Blackwater river

Comparison between white and black waters

Table 1: Mean ionic composition, specific conductivity (μS/cm), and pH in Amazon waters.^[3]
	Solimões or Amazon River – whitewater.	Rio Negro – blackwater.
Na (mg/L)	2.3 ± 0.8	0.380 ± 0.124
K (mg/L)	0.9 ± 0.2	0.327 ± 0.107
Mg (mg/L)	1.1 ± 0.2	0.114 ± 0.035
Ca (mg/L)	7.2 ± 1.6	0.212 ± 0.066
Cl (mg/L)	3.1 ± 2.1	1.7 ± 0.7
Si (mg/L)	4.0 ± 0.9	2.0 ± 0.5
Sr (μg/L)	37.8 ± 8.8	3.6 ± 1.0
Ba (μg/L)	22.7 ± 5.9	8.1 ± 2.1
Al (μg/L)	44 ± 37	112 ± 29
Fe (μg/L)	109 ± 76	178 ± 58
Mn (μg/L)	5.9 ± 5.1	9.0 ± 2.4
Cu (μg/L)	2.4 ± 0.6	1.8 ± 0.5
Zn (μg/L)	3.2 ± 1.5	4.1 ± 1.8
Conductivity	57 ± 8	9 ± 2
pH	6.9 ± 0.4	5.1±0.6
Total P (μg/L)	105 ± 58	25 ± 17
Total C (mg/L)	13.5 ± 3.1	10.5 ± 1.3
HCO₃-C (mg/L)	6.7 ± 0.8	1.7 ± 0.5

Black and white waters differ significantly in their ionic composition, as shown in Table 1. Black waters are much more acidic, resulting in an aluminium concentration greater than that of the more neutral white waters. The major difference is the concentrations of sodium, magnesium, calcium and potassium; these are very low in black waters. This has considerable ecological implications. As some animal groups, such as snails, need much calcium with which to build their shells, they are not abundant in black waters. The lack of dissolved ions in black waters results in a low conductivity, similar to that of rainwater.

Black and white waters also differ in their planktonic fauna and flora. Tables 2 and 3 compare the number of planktonic animals caught in black and white water localities only a few meters apart. In fact, the black water was not as extreme an example as can be found in the Rio Negro system. However, it can be seen that the black water held far greater numbers of rotifers but fewer crustaceans and mites. These crustaceans are important foods for larval fish. The zones where the two waters mix are particularly attractive to ostracods and young fish. These mixing zones tend to have high numbers of animals. The high abundance of animals is shown clearly in Table 3, which compares the numbers of animals present in 10 litres of water in each habitat sampled.^[4]

Table 2: Different planktonic organisms collected in black (Japura) and white (Solimoes) waters.^[3]
Animal groups present	Black water	Mixed water	White water
Rotifera	284	23	0
Cladocera	5	29	43
Ostracoda	39	97	29
Calanoida	11	51	66
Cyclopoida	22	49	61
Chironomidae	0	3	3
Acari (mites)	0	0	2

Table 3: Number of planktonic organisms collected in 10 L of black, white and mixed waters.^[3]
	Black water		Mixed water		White water
Animal groups present	Open water	Forest	Open water	Forest	Open water	Forest
Volvocaceae	42		38
Rotifera	87	5	34
Cladocera	6		5		8	1
Ostracoda	2	11	3		7
Calanoida	23	3	10
Cyclopoida	5	27	19	1	13	1
Mysidacea		1
Diptera					1
Acari (mites)			1		1
Larval fish			1		1

Blackwater rivers of the world

Indonesia

Sabangau River

Amazonia

Apaporis River: A tributary of the Yapura River.
Arapiuns River: A tributary of the Tapajós River.
Coari River
Mirití-Paraná River
Rio Negro: The largest blackwater river in the world; one of the largest Amazonian tributaries.
Piorini River
Tahuayo River
Tefé River
Uatamã River
Urubu River
Vaupés

Orinoco basin

Atabapo: from the Guiana Highlands of Venezuela west into the Orinoco
Caroní River: from the Guiana Highlands of Venezuela west into the Orinoco
Inírida: from Colombia northeast into the Guaviare River which flows into the Orinoco
Ventuari: from eastern Venezuela southwest into the Orinoco
Vichada: from Colombia east into the Orinoco
Tomo: from Colombia east into the Orinoco
Tuparro: from Colombia east into the Orinoco

