Sunday November 12 2017

Climate change causing ocean and sea acidification

A marine ship used by scientists at Geomar Helmholt

A marine ship used by scientists at Geomar Helmholtz Institute for Ocean research Keil University Germany for the research work on ocean and accidification parked at Baltic sea shore in Keil. Photo by Lominda Afedraru 

By Lominda Afedraru

There is an increasing level of pollution in terms of acidification resulting from human activities in major seas and oceans surrounding developed countries in the world.
There is no any difference in fresh water bodies in Africa particularly Lake Victoria one of the world’s fresh water lakes surrounding the East African countries, Uganda Kenya and Tanzania.

However scientists globally are carrying out research to establish the level of acidification especially in Baltic Sea, Antarctic Ocean, Pacific Ocean and Atlantic Ocean.
The head research unit in the Biological Oceanography Geomar Helmholtz Institute for Ocean research Keil University Germany Prof Ulf Rebesel explaining the trends of ocean acidification in water bodies surrounding European countries, USA and Asia among others to a group of science journalists attending the 2017, oceans and seas press tour notes that it is amazing to think that just ten years ago hardly anyone had heard of ocean acidification.

It is now much more widely understood that the increasing amount of carbon dioxide being emitted from human activity into the air is reacting with the ocean to alter its chemistry and push it along the scale towards acidity and is reducing the availability of carbonate ions needed by many marine animals and plants to build their shells and skeletons.

He explained that there has been 35% increase in ocean acidification research and about 2%-8% on average annually between the years 2000 – 2014.
His team at the Institute in collaboration with scientists from other parts of the globe is carrying out research to establish the magnitude of ocean acidification and possible solution to the same.

He explained that the major cause of Ocean acidification is absorption of human made carbon dioxide from materials such as fossil fuel resulting from burning of coal and gas.
Giving the statistics he stated that 44% of the carbon dioxide is released to the atmosphere, 29% is taken by the environment and 27% goes to the water bodies and the oceans absorb a quarter of the total carbon dioxide produced.

In 2016 the total absorption was 36.4 Giga tons and in 2015 it was 36.3 Giga tons. All these react with water to get carbonate acid which makes the water to taste acidic. If not treated it is dangerous to human health and aquatic life.

In 1950 the PH, a figure expressing the acidity level was 1.5 and it has since increased by 30%. By 2030 it is estimated to be between 7 and 8 with polar seas affected most and becoming corrosive in respect to calcium carbonate.


Challenges and solutions
This according to Prof Rebesel will pose a huge challenge to marine species leading to decline and some ocean ecosystem will be lost. This will impact on humanity who depend on marine species such as fish for food protein. This is because the fish catch is already reducing in the water bodies.
Scientists involved in the research work are advising governments to ensure the gas emission to the atmosphere is maintained at 2 degrees Celsius.
This is possible through geo engineering technologies where the radiation increase in sun reflection into the space is made less to avoid global warming.
This can also be made through Carbon dioxide air capture by providing storage facilities though this may be expensive to countries that may not be in position to afford. Other ways are putting lime into the ocean to absorb the acidity and using nutrient rich matter.

Afforestation is also another good solution and it is affordable to all nations in the world.


Challenges arising from sea level rise and solutions
Dr Anthanasios Vafeidis from the department of Geography, Coastal Risks and Sea level in Keil University explaining the impacts of sea level rise and its uncertainties notes that apart from acidification effects, sea level rise have a big impact on humanity and marine ecosystems.

It has been estimated that since the year 1993 the sea level is increasing by 1.7mm per year. Scientists establish this through satellite measurements and there is prediction that it will increase to 2mm as a result of climate change effects namely, glacier breaking, Greenland ice sheets and thermal expansions.
Others are hurricanes leading to over flooding and causing coastal erosion.

Dr Vafeidis explains that there is need for protected human settlements where governments will be urged to protect unnecessary flow of water using dykes and the need for storage facilities to absorb water caused by hurricanes from over flooding.

