Evaluation of the quality of mangrove ecosystems using macrozoobenthos as bioindicators in the Southern Coast of East Java, Indonesia

Abstract

Abstract. Retnaningdyah C, Febriansyah SC, Hakim L. 2022. Evaluation of the quality of mangrove ecosystems using macrozoobenthos as bioindicators in the Southern Coast of East Java, Indonesia. Biodiversitas 23: 6480-6491. The mangrove ecosystem in East Java has been degraded due to land use change. Some of these mangrove ecosystems have been restored. However, the success of these restoration activities has never been evaluated. This study aimed to evaluate the quality of some mangrove ecosystems on the Southern Coast of East Java by observing the physical and chemical quality of water and macrozoobenthos that live in mangroves, especially crustaceans and gastropods, as bioindicators. Samplings were carried out on seven mangrove ecosystems, namely restored ecosystems (Cengkrong, Sine, Getem, Kondang Merak, Clungup Mangrove Conservation/CMC) and natural ecosystems as reference sites (Alas Purwo National Park/TNAP and Sempu island). The water quality parameters observed were pH, conductivity, Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), nitrate, orthophosphate, Total Suspended Solid (TSS), salinity, sulfide content (H2S), oil and fat content, and dissolved lead (Pb) content. The macrozoobenthos communities observed were gastropods and crabs, while the mangrove communities monitored were only trees, using plots, each measuring 10x10 m. The results showed that some water quality parameters did not meet the sea water quality standards for marine life, namely DO and nitrate levels for all locations, H2S, and oil/fat in some locations. The quality of the restored mangrove ecosystem in the Cengkrong and CMC areas was better than that of other sites, with a Shannon-Wiener species diversity index (H') for mangrove trees of 2.796 and 2.235 and was close to the quality at the reference sites, namely Alas Purwo and Sempu island (H' 2.953 and 2.356). The H' value of macrozoobenthos in the Cengkrong and CMC mangrove ecosystem was also high (4.37 and 3.47) and almost the same as the H' value of Sempu Island and Alas Purwo (3.45 and 3.88), while in other mangrove ecosystems it ranged from 1.33 to 2.60. The species diversity of mangrove vegetation had a significant (? 0.05-0.1) to very significant (? <0.05) positive correlation with the diversity of crabs and gastropods, so the diversity of macrozoobenthos (crabs and gastropods) can be used as a bioindicator of the quality of the mangrove ecosystem.

Community Structure and Fish Diversity in Some Mangrove Ecosystems with Varying Levels of Naturalness and Human Activity on Bawean Island, East Java, Indonesia

“…as well as environmental pollution and climate change [6][7][8][9]. A similar case occurred in the mangrove ecosystem of East Java that was found to be deforested and its area decreased from 57,500 Ha to 22,700 Ha in 2008 and continued to decline to 11,800 Ha in 2019 [10][11][12][13].…”

Checklist of mangrove snails (Gastropoda: Mollusca) on the coast of Lamongan District, East Java, Indonesia

“…Gastropods are animals that have the potential to be able to monitor species stability and also the environment; they can also be bioindicators of ecosystem changes (Theofilius et al 2021;Retnaningdyah et al 2023). Given the community species richness similarity between the stations, regular monitoring may detect changes in the community composition of key species more sensitive to environmental change (Islamy and Hasan 2020).…”

Lead Level Analysis in Roots and Leaves of Mangrove Plants Ceriops tagal and Rhizophora apiculata in Clungup Mangrove Conservation

“…It can be assumed that there is a high possibility of Pb content originating from plastic waste and ship fuel from fishing boats that can pollute the Clungup Mangrove Conservation area. According to previous studies, Clungup Mangrove Conservation has a lead content in water of 0.0015 mg/l in 2022 [13]. Based on sample testing, Pb levels in soil The average Pb concentration in the sediment was 5.8881 ppm ± 0,079.…”

“…Clungup Mangrove Conservation in Tambakrejo Village, managed by the local Sendang Biru community, is possibly affected by carried garbage from river currents, nearby settlements, small harbors, and possibly metal pollution sources. Based on previous literature, it was found to contain Pb in water at a concentration of 0.0015 mg/l in 2022, as well as several other metal elements [13]. Heavy metals can bind to organic matter easily, settle to the bottom of the water, and blend with sediments, so that the heavy metal content in sediments can be higher than that in water [14].…”