Corals are disappearing across the world’s oceans, and most scientists have pointed to warming water temperatures — the result of climate change — as the primary driver.
But new research suggests nitrogen pollution is the main cause of coral bleaching in Florida.
The study, published this week in the journal Marine Biology, was compiled using the three-decades worth of observational data collected at the Looe Key Reef in the lower Florida Keys.
“Our results provide compelling evidence that nitrogen loading from the Florida Keys and greater Everglades ecosystem caused by humans, rather than warming temperatures, is the primary driver of coral reef degradation at Looe Key Sanctuary Preservation Area,” lead study author Brian Lapointe, research professor at Florida Atlantic University’s Harbor Branch Oceanographic Institute, said in a news release.
Data collected at the test site showed nutrient runoff has boosted the nitrogen-phosphorus ratio in reef algae.
As more and more treated sewage and fertilizers from commercial farms rinse into local waterways and flood the oceans with nutrients, including reactive nitrogen, corals are unable to absorb sufficient levels of phosphorous.
“Our results provide compelling evidence that nitrogen loading from the Florida Keys and greater Everglades ecosystem caused by humans, rather than warming temperatures, is the primary driver of coral reef degradation at Looe Key Sanctuary Preservation Area,” lead study author Brian Lapointe, research professor at Florida Atlantic University’s Harbor Branch Oceanographic Institute, said in a news release.
Data collected at the test site showed nutrient runoff has boosted the nitrogen-phosphorus ratio in reef algae.
As more and more treated sewage and fertilizers from commercial farms rinse into local waterways and flood the oceans with nutrients, including reactive nitrogen, corals are unable to absorb sufficient levels of phosphorous.
In 1984, coral cover in the Looe Key Sanctuary Preservation Area was estimated at 33 percent. By 2008, it was just 6 percent. Today, it’s less than 4 percent. The Florida Keys National Marine Sanctuary has the lowest coral cover anywhere in the Caribbean.
Scientists found periods of accelerated coral decline followed heavy periods of rainfall and water releases from the Everglades. The correlation highlighted the negative impacts of nutrient loading on coral health.
Climate models suggest the region will experience increasing levels of rainfall. Rising water temperatures, however, will only make matters worse, researchers warn.
Read more at UPI
I find this claim to be completely plausible. Land-use management is horrible, even in the US. Attempts to control what we spread across the countryside and the run-off are feable and largely ineffective in the long-run. Irrigation practices can stand lots of improvement as well, especially the water-mining of aquifers all over the world, which are a significant source of slow sea-level increases. These are factors which can be improved without completely wrecking economies and casting society into the neo-Dark Ages.
So humans are still causing the bleaching, but it is from fertilizer runoff.
Solution: only organic farming, so we can drop yields on all farms to 1800’s level. Of course, the population is higher than back then, so the people in the poor countries will just have to starve. You know, to save the planet.