Ocean Acidification

How will ocean acidification affect marine biodiversity and ecosystem function and what measures could mitigate these effects?

What is Ocean Acidification? Ocean Acidification is brought about when there are substantial changes in the chemistry composition of the ocean. There is an increased amount of Carbon Dioxide (CO₂) which is no longer being able to get absorbed by the oceans. The rise is predominantly  due to an increase in human activities for example the burning of fossil fuels and carbon emissions from industries. The excess CO₂ reacts with the seawater resulting in a very acidic environment.

What does Ocean Acidification do to our oceans and marine ecosystems ?

• reduces organisms ability to make skeletons containing calcium carbonate
• marine organisms eventually struggle to breathe
• affects the food web
• disrupts organisms interactions within their ecosystem
• decrease in the organisms quality of life

Effects of Ocean Acidification

The increase of CO₂ reduces the ability that plants and animals have to make skeletons/structures containing calcium carbonate, as the acidity dissolves their skeletons (Global Issues, 2014). It also reduces the biodiversity in marine ecosystems.

Ocean acidification urgently needs conservation biology in order to preserve the current organisms and to prevent further reduction!

What measures could individuals take to mitigate these effects?

• make every effort to reduce our carbon dioxide emissions wherever possible
• car pool / utilize public transport
• continuous maintenance on all vehicles ensuring they are running efficiently
• support nature reserves ensuring they are able to continue to protect the environment
• support Eco friendly products
• consume sustainably grown produce

Ocean acidification urgently needs conservation biology in order to preserve the current organisms and to prevent further reduction. There are many ways that individuals within society can do to reduce their CO₂ emission. Where possible people could make use of public transport, alternatively car pooling would reduce the amount of cars that are on the road. Maintaining the condition and efficiency of your vehicle can lower the amount of CO₂ vehicles emit. Visiting, and/or, supporting local nature reserves and protected areas allow them to receive funding and continue the conservation work they are doing in order to protect and preserve species numbers and their surrounding environment. Using, buying and eating Eco-friendly  products /produce enables us to reduce the need for deforestation to take place for new agricultural areas.  Also makes sure that the produce is harvested in a sustainable manner (Humans can take action to slow the process of ocean acidification, 2013).

What measures could companies/industries take to mitigate these effects?

• monitor pollution outputs
• control agricultural runoff
• obey all regulations regarding emission output
• tax industries based on emission output / excess over limit
• find alternative energy methods e.g. wind, solar
• monitor aquaculture facilities e.g. output, pollution, excess feed, disease
• avoid any oil spill into the ocean, control effectively if needed
• reduce the amount of methane produced by livestock
• create “carbon sinks” i.e. mangroves, seagrass beds, marshes

Companies need to make a concerted effort in monitoring and controlling the amount of CO₂ they emit. As the pollution and surface run off from industries aids in increasing ocean acidification and affects all marine life (Humans can take action to slow the process of ocean acidification, 2013).

MPA’s (Marine Protected Areas) along South Africa’s coastline  shelter the ocean from environmental stressors. Giving the ecosystem a chance to recover in population size and diversity. If we fish sustainability, follow regulations, size limits and quota it will give lowered fish stocks a chance to reproduce to acceptable and stable population numbers.

What will be the impacts of climate changes in phytoplankton and oceanic productivity and what will be the feedback of these impacts on the climate? 

The acidification will greatly affect marine biodiversity and ecosystem function. It has a cascading effect throughout the marine ecosystem. There will be changes in the food web, organisms interactions and quality of life within the ecosystem. These effects will target vital organisms resulting in a negative effect of organisms that are at lower trophic levels (Committee et al, 2010). Phytoplankton is a large component that will be impacted upon.

When the productivity of benthic organisms and phytoplankton are affected, it will as a consequence, decline fish communities and stock number in higher feeding levels.

Studies have shown that acidification levels rise quicker in colder ocean regions. Colder oceans have the most abundant sea life and are high productive sites due the cold upwelling’s the area receives. Thus a greater amount of marine life will be lost in these areas which is overall extremely detrimental to the global biodiversity (Doubilet & Images, 2016).

 

How will multiple stressors especially fishing, pollution, sea temperature, acidification and disease interact to affect marine ecosystems.

Image – Depicting how interlinked multiple stressors are, and that all can affect one or another species including whole ecosystems in some situations. Marine ecosystems contain complex and extremely integrated food chains and trophic levels.

Climate change is able to introduce multiple stressors on marine ecosystems at any one time. Stressors can be independent of one another, or alternatively, they can act in conjunction with another stressor which would amplify the overall effect that is brought upon the ecosystem or organism present (Ocean and Institute, 2010).

Hypoxia – Refers or organisms being depleted of oxygen due to a reduced level of oxygen in the water itself. Thus reducing their ability to survive and in turn maintain and support the ecosystem they are in. In most situations the ecosystem eventually dies off completely.

Acidification – An increase in acidification pressurises the organisms who rely on calcium carbonate in order to produce their skeletal structures. A lowered pH and increase in CO₂ emissions causes this disruption within an ecosystem to occur.

Salinity –  This has a major impact on organisms and their larvae. It can result in the composition of the ecosystem having to change in order to balance the shift made by the salinity. Disrupting biodiversity and potentially producing declined population numbers due to organisms being unable to survive the salinity change.

Sea temperature – Reduces the oceans ability to mix water adequately thereby reducing the nutrients the organisms are able to receive, impacting on marine biodiversity.

Disease  – Marine organisms are at a higher risk of contracting diseases due to the rise in sea temperature (Ocean and Institute, 2010). Particularly noticeable in corals, molluscs, mammals, turtles and echinoderms. Besides causing an increase in the mortality rate of the organism, it also has a detrimental effect on the functioning of the surrounding environment.

The combination of stressors will have a significant effect on the shellfish aquaculture industries around the globe that rely on balanced oceanic systems.

Climate and Carbon Dioxide changes are having a substantial influence and impact on marine organisms. It is altering their behaviour, physiology, species populations, community composition and biodiversity levels.

What research has been done to address the above questions ?

Ocean acidification is an extremely broad and interlinked topic. Knowledge and expertise on this topic is not globally well known. So countries and organisations are still trying to build foundations in how to combat this situation and problem at hand. Before adequate research can be performed .

• Researchers have mapped areas most vulnerable to ocean acidification

(Enabling us to focus our conservation efforts  on particular areas)

• Effects of ocean acidification on nitrogen (N2) fixation rates and on the community composition of N2-fixing microbes (diazotrophs) increased
• GOA-ON (Global Ocean Acidification Observing Network) – interactive map  with real time data giving public an early warning system illustrating a decline in water quality.  This would  help protect shellfish industries from getting affected.
• Geo-engineering proposals have been put in place in an effort to reduce the effect Ocean Acidification has on the environment and ecosystems.
• NWP ( Nairobi Work Programme) aims to help pubic understand & assess the effects of Ocean Acidification through scientific work and studies

Have there been any major findings?

• Carbon Dioxide is the leading cause for an increase in acidification
• Decline in Calcium Carbonate levels impacting a large sector of organisms
• Calcareous habitats are major concern as they are unable to build their ecosystems as their skeletons are dissolving
• Carbon Dioxide is affecting the biodiversity of plankton – the building blocks in the food chain. Reduced and/or no plankton is going to be disastrous for all marine organisms.
• Behavioural & sensory changes in many marine fish species
• Disrupted ecosystems will impact on human development

 

Hope that you are able to share the importance of our oceans to your friends, family & surrounding community.

Fiona 🙂