Discovered and named in 1987, Palmaria decipiens is a polar seaweed that thrives in the icy waters of the Antarctic Ocean. Scientists have learned much about the resilient algae since its discovery and were recently excited to find it growing in much deeper water than expected. Experts have known Antarctic seaweed grows at depths of 40m, but the recent find showed this seaweed growing in waters nearly twice as deep. The exciting information can help scientists learn more about the Antarctic and potentially help with addressing global warming.
Antarctic algae have developed survival techniques that enable them to thrive in seemingly inhospitable environments. Shade-adapted, the seaweed requires only half the annual sunlight of species found in temperate waters. Despite 24-hour periods of sunlight in an Antarctic summer, the ice covering the waters reduces the amount of light reaching the aquatic plants and algae below. Palmaria decipiens adaptions have allowed it to develop its blades in August but delay its growth and reproduction until the winter and spring.
Using remotely operated vehicles (ROVs), the scientists previously observed the seaweed at depths of 70 meters. In the initial observations, they could not remove samples to determine if the algae were growing or decaying on the bottom. Glacial movement uproots seaweed, dragging and dropping the loose clumps as it drifts. Scientists believed the seaweed observed in their studies was loose and decaying.
The most recent discovery funded by the UK Natural Environment Research Council used ROVs to find and collect pieces of seaweed from depths of 70 meters. A small boat released the ROVs that then located and collected a sample during two separate drops. The drops had time limits due to the depths and conditions, so the team had only enough time to gather one plant sample during each drop. The two samples underwent DNA testing to identify the species and determine if they were alive at the time of collection. A study of the collected material proved the algae to be living samples of Palmaria decipiens. The experts now believe the seaweed may have the ability to grow at 100m or deeper in arctic waters. In clear, temperate water, some species of seaweed grow at depths of 200 meters but considered unlikely the growth of this species is deeper than 40 meters in the Antarctic.
People need to understand the importance of seaweed. This marine life offers shelter and protection to fish and other ocean creatures. Seaweed is also a food source for many animals and humans and has many uses in the cosmetic industry. Seaweed can also protect the environment and reduce the potential for global warming. The algae capture and store carbon, like trees on the land, and reduce the level of carbon in the air. As seaweed dies, it drifts to the ocean floor, where it decays. The process reduces ocean acidification and keeps the water more balanced and safer for marine life.
The recent discovery, therefore, of this seaweed living at lower depths in the cold waters of the Antarctic than expected increases the hope of its ability to thrive. As the oceans warm, the waters have become less hospitable for certain species of seaweed and prevented the growth and reproduction needed to provide shelter and other benefits. The adaptations and survivability of the species in the Antarctic offer the potential for them to continue to thrive. Extra growth of these species could potentially balance the carbon capture lost in other parts of the world.
Knowing how this marine life grows and how it adapts can enable aquaculture practices to enlist these tactics to produce more abundant crops. Increased seaweed farming could reduce agricultural pollution and provide further environmental benefits. Larger seaweed crops in the ocean may lower the risk of algae blooms that drop oxygen levels and kill marine life. Seaweed can filter ocean water and remove the nitrogen and phosphates that cause the blooms.