Introduction of the Nile Perch No specific date has been recorded for when the Nile perch, a large fish that reach over 2 meters long, was introduced into Lake Victoria. According to Pringle, (2004), the fish was introduced into the lake from Lakes Albert and Turkana in the 1950s and 1960s by the Uganda Game and Fisheries Department as part of an effort to improve sport fishing on the one hand and to compensate for depleting commercial fisheries on the other. Kariuki (2012) states that the introduction of Nile perch in Lake Victoria in the 1950’s stimulated the development of the fisheries sector, which expanded rapidly throughout the 1980s and 1990s. Kenya, Tanzania and Uganda poured large sums of money into the now lucrative industry that also creating employment opportunities both indirectly and directly for the communities around the lake. The demand for Nile perch saw catches increase from 4439 tons in 1980 to 338,115 tons in 1990 However, Balirwa (2003), found out that the decline in fish species in Lake Victoria coincided with the dramatic increase in the stock of the Nile Perch in the 1980s.
Organic wastes from fish cages can have a significant effect on water quality and the population structure of organisms, beyond the boundaries of the fish pens, increasing the occurrence of toxic algal blooms. Scotland, as well as Chile and China, has had serious toxic algae blooms. Algal blooms can cause the death of huge numbers of wild fish and other species, and great harm to wild fisheries. However, even a month of fallow time can return the area to pristine
For fish oil, it is estimated that millions of tons of other fish are catched and processed to obtain fish oil. Currently , more than 50 percent of the world fish oil production is feed to farmed salmon and salmon farms currently use about 573,000 tons of processed fish meal and 409,000 tons of fish oil
Cichlids have the largest number of endangered species among invertebrate families, most in the haplochromine group (Reid, 1990). Cichlids display similar diversity of body shapes ranging from toughly literally compressed species to species that are cylindrical and highly elongated (Loiselle, 1994). Generally, however, cichlids tend to be of medium size, oval in shape, generally similar to the North American sun fishes in morphology, behaviour and ecology (Helfman, 1997). Cichlids are predominantly well known for having evolved rapidly into a large number of closely related but morphologically diverse species within large lakes particularly Tanganyika, Victoria, Malawi and Edward (Snoeks, 2004). Their diversity in the African great lakes is
THE USEFUL AND HARMFUL EFFECTS OF FUNGI. A fungus (plural: fungi or funguses) is any member of the group of eukaryote organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from the other eukaryotic life kingdoms of plants and animals. Fungi do not have chlorophyll and are therefore incapable of carrying out photosynthesis. Many play an ecologically crucial role in decomposing dead organic matter, some are an important source of antibiotics or are used in fermentation, and others, cause disease.
Fisheries In Egypt Introduction In Egypt, the consumption of fish is a traditional and an important source of the Egyptian food, and is one of the main sources of cheap mammal protein for the growing population. Fisheries in Egypt are also one of the most important sources of national income, Fisheries operates in Egypt vast tracts of more than 13 million acres, Although Egypt has various inland resources, include the Nile River with many irrigation canals, six northern coastal lagoons opening to the Mediterranean Sea (Maruit, Edku, Burollus, Manzala, Port Fouad and Bardawil) and two opening to the Suez Canal (Timsah and Bitter Lakes), with two closed lakes (Qarun and WadiAl Raiyan), and the great reservoir behind the Aswan High
As students we have learned in school that every animal and plants can be species. The definition of invasive species is an alien species whose introduction does cause an economic harm or harm to human health. (Sarah Zielinski,2011) My own interpretation of invasive species would be animals or plants from another region of the world that don’t belong in their new environment. Invasive species are introduced into an area through ship waters, accidental release, and also by humans. Invasive species can have harmful effects to the environment such as, affecting the ecosystem; limiting biodiversity; and using resources available to the existing habitats.
Cladocerans are commonly known as water fleas due to their size and jerky swimming motion (Brian, 2010). They play a significant role in clearing lake water by their combined direct (efficient filtering) and indirect (suppression of ciliates and rotifers) impact on nutrient sedimentation from internal cycling (Karabini, et al., 2007). Planktonic copepods are important ecological link in the aquatic food chain linking microscopic algal cells to juvenile fish to whales. They also have the potential to act as control mechanisms for malaria by consuming mosquito larvae, and contrarily are intermediate hosts of many human and animal parasites (Walter & Boxshall,
It is one of the great white shark diving destinations in the world and should not be missed during African Vacations. We had some of the most thrilling as encounters with the great white whales in their own underwater territory. To add to our adventure, we enjoyed the whale watching boat tour from Gansbaai to Pearly Beach, Dyer Island and Geyser Rock. Gansbaai is a popular place as it is the home to the Marine Big Five including the whales, dolphins, seals, sharks, and penguins and should definitely be the part of your next African safari vacations for an unforgettable experience of the abundant marine animals in its full
(1985) study of environmental factors affecting the population growth of American catfish, showed that, besides available food and oxygen, non-ionized ammonia in the water is also an important factor. The natural food of the studies fishes have been determined by several works by examining the gut contents (Kumar et al., 2007; Kumar and Chakarbarti, 1998; Chakarbarti, 1998; Jhingran,