Variasi Struktur Komunitas Dan Diversitas Moluska Di Beberapa Ekosistem Mangrove Pantai Utara Jawa Timur

Angelina, Aulia and Prof. Dr. Dra. Catur Retnaningdyah., M.Si and Nia Kurniawan, S.Si.,MP.,D.Sc (2024) Variasi Struktur Komunitas Dan Diversitas Moluska Di Beberapa Ekosistem Mangrove Pantai Utara Jawa Timur. Magister thesis, Universitas Brawijaya.

Abstract

Mangrove adalah vegetasi khas yang tumbuh di daerah pasang surut pantai berlumpur, dengan berbagai peran ekologis dan ekonomis yang signifikan antara lain: Penahan Abrasi: Mangrove melindungi pesisir dari erosi, gelombang besar, badai, dan tsunami. Penyerap Karbon: Kemampuan tinggi menyimpan karbon menjadikan mangrove ekosistem penting dalam mitigasi perubahan iklim. Habitat dan Filtrasi Air: akar kompleksnya menyediakan habitat bagi beragam fauna, termasuk ikan, kepiting, dan burung, serta berfungsi sebagai penyaring polutan untuk menjaga kualitas air. Indonesia memiliki hutan mangrove terluas di dunia, dengan sekitar 3,7 juta hektar. Di Jawa Timur, hutan mangrove mencakup 27.221 Ha atau sekitar 48% dari total hutan mangrove di Pulau Jawa. Hutan mangrove di daerah ini tidak hanya berfungsi ekologis tetapi juga menopang kehidupan masyarakat lokal melalui sumber daya ekonomi dan perlindungan lingkungan. Moluska merupakan invertebrata dominan yang memainkan peran penting dalam ekosistem mangrove: peran ekologi moluska yaitu berfungsi sebagai filter feeder, dekomposer, dan sumber energi bagi organisme lain dalam rantai makanan. Indikator Lingkungan: Keberadaan dan keanekaragaman moluska mencerminkan kondisi kesehatan ekosistem mangrove. Siklus Karbon: Cangkang moluska yang mengandung kalsium karbonat turut berkontribusi dalam siklus karbon. Ekosistem mangrove menghadapi ancaman serius akibat: hilangnya habitat: abrasi pantai dan konversi lahan untuk pemukiman atau industri menyebabkan penurunan luasan mangrove. Sampah Laut dan Polusi: Pencemaran lingkungan berdampak negatif pada keanekaragaman flora dan fauna, termasuk moluska. Kurangnya Informasi Biogeografi: Informasi dasar tentang distribusi dan pola biogeografi moluska di ekosistem mangrove masih terbatas, sehingga sulit untuk mengembangkan strategi konservasi yang efektif. Penelitian ini bertujuan untuk menentukan profil variasi struktur komunitas diversitas moluska dan kualitas air pada ekosistem mangrove pesisir pantai utara Jawa Timur (Tuban, Gresik, Pasuruan, Probolinggo, dan Situbondo) serta7 menganalisis keterkaitan antara variasi struktur komunitas diversitas moluska dengan kualitas air yang terdapat di ekosistem mangrove pesisir pantai utara Jawa Timur berdasarkan analisis PCA. Penelitian dilakukan pada musim hujan dan pada waktu siang hari. Sampel moluska diambil dari lima pantai yang tersebar di wilayah pantai utara Provinsi Jawa Timur, Indonesia. Lima pantai tersebut antara lain Pasuruan (Nguling), Tuban (Jenu), Probolinggo (Randutatah), Gresik (Mengare), dan Situbondo (TN Baluran). Penelitian ini dilakukan dengan metode ex post facto pada ekosistem perairan lima pantai yang terletak di wilayah pantai utara Jawa Timur. Variabel terikat dalam penelitian ini adalah parameter fisika-kimia kualitas air antara lain pengukuran suhu, ph, DO, dan salinitas, serta pengukuran struktur komunitas moluska, sedangkan variabel bebas adalah kondisi lingkungan dan atau aktivitas manusia di sekitar ekosistem perairan pantai. Pengambilan sampel pada tiap-tiap pantai dilakukan