Kelp forests: how these are good for the ecosystem

By Rinshi Ansari

There are more than 640 different species of seaweed in the Pacific Northwest. They come in a wide variety of sizes and forms. However, they are frequently categorised into the three colours red, green, and brown. According to Dr. Bridgette Clarkston, author of the indispensable “A Field Guide to Seaweeds of the Pacific Northwest,” although these various types of seaweed coexist in the water and on the shoreline, they are truly separated by “many millions of years of evolution.”

The diversified kelp forest ecosystem

Kelp is a fascinating collection of brown seaweed species. They have the capacity to multiply so rapidly that they can build extraordinarily diversified underwater algae forests. Some species, such as bull kelp and gigantic kelp, reach heights of up to 50 metres, creating the forest canopy. The forest understory is made up of shorter species like walking stick kelp.

The kelp forests are a haven for life because they are so rich and diversified. In reality, they serve as crucial habitats for a variety of marine species, including kelp crabs, salmon, rockfish, and starfish. They serve as an essential nursery for herring, which spawn on kelp and release eggs. Kelp forests shield the eggs by delaying water flow with their soaring stipes and blades. This prevents them from dispersing.

Much of North America’s west coast is home to kelp forests. Large brown algae known as kelp are found in shallow, chilly seas close to the beach. They develop in close-knit clusters that resemble a forest on land. Numerous fish, invertebrate, and marine mammal species find food and shelter in these underwater kelp towers.

Compared to practically any other ocean habitat, kelp forests are home to a wider variety and higher diversity of plants and animals. Numerous organisms employ the dense blades to protect their young from predators and even violent storms.

Seals, sea lions, whales, sea otters, gulls, terns, white egrets, great blue herons, cormorants, and shorebirds are just a few of the numerous mammals and birds that use kelp forests for shelter or foraging.

These thick algae canopies typically develop in cold, nutrient-rich environments. Kelp forests only occasionally occur deeper than 49–131 feet due to their reliance on light for photosynthesis. Instead, they are typically found in shallow open waters.

NOAA scientists study kelp forests by returning to the same places repeatedly to determine the existence and quantity of various creatures. Marine experts can monitor the kelp forest to see if it evolves over time and to discover if natural or human factors are to blame.

In cold, nutrient-rich seas, kelp grows well. Kelp forests are always coastal and require shallow, somewhat clear water because kelp adheres to the seafloor and eventually grows to the water’s top and depends on sunshine to produce food and energy. Kelp forests do not overlap with coral reefs, mangrove forests, or warm-water seagrass beds because kelp is located farther away from the tropics.

For hundreds or thousands of species of crustaceans, fish, and other algae, the forests provide a vital three-dimensional underwater habitat. In kelp forests, some species congregate and spawn, or they use the ecosystem as a juvenile nursery. Long pathways that grow in kelp forests are known to be used for hunting by large predatory species of sharks and marine animals.

Kelp forests are significant ecosystems wherever they are found, but they are more dynamic than the other described systems. In other words, depending on the oceanographic conditions and the populations of their main herbivores, they may vanish and then reemerge. Summers that are warmer than usual and seasonal current fluctuations that reduce the amount of nutrients that kelp forests receive combine to weaken kelps and endanger their survival in some years. Large kelp forests can be destroyed by powerful individual storms that uproot the kelp plants from the seabed.

The main herbivore in kelp forests, sea urchins, can build huge swarms that prevent kelp plants from developing into forests. In areas that are conducive to the growth of forests, the cycle between these so-called “urchin barrens” and fully formed kelp forests has been extensively researched. The community of invertebrates and fishes that inhabit this ecosystem are impacted by each of these natural changes to the density or overall size of the kelp forest. The success of kelp growth each year determines the size of the populations of many of these species, including several that are significant food species commercially.

It is well recognised that destructive fishing methods, coastal pollution, and unintentional harm from boat entanglement have a deleterious impact on kelp forests. The protection of kelp forests from excessive human usage or damage is known to be accomplished by area-based management (such as the declaration of marine protected areas).

