Dead zones are typically seen in shallow waters, near coastlines, and in areas where low-oxygen water is prone to be. There are many around the world, like those found in the Gulf Coast region. These dead zones are tricky though because they make it difficult for life to grow and exist. That means the wildlife, like plant life that is typically seen, dies off, and as that happens – the populations of fish then also die out. This combination ultimately causes the dead zone to form. There isn’t any life in this type of place, and it worries scientists because they form for a number of reasons.

The biggest reason they form is due to runoff that ultimately isn’t suitable and detracts from the quality of the water. However, the second cause has to do with the circulation of water. As water sits in a region, sometimes a whirlpool is formed. These whirlpools often harm the overall body of the water because it will trap water within its constraints, leaving the water inside deprived of oxygen.

The long-term consequences of this are pretty clear. First, as more of these zones develop, the problems will likely sit in the realm of determining where life is able to happen, and where it is not. As these spaces move, or as these dead zones move, we’ll be seeing marine life disappear in these zones. One of the major concerns that scientists have is how long it will take for these regions to recover once they have been deprived of oxygen, and the body can move again. Another concern, obviously, is that these spaces could continue to grow, ultimately causing issues for all sorts of life in these regions.

The human impact is pretty clear. Less marine life means that people will have fewer jobs, less food, and the broader impacts on the planet as a whole since the ocean contributes largely to creating a better planet – will hurt the bottom line of our species. As well as those millions which would be lost due to the dead zones shifting, expanding, or killing off species.

Johannes Karstensen of the University of Bremen pointed out, “The fast rotation of the eddies makes it very difficult to exchange oxygen across the boundary between the rotating current and the surrounding ocean. Moreover, the circulation creates a very shallow layer – of a few tens of meters – on top of the swirling water that supports intense plant growth.”

Karstensen went on to point out that, “This could cause the coast to be flooded with low-oxygen water, which may put severe stress on the coastal ecosystems and may even provoke fish kills and the die-off of other marine life.” This is the biggest concern of the scientists involved with this study, but at this point, it remains to be seen how these dead zones will act in the coming years.