Southern United States

Ashepoo River: Along with the Edisto and the Combahee Rivers in South Carolina makes up the ACE Basin National Wildlife Refuge.
Big Cypress, Black Cypress, and Little Cypress and the small rivers in the watershed of Caddo Lake in Texas and Louisiana.
Blackwater River: a tributary of the Chowan River in Virginia.
Blackwater River: a major river in the western Florida panhandle.
Black River: a tributary of the Pee Dee River in North and South Carolina.
Cape Fear River, North Carolina: flows into the Atlantic Ocean.
Cashie River, North Carolina: flows into Albemarle Sound.
Caloosahatchee River, Florida: flows west from Lake Okeechobee to the Gulf of Mexico.
Chowan River, North Carolina: flows into Albemarle Sound.
Edisto River, South Carolina: flows into the Atlantic Ocean; the longest undammed, unleveed blackwater river in North America.
Econlockhatchee River, a tributary of the St. Johns River in Central Florida.
Four Hole Swamp, a tributary of the Edisto River in South Carolina.
Great Coharie Creek, North Carolina: flows into the Black River.
Little Pee Dee River, South Carolina: flows into the Pee Dee River.
Lynches River, South Carolina: flows into the Pee Dee River.
Lumber/Drowning Creek: located in North and South Carolina. Part of Lumber River State Park
Ogeechee River: A 245-mile river in eastern Georgia that passes to the south of the city of Savannah and enters the Atlantic Ocean at Ossabaw Sound.
Pithlachascotee River: A small river in central Florida.
Santa Fe River: A river in northern Florida.
Satilla River: A river in southeast Georgia that flows through the city of Waycross and empties into the Atlantic Ocean near Cumberland Island.
Scuppernong River: A small river in Washington and Tyrrell Counties in eastern North Carolina at Pettigrew State Park.

St. Marys River (Georgia): http://www.saintmarysriver.org/history.html

St. Johns River: The largest river in Florida. Flows north through Jacksonville and into the Atlantic.
Suwannee River: A large river in southern Georgia and northern Florida flowing into the Gulf of Mexico.
Upper Little River, North Carolina: flows into the Cape Fear River.
Blackwater River, West Virginia: Located in the Blackwater Canyon in Tucker County. Blackwater Falls a five-story waterfall is located along this river with rapids ranging from Class III-V+
Waccamaw River, North and South Carolina: flows into the Atlantic Ocean.
White Oak River, North Carolina: flows into the Atlantic Ocean.

Northern United States

Black River, New York: A river starting in the western Adirondacks that flows into Lake Ontario.
Tahquamenon River, Michigan: A river in the Upper Peninsula that flows into Lake Superior.
Tuckahoe River, New Jersey: A short river in southern New Jersey that flows into Great Egg Harbor.
Gooseberry River: A river in northern Minnesota that leaches from peat bogs and pine forests.

Australia

Gordon River, Tasmania: A river rising in the centre of the island and flowing westward, emptying into Macquarie Harbour on the West Coast.

Europe

Morava river, flowing into the Danube
River Blackwater, is in Hampshire. UK. runs with the River Whitewater eventually into the River Loddon.
River Blackwater, is in Northern Ireland. it divdes coutny Armagh and county Tyroneit eventually runs into Lough Neagh.

Images of blackwater rivers

References

^ Janzen, D H (July 1974). "Tropical Blackwater Rivers, Animals, and Mast Fruiting by the Dipterocarpaceae". Biotropica 6 (2): pp. 69–103. doi:10.2307/2989823. JSTOR 2989823.
^ Sioli, Harald (1975). "Tropical rivers as expressions of their terrestrial environments". Tropical Ecological Systems/Trends in Terrestrial and Aquatic Research (New York City: Springer-Verlag): pp. 275–288.
^ ^a ^b ^c J S B, Ribeiro; A J Darwich (1993). "Phytoplanktonic primary production of a fluvial island lake in the Central Amazon (Lago do Rei, Ilha do Careiro)". Amazoniana (Kiel) 12 (3-4): pp. 365–383.
^ "Comparison between white and black waters". Amazonian Fishes and their Habitats. Pisces Conservation Ltd. http://www.amazonian-fish.co.uk/indexc30.html. Retrieved 2006-05-21.