The carbon dioxide we pump into the air is seeping into the oceans and acidifying them. In 2008 over 150 leading researchers declared that they are “deeply concerned” about changes in ocean chemistry that could “severely affect marine organisms, food webs, biodiversity, and fisheries.”
By 2100, if carbon dioxide emissions keep growing, many areas of the ocean floor will be nothing but mats of algae. In polluted harbors there are normally just a few weed like plant species able to survive the conditions. It’s like that when carbon dioxide is high. This could happen throughout our seas.
The atmosphere has a higher concentration of carbon dioxide today than at any point in the past 800,000 years – and probably a lot longer. The air and the water constantly exchange gases, so part of anything emitted into the atmosphere ends up in the sea. A 15-year study analyzed over 77,000 seawater samples from all over the world. The oceans have absorbed 30% of the carbon dioxide released by humans over the last 200 years. They continue to absorbed about a million tons – EVERY HOUR!
That absorption greatly helps life on the land. But it’s a very serious risk to life in the seas. If current trends continue, by 2100 the water be 150% more acidic than it was in 1800. As carbon dioxide levels go up, the carbonate used to make shells and skeletons by snails, barnacles, sea urchins, corals, and many more life forms goes down. Acidification interferes with reproduction in some species. Coral reefs may not survive.
The only feasible way to even reduce this extreme situation is to dramatically reduce carbon dioxide emissions.
For a more complete story see: Acid Seas.
Salmon in the Thames
Researchers collected genetic data from salmon in the Thames. The results suggest that habitat restoration was more effective than species re-introduction.
Historically, England’s longest river has a significant salmon population. Salmon are mentioned in the Magna Carta, written in 1215. A substantial fishery existed until the early 1800s. But the last salmon noted in the river was in 1833.
Since the 1970s there have been a number of attempts to reintroduce salmon, none previously successful.
These results suggest that habitat recovery may be the more effective way to reintroduce species over putting farmed fish in, which are always weaker.
Salmon in the Thames is one indicator of the fact that UK rivers are the healthiest they have been in 2 decades.