Gastropod Community Structure in Mangrove Pancer Cengkrong Ecosystem, Trenggalek Regency, East Java
Gastropod Community Structure in Mangrove Pancer Cengkrong Ecosystem, Trenggalek Regency, East Java
ISSN No:-2456-2165
Abstract:- The condition of mangrove vegetation habitat conversion of mangrove land into aquaculture ponds and
determines the community structure of organisms plantation land by the community. Damage to mangrove
associated with it, including gastropods. Mangrove ecosystems, has an impact on the disconnection of mangrove
Pancer Cengkrong is located in Trenggalek Regency, ecosystems with other ecosystems [1]. This causes a decrease
which is a conservation and ecotourism area. The purpose in the ability of mangroves, in supporting the lives of biota
of this study is the identification of gastropods that inhabit it, one of which is gastropods [3]. Gastropods in
morphologically and the abundance of gastropod species. mangrove ecosystems, act as environmental bioindicators, so
The research was conducted in August 2024, using the their existence is very important for the ecosystem [4].
survey method, at 6 research points using transects, the Pressure caused by human activities can change habitat
size transect is 10 x 10 m. Mangrove species found as conditions and disrupt the survival of gastropods [5]. A
many as 9 species, with mangrove density ranging from decrease in gastropod density may indicate compromised
0.038 - 0.078 ind/m2. Gastropods found as many as 10 ecosystem health [6]. Therefore, research on the
genus, consisting of Cerithidea genus, Littoraria, Faunus, identification and density of gastropods in mangrove
Tarebia, Clypeomorus, Crassispira, Nerita, Terebralia, ecosystems is very important to determine the environmental
Neritina, and Cassidula. The abundance of gastropod conditions in the Mangrove Pancer Cengkrong area. The
species ranged from 34.4 - 92.4 ind/m2, with the highest results of this study are expected to be a reference in the
abundance in the Cerithidea genus and the lowest in the management and protection of mangrove ecosystem
Nerita and Neritina genus. The diversity index ranged resources and the biota that inhabit it.
from 0.84 to 1.30 (low-medium), the uniformity index
ranged from 0.36 to 0.57 (low-medium), and the II. METHOD
dominance index ranged from 0.37 to 0.60 (some points
had genus dominance). Water temperature (27.2 - 28.8℃), The research was conducted at Mangrove Pancer
pH (7.2 - 7.8), DO (4.48 - 5.31 mg/L), and salinity (24 - 29 Cengkrong (MPC), Karanggandu Village, Watulimo District,
ppt), water quality parameters are considered good for Trenggalek Regency, East Java Province. The research was
gastropod life. The structure of the gastropod community conducted in August 2024, method is a survey method with
in the MPC ecosystem is classified as slightly unstable, purposive sampling. The research location is in the form of
because there are still several points that have low transects totaling 6 points, where the transect size is 10 x 10
diversity and uniformity values, and there are points that m, with 5 plots measuring 1 x 1 m. The description of each
have a dominance value close to the value of 1, which sampling point is as follows:
means there are several genus that dominate. Continuous
monitoring and management of mangrove ecosystems are Point 1, at coordinates -8.302897° N and 111.74674° E,
needed so that the gastopod community remains in a natural mangrove area
balanced condition and there is a need for efforts to utilize Point 2, at coordinates -8.296539° N and 111.70637° E,
Cerithidea gastropods. rehabilitated mangrove area.
Point 3, at coordinates -8.296847° N and 111.706453° E,
Keyword:- Gastropods, Habitat, Mangrove, Community near the entrance to the ecotourism area.
Structure, Trenggalek Point 4, at coordinates -8.284983° N and 111.71693° E,
river estuary area.
I. INTRODUCTION Point 5, at coordinates -8.303292° N and 111.70499° E.
Point 6, at coordinates -8.302771° LS and 111.706331° E,
Mangrove ecosystems in Indonesia are evenly inland mangrove zone.
distributed, and have many ecosystem services. Trenggalek
Regency has a mangrove ecosystem area, namely Mangrove
Pancer Cengkrong (MPC), which is included in the
conservation and ecotourism area. It was recorded that
mangrove damage in this area reached 50% in 2003 [2].