pada tiga stasiun yaitu ekosistem perairan pantai yang mempunyai variasi kualitas lingkungan diakibatkan oleh variasi aktivitas manusia di sekitarnya. Pengambilan sampel pada tiap-tiap stasiun tersebut dilakukan dengan membuat tiga belt transect yang ditentukan secara acak. Pada setiap transek dibuat tiga plot sebagai ulangan. Parameter kualitas fisika-kimia air yang diukur adalah pH, DO, suhu, salinitas, dan kecerahan. Selain itu juga, pengamatan faktor lingkungan dilakukan meliputi kondisi pemanfaatan lahan di wilayah penelitian serta aktivitas manusia. Pengamatan terhadap struktur komunitas dan diversitas moluska dilakukan dengan membuat plot berukuran 1x1 m2 secara acak pada stasiun yang telah ditentukan. Moluska yang berada pada permukaan substrat diambil dengan cara langsung, sedangkan moluska yang berada di dalam substrat diambil dengan menggunakan bantuan sekop sampai kedalaman maksimal sekitar 25 cm. Hal ini dilakukan karena beberapa spesies kerang mempunyai kemampuan untuk membenamkan diri ke dalam substrat dasar sekitar 5-25 cm. Hasil penelitian menunjukkan variasi parameter fisik dan kimia air di lima lokasi antara lain suhu di wilayah Tuban memiliki suhu tertinggi (~32°C) akibat aktivitas industri yang tinggi, sementara Situbondo memiliki suhu terendah (~28°C). Suhu rata-rata relatif stabil di semua lokasi. Nilai DO rata-rata berkisar antara 3 mg/L hingga 7 mg/L. Lokasi Situbondo menunjukkan DO tertinggi (~4,5 mg/L), menunjukkan kualitas yang lebih baik, sedangkan lokasi seperti Tuban dan Pasuruan memiliki DO lebih rendah (~3,0 mg/L), dikategorikan tercemar sedang. Nilai pH berkisar antara 7,8 - 8,6, menunjukkan lingkungan yang cenderung netral hingga basa. Semua lokasi memiliki pH sesuai dengan standar untuk ekosistem mangrove. Nilai kecerahan tertinggi ditemukan di Situbondo (~1 meter), yang mendukung penetrasi cahaya lebih baik. Lokasi seperti Pasuruan dan Gresik memiliki kecerahan rendah8 (~0,2 meter), terkait dengan aktivitas manusia dan sedimentasi. Salinitas berkisar antara 27%- 35%. Situbondo menunjukkan salinitas tertinggi (~35%), sedangkan Tuban memiliki salinitas lebih rendah (~27%). Total kepadatan spesies moluska bervariasi di lima Lokasi antara lain Pasuruan memiliki indeks didominasi spesies Tresus nuttallii (10 ind/m²) dan Perna viridis (6 ind/m²). Situbondo memiliki kekayaan spesies tertinggi dengan tambahan spesies seperti Codakia tigerina (10 ind/m²). Lokasi lain seperti Tuban dan Probolinggo memiliki kepadatan spesies lebih rendah dibandingkan Situbondo. Moluska yang ditemukan berasal dari berbagai ordo, termasuk: Venerida (Famili: Mactridae, spesies: Tresus nuttallii). Cycloneritida (Famili: Neritidae, spesies: Nerita lineata). Mytilida (Famili: Mytilidae, spesies: Perna viridis). Situbondo menunjukkan diversitas tertinggi dengan banyak spesies unik, seperti Vexillum formosense. Faktor-faktor seperti suhu, salinitas, dan kecerahan berpengaruh signifikan terhadap keanekaragaman dan distribusi spesies. Lokasi dengan kualitas air yang lebih baik (seperti Situbondo) menunjukkan diversitas moluska lebih tinggi. Hubungan antara variasi struktur komunitas dan kualitas air menunjukkan korelasi antara parameter kualitas air dengan variasi komunitas moluska yaitu lokasi dengan DO dan kecerahan lebih tinggi memiliki diversitas moluska lebih besar. Lokasi dengan salinitas lebih rendah cenderung memiliki spesies dengan toleransi lingkungan yang lebih luas.

