Anthropogenic impact on Indonesian coastal water and ecosystems: Current status and future opportunities

Levels of Potentially Toxic and Essential Elements in Water and Estimation of Human Health Risks in a River Located at the Interface of Brazilian Savanna and Amazon Biomes (Tocantins River)

The Tocantins-Araguaia basin is one of South America's largest river systems, across three Brazilian states (Maranhão, Tocantins, and Pará), within the Legal Amazon region. Despite draining extensive Cerrado savanna and rainforest ecosystems, it has suffered significant degradation, notably in the past 40 years. Human activities, including agricultural expansion, deforestation, and the introduction of non-native species, have worsened the environmental damage, which is alarming since many residents and villages along the middle Tocantins River rely on it for water supply, recreation, and fishing. This study assessed the concentration of potentially toxic and essential elements in water samples from four sampling sites distributed along the middle Tocantins River. The monitoring occurred throughout 2023, involving the measurement of parameters both on-site and in the laboratory. Water quality and its health implications were evaluated using the Weighted Arithmetic Water Quality Index (WAWQI), the Water Quality Index (WQI), and the health risk assessment index. The levels of aluminum, copper, iron, magnesium, and selenium exceeded legal standards. Seasonal fluctuations indicate a complex dynamic influenced by climatic or seasonal factors, with February showing the highest values. Site P1, located in urban areas, exhibited elevated mean concentrations for conductivity, total dissolved solids (TDS), and chlorophyll, indicating the need for continuous monitoring. The nitrogen concentrations at P1 raise concerns regarding drinking water quality, which is a concern for the region's residents who use untreated river water. Despite seasonal variations in element concentrations, the overall WAWQI categorized all sections as "Excellent," and the WQI rated as "Good." Human health risk assessments detected no risks, but continuous monitoring and interventions are crucial for sustained water quality improvement.

Spatial variability of aragonite saturation state (Ωarag) in Indonesian coastal waters

The effects of Ocean acidification (OA) on the coastal waters of small islands in Indonesia have yet to be extensively studied. This research aims to investigate the process of OA in the coastal waters of small Indonesian islands and examine how land-sea interactions impact carbonate mineral saturation. We collected seawater samples from seven locations on small islands in Indonesia between 2015 and 2021 to analyze the aragonite saturation state. The result shows that most of Indonesia's coastal waters are accompanied by supersaturation of aragonite saturation state (Ωarag>1). Selayar Island's waters had the highest aragonite saturation, averaging 4.96 ± 0.48, while Pari Island's coastal waters had the lowest, averaging 2.49 ± 0.50. Salinity had the greatest effect on Ωarag in all of the sampling sites, ranging from 24.13% to 52.92%, except Aceh Island, where temperature had a greater impact (34.35%) than salinity (26.99%). By the end of this century, Ωarag is predicted to decline based on projections related to climate change. Small island coastal waters are expected to experience a more substantial decline compared to those near the mainland, ranging from 4.71% to 79.58%. The coastal waters of Weh and Selayar Island are probably going to decline the greatest, while the coastal waters of Sorong (mainland) are probably going to decline the least. All seven sampling locations are expected to observe the decrease. This decline will be observed at all seven sampling locations, with Ωarag values ranging from 1.91 to 3.35.

Analyzing socio-environmental determinants of bone and soft tissue cancer in Indonesia

BACKGROUND

This study is designed to explore the potential impact of individual and environmental residential factors as risk determinants for bone and soft tissue cancers, with a particular focus on the Indonesian context. While it is widely recognized that our living environment can significantly influence cancer development, there has been a notable scarcity of research into how specific living environment characteristics relate to the risk of bone and soft tissue cancers.

METHODS

In a cross-sectional study, we analyzed the medical records of oncology patients treated at Prof. Suharso National Referral Orthopedic Hospital. The study aimed to assess tumor malignancy levels and explore the relationships with socio-environmental variables, including gender, distance from the sea, sunrise time, altitude, and population density. Data were gