler deep water below)

Significance:

• Kelp forests provide food and shelter for thousands of species such as seals, sea lions, whales, sea otters, gulls, terns, snowy egrets, great blue herons, cormorants, and shore birds.
• Kelp forests provide underwater habitats to hundreds of species of invertebrates, fishes, and other algae and have great ecological and economic value.
• Loss of kelp forests will also lead to a decline of the unique biodiversity that they support
• There is high evolutionary diversity in the low-latitudes as many marine organisms were only able to persist within ice-free refuge areas at lower latitudes during the Ice Age
• 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.

Threats

• 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

Source DTE

Previous Year Question

Q1) Consider the following statements: (2018)

1. Most of the world’s coral reefs are in tropical waters.
2. More than one-third of the world’s coral reefs are located in the territories of Australia, Indonesia and Philippines.
3. Coral reefs host far more number of animal phyla than those hosted by tropical rainforests.

Which of the statements given above is/are correct?

1. 1 and 2 only
2. 3 only
3. 1 and 3 only
4. 1, 2 and 3