@@ -42,7 +42,7 @@ A major component in such fertilizers is nitrates. With this conventional intens
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<imgsrc="https://static.igem.wiki/teams/5306/map-provinces-netherlands-en-svg.png"alt="Map of Dutch Provinces"width="50%"/>
<p><b>Figure 4.</b> A map of Dutch provinces (Wikipedia, 2010).</p>
<p><strong>Figure 4.</strong> A map of Dutch provinces (Wikipedia, 2010).</p>
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Furthermore these anthropogenic activities have led to the development of marine dead zones due to the hypoxic and toxic conditions related to nitrate-induced algal bloom and decomposition (Figure 5). As the nitrogenous compounds are uptaken by present algae for nutrients, the resultant algal bloom has a wide array of consequences. The overgrowth of algae first leads to the blockage of sunlight for the shallow primary producers of the marine food chains. As such, these plants are unable to perform photosynthesis and die, causing damaging rippling affects across the food web. Additionally, some of these algae produce toxins, leading to harmful algal blooms (HABs), directly poisoning local life. As this algae begins to decay due to nutrient depletion and overpopulation, bacterial decomposers break down this organic matter. This decomposition process uptakes large amounts of dissolved oxygen in the water bodies, creating hypoxic conditions. These hypoxic conditions create dead zones that have insufficient oxygen to support marine life. Fish and other marine life either migrate to oxygen rich areas or die off. This leads to a loss of coastal biodiversity, while subsequently posing dangers to human health as well (Sanseverino et al., 2016). Another byproduct of algal decomposition is the release of carbon dioxide into the water. Carbon dioxide dissolves in the water, forming carbonic acid (H₂CO₃), lowering the pH of the water, contributing to ocean acidification. Such acidification decreases the availability of calcium carbonate which is crucial for marine organisms like corals, mollusks and plankton physiology (Rastelli et al., 2020). Oxygen depletion and ocean acidification have also have shown to lead to mass proliferation of hypoxia tolerant species such as Noctiluca scintillans, which is toxic to fish, and damage to shallow marine vegetation (do Rosário Gomes et al., 2014; Glibert, 2017.)
