bin

Small Blackwater stream in Lalang Tanjung

Sponsored by

Indonesia, Riau Province, Lalang Tanjung

Lalang Tanjung is located in the Meranti Islands Regency in the province of Riau, Indonesia. The water found are the type of peat blackwater which are dominant along the forest stream. The peat soil and dried leaves contribute to the acidic tannins. The water pH varies between 4-5; temperature is around 24-26°C. The type of vegetation mainly consist of ferns and moss, also some riparian grass like Sphaerocaryum sp., while a variety of species of small fishes, such as Brilliant rasbora, Betta simorum and Chocolate gourami, can be found living in this type of habitat.

Submitted by
Andre Chandra
Approved by
Greg Martin & Peter Unmack
GPS
0.9023000, 102.6445999
Geographical region
Southeastern Asia
Drainage Basin
River catchment
Sungai Tohor
Water body type
Stream
Water body name
Sungai Tohor
Water body part
Water body course
Middle course
Water body: tributary of
Stream
Tributary name

Water Chemistry

Water information

Water type
Fresh water
Water color
Black water
Water transparency
High
Concentration of sediments
Low
Water temperature
24-26 °C
Water flow/curent
None

Chemical parameters

pH
4.0
Conductivity
GH
KH
Dissolved Oxygen

Substrate in nature

Sand
None
Pebble/Gravel
None
Stone
None
Stone form
Silt/Mud
Leaves
Many
Driftwood
Few
Submerged terrestrial vegetation
no

Aquatic Biotope

Date of collecting
May 2021
Collecting area
Centre
Water depth
0,5m
Air temperature
Sunlight
Partial shade

Environment

Environment
Untouched
Surrounding area

The surrounding area is still mostly untouched; most of the villages were located distant from the spot, whic has only been used by small numbers of villagers to fish.

Underwater landscape

The water is filled with leaf litters, few twigs, branches and trunks in the banks, the only sediment is peat.

Fish:

  • Rasbora einthoveinii
  • Rasbora kalochroma
  • Sphaerichthys osphromenoides
  • Desmopuntius hexazona
  • Betta simorum
  • Betta pugnax

Crustaceans:

  • Macrobrachium malayanum
Threats to ecology

Riau province is known to be a province with a high amount of palm oil plantations. Land developments for palm oil may cause problem to the ecology, as most of land clearance requires burning forest and often this may cause habitat destruction for the fish.

Riparian zone

Trees near the aquatic habitat
Many -

Comment by the expert

Greg Martin: Well researched.

Peter Unmack: Overall a very solid effort.