Archive for Ocean Acidification
www.independent.co.uk 16th August 2012
Scientists have created a “systematic way of scoring the health of the world’s oceans” in an attempt to evaluate their health in the face of growing problems such as pollution, overfishing, and acidification. The Ocean Health Index (graph below) places the overall health of the world’s oceans at 60 out of 100. The worst affected areas included the territorial waters of Sierra Leone, which scored just 37 and failed in every one of the ten measures the index uses to measure the sea’s health. Measures include water quality, biodiversity, and the sustainability and productivity of local maritime industries, such as fishing and tourism. Interestingly, the survey found that waters of the coasts of developed countries such as Germany differed little on the index than those in remote areas such as Jarvis Island in the Pacific Ocean. The survey was put together by 30 scientists and published in Nature. Only 5% of countries rated over 70 whereas a third were below 50. Great Britain weighed in at 61, just above the global average but below the US (63) and Germany (73).
www.sciencedaily.com 1st March 2012
A new study by Colombia University’s Lamont-Doherty Earth Observatory indicates that today’s ocean acidification through human carbon emissions is happening faster than at any time during the past 300 million years. Over this time there have been four mass extinctions caused by natural ‘pulse’ emissions of carbon into the atmosphere, which sent temperatures soaring. According to lead author Bärbel Hönisch, ”What we’re doing today really stands out. We know that life during past ocean acidification events was not wiped out — new species evolved to replace those that died off. But if industrial carbon emissions continue at the current pace, we may lose organisms we care about — coral reefs, oysters, salmon.” The study is the first to explore the geological record for signs of ocean acidification over time. The research team behind the study came from five different countries and reviewed hundreds of paleoceanographic papers to come to their conclusion. In the past 300 million years, there was only one time period where the ocean acidified as quickly as it is today. Spanning 5,000 years roughly 56 million years ago, a mysterious surge of carbon into the atmosphere caused an estimated 6 degree rise in global temperatures. The carbonic acid created in the ocean by the absorption of CO2 led to the dissolving of carbonate plankton shells on the seafloor creating a layer of mud. Normally these shells help regulate the acidity of the oceans.
www.seaweb.org 6th July 2011
In the absence of a global move to reduce carbon emissions, many have asked the question whether anything can really be done to reduce the effects of ocean acidification on the marine environment. A new paper, released in the journal Science, has tried to tackle this question by putting forward a number of ideas that could be implemented by local and national governments to better protect their coastlines. Although the growing amount of CO2 in our atmosphere is increasing the level of the gas absorbed by the oceans (thereby creating carbonic acid), several other factors also play a role in this process. Freshwater input from rivers, pollution, and soil erosion all affect the acidic level of seawater. Although the report, headed by Ryan Kelly of the Center for Ocean Solutions at Stanford University, is aimed towards the United States, it’s lessons are relevant on a global scale. The first issue they tackle is to reduce acidification-related runoff. This can be done by using state funding and the Clean Water Act to prevent stormwater surges, upgrade water treatment facilities, and restore wetland areas. Secondly, in order to reduce coastal erosion (which carries with nutrient runoff and acidification-inducing fertilisers) local governing bodies should encourage vegetation growth that stabilises coastal sediment. Thirdly, “enforcement of federal emissions requirements for such industrial pollutants as nitrogen oxide and sulfur oxide should provide local benefits given these pollutants’ short atmospheric resident times.” The paper insists that these more local moves challenge the commonly held belief that the problem of ocean acidification can only be dealt with on a national scale.