Interesting Facts About Kelp Forests

Kelp forests are made up of numerous distinct species of kelp, which are actually very huge brown algae.
Some kelp species have a maximum length of 150 feet (45 metres). Kelp may grow 18 inches (45 cm) every day in the right physical circumstances.
One of the ocean’s most diversified ecosystems is made up of kelp forests. Seabirds and marine animals like sea lions, sea otters, and even grey whales use kelp forests as protection from predators and storms, and many fish species use them as nurseries for their young.
By travelling in herds, sea urchins can completely destroy kelp forests at a rate of 30 feet (9 m) each month. The stabilisation of sea urchin populations by sea otters is essential for the development of kelp forests.
From kelp forests, giant kelp is harvested and utilised as a binder in a variety of goods, including ice cream, cereal, ranch dressing, yoghurt, toothpaste, moisturiser, and more.

The effects of reintroducing sea otters to British Columbia

Sea otters are crucial to the health of kelp forests in several areas of the Pacific Northwest. They are regarded as keystone species because the way they feed can lead to a significant chain reaction of changes. Sea urchins eat a lot of kelp, and if predators don’t keep up with them, they can wipe out entire forests. Sea otters manage sea urchin populations because they make a good snack out of them, which helps to preserve the health of kelp forests.

The Pacific Northwest’s sea otter populations were nearly wiped out by the fur trade in the 19th century. 89 sea otters were reintroduced throughout the BC coast between 1972 and 1979. Due to the Species at Risk Act’s (SARA) protection, their population exploded to over 6,000, which caused kelp forest to multiply twenty-fold. British Columbia benefited greatly from this in numerous ways. In the area where otters live, there is now 37% more marine life, which has led to the emergence of new fisheries. According to CBC, as the otter tourism sector has grown, carbon storage has as well.

While many people gained financially from the otter reintroduction program, it’s crucial to remember that many coastal communities, both Indigenous and non-Indigenous, whose economies depended on large clam populations, suffered losses as a result. According to a recent study, various clam, crab, and sea urchin fisheries have suffered a loss of $7.3 million as a result of sea otters chewing away on marine invertebrates. However, initiatives are being undertaken to reestablish a healthy ecological, social, and economic balance. Visit this Narwhal article to learn more about the traditional food sources in Haida Gwaii and how fusing traditional wisdom with modern science is assisting in bringing this coastal environment back into balance.

Coastal habitats offer environmentally friendly climatic solutions

Even if stopping the flow of carbon produced by humans is the best approach to address climate change, many experts think this won’t be enough to prevent a global warming catastrophe. According to the International Panel on Climate Change (IPBES), in order to balance carbon emissions, we must actively remove carbon from the atmosphere. Although carbon capture technology is getting a lot of attention, there are many potential natural climate solutions. This term “describes approaches to tackling a variety of human challenges (such as food production, flood management, waste and wastewater, temperature change, etc.), which focus on enhancing ecosystems to address these issues,” as explained by Dr. Robert Newell in a previous NET blog. Enhancing kelp forests is one such solution.

When it comes to sequestering carbon, trees often receive the most attention, yet coastal ecosystems are incredibly effective at reducing the effects of climate change. They are also less vulnerable to fires than forests on land because of their aquatic habitat. Tidal marshes, seagrass meadows, and mangroves all “sequester and store more carbon per unit area than terrestrial forests,” according to the International Union for Conservation of Nature (IUCN). According to researchers at Harvard University, coastal ecosystems “may trap up to 20 times more carbon per acre than land forests.” This is known as “blue carbon” in nature.

Kelps sequester carbon in what way?

Cold-water kelp forests also experience carbon sequestration processes. Through photosynthesis, large kelps, a kind of macroalgae, convert carbon dioxide into seaweed biomass. Additionally, because they grow so quickly (up to 2 feet per day), they absorb carbon at a breakneck rate. In fact, according to one study, macroalgae store a staggering 200 million tonnes of carbon dioxide annually. Once carbon has been sequestered in kelp, it can either be extracted for use, sink to the ocean floor, or be stored underground.

According to National Geographic, many experts are advocating for industrial-sized farms where seaweed is grown to maturity, harvested, and submerged in the deep ocean. This is because of their incredible capacity to absorb carbon. In essence, this would guarantee that the captured carbon stays buried for a very long time. But these processes are still in the early stages of study and development.

What can you do to support kelp and coastal ecosystems?

Kelp forests confront numerous dangers, much like terrestrial forests do. The creation of marine protected areas can aid in the fight against pollution, dredging, and unsustainable fishing methods.
1. Get in touch with your local officials if you reside in a coastal area to learn more about how they are promoting sustainable ecosystem management.
2. Discuss the value of marine protected areas with your loved ones.
3. Participate in off-peak beach cleanups.
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