Factors that are thought to affect this damage is the
𝐻 ′ = − ∑ 𝑝𝑖 ln 𝑝𝑖 …(3)
Description:
𝑁
𝑅𝐷𝑖 = ∑ 𝑖 𝑥 100% … (2) D = Dominance index
𝑛 ni = Number of individuals of each species
n = Total number of individuals
Description:
Classification of Community Conditions:
Di = Density
Ni = Number of individuals of species i 0<C≤0,5 = No dominance
A = Total area of sampling area 0,5<C<1 = There is dominance
Rdi = Relative density (%)
Ni = Number of individuals of the lth species (ind)
∑n = Total number of individuals (ind)
Gastropod Distribution Pattern as major mangroves and natural mangroves, so the mangrove
Gastropod Distribution patterns were calculated using species are more heterogeneous.
the Morisita Index [9]:
Table 1: Mangrove Species Density
∑ 𝑋 2 − ∑ 𝑋𝑖 Point Mangrove Density
𝐼𝐷 = 𝑛 ((∑ 𝑋𝑖)2−∑ 𝑋𝑖) … (8)
1 0.063
2 0.060
Description: 3 0.050
4 0.078
ID = Morisity Dispersion Index
5 0.042
n = Total number of quadrants
6 0.038
∑Xi = Total number of gastropod species
∑Xi2 = Number of i-th gastropod species
Variations in mangrove density can be influenced by
environmental conditions at the study site. In the mangrove
Furthermore, the calculation of chi square (x2) with n-1
rehabilitation zone, mangrove species tend to be more
free degrees, for the significance of Morisita Index
homogeneous. This condition is similar to Point 3, where
calculation, namely:
mangrove stands are dominated by seedlings and saplings,
Uniformity Index:
with the species Rhizophora apiculata. The Rhizophora genus
𝑋 2 0.975−𝑛+ ∑Xi thrives in areas influenced by tides. The pattern of adaptation
𝑀𝑢 = (∑Xi)−1
… (9) to the environment is very good, so that the seeds are easily
spread, grow, and develop in the region [10].
Mu = Moricity Index for uniform distribution pattern
Mc = Moricity Index for clustered distribution pattern C. Gastropod Community Index
X20.975 = The chi square value for n-1 free degrees Gastropod observations in Mangrove Pancer Cengkrong
X20.025 = The chi square value for n-1 free degrees (MPC), there are 10 genus identified, namely the genus
Xi = Number of individuals in the plot Cerithidea, Littoraria, Faunus, Tarebia, Clypeomorus,
n = total number of sampling plots Crassispira, Nerita, Terebralia, Neritina and Cassidula.
Gastropods were highest at Point 1, with a total of 462
Determination of Gastropod Dispersal Patterns: individuals and lowest at Point 3, with a total of 172
individuals. The Cerithidea genus was found the highest with
Id > 1 = clustered a total of 1314 individuals, while the lowest was the
Id < 1 = same nature Terebralia genus with 2 individuals. The difference in the
Id = 1 = random number of individuals found can be influenced by
environmental conditions, adaptation patterns, food sources,
III. RESULT AND DISCUSSION and individual distribution patterns [11]. Differences in
density and composition of gastropod species cause the
A. Mangrove Vegetation Structure formation of gastropod zonation. The differences that occur
Mangrove species found totaled 199 individuals, can be caused by differences in sampling distance and
including Avicennia alba, Bruguiera gymnorrhiza, environmental factors.
Rhizophora apiculata, Rhizophora mucronata, Sonneratia
alba, Sonneratia caseolaris, Aegiceras floridum, Ceriops D. Gastropod Abundance Index
tagal, and Avicennia marina. The highest amount of The results of the gastropod abundance index in the
vegetation was found at Point 4 with a total of 47 individuals, MPC, ranged from 34.4 - 92.4 ind/m2. The highest abundance
while the lowest was at Point 6 with 23 individuals. value was found in the Cerithidea genus at Point 1 at 67.6
Rhizophora apiculata species were found most at Point 3, and ind/m2 and the lowest was the Nerita genus at Point 3,
Aegiceras floridum was found least at Point 2. The large Terebralia genus at Point 2, Neritina genus at Points 3 and 4,
number of Rhizophora apiculata species found, can be with an abundance of 0.2 ind/m2 (Fig 1). The highest
influenced by mangrove rehabilitation activities carried out in abundance was found in the Cerithidea genus, where this
dominated by this species, so the number is more than other genus was spread across all observation points. The high
species. abundance of the Cerithidea genus, because this genus
belongs to the Potamididae family, which is a native family
B. Mangrove Density of mangrove forest dwellers.
The highest mangrove species density was found at
Point 4 at 0.078 ind/m2, followed by Point 1 at 0.63 ind/m2,
and the lowest at Point 6 at 0.038 ind/m2 (Table 1). The
highest species density by Rhizophora apiculata species and
the lowest by Bruguiera gymnorrhiza species. Mangrove
species at point 4 (near the estuary) and point 1, are classified
The high diversity index value at Point 3 can be species dominate, then the community is said to have low
influenced by the number of species and species distribution. species diversity [15].
