Healthy Oceans Need Healthy Sharks As They Keep the System Balanced, Expert

Sharks are essential for a healthy ocean system, according to an expert.

Healthy Ocean Needs Healthy Sharks

Sharks have gained a bad reputation due to reports of them attacking humans. However, sharks are essential for oceans to survive.

Shark scientist Melissa Cristina Marquez previously appeared on NPR's "Short Wave" to discuss the importance of sharks. The outlet released the interview to mark Shark Week. According to Marquez, the saying, "Healthy oceans need healthy sharks," is very true.

Marquez said sharks are vital to coral reefs. Their presence alters the reef's dynamics in a noticeable way.

For instance, several fish in Fiji are herbivorous, meaning they consume seaweed and algae found in coral reefs. In fact, they will stay away from reef shark patrol zones. Because no fish are consuming them there, the seaweeds have an opportunity to enjoy a sort of sanctuary in that location. Thus, it permits the existence of that dynamic.

Host Maddie Sofia admitted she didn't think sharks were there to protect the plant species. She was amazed that their presence alone could make a difference.

Marquez confirmed that the presence of a shark alters the appearance of an environment simply by influencing the behavior of the fish they consume. She also added that sharks keep the ocean system and prey numbers balanced.

To make her point clear, Marquez offered an example. According to her, if there's a large predator fish, and there are many of them because they thrive due to the absence of sharks, then any vegetation or herbivorous fish that have been somewhat protected or kept in check suddenly become unbalanced because there is nothing to keep those other predatory fish in check. Without sharks, the predatory fish would consume whatever they want, destroying ecology.

Sharks also help with climate change. For instance, a few tiger shark species patrol the seagrass beds in this part of Western Australia, and it appears that this causes two sea turtles and dugongs to reduce their intake of seagrass.

She added that limiting the seagrass consumption boosts primary production-CO2 uptake-which keeps carbon sediment stores stable. Furthermore, marine sediments are essential for controlling climate change since they are one of the planet's most costly and important carbon repositories.

Sharks' Migration Also Offers Benefits

Sharks are migratory, and they still benefit the ecosystem when they migrate. According to Marquez, they do not stay in one area their entire lives, and some species even migrate long distances.

During migration, they transfer nutrients from different parts of oceans through their poop. The expert said it makes sense when you consider that their excrement is a form of fertilizer for the area in which it finds itself. Gray reef sharks, found in the Central Pacific, are a prime example of this; they forage offshore of their habitat at night. And during the day, they come back to this atoll to rest. Thus, they are continuously moving nutrients from that part of the outer ocean into a coral reef area that is more densely populated.

Since coral reefs are typically nutrient-limited, scientists estimate that daily inshore water migration brings roughly 95 kg of nitrogen to the reef. This helps to maintain the ecosystem's general health. Therefore, yes, I do believe that shark poop fertilizer will not be available in our stores very soon, but it is still a good fertilizer.

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