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Marinjung bridge, Sungai Cimaja, Sukabumi, Indonesia

Indonesia, Jawa Barat, Sukabumi

Cimaja River is one of the rivers that flows from Mount Halimun National Park into the Indian Ocean. The southern region of Mount Halimun National Park is a unique and very specific area. It was formed from the geological process “Bayah Dome”.

This geological process makes this river seem to have no access to other freshwater rivers on the island of Java. Therefore, this river is inhabited by the amphidromus goby species.

Submitted by: Margo Prasetya
Approved by: Greg Martin & Peter Unmack

GPS: -6.9525447, 106.4818420

Geographical region: Southeastern Asia
Drainage Basin: Bayah Dome River
River catchment: Mount Halimun National Park
Water body type: River
Water body name: Sungai Cimaja
Water body part: Open water
Water body course: Lower course
Water body: tributary of: River
Tributary name: Sungai Cimaja

Videos above and below water

Water Chemistry

Water information

Water type: Fresh water
Water color: Clear water
Water transparency: Medium
Concentration of sediments: Medium
Water temperature: 22-27 °C
Water flow/curent: Strong

Chemical parameters

pH: 7
Conductivity
GH: 100 mg/l
KH: 90 mg/l
Dissolved Oxygen

Substrate in nature

Sand: Grey
Pebble/Gravel: Grey
Stone: Mixed
Stone form: Roundish
Silt/Mud: Brown
Leaves: No
Driftwood: Few
Submerged terrestrial vegetation: No

Aquatic Biotope

Date of collecting: 20/03/2020
Collecting area: River bank
Water depth: 0,2m
Air temperature: 30 °C
Sunlight: Full sun

Environment

Environment

Affected by human activity

Affected by human activity

Pollution

Pollution

Moderate

Surrounding area

This biotope environment, is located close to the estuary, about 0.5-1 km from the coast. The strength of the water current causes the water to be fresh. This river is known as a dangerous river because of the sudden floods.

In the northern part of the Marinjung bridge, the banks of the river are still covered with forests and fields. while the southern part of the bridge is more likely to be a fish pond owned by residents.

Underwater landscape

The bottom of the river is very rocky with a predominance of rounded and beautifully colored stones.

Fish: Awaous grammepomus, Sicyopterus macrostatholepis, S. microcephalus and S. micrurus. Schismatogobius marmoratus, Stiphodon elegans, Gymnothorax polyumnodon, Anguilla bicolor and Puntius Binotatus.

Threats to ecology

The ecology of this river is very vulnerable to the presence of foreign species such as cichlid fish and suckermouth catfish.

The geological history that takes place in this area makes the types of fish in the southern river of Mount Halimun different from the types of fish that are common in Java. On the island of Java, there is no river that has as much population and variety of goby fish as this river. Even people in Java are very foreign to this type of goby fish.