Population growth and its effects

Population growth and distribution of said population are key factors in trying to implement global and local environmental management and sustainable living. There are many contributing factors to consider to ensure that environmental management will be successful in the future.

Ultimately, the success of how effective environmental management in conjunction with the sustainability of our resources comes down to the rate at which our population is growing.

Environmental Management with regards to Water Resources

Immediate and appropriate local and global management is required to ensure that our water supply is able to meet and keep up with the demand of a growing population.  “Nearly 2 billion cope daily with the problem of finding enough water and as many as 3.5 billion – almost half the worlds projected population – could face water shortages by 2025. Africa is at particular risk.” (Livernash, 2002)

Sustainable management of this critical resource needs to ensure that all people have access to clean and safe water. Concurrently, we need to sustain our natural water areas and implement environmental management in order to reduce/ prevent water pollution. “Worldwide 54% of the annual available fresh water is already being used. This is based on unequal consumption. Some 1.1 billion people do not have access to fresh water or consume less than the basic daily requirements of 50 litres” (Rosenberg, 2008).

Globally 70% of water is used for agricultural use, 22% industrial and 2% domestic use (UNESCO, 2003), whereas in Africa 85% of water is used in agriculture, 5% industrial sector and 10% used in domestic sector (Water, 2016).

The UN states that humans need a minimum of 50L of water per day for cooking, preparing of food, cleaning and reducing the spread of disease (Water, 2016). If we were to multiply this minimal amount by the number of people on Earth, it would be an extremely high figure which excludes industrial water consumption and agriculture. We are going to battle with keeping up with our water demands.

Food Production & Land Availability

Suitable land availability is declining, thus making basic food production difficult. “Long term gains in food production, especially in developing countries, are threatened by land degradation and by growing competition for water from industrial and municipal sources” (Livernash, 2002). Environmental management needs to ensure that we utilise our land space and resources efficiently. This will allow us to remain as close to sustainable as possible.”By 2030 the world will need at least 50% more food, 45% more energy and 30% more water (High Level Panel on Global Sustainability, 2012). Sustainability is extremely hard to achieve when the population growth rate is exponential. According to (Outlook, 2014) in 2013, 23% of households did not have adequate access to food and 13% experienced hunger.

“In 1997 the world demand for meat was 208 million metric tons and in 2020 its projected to be 327 million metric tons” (IFPRI Impact Projections, 2011). Even on a basic linear scale it is not possible to sustain this growth. With our already limited supply of resources, it is virtually unachievable to produce this amount of meat to feed and maintain our population.

We consume more water than we realise. Professor Tony Allan conceptualised the notion of virtual water. It is the amount of water we consume that is not visible to us, which goes over and above our minimum daily intake of 50 litres. A major contributor to virtual water is food production and consumption.15 455 litres of water is required in order to produce 1kg of beef (Water, 2016).  Cacao requires 27 000 litres for ever kilogram produced (Water, 2016).


Fiona 🙂

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.

cartoon corals

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 🙂

Saturday Suprises

Great times can be few and far between, so when Fiona came running over to show me the weather report, I knew it only meant one thing. A good weather Saturday. After fierce negotiations, we settled on a compromise. We could go for a long paddle towards Cape Point. I could explore some new dive spots and then return to a braai ( Barbecue) on the beach. I wanted to test my new (Cant burn the chicken stand) that I had made a while ago. If I played my cards right I could slip off for a quick surf while she cooked the food. I was optimistic to say the least.

After a few touch-and-go moments launching (Always good for a laugh) we made our way South. Conditions did not allow me to slip into the water for that dive, but never the less we had a great relaxing paddle.


On our way home we heard shouting in the distance, It was a fellow kayaker checking to see if we were okay as the wind had picked up a little. We soon made contact with him and we  explained that all was okay. He was very excited to tell us about the two fish he had just caught. I think that its really great even though he is on a fishing kayak the community is still inclined to keep a eye out for each other. We ended up chatting and paddled back to were he launched so we could get a glimpse of his fish.


After lighting the fire I slipped of for a quick surf while Fiona stood guard protecting our food from the local Baboons. I ended eating way to much as I always seem to do. Fire grid proved to be a winner so no more balancing grids on rocks. Yay!!

We returned home with sun kissed faces and full bellies. I could not ask for a better day. Fiona being Fiona took great delight in reminding me that the last part of the deal for the day was a 5km run!! Have I ever mentioned how I really have a dislike of running. Its right up there with washing dishes and renewing my drivers license. I did what I could to stall but a deal is a deal so we ran. …Truth be told I actually enjoyed it all. I wonder what is in store for us on Sunday.  Dan

Winter is coming



Many people dream of living on some far away deserted island. The idea in itself is so appealing, however the reality of it may not be. Hot humid sunny windless days followed buy hot sticky humid nights. This monotony only broken by down pours of rain. Not as great as we first thought hey?  Well not for me anyway.

As humans I feel we resist change, one moment we are complaining its to hot and the next its to cold. Well for us down at the very tip of Africa we have no choice. We have had a great hot summer but as each day rolls by it is clear that it is changing. Winter is coming. Most people recoil at the thought. I choose to believe its all about perspective.

I look forward to less tourists clogging the roads as well as ample parking. No more South East wind.( This can blow for two weeks solid). No more crammed beaches filled with peoples litter. I look forward to the chill in the air. The dramatic red sunsets and beautiful still days. Winter swell that is great for surfing. Cold water upwelling’s that bring a burst of life into our bay.

Passing Shoal

Most of all I look forward to the clear blue water. I always joke that it looks so clear and blue becouse its act a block of ice.

Lets face it the water temp drops from a balmy 22 deg in the hight of summer down to a refreshing 12 deg which can even drop to 10 in places. Fiona and I don’t wear wet suits as we think it isolates you to much from the environment. I do wear a hoody and ear plugs to stop the bones in my ears growing closed.(Its the side effect of swimming in cold water to much). The rash vest is to stop jelly stings and some irritating rash I tend to get on a type of fire coral. Wet suits are such a faff anyway, so why bother. The freedom to swim like a fish and feel the thermoclines, touch the kelp and be as close to immersed in this world as possible. That’s the key.

The accepted theory is that our Great White shark population moves a little offshore to a place in the middle of the bay called Seal Island, feeding on the new seal pups. This leaves us in relative safety to venture into deeper waters. We now have more time to get to know some of the locals!


So its on. Now we can find parking, go exploring new places in the rain, drag my kayak down to the beach and get some great surf. So never mind the cold and rain its all part of this change. The best part for me is defiantly the swimming. We can now swim in cold clear relatively safe water. Fiona and I both really look forward to this time of year. Finally  we can dare ourselves to swim out into deep water caves and start exploring again.

cold water exploring

I cant resist exploring sea caves


 Dont get me wrong Summer is great but Winter  is when you know you are Alive.