Low species similarity and few species population values are
some of the factors that can affect the low value of the F. Gastropod Uniformity Index
diversity index in an ecosystem [14]. A community can be The value of Diversity Index (E) of gastropods in
said to have high species diversity if it is composed of many Mangrove Pancer Cengkrong ranges from 0.36 - 0.57. The
species with the same or almost the same abundance. highest uniformity index value is found at Point 3 with a value
Conversely, if it is composed of a few species and only a few of 0.57 (medium category). The lowest uniformity index
value is found at Point 4 and 5 with a value of 0.36 (Fig 3).
The low uniformity index of gastropods, in the range of makes one species more dominant. High uniformity reflects
0.00<E<0.50, reflects that the community is under stress. The an ecosystem that supports a variety of species in a balanced
highest uniformity index value is found at Point 3 with a value manner [17].
of 0.57. Although it has the highest value of all observation
points, the uniformity index at Point 3 is classified as G. Gastropod Dominance Index
moderate. The lowest uniformity index values were found at The Dominance Index (C) value of gastropods in
Points 4 and 5 with a value of 0.36. A uniformity index that Mangrove Pancer Cengkrong ranged from 0.37 - 0.60 (Fig 4).
reaches 1.00, indicates that the organisms in the ecosystem The highest gastropod dominance index was found at Point 2
have the same number and type of organism [16]. This at 0.60 (there is species dominance), while the lowest was at
condition is caused by an environmental imbalance that Point 3 at 0.37 (no species dominance).
The highest gastropod dominance index was found at followed by a high uniformity index. This correlates with the
Point 2 at 0.60, while the lowest was at Point 3 at 0.37. The uniformity index value found at point 3. In accordance with
dominance index category at point 2 is included in the the statement that the high and low dominance index values
category of dominant species. The lowest dominance index are interrelated with the uniformity index value. A low
value is found at point 3, with a value of 0.37. This value dominance index value states that there is no dominating
indicates that at point 3, the dominance index value is species [19].
included in the category of no species dominance [18].
Generally, a low dominance index value will always be
H. Gastropod Distribution Patterns group. There is 1 genus with random distribution and 9 genus
The distribution pattern of gastropods found in the with group distribution pattern (Table 2).
Pancer Cengkrong Mangrove ecosystem is random and
The Cerithidea genus with a random distribution Salinity values ranged from 24 - 29 ppt. The highest
pattern, it can be said that this genus has a high adaptability salinity was found at Point 4, which was 29 ppt, and relatively
to various environmental conditions. In this study, the genus the same at Points 1, 2, and 3, which were 24 ppt. The high
found clustered, tending to be found only at certain points. salinity at Point 4 was influenced by the measurement
The existence of a clustered distribution pattern is a natural location at the mouth of the river, so the salinity value was
thing that occurs in nature, where there is a collection of higher than other points. The quality standard of salinity for
individuals at a certain point. This can occur because the form gastropod life ranges from 25-40 ppt [24].
of adaptation in each genus is different to environmental
changes [20]. IV. CONCLUSION
[4]. I. Aditya and W. A. Nugraha, “STRUKTUR [15]. D. Alwi, S. H. Muhammad, and H. Herat,
KOMUNITAS GASTROPODA PADA “Keanekaragaman dan Kelimpahan Makrozoobenthos
EKOSISTEM MANGROVE DI PANCER Pada Ekosistem Mangrove Desa Daruba Pantai
CENGKRONG KABUPATEN TRENGGALEK,” Kabupaten Pulau Morotai,” JURNAL ENGGANO,
Juvenil:Jurnal Ilmiah Kelautan dan Perikanan, vol. 1, vol. 5, no. 1, pp. 64–77, Apr. 2020, doi:
no. 2, pp. 210–219, Aug. 2020, doi: 10.31186/jenggano.5.1.64-77.
10.21107/juvenil.v1i2.7575. [16]. B. Ramadhan, M. Sari, J. Sofiana, and S. Minsas,
[5]. A. Alwidakdo, Z. Azham, and L. Kamarubayana, “Kepadatan dan keanekaragaman makrozoobenthos di
“Studi Pertumbuhan Mangrove Pada Kegiatan kawasan mangrove Setapuk Besar,” 2023.
Rehabilitasi Hutan Mangrove,” Agrifor, vol. 13, no. 1, [17]. T. R. F. Siahaan et al., “Komunitas gastropoda pada
pp. 11–18, 2014. ekosistem mangrove di Pulau Padaidori, Kabupaten
[6]. A. L. Mawardi, M. Khalil, T. M. Sarjani, and F. Biak Numfor, Papua,” J Mar Res, vol. 11, no. 4, pp.
