In recent times, rapid rises in global temperatures have led to a boost in mercury levels in fish by up to seven times the current rate, increasing by 200% and 500% researchers have concluded.
Experiments have been carried out by researchers and scientists, in which they have found that the extra rainfall drives up the amount of organic material flowing into our seas. With this extra organic material, food chains are altered and the concentration of mercury increases. Along with this, mercury is bioaccumulating, and is built up in the adipose tissue of successive trophic levels; leading up to larger fish, and this causes an overall increase in the amount of mercury in fishes, furthermore leading to many issues. Mercury has a significant impact on the central nervous system, and produce harmful effects on the digestive and immune systems, too much mercury can lead to fatal consequences, and we need to solve this issue.
Mercury is one of the world’s most toxic metals. It is also one of the top ten threats to public health, according to the World Health Organization. The effects high levels of mercury can have are substantial, with damage to the nervous system, paralysis and mental impairment in children just some of them. One of the most common form of exposure to mercury is by eating fish which contain methylmercury. This is an organic form of the metal which forms bacteria, when reacted with mercury found in water, soil or plants, at the expense of phytoplankton.
Under the warmest climate scenario, there would be an increase in organic matter runoff of 15-20% by the end of the century. This would see levels of methylmercury in zooplankton, which is the bottom link in the food chain, grow by two to seven fold. There would be different impacts suffered around different parts of the world, with lakes and coastal waters in the northern hemisphere being most likely to have a significant increase in methylmercury fish. The mediterranean and Southern Africa will likely see reductions.
Researchers hope that the Minamata treaty will be successful and countries reduce the amount of mercury being produced. With many countries relying heavily on fish as a source of food, and the level of fish being eaten all over the world, the level of methylmercury within human bodies is likely to increase. If the level is not decreased, the impacts to human health could be severe. To add to our woes, the appointment of Donald Trump’s cabinet, contains many climate change sceptic members, and this could lead to an increase in the mercury problem we are facing.