Sea level rise may not cause a major challenge to marine life apart from affecting coastal ecosystems like coral reefs but the challenge is huge on people living along coastal areas.
Background
A look at a paper prepared by the International Ocean Acidification Reference User Group, in partnership with national research programmes providing essential information and actions needed on ocean acidification by Governments, it is stated that there is little doubt that the ocean is undergoing dramatic changes that will impact many human lives.
Previous acidification events in the Earth’s geological record were often associated with extinctions of many species but when experts met at Rio+20 in June 2012 in Rio de Janeiro at the United Nations meeting on Sustainable Development, Ocean issues featured more highly than ever before.
World leaders in this meeting observed that there is need to support initiatives that address ocean acidification and the impacts of climate change on marine and coastal ecosystems and its resources.

This they say can be arrived at by supporting scientific research about the subject matter to find solutions to what needs to be done.
Some of the initiatives in progress include formation of Ocean Acidification International Coordination Centre to serve the scientific community, policy makers and the wider public focusing on international activities that are not currently funded at national or international levels.

The centre, the formation of which resulted from the concerted actions of the global ocean acidification research and user communities, will focus on international activities that are not currently funded at national or international levels

It is supported by International Atomic Energy Agency (IAEA) Member States, with advisory overview by the U.N. Intergovernmental Oceanographic Commission, the U.S. National Oceanic and Atmospheric Administration and the U.N. Food and Agriculture Organization among others.

Statistics indicate that this hidden ocean service has been estimated to represent an annual subsidy to the global economy of US$86 billion per year.
Other initiatives are Australia Ocean acidification research focusing on impacts from the Southern Ocean through to the Great Barrier Reef and into Papua New Guinea led by the Southern Ocean and the Antarctic Climate & Ecosystems Cooperative Research Centre.
China Ministry of Science and Technology and National Science Foundation of China have also started to support research into ocean acidification in a five year project called CHOICE-C to study high level of carbon dioxide and ocean acidification in Chinese marginal seas. Others countries already involved are UK, USA, Japan, and European Union countries among others.
What is going on in East Africa’s Lake Victoria?
In the fresh water bodies, the pollution may not be necessarily acidification but industrial chemical waste ending up in the water bodies. In the case of Uganda and East Africa, Lake Victoria is already faced with the challenge.

In a publication by Air Water Earth (AWE) Ltd, an environmental and engineering firm based in Uganda about why Lake Victoria levels are rising, it is stated that,
“The causes of rising pollution levels in the Lake are as many as they are diverse and each of the three East African nations is liable. The Lake has for a long time been a sink to excessive nutrients and untreated effluent that have led to fish species dying, algae buds and the spread of hyacinth coupled with waterweed is another major problem although this has been eradicated to a good extend,”

The remnants of hyacinth on Lake Victoria have dissolved causing rise in carbon dioxide absorption. Along the shoreline, hyacinth provides habitat for malaria mosquitoes and snails which habour bilharzia parasites.

The Lake is shared by East African states of Kenya (6%), Uganda (45%) and Tanzania (49%).

Its basin is used by communities and industries as a source of food, energy, water and transport. It is a sink for human activity, agricultural and industrial waste and nearly one third of the total population of East Africa derives their livelihood from it.

In Uganda the biggest Nakivubo channel point running in the middle of the city acts as source of sewage and industrial waste plants which ends up in the lake.
Small scale workshops, waste oil from parking lots and car repair garages are major sources of pollution load for the lake.

The sewer system in Kampala city serves only a small fraction of the city population and only 10% of all sewage generated in Kampala gets treated.

Guesthouses, slum dwellings and industries discharging untreated waste in Nakivubo channel, which flows into Murchison Bay contributing the pollution load.
It is further stated that the picture in Kenya is not rosy either. Towns of Kakamega and Kisumu discharge inadequately treated sewage in rivers draining into Lake Victoria because of deficient treatment plants. Kisumu’s sewage plant at river Kisat with a design capacity of 9000 cubic meters now receives 15000 cubic meters of effluent, much of which flows into Lake Victoria without treatment.

Tanzania’s town of Mwanza located near Lake Victoria discharges large quantities of untreated waste into the lake and this include waste from fish processing factories, oil processing plants and textile facilities which is discharged pretreated.
Some of the affluent contain metals such as Zinc, Mercury and lead which are dangerous to human health and aquatic species.
alominda@ug.nationmedia.com

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