English Abstract

Mangroves are typical vegetation that grow in tidal areas of muddy coasts, with a variety of significant ecological and economic roles, including: Abrasion Barrier: Mangroves protect the coast from erosion, large waves, storms, and tsunamis. Carbon Sequestration: The high ability to store carbon makes mangroves an important ecosystem in climate change mitigation. Habitat and Water Filtration: Their complex roots provide habitat for a diverse range of fauna, including fish, crabs, and birds, and serve as filters for pollutants to maintain water quality. Indonesia has the largest mangrove forest in the world, with approximately 3.7 million hectares. In East Java, mangrove forests cover 27,221 hectares, or about 48% of the total mangrove forests in Java. Mangrove forests in this area not only function ecologically but also sustain the lives of local communities through economic resources and environmental protection. Molluscs are dominant invertebrates that play an important role in mangrove ecosystems: the ecological role of molluscs is to serve as filter feeders, decomposers, and energy sources for other organisms in the food chain. Environmental Indicators: The presence and diversity of mollusks reflect the health of the mangrove ecosystem. carbon cycle: mollusk shells containing calcium carbonate contribute to the carbon cycle. Mangrove ecosystems face serious threats due to: Habitat Loss: Coastal abrasion and land conversion for residential or industrial use have led to a decline in mangrove area. Marine Debris and Pollution: Environmental pollution negatively affects the diversity of flora and fauna, including mollusks. Lack of Biogeographic Information: Basic information on the distribution and biogeographic patterns of mollusks in mangrove ecosystems is limited, making it difficult to develop effective conservation strategies. This study aims to determine the profile of variations in mollusk diversity community structure and water quality in mangrove ecosystems on the north coast of East Java (Tuban, Gresik, Pasuruan, Probolinggo, and Situbondo) and analyze the relationship between variations in mollusk diversity community structure and water quality in mangrove ecosystems on the north coast of East Java based on PCA analysis.10 The study was conducted during the rainy season and during daylight hours. Mollusc samples were taken from five beaches spread across the north coast of East Java Province, Indonesia. The five beaches were Pasuruan (Nguling), Tuban (Jenu), Probolinggo (Randutatah), Gresik (Mengare), and Situbondo (Baluran National Park). This research was conducted using the ex post facto method on the aquatic ecosystems of five beaches located on the north coast of East Java. The dependent variables in this study were physico-chemical parameters of water quality, including temperature, ph, DO, and salinity measurements, as well as measurements of mollusc community structure, while the independent variables were environmental conditions and or human activities around the coastal aquatic ecosystem. Sampling on each beach was carried out at three stations, namely coastal water ecosystems that have variations in environmental quality caused by variations in human activities around them. Sampling at each station was carried out by making three belt transects which were determined randomly. In each transect, three plots were made as replicates. The physico-chemical water quality parameters measured were pH, DO, temperature, salinity, and brightness. In addition, observations of environmental factors were made including land use conditions in the study area and human activities. Observations on the community structure and diversity of mollusks were made by making 1x1 m2 plots randomly at predetermined stations. Molluscs on the surface of the substrate were taken directly, while molluscs in the substrate were taken using a shovel to a maximum depth of about 25 cm. This was done because some mussel species have the ability to bury themselves into the bottom substrate around 5-25 cm. The results showed variations in the physical and chemical parameters of water in the five locations, including temperature in the Tuban region having the highest temperature (~32°C) due to high industrial activity, while Situbondo had the lowest temperature (~28°C). The average temperature was relatively stable across all sites. Average DO values ranged from 3 mg/L to 7 mg/L. Situbondo site showed the highest DO (~4.5 mg/L), indicating better quality, while sites like Tuban and Pasuruan had lower DO (~3.0 mg/L), categorized as moderately polluted. The pH values ranged from 7.8 - 8.6, indicating an environment that tends to be neutral to alkaline. All sites had pH in line with the standard for mangrove ecosystems. The highest brightness value was found in Situbondo (~1 meter), which supports better light penetration. Sites such as Pasuruan and Gresik had low brightness (~0.2 meters), associated with human activities and sedimentation. Salinity ranged from 27%-35%. Situbondo showed the highest salinity (~35%), while Tuban had lower salinity (~27%). Total mollusc species density varied across the five sites, with Pasuruan having the highest species richness with Tresus nuttallii (10 ind/m²) and Perna viridis (6 ind/m²). Situbondo had the highest species11 richness with additional species such as Codakia tigerina (10 ind/m²). Other locations such as Tuban and Probolinggo had lower species densities than Situbondo. Molluscs found were from various orders, including: Venerida (Family: Mactridae, species: Tresus nuttallii). Cycloneritida (Family: Neritidae, species: Nerita lineata). Mytilida (Family: Mytilidae, species: Perna viridis). Situbondo showed the highest diversity with many unique species, such as Vexillum formosense. Factors such as temperature, salinity and brightness had a significant effect on species diversity and distribution. Sites with better water quality (such as Situbondo) showed higher mollusc diversity. The relationship between variation in community structure and water quality showed a correlation between water quality parameters and mollusc community variation, with sites with higher DO and brightness having greater mollusc diversity. Sites with lower salinity tended to have species with a wider range of environmental tolerances.

Item Type:	Thesis (Magister)
Identification Number:	0424090084
Divisions:	S2/S3 > Magister Biologi, Fakultas MIPA
Depositing User:	Unnamed user with username nova
Date Deposited:	03 Feb 2025 08:00
Last Modified:	03 Feb 2025 08:00
URI:	http://repository.ub.ac.id/id/eprint/235627

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