You may be surprised to hear that, but human carbon emissions will actually boost the plant life in the oceans. It sounds bizarre, because we tend to look at our carbon emissions in a negatyve way only. However, scientists from the University of Adelaide discovered that not all the plants will benefit equally – carbon emissions with help small weed-like species, but not kelps.
Weed-like plants in the ocean are quicker to adapt to changing environment. This means that they will quickly adapt to increased carbon content in the sea. Carbon will act as a nutrient for weeds and they will thrive to become dominant over large tracts of coastal habitats. And so, with carbon levels rising and oceans becoming more acidic, it is already obvious that weeds are going to grow faster than their natural predators will be able to consume them. This is especially bad news for natural kelp forests, because they will simply be overpowered by weed proliferation.
This is actually bad news. While carbon can be a nutrient for plants, human carbon emissions are going to favour certain species. Kelp forests are important higher coastal productivity and biodiversity. They are ecologically more valuable than big patches of weeds. Scientists used volcanic CO2 eruptions to predict how human carbon emissions could change the ocean floor in the future. And so they found that in a couple of decades the marine life will be dominated by fast-growing and opportunistic species, while all the other ones, often more valuable, will decrease.
The issue is also related to natural predators of weedy plants. Professor Sean Connell, project leader, said: “In our study, we found that while elevated CO2 caused some weeds to be eaten in greater amounts, the dominant sea urchin predator ate these weeds at reduced amounts. This enabled the weeds to escape their natural controls and expand across coasts near the elevated CO2”. But scientists are still hopeful – there are some things we can do.
Of course, the best thing would be to cut our carbon emissions. But we can also promote predators that eat weeds. This could help control weedy plant populations while promoting biodiversity.
Source: University of Adelaide