Armanda, “Diversity and habitat characteristics of 598–608, Nov. 2022, doi: 10.14710/jmr.v11i4.33933.
gastropods and bivalves associated with mangroves on [18]. R. N. Fadilla, W. R. Melani, and T. Apriadi,
the east coast of Aceh Province, Indonesia,” “Makrozoobentos sebagai bioindikator kualitas
Biodiversitas, vol. 24, no. 9, pp. 5146–5154, 2023, perairan di Desa Pengujan Kabupaten Bintan,”
doi: 10.13057/biodiv/d240959. Habitus Aquatica, vol. 2, no. 2, pp. 83–94, Jan. 2022,
[7]. R. H. R. Tanjung, A. Kabelen, and A. Antoh, “Analisis doi: 10.29244/haj.2.1.83.
Vegetasi Mangrove di Pulau Liki, Distrik Sarmi Kota [19]. L. Pramika, Muliadi, and S. Minsas, “Stuktur
Kabupaten Sarmi,” Jurnal Biologi Papua, vol. 7, no. Komunitas Makrozoobentos di Perairan Pulau
1, pp. 22–28, 2018, doi: 10.31957/jbp.428. Kabung,Kabupaten Bengkayang Kalimantan Barat,”
[8]. Y. Y. Amin, Jamaluddin, and E. S. Kaseng, Jurnal Laut Khatulistiwa, vol. 4, no. 1, pp. 10–19,
“Keanekaragaman Makrozoobentos Sebagai Indikator 2021.
Kualitas Air di Hutan Mangrove Pantai Kuri Caddi di [20]. Y. Laraswati, N. Soenardjo, and W. A. Setyati,
Kabupaten Maros,” Jurnal Ilmiah Wahana “Komposisi dan Kelimpahan Gastropoda Pada
Pendidikan, vol. 9, no. 10, pp. 359–369, 2023. Ekosistem Mangrove Di Desa Tireman, Kabupaten
[9]. G. Maura et al., “Composition and Distribution Rembang, Jawa Tengah,” J Mar Res, vol. 9, no. 1, pp.
Pattern Of Gastropods on The Bakau Besar Laut 41–48, Feb. 2020, doi: 10.14710/jmr.v9i1.26104.
Village, The District Of Sungai Pinyuh, Mempawah [21]. Djunaidi, T. D. Pramesthy, P. P. Kelana, M. N.
Regency,” Online, 2021. [Online]. Available: Arkham, and R. B. K. Haris, “Inventarisasi
http://jurnal.untan.ac.id/index.php/lk Makrozoobenthos, Kualitas Air dan Substrat di
[10]. I. E. Bayan, F. Yulianda, and I. Setyobudiadi, Ekosistem Mangrove Kota Dumai Provinsi Riau,”
“Degradation analysis of mangrove ecological 2023.
function as macrozoobenthos habitat and its [22]. M. Sabar, “Biodiversitas dan Adaptasi
management in the Angke Kapuk Coastal Area, Makrozoobenthos di Perairan Mangrove,” Jurnal
Jakarta,” Bonorowo Wetlands, vol. 6, no. 1, pp. 1–11, Bioedukasi, vol. 4, no. 2, pp. 529–539, 2016.
Jun. 2016, doi: 10.13057/bonorowo/w060101. [23]. M. Yanti, S. Susiana, and D. Kurniawan, “Struktur
[11]. L. Putri, F. Yulianda, and Y. Wardiatno, “Pola zonasi Komunitas Gastropoda dan Bivalvia di Ekosistem
mangrove dan asosiasi makrozoobentos di wilayah Mangrove Perairan Desa Pangkil Kabupaten Bintan,”
Pantai Indah Kapuk, Jakarta,” Bonorowo Wetlands, Jurnal Akuatiklestari, vol. 5, no. 2, pp. 102–107, May
vol. 5, no. 1, pp. 29–43, 2015, doi: 2022, doi: 10.31629/akuatiklestari.v5i2.4063.
10.13057/bonorowo/w050104. [24]. A. E. Saputri, B. Amin, and D. Yoswaty, “Structure of
[12]. A. Arfan, W. Sanusi, and M. Rakib, “Analisis The Macrozoobenthos Community in The North
Kerapatan Mangrove dan Keanekaragaman Coastal Waters of Bengkalis Island, Riau Province,”
Makrozoobenthos di Kawasan Ekowisata Mangrove 2021.
Lantebung Kota Makassar,” J Mar Res, vol. 12, no. 3,
pp. 493–500, Jul. 2023, doi:
10.14710/jmr.v12i3.38060.
[13]. Nurrudin, A. Hamidah, and W. D. Kartika,
“Keanekaragaman Jenis Gastropoda di Sekitar
Tempat Pelelangan Ikan (TPI) Parit 7 Desa Tungkal I
Tanjung Jabung Barat,” 2015.
[14]. M. Labbaik, I. W. Restu, and M. A. Pratiwi, “Status
Pencemaran Lingkungan Sungai Badung dan Sungai,”
Journal of Marine Sciences and Aquatic, vol. 4, no. 2,
pp. 304–315, 2018.