Reverend Jan Scholtz
Back in the day, the word climate change had no effect on an ordinary man’s life, until the scientific findings combined with the present phenomenon brought clear comprehensive evidence to modern man.
Namibia has one of the most productive fishing grounds in the world, based on the Benguela Current system, one of the four eastern boundary upwelling systems in the world (the others are off North-West Africa, off California and off Peru). These systems support rich populations of fish, which form the basis for the Namibian marine fisheries sector.
Climate change is the gradual change in the statistical distribution of weather over a period (decades to millions of years) it can be limited to a specific region or may happen across the whole world.
Mariculture is the cultivation of fish or any marine species to produce food and/or income generation.
The concept of climate change may be qualified as anthropogenic climate change, more generally known as “global warming” or “anthropogenic global warming”, it has both direct and indirect impacts on marine species which are exploited commercially both nationally and beyond borders for food security and income generation.
Direct effects act on physiology and behaviour and alter growth, reproductive capacity, mortality, and distribution. Indirect effects alter the productivity, structure, and composition of the marine ecosystems on which cultivated species depend for food.
The build-up of carbon dioxide and other greenhouse gases in the atmosphere as a result of human interaction with nature is changing several of the features of the earth’s climate, such as oceans, coastal and freshwater ecosystems that affect fisheries and aquaculture in general, air and sea surface temperatures, rainfall, sea level, the acidity of the ocean, wind patterns, and the intensity of tropical cyclones are all affected as the result of the build-up of carbon dioxide.
Fish farmers and coastal inhabitants will bear the full force of these impacts through less stable livelihoods, changes in the availability and quality of fish for food, and rising risks to their health, safety, and homes.
Many fisheries-dependent communities already live a precarious and vulnerable existence because of poverty, lack of social services and essential infrastructure.
The fragility of these communities is further undermined by over-exploited fishery resources and degraded ecosystems. The implications of climate change for food security and livelihoods in small island states and many developing countries such as Namibia are profound.
Climate change is modifying the distribution and productivity of marine and freshwater species and is already affecting biological processes and altering food webs. The consequences for the sustainability of aquatic ecosystems, fisheries and aquaculture, and the people that depend on them, are uncertain.
The following aspects will help us understand the link between modern mariculture and the continual climate change as we brief each at a time.
Changes in species abundance may have a variety of direct and indirect economic and social effects. We may summarise potential effects of climate change on fish harvests as follows:
- Climate change is likely to reduce the abundance of some species while increasing the abundance of others.
- Changes in harvests: As the abundance of a species changes, fishermen will catch more or fewer fish.
- Changes in fishing and processing employment: Changes in harvests affect employment opportunities in fish harvesting and processing industries.
- Changes in prices: Fisheries markets are highly sensitive to supply. Changes in harvests tend to have opposite effects on prices.
- Social stresses: Changes, particularly reductions, in income and employment may contribute to a wide variety of family and community stresses.
- Political conflict: Changing relative harvest levels can upset the political balance in agreements over allocation of mixed-stock fisheries both national and beyond borders. Changes in the physical environment, such as weather and ice conditions, may affect where and when fishing is physically possible as well as the costs of fishing.
Modelling is a necessary tool for assessing future impacts of climate change. A major comparative study Sarmiento simulated the effect of greenhouse gas emissions using six Atmosphere-Ocean General Circulation Models (AOGCMs) to examine which aspects of the models determine how ocean biology responds to climate. The study compared “realistic” emission scenarios for the period from pre-industrial to 2050 and 2090 with a control in which emissions remained at pre-industrial levels.
In Namibia, mariculture has never been a thing of the past as it was widely accepted by locals since its inception and the potential involved to increase the production, include the 1 500 km largely uninhabited coastline, unpolluted high quality marine waters, high natural primary productivity of the seawater,
However, factors such as lack of finances and lack of interest by financial institutions to finance fish farmers as well as innovative and strategised promotion mechanisms might hamper the future expansions and development of this sector.
Most Namibian coastal towns such as Walvis Bay and Lüderitz serve as the pillar of marine resource exploitation creating job opportunities and contributing highly to the GDP of the country as the fishing sector is one of the important backbones of the Namibian economy.
Namibia has favourable conditions for marine aquaculture and thus Lüderitz is one of the ideal places for the exploitation of economic species such as oysters, mussels, and abalone, etc.
A strategised project needs to be implemented that will serve as the catalyst in pinpointing vulnerabilities within the community and identify strategic mechanisms through which the community can be strengthened in order to ensure sustainable livelihoods, food security job creation and nutrition.
In conclusion, potential individuals capable of changes and amendment of strategies in accordance with the changing climatic condition are thus needed to carry out the task of environmental adjustment.
Climate change in the 21st century could trigger fundamental and catastrophic aspects of marine ecosystems and could not be realised by many until after such a century.
Almost all the studies exhausted estimate that there will be increasing adverse impact beyond an approximate 3-4 degrees Celsius in global mean temperature.
A continuous observation and analysis need to be carried out that will lay the foundation for improved management of fisheries and marine ecosystems, therefore, management advice must include complete and transparent information on risks and uncertainties which arise from data quality and from structural deficiencies in the assessment models.
In many instances, adaptation measure is well known by marine farmers’ cooperate advisers and decision-makers, but political will and action are often lacking thus creating a circle of under-development of the sector as the three spheres of life (social, economic and political) cannot be separated one from another.
*Reverend Jan A. Scholtz is the former chairperson of //Kharas regional council and former !Nami#nus constituency councillor and is a holder of a Diploma in Theology, B-Theo (SA), a Diploma in Youth Work and Development from the University of Zambia (UNZA), Diploma in Education III (KOK) BA (HED) from UNISA.