The marine environment is very complex and it is difficult to get to grips with the complexity. It is expensive and difficult to conduct research in the marine environment. In order to assess a fishery we work on how efficiently we are able to kill them, based on a measure called catch per unit effort, which measures how many fish of a certain species are caught in a specified period of time. We are also limited in terms of the depth to which we can research.
Fish species can disappear without us even realizing that they are gone. Fish such as Dageraad, Red Roman and Cob are dependent on marine protected areas for their survival, but in South Africa local communities are being given the right to fish in these areas.
How do we preserve the marine environment? It is very costly to defend a long coastline from illegal fishing. With environmental pressures such as climate change, species are going to become extinct at a greater rate.
Biomass underpins biodiversity. There is a critical mass of creatures that create a marine environment and these animals interact with one another in a complex manner. The ocean has been a stable environment for a very long time, much longer than land systems. But we are changing such environments within mere decades.
An ocean is a living entity – if you take a cup of seawater and leave it on a shelf, it will rot. Red Tides are caused by micro-organisms growing too fast and then dying and rotting, which causes a lack of oxygen in an area which then kills off everything else. This gives an indication of how complex the ocean is.
We are at a tipping point – there are many things going wrong in the oceans, e.g. huge blooms of jellyfish that even stop ships from moving. These are symptoms – are these symptoms of the oceans dying or are they reversible?
We have to take individual responsibility and ask what can we do to halt the degradation?