Marine plant life has a significant part to play in sustaining our oceans’ ecosystem
Dead zones are becoming more and more frequent in our oceans, particularly in places of high seafood cultivation. Usually the result of human activities like industrial scale farming, dead zones describe areas of the ocean where there is no oxygen, meaning a complete lack of marine life. This lack of oxygen is primarily caused by a surplus of carbon dioxide, nitrogen, and other potentially disruptive chemicals.
As such, experts are continuously seeking ways to protect the health of our oceans. A team of researchers from UC Santa Barbara has recently published a study in the journal Marine Policy arguing that seaweed aquaculture could help to reduce the size and number of oceanic dead zones.
They conclude that, by absorbing the excess nitrogen and phosphorus in the water that causes these dead zones to appear, seaweed cultivation could significantly reduce the number and severity of these areas.[1]
The study
The study analysed data from the Gulf of Mexico. Currently, more than 800 watersheds – different areas of sea separated by land and ridges – deliver nutrients to the Gulf, across 32 states. This has led to a growing low-oxygen dead zone which, in 2019, was reported to stretch just over 18,000 square kilometres.[1]
The team used open-source oceanographic and human-use data to identify roughly nine percent of the US’s exclusive economic zone in the gulf that could support seaweed aquaculture.
Speaking on the potential of seaweed cultivation, lead author and PhD candidate at UCSB’s Bren School of Environmental Science & Management Phoebe Racine, commented: “Cultivating seaweed in less than 1 percent of the US Gulf of Mexico could potentially reach the country’s pollution reduction goals that, for decades, have been difficult to achieve.”
Seaweed is a secret weapon in the fight against rising carbon levels
As co-director of UCSB’s Ocean and Fisheries Program, Darcy Bradley, said: it is human activity and interference which “tends to tip things out of balance.”
The likes of industrial scale farming sends a great deal of nutrients into the ocean which cause massive algal blooms, but while these algae produce oxygen when they are alive, they die so suddenly and in such huge volumes that their rapid destruction consumes all available oxygen in the water. This creates dead zones.[1]
However, as authors of the study claim, cultivated seaweed could draw down available nutrients, limiting the available resources for the unchecked growth of nuisance algae and microbes. Seaweed also produces oxygen, which could alleviate the development of hypoxic dead zones.
Like land plants, seaweed absorbs carbon dioxide and produces oxygen, but on a huge scale. Species such as giant kelp requires huge amounts of carbon in order to fuel its growth, which can reach as much as 60cm in one day.[1] It can therefore produce large quantities of oxygen.
One 2015 study explored this potential, suggesting that covering nine percent of the world’s oceans in seaweed and capturing its carbon could offset the annual carbon emissions of the entire globe.[2]
Sustainable seaweed shopping is vital for our future
In order to make the most of what seaweed has to offer in terms of supporting the environment, businesses and consumers alike must support the sustainable harvesting of marine plant life. With documentaries like Netflix’s Seaspiracy raising intense conversations about preserving marine ecosystems, the demand for sustainable sea products has never been higher.
As well as supporting the protection of our oceans, seaweed falls in line with the current rise in demand for plant-based seafood, and vegan eating in general, being the only viable vegan source of iodine. Of the thousands of people now converting to veganism, a third are doing so for environmental reasons.[1]
If you want to get involved in the seaweed revolution, discover PureSea®. We sustainably analyse every batch of our seaweed to ensure that it provides significant health benefits, including its status as a plant-based source of iodine. PureSea® is natural, sustainably sourced, and easy to incorporate into a wide range of food and nutrition applications.