Frontosa reef, Lake Tanganyika, Afrika, Kollwe Point, Cape Mpimbwe
__st place in Biotope Aquarium Design Contest 2018
Ukraine. Sergey Kovalev
Volume: 1000 L
Dimensions: 300х55х65 cm
List of fishes: Cyphotilapia frontosa “Burundi”, Cyphotilapia gibberosa “blue Zaire” Moba
List of plants: N/A
Description of decorations: Natural stones of various shapes and sizes (Carpathian basalt) are not from this lake, but according to external characteristics are similar to the natural stone from this biotope. On the bottom there is quartz sand with grain size of 0.1-0.3 mm.
Description of equipment: External canister filter Hagen Fluval FX6 (2130 lph), external canister filter Hagen Fluval 406 (1450 lph), air pump SunSun YT-838 (45 l/min) heater with thermostat Eheim Jager 300W, 3 waterproof (IP44 ) LED lamps RIGID BAR (length 1m, 220V, 12W). Waterproof (IP67) LED tape with a JW-66U D4 unit (length 3m, 220V, 24W, 8 programs, blue light is used).
Water parameters: The temperature is 24-27°C, clear water, light intensity depends on the time of the day, GH is 10-12, PH is 8.
INFORMATION ABOUT BIOTOPE
Description of the area surrounding the biotope: Lake Tanganyika is the second largest lake in East Africa. In addition, it is also the longest (660 km) freshwater lake and the second deepest (1,436 meters) lake in the world. It is relatively narrow, its width varies from 16 to 72 km. It covers about 32,900 square meters. The GPS coordinates for Lake Tanganyika are -6°29’59.99″S 29°29’59.99″E. The lake is divided between 4 countries: Tanzania, Democratic Republic of Congo (DRC), Burundi and Zambia, with Tanzania (46%) and DRC (40%), having most of the lake. It occupies the southern part of the Western Rift Valley, almost all the land along its banks rises sharply and consists of rocky and sandy beaches or steep slopes. The lake is not the center of an extensive drainage zone, however it is fed from sediments and tributaries. Moreover, precipitation accounts for about 63% of the water, and inflows provide only 37%. In total, the reservoir receives about 65 cu. km of moisture. 61 cu. km evaporates, and through the river Lukugu about 4 cubic km flows away. The largest rivers flowing into the lake are the Malagari, Ruzizi and Kalambo, which has one of the highest waterfalls in the world (215 meters). Its exit is the river Lukuga, which flows into the river Lualaba. Lake Tanganyika is so deep that it contains more than a third of all the fresh water on the planet. The lake has no access through rivers that could connect it with other lakes. The pool is known for its terrestrial biodiversity and scenic beauty, like Lake Tanganyika. In the vicinity there are many animals, mostly hippopotamuses and crocodiles. There are also many species of birds there. In the vicinity of Lake Tanganyika there are several forest reserves and national parks. The lake and its surrounding areas provide a wide range of ecosystems that support the lives of millions of people. The surrounding area of Ikola is located in the same area of the general coast of Tanganyika. In addition, it consists of two types of beaches, such as sandy and rocky beaches. As for the coast of Kitumba, we can say that it is of the same type as the coast of Ikola, but less covered with plants. Huge areas of rocky and sandy beaches and steep huge stone walls create various biotopes under water in both the Ikola region and Kitumba, which include magnificent views. If we move further from the coast of Kitumba, we see that huge stone walls come from the bottom of the lake to the surface (not visible on the surface during wet seasons), they also create different types of biotopes for many different species.
