Earth’s oceans are the heartbeat of the planet. If the oceans fail, life on every part of the Earth is at risk.
A new report from the International Program on the State of the Ocean (IPSO) has discovered strong evidence that ocean ecosystems are collapsing, maybe irreversibly. The report concentrates on 7 key points:
1. Human actions have resulted in acidification and warming of the oceans and are now causing increased hypoxia.
Lack of oxygen (hypoxia) is already resulting in vast dead zones where only anaerobic bacteria can survive. Although other factors may be implicated in warming, the IPSO report identifies human action as a major cause. Either way, the combination of warming, acidification, and hypoxia has caused disruptions of the carbon cycle in the past, which have been associated with 5 previous mass extinctions.
2. The speed of negative changes to the ocean correspond with worst-case scenarios, or are even faster. The speed of many changes is accelerating.
Changes which match or exceed worst-case scenarios include the rate of melting of Arctic sea ice, the Greenland icesheet, and the Antarctic ice sheet. They also include sea level rise and release of trapped methane from the seabed. In turn, these changes are also compounding other changes, such as the destabilization of food webs and the loss of fish species.
3. The magnitude of the cumulative impacts on the ocean is greater than previously understood.
Many factors which individually affect the oceans also combine to create a greater effect. For example, combining nutrient runoff with the introduction of non-native species often makes algal blooms and dead zones much worse than they would otherwise be.
4. Timelines for action are shrinking.
The longer the current level of emissions is allowed to continue, the harder it will be to turn the process around. It will also cost much more. In the meantime, the environmental damage will continue to get worse.
5. Because of all these stressors, the ocean is no longer as resilient as it once was.
The ocean can’t bounce back the way it used to. The combined impact of all stressors, including factors such as chemical pollutants and loss of genetic diversity due to overfishing, is too high.
6. The ecosystems are collapsing.
As a result, the marine food web has been severely impaired. Every level of the marine food web is under stress to the point where it can no longer function as an ecosystem. This is one reason why the number of harmful algal blooms have been increasing.
7. The extinction threat to marine species is rapidly increasing.
Climate change means rapid loss of habitat for organisms which cannot move, such as reef-forming corals. Ocean currents will change, which will affect the food supply. When these factors are added to existing levels of overexploitation, many species may not be able to survive.
What’s even worse is that the effects are already being felt. This is not something that won’t be noticed for centuries. If current trends continue, Alex Rogers, the Scientific Director of IPSO, says that, “We are looking at consequences for humankind that will impact in our lifetime and, worse, our children’s and generations beyond that.”
Rogers does not speculate whether immediate human action can turn the trend around. However, the report emphasizes that timelines for action are shrinking. If human intervention can save the oceans, the time to take action is now.
