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A new review suggests that the climbing amounts of carbon dioxide may soon make the ocean so acid that several species of seafood and fish may go extinct.
The recent review contains data from several studies on rising greenhouse emissions and their impact on marine life, which is already under a lot of stress from overfishing, pollution and habitat losses in the coastal areas.
William Cheung, the lead author of the review and professor at the University of British Columbia, explained that in the not-so-distant future we may see entirely different types of fish on our dinner plates. The researchers said that fisheries will start catching smaller sized-species that are more resistant in warmer waters caused by global warming.
The team believes that the scenario would affect the domestic and international fish supply along with the imports. Although the recent review didn’t mention what the most endangered species of fish may be, several studies have suggested that the freshwater salmon, which needs the sea to reach maturity, would very likely be affected by ocean acidification.
Acidification kicks in when too much carbon dioxide makes its way to waters. Biologists worldwide have reported that hard-shelled marine creatures including crabs, mollusks and corals grow softer shells as they find it harder to accumulate calcium.
But acidification does not affect only oceans, freshwater is also in peril. A recent study conducted by University of British Columbia researchers revealed the negative impacts freshwater acidification may have on pink salmon populations. During their experiments, scientists used two water tanks and several salmon embryos.
One of the tanks matched the current levels of CO2, while the water had the CO2 levels predicted for the future. The pink salmon embryos were left to develop for ten weeks in the two tanks.
After 10 weeks, researchers noticed that the fish reared in more acid water were smaller than their peers living in the other water tank. And smaller fish is an easier prey to their predators, the team explained.
Moreover, the smaller salmon had an altered sense of smell which is another drawback than can expose them to their predators.
In a second stage of the experiments both types of fish were placed in seawater at control or high levels of acidification. Scientists observed that CO2 concentrations stunted the growth in fish, regardless of their birth environment.
Co-author of the study Colin Brauner argues that acidification does not affect only marine species, but it can do a great deal of harm to freshwater species too. Plus, acidification does not only stunt the fish’s growth, but it also deters pink salmons from reaching their freshwater breeding grounds.
NOAA has recently conducted a separate study on acidification and its impact on coastal shellfish hatcheries along the Alaskan coast. The study had revealed that acidification may make it nearly impossible for local waters to support hatcheries by 2040. Official data show that Alaska’s commercial fisheries currently catch about 60 percent of the fish commercialized in the United States.
Image Source: CNN