Description of the underwater landscape of the biotope: Located 4 km from Kollwe Point, Cape Mpimbwe, Frontosa Reef is one of the most amazing diving sites in Lake Tanganyika. The smallest reef depth is about 40 meters, and it consists of huge boulders, some more than 10 meters in diameter. The deeper areas of the reef are covered with a thick layer of hard fragments. The scree zone consists of rocks and debris of rocks of various sizes. Among their conglomerates, cracks and caves were formed, which are excellent shelters for many fish. There are absolutely no higher aquatic plants, but in clear water, under the rays of the sun, algae quickly develop on rocks, mostly in shallow water, but it is often possible to meet at a decent depth. The most common species of fish found on the reef is Cyphotilapia gibberosa, a species that was not identified as a separate species until 2003 (Takahashi and Nakaya 2003). Previously, the fish at the reef was known as Chifotipiliya with big forehead. C. gibberosa are very curious by nature and swim up easily to divers. They are found at the reef in very large quantities, and among the rocks at a depth of 50 meters, sometimes we saw individuals more than 40 cm in size. They tend to be solid blue. Open areas with scattered boulders of medium size are found in some deep places. Julidochromis regani is common in these areas. The variant here is one of the largest in the lake. An unidentified species of Telmatochromis lives in the same habitat, as well as Xenotilapia nasus. Under the boulders in the deeper areas of 50 meters or more, you can find one of the lesser-known types of lake fish. This is Trematochromis benthicola (syn. Trematochromis schreyeni (Takahashi et al., 2006)). This is a “timid species” and spends most of its daytime hiding in a rocky environment. In rare cases, orange mutant variations can be seen. Such a color change of this species is known to be found in other places in the lake, in Uvira and Pemba, in the northern part of the lake (Poll 1979). Further in depth, exceptionally large Benthochromis tricoti individuals hover over boulders. Neolamprologus sp. “Calliurus giant” may well be synonymous with N. calliurus, which in turn is synonymous with N. brevis, at least according to Poll (1986) and according to a number of scientific studies and “field observations”, for example, Ota et al. (2012). However, Neolamprologus sp. “Calliurus giant” behaves differently than “ordinary” N. calliurus (syn. N. brevis). On the reef, none of the members of the N. savoryi species complex Verburg and Bills 2007 was seen (personal observations), and the personal niche, which in other places, as a rule, is occupied by some of the members of the N. savoryi complex, here, on the Frontosa Reef, is densely populated by Neolamprologus sp. “Calliurus giant”. They live here in large numbers. Striking orange spots are on the heads of the fish. Both males and females are known to grow relatively large in size, usually 11 and 9 cm, respectively. They do not breed in empty shells, but are populated in crevices and holes in rocky habitats; and they usually live in open water, feeding on plankton, sometimes gathering in huge flocks. This behavior is very similar to most members of the N. savoryi complex in other places. In the least deep-water areas, the first species of fish that you will certainly encounter are Cyprichromis sp. “Mpimbwe zebra”, C. pavo, Neolamprologus sp. “Calliurus giant” and Lepidiolamprologus mimicus. In appearance and behavior Cyprichromis sp. “Mpimbwe zebra” is similar to C. zonatus from Zambia. The latter was before the formal description known as C. sp. “Zebra” (Takahashi et al. 2002; Konings 2003). Two species can be closely related, and intermediate “similar” groups of fish along the coast of Tanzania have been discovered by us. Males and females (which is rare in cyprichromis) of C. sp. “Mpimbwe zebra” are beautiful; the males are bright orange and the females are yellow.
Description of the parameters of the habitat: Lake Tanganyika is the second largest in the world in size, which means that temperature and pH fluctuations in it are very low, and the environment is stable. All Tanganyika cichlids need a stable temperature and a large amount of dissolved oxygen in water. The temperature in the lake ranges from 24-30°C with a decrease relative to the depth. Also the water in the lake is very hard (12-19 dGH) depending on the part of the lake and acidic (ph is 8.0-9.5), while the transparency of the water reaches 33 meters. Due to the immense depth and lack of bottom currents in the lake there is no full circulation of water. This causes a high concentration of hydrogen sulfide in the lower water layers. From the depth of 200 meters the “dead zone” begins. There is no life in it, because there is no oxygen.
List of fishes and invertebrates occurring in the nature biotope: Cyphotilapia sp., Burundi, Cyphotilapia gibberosa Blue Zaire Moba, Cyprichromis, Neolamprologus, Trematochromis benthicola, Benthochromis tricoti, Julidochromis regani, Xenotilapia nasus.
List of plants found in the nature biotope: N/A
Threats to the ecology: Nowadays, the lake water is gradually polluted more and more. Industrial and agricultural waste is dumped into it. Household waste also contributes to it. On the banks of the reservoir there are a huge number of people, but there is no sewage and water supply. All this not only pollutes the water, but also serves as the cause of infectious diseases. After all, the discharge of feces and drinking water are located in the same places. Also, new types of plants are planted, which do not always positively affect the ecosystem. As an example of this, the water hyacinth (Eichhornia crassipes), a plant with a huge speed grows over the lake like a dense carpet and thereby prevents sunlight from entering the water and disrupts the natural oxygen exchange inside the system. And as we remember, the life in the lake is maintained at depths of up to 200 meters, and over it there is already the zone without an oxygen there. So in this regard, the situation is quite tense and deserves the close attention of local government officials, politicians and volunteers from around the world! Directly on the shores of the lake about 1 million people live. The basin of the reservoir is home to 10 million people. The main type of industry is fishing. But nowadays, fish are caught less than in earlier times. In 1995, 180 thousand tons of fish were caught. To date, this figure is less than 30%. In 2017, the lake was recognized as one of the most polluted lakes in the world! With such a pace, this lake may soon die forever or for a long time, and it is quite possible that out of 250 species of cichlids, of which 98% are endemic to the lake, most of them can be found only in aquaria around the world! And this is very sad.
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