Sea Reefs
Around 70% of earth's surface is covered by water. South Africa's coastline stretches 2 798 kilometres.
The question is, with such a vast potential resource, why is our sea not enhanced so that the resources we want from it multiplies.
We harvest from the sea, with the result the resource gets depleted. Fish and other marine life is under pressure, we can however change the situation around !
But how ?
Well, we have more control over a small strip and basically the shallow areas along our coastline. If this strip can be enhanced to multiply the marine life quantities, it could bring relief to a lot of resources that is getting depleted while user demand is on the increase.
In other words if we can create farms, similar to what we do on land, then we can increase our marine quantities. Many water plants and sea creatures needs some form of structure for protection. The difference between a sandy area and a reef is in a reef there is a lot more and a larger diversity of sea life. Also keep in mind that reefs are not shaped perfectly so with what there is the diversity has to make do with.
There are relatively very little natural structure along South Africa's coastline with the result that what is there is always under pressure. It will then stand to reason that if we can produce artificial reefs with prefabricated cavities that can house many sea creatures and of varying sizes that these sea creatures would flourish and their quantities can multiply many times over compared to what is possible with what we have currently.
Keep in mind that sea animals breed themselves and that we do not have to feed them and no maintenance is further required once such a reef is in place. All we have to do is give them enough place to live and multiply in and they will follow suite. Like planting a tree and you can harvest the fruit for many years to come.
So who will benefit ?
Everybody. There can be enough produced naturally to make a big difference to our available food resources.
Anglers of course, as well as divers and hence the tourism industry.
And that's not all. Reefs can be constructed to enhance certain features like boost wave heights, or reduce swell heights in other areas by diverting sea currents. It has been done before so we can enhance surfing in some areas for, wel, surfers, and in other areas reduce swells and calm the water to make access for boats a lot safer and accessable for more users. You can also google success of artificial reefs and see how well this worked already.
One of the reasons Mozambique is a favoutite destination, apart from almost no crime - unlike South Africa, is the natural reefs offers easy access to the sea and also produces more fish.
Some more advantages would be job creation, it's no small task manufacturing such reefs and the components will have to be manufactered, and also installed.
Since I have had an interest in this becoming a reality for some years, I also designed a possible building stone these reefs can be built from. It has to be a simple part that is easy to manufacture and that can be stacked in more than one way to offer housing to more creatures of different sizes. I don't claim it is perfect and if someone else can offer a better design, please offer it as a possible solution.
The model will be a concrete building block that can be stacked and interlock with other same parts. The parts should be placed with their open ends pointing to the beach and to the open sea. The idea is you can build a reef up, almost like building a house with bricks. Concrete lives a long time in sea water.
Manufacturing will require a mould where the concrete is cast into, the same mould can make many parts.
There are two ways these parts can be stacked to make up a reef.
This way of stacking produces relative small cavities.
And this way it will produce larger cavities. Both stacking ways can be combined as well so a veriety of cavities exist in the same reef. There is no limit to the length this reef can be made.
A side view of a possible reef. The amount of parallelles and stack height can be made up depending on the water depth and size of the available area. The swell can pass through the open ends of each stack, the turbulence is what will slow the water movement. Also keep in mind water cannot be compressed.
The more rows are stacked the more housing for sea life is created, same with height.
Top view, the building blocks does allow for some bending the reef if it is required, but the stack can also be interrupted and continue into another direction.
Placing such a reef will require little equipment and can be done by divers. For example a 100kg piece of concrete weighs only 5kg in water if a 95kg per volume light weight air tank is attached to it. Once in place the air tank can be released to surface to be attached to the next part and the placed part remains below.
The building blocks can be taken to the build area either by boat, then lowered into the water, or dragged into the water from the beach with a pulley system looping at a boat anchored beyond the area.
This is an opportunity for anglers to become independant from government intervention.
Apart from large amounts of funds that will probably just disappear again to name one problem re government and a project that may never be finished, the anglers and boaters can become self governing and have a positive and dynamic role in controlling the resource. In the case of an individual doing this users will be paying expensive again. This is our right to have and to have access to, and not for any one or organization to exploit at other's expense.
When self governing becomes a
reality, unreasonable license fees, bag limits, access and mostly every thing
else that creates problems can be eliminated. Government is accusing
anglers for instance that they deplete the resources therefore have to
pay. If the resource is maintained and monitored by us then
government can make no demands.
If you have any comments and
contributions, please email or call me.
Regards
Fanie
Phone +27 12 661 4751
Fax +27 12 661 9949
Mobile 082 456 6925