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Several factors lead to biodiversity loss, including:
- Lack of awareness about the importance of maintaining diversity;
- Lack of information and knowledge about diversity within a particular area and region;
- Failure to implement adequate biological survey or impact assessments in the course of
major developments;
- Land use planning that fails to incorporate, and act upon, sound biodiversity information;
- Unplanned or uncontrolled settlement and land conversion;
- Unsuitable over-exploitation of particular species of commercial value; and
- Severe economic hardship leading to over-reliance on natural resources.
The first three causes of biodiversity loss can often be attributed to a lack of understanding
the importance of maintaining biodiversity (biological processes) and an absence of good
biodiversity information for incorporation into planning processes. The last four are more
complex, particularly in Southern Africa, as they touch on social issues of rural communities,
many of which are in a serious poverty trap.
Unfortunately for Southern African States, the understanding of both biological issues and
social issues as they relate to fish biodiversity is limited by lack of human capacity and
funding for in-depth studies. As an example, the skills involved in identifying fish in the
field, which are essential to biodiversity conservation, are not available in most countries. In
some cases, trained experts are retired or move away, and fewer younger people undergo the
intensive training required. Socio-economic issues such as those that have led to demise of
Chambo fishery in Lake Malombe, keep baffling the few scientists that are available.
Combining good science with capacity building should improve understanding of fish
biodiversity and therefore management thereof. It should also be able to put fish biodiversity
into its rightful position within government’s policy frameworks and therefore lead to
sustainable use and conservation for decades to come.
Successful management of freshwater fisheries depends on a good understanding of fish
migrations and habitat preferences in often complex and variable ecosystems. There is
therefore a need to embark on studies that provide fisheries managers with important
information on their resources. Such data will also provide basis for coordinating local and
regional management regulations in order to sustain fisheries and protect fish resources.
Most of the rivers of southern Africa flow through or border on several countries, which
suggests that fishes swim through several countries. This means that they are international
resources, which necessitates harmonized management regimes. The extent to which fish
migrate in most of the rivers of southern Africa has not been studied. Preliminary studies
have been carried out on the Zambezi River, but there are several more rivers in the region
that need to be studied so that migratory patterns of their major species are understood. There
are seven principal river basins in Southern Africa shared by at least two of the 11 countries –
the Congo, Zambezi, Okavango, Limpopo, Orange, Ruvuma, and Cunene, with a total
catchment area of 6.76 million km².
Application of telemetry has provided opportunities for scientists to collect more informative
data than the traditional procedure of marking (tagging) and releasing a fish and then
recapturing it at a later stage. The telemetry technique involves wireless transfer of data from
one place to another, enabling researchers to track movements, behaviour, and activity
patterns of individual fishes equipped with transmitter tags.
Application of molecular genetics tools like DNA analysis to understand phylogenetic
relationships among several populations of fishes in a riverine system or drainage system has
been applied to a very limited extent in southern Africa. Most of the studies have
concentrated on cichlids of large lakes like Lake Malawi; yet rivers play major role in
reseeding the lake populations. Unless management of biodiversity in the rivers is well
programmed in the region, there is risk of losing founder stocks for most of the lakes.
The biological diversity (biodiversity) of inland water fishes of southern Africa stayed intact
and healthy through exploration time and beyond. Records from several EURpean
expeditions give credit to innovative, indigenous African means and ways of environmentally
friendly use of natural resources. These records cite Indigenous Knowledge, which went into
naming fish and developing various fishing gear by Africans living on the shores of the great
natural lakes and mighty rivers. The records acknowledge that the majority of methods in use
for harvesting from inland waters did not destroy or change the ecosystems, thus conserving
the biodiversity of fishes. In southern Africa, the indigenous naming of fishes and
development of fishing gear and vessel were done at local levels, but with similar trends
spreading out throughout the regions of continent Africa. As a matter of fact it is amazing
how subsistence and artisanal fishers’ behavior and gear modifications seem likely to have
mono origin.
The state of the biodiversity of inland water fishes of southern Africa changed drastically,
with the advent of colonialism. English common names were introduced that served beyond
local levels. Taxonomists named fishes according to the International Code of Zoological
Nomenclature. Industrial and commercial period, introduced modern gear, and exploited
natural resources to gain wealth from exportation. As a result, local fish names have been
rendered redundant. Use of indigenous gear became obsolete. The transfer of Indigenous
Knowledge for gear and vessel making from generation to generation slowed down. High
petroleum and oil cost required for running of modern fishing gear has rendered the
subsistence and artisanal fisher out of the business picture. This modern fishing gear is
improved every day for efficiency and profits, causing environmental degradation without
mitigation.
There have been various modern attempts to list English common and scientific names of
inland water fishes of specific southern African natural and man-made lakes, and rivers. The
literature, however, shows only scattered records of the local fish names and the indigenous
names of fishing gear and vessels. Whilst there is limited published work which fully records
in local languages the names of fish and indigenous fishing gear in the inland water systems
of southern Africa, this proposal tries to fill the gap in major regional languages. The
information presented thereof should also fill a gap in ‘FishBase’, which lacks local fish and
fishing gear names. It is hoped that this action will also stimulate interest in inland water
fishes and their conservation by improving the knowledge of conservation managers and will
aid in communication between interested groups such as the local fishers.
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