Lake Tanganyika, benthic waters of Kungwe Point, sedimented rocky habitat, Tanzania

_ place in Biotope Aquarium Design Contest 2019

Volume: 487 L
Dimensions: 150x50x65 cm
List of fishes: Neolamprologus brichardi  and   Cyphotilapia frontosa
List of plants:
Description of decorations: 1-30 kg of nautral argonit sand (taken from sea floor)
2-150 kg of rocks in variable sizes
3- Turquaz Background
Description of equipment: 1-Ligthining: 4x led fluorescent (24 watt,120 cm,6500 K, Dayligth),
2-Filtering: Sump system 3000 L/H,
3-Heating: 300 watt heater.
Water parameters: Ph: 8,2-8,4, Temp: 24,3°C, Electirical Conductivity:680 μS, GH:14, KH:11 in addition Nitrate: 5- 15 ppm and Nitrite: 0 ppm
Additional info: Weekly %20 water change and maintanence. During weekly maintanence sump pump, pipes, heater and glasses are cleaned. In every six mouths sump materail is cleaned.
PS: Cyphotilapia frontosas added in small size to make them to learn get along with Neolamprologus brichardis and not to see them as preys.Till now no serious agression is seen from Cyphotilapia Frontosas. But unfortunately that doesn’t mean there won’t be because Cyphotilapia frontosas are one of the calmest predators of lake Tanganyika.

INFORMATION ABOUT BIOTOPE

Description of the area surrounding the biotope: Lake Tanganyika is second largest lake of eastern Africa. It is the longest freshwater lake in the world with it’s 660 km length and the second deepest with it’s 1,436 meters depth after Lake Baikal in Russia. Comparatively narrow, varying in width from 16 to 72 km, it covers about 32,900 square km.(1) Lake tanganyika is formed 12 million years ago by techtonic movements and it’s very different from modern lakes formed by glaciers.(2) Lake is having two seasons which are wet season and dry season. In wet season lakes climate is with high humidity, much precipitation, unconsiderable winds, many thunderstorms and in dry season with strong, southerly winds and little precipitation. These seasonal changes are caused because of large-scale atmospheric processes.(4) These very different two seasons have some effects on underwater life by changing temperature, depth and water chemistry. Lake’s main way to renew it’s water is evaporaiton(8) but the lake never suffer rapid change in depth thanks to it’s large basin and three major feeding rivers.(5) Lake’s mostly steep sides help to maintain surface area against changing water levels.(8) The Malagarasi River, the Ruzizi River, and the Kalambo River are main inflows to lake. Along way to lake rivers pass many small or big falls espacially the Kalambo River so this makes water so oxygen rich. The Lukuga River is only outflow of lake. (4,*) Lake is having effects of surroudning area habitants severly because there are about one million people who are depended on lake for protein, drinking water and transportation.(2) Surrounding area of lake is not very suitable for husbandry as a result of this fish from lake are main protein source for surrounding residents. Shore parts of lake contains some large forests and has stoney/rocky beaches or no beaches just steep cliffs. Residental occupations around lake is in a spectacular scale compared to inner parts.(6) My biotope is from Kungwe Point which has mostly no beaches just bushy or rocky steep cliffs, behind shores land rises and a thick forest starts named as Kungwe Bay Forest Reserve. (7) Forest reserve is suitable for land fauna and flora to thrieve.(*)

Description of the underwater landscape of the biotope: Lake Tangayika has three major biotopes, the pleagic, the deep water and littoral.(8) Lake Tanganyika is valuable for both, the presence of unique, endemic species and microcosm so value of lake to Global Biodiversity can’t be measured.(2) But all depths of Tanganyika are not inhabitable due to oxgen deplation. In northern basin till 100 meters and in southern basin till 200 meters oxygen can be found. Being thermocycline and oxycline shapes lake’s species’ regions. Lake Tanganyika formed by rifting so underwater structers of lake tanganyika are extensions of surrouding lands mostly steep rocky bottoms then changing into muddy or sandy bottoms.(8,10) These kind of bottom structures in lake promotes lots of species inhabit which are in needs of feeding, sheltering and spawning or in other words species evolved according to what is abundant and necesarry in habitat according to adaptive radiation.(*) My biotope is benthic (deep water) parts of Kungwe point (5°37’43.2″S 29°52’11.7″E) and depth is 15 meters with huge, steep sediment covered rocky structures.(15) Rock’s sizes are between 30 cm to 3 meters When going deeper rocks leaves it’s place to fine sand in combination with more coarse sand.(7,9,15,*,18) Due to being warm during all seasons in these depths water is always less oxygented and less ligthened then upper parts. Species living in these depths spread to area till mostly to 60 meters where oxygen level drops to %10 and H2S is more abundant.(8,10) Because of low sunligth and less water movement rocks are mostly covered with sediment instead of algea.(9) Lack of seasonal changes in benthic habitats lets microbial communities and other organisms to exist all the time so this stituation helps stromatilites always grow then triger life cycle in depths and pelagic waters.(11) Benthic habitats get nutriens from it’s bottom and pleagic waters and thanks to high ability of seeing in dark Benthic species hunt and get feed easliy. Main nutrients in habitat are invertebrates, decays and visitors coming down from pleagic waters in purpose of breeding or dying. Water is less blurry in compare with littoral parts.(*,12)

