Biodiversity Program

Several notable findings at the study site include the Nordmann’s Greenshank (Tringa guttifer) and the Marsh Sandpiper (Tringa stagnatilis). The Nordmann’s Greenshank is a migratory shorebird rarely observed in Indonesia, with prior records from only four locations: the northern coast of Sumatra, Muara Gembong (Bekasi), Trisik Beach (Kulon Progo), and Wonorejo (Surabaya). The record in the aquaculture pond area of Tluwuk Village represents a new sighting for the northern coast of Java. Meanwhile, an observed Marsh Sandpiper featured a leg flag combination of black (top) and white (bottom). This bird was originally captured and tagged in China—specifically at Shanghai Chongming Dongtan on September 17, 2015. Such tagging practices are routinely conducted by migratory bird researchers to track avian movement and migration flyways.

Herpetofauna Diversity

Observations across three transects identified 5 herpetofauna species totaling 98 individuals, all belonging to the reptile class: Gekko gecko, Hemidactylus frenatus, Eutropis multifasciata, Cerberus schneiderii, and Fordonia leucobalia. These 5 species span three families: Gekkonidae, Scincidae, and Homalopsidae.

Species from the Homalopsidae family are commonly found in coastal environments such as mangroves and aquaculture ponds, where they adapt well to intertidal conditions. The other three species exhibit broader distribution ranges, stretching from lowlands to mountainous areas. In terms of legal protection status, most identified species are classified as Least Concern (LC) on the IUCN Red List, with the exception of Cerberus schneiderii, which is listed as Not Evaluated (NE). One species, Gekko gecko (Tokay Gecko), is listed under CITES Appendix II due to commercial trade associated with culinary and pharmaceutical demands.

Fish Diversity

Monitoring in Tluwuk Village in 2024 identified 9 fish species across 8 families. All species with IUCN threat assessments are classified as Least Concern (LC). No species listed under CITES Appendices were observed. Furthermore, under Indonesian law (MoEF/Permen LHK Regulation No. P.106/2018), none of the fish species recorded in Tluwuk Village carry protected status.

Trichopsis vittata (Croaking Gourami) recorded the highest individual count with 25 specimens captured, representing a widely common species categorized as Least Concern (LC) by the IUCN. The family Gobiidae was the most diverse, represented by 2 mudskipper species observed atop mangrove mudflats.

Gastropod Diversity

The 2024 monitoring in Tluwuk Village recorded 18 gastropod species belonging to 13 families. Among them, only 4 species have been evaluated by the IUCN, all rated as Least Concern (LC), while the remainder remain unassessed. No gastropod species listed under CITES Appendices or protected under MoEF Regulation No. 106/2018 were present at the site.

The family Arcidae exhibited the highest abundance and species richness, with a total of 211 individuals observed. Arcidae species are highly ubiquitous along the observation transects and were represented by three species: Anadara pilula, Anadara granosa, and Anadara gubernaculum, none of which are currently evaluated on the IUCN Red List. Arcidae specimens were predominantly observed burrowing along the muddy banks of water bodies, dominating the sampling area as the most abundant taxon.

Malacostraca Diversity

A total of 5 Malacostraca species across 5 families were recorded during the 2024 monitoring in Tluwuk Village. None of the observed Malacostraca species currently hold formal conservation ratings on the IUCN Red List, nor are any listed under CITES Appendices or protected under MoEF Regulation No. 106/2018.

Parasesarma guttatum (locally known as the wideng crab) was the most abundant species, with 66 individuals recorded along the transects. Although not yet evaluated by the IUCN, Parasesarma guttatum was frequently observed burrowing along riverbanks and tidal margins, dominating the study area as the most prevalent decapod species.