Description of the parameters of the habitat: Lake Tanganyika has uniform water chemstry for it’s all length and depth except for the nutrient minerals, ammonia, nitrate, phosphate, and silica. Saturation and temperature of water changes accoding to depth and at 70 meters strong thermocline are observed. (13) Thanks to depthness in my biotope water temperature stable irrespectively with seasons and it is around 24 °C. This triggers debate about if lake bottom touches earthcore. Due to low temperature in compare with upper parts PH is lower and chemicals in water are less deluted.(1,*) About saturaion Lake Tanganyika has same characteristic with black sea after 150-200 meters depths it s water turns to be anoxic and not uninhabitable for most of species. (13)
Tempeture: Changing according to seasons (wet season/dry season) between 24-28°C, but at depths greater then 400 meters is more stable between 23,1-23,4°C, (1)
Ph: Around 9 at depths of 0-100 meters, 8,7 below this and 8,3 at deepest parts, (1)
Electirical Conductivity: Upper parts 670 and deepest parts 690, (1)
Other Parameters: GH 12-20, and the KH 10-15. (*)

List of fishes and invertebrates occurring in the nature biotope: If we accept region as Halembe;
Altolamprologus compressiceps, Chalinochromis brichardi, Cyathopharynx foae , Cyphotilapia frontosa, exLamprologus brevis, exLamprologus callipterus, exLamprologus lemairii ,exLamprologus similis, Julidochromis marlieri, Neolamprologus leleupi longior, Neolamprologus pulcher, Ophthalmotilapia nasuta, Ophthalmotilapia ventralis, Petrochromis ephippium, Petrochromis sp. ‘kasumbe’, Tanganicodus irsacae, Tropheus duboisi, Tropheus sp. ‘viridescens’ , Xenotilapia spilopterus Neolamprologus Brichardi , various invertabres(14)

List of plants found in the nature biotope: N/A

Threats to the ecology: Lake Tanganyika is under threat like lots of other habitats of world. I want to inform you about sedimentation danger in Tanganyika. Because my biotope is a heavliy sedimented area. Sedimentation pollutes water, prevents natural vegetation from growing and kills fish. Sedimentation is a consequence of defrostration of surrounding area. Defrostation is mostly done by human like everything bad to nature. In defrostated areas eroded sediments are carried in to lake and pollute narrow shore line where species are living, this stituation is like a death trap to species because they can’t move down to depths, there is no oxygen and they can’t move up, they are already close to shore so only thing to do for them just to be extinct. As a result some regions lost it’s diversty more then 150 years ago. Solution to prevent danger of sedimentation is frostration of lands around lake espacially hill type shores. (16,17)

Sources of information:

*- My conclusions from resources, videos and maps.

1-https://www.britannica.com/place/Lake-Tanganyika https://yandex.com.tr/turbo?text=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FLake_Tanganyika

2- https://iwlearn.net/resolveuid/10643e2ead9328f9de98a2dfdc361714  (pg.1)

3-https://www.hindawi.com/journals/ijbd/2013/269141/

4-https://www.lakepedia.com/lake/tanganyika.html

5- https://www.africangreatlakesinform.org/article/lake-tanganyika

6- https://satellites.pro/#-6.298919,30.278320,7

7-https://www.google.com/maps/place/5%C2%B037’43.2%22S+29%C2%B052’11.7%22E/@-5.6286613,29.590937,199685m/data=!3m1!1e3!4m6!3m5!1s0x0:0x0!7e2!8m2!3d-5.6286729!4d29.8699177?hl=en

8-https://books.google.com.tr/books?hl=tr&id=ZbIuGfu3A_kC&q=tanganyika#v=onepage&q&f=true

9-https://www.youtube.com/watch?v=CR6ssYVQf0A&t=34s&fbclid=IwAR07cXwGqq96jG5crDC1Bbz4VOueyl7nLb9uP9vlHCU2HoEvxQc_usAW1nI (Between 2:20-3:10)

10-https://page-one.springer.com/pdf/preview/10.1007/BF00602986

11-http://awramik.faculty.geol.ucsb.edu/pubs/COHE9740.pdf

12- http://www.ltbp.org/FTP/SSS15.PDF

13- https://page-one.springer.com/pdf/preview/10.1007/BF00602986

14-https://www.cichlidae.com/?fbclid=IwAR3T_i-69ey6f75raO-FTveh1kiBoltrJEofXLWeemtwC8K2MHyso8-Nxjg

15- https://www.facebook.com/africandivingltd/posts/1943010415929982?__tn__=-R

16- http://theconversation.com/the-fate-of-africas-lake-tanganyika-lies-in-the-balance-75467

17- https://stories.undp.org/lake-tanganyika-what-the-future-holds

18- https://blog.africandivingltd.com/2019/03/lamprologinipart-3.html?fbclid=IwAR3s66_nkXyzLLjDUmM5_jpmGjKnx7cxL_GXSdmd5uYm0z2-zPBRrwZh1lE#app6

Comments of the members of the jury of Biotope Aquarium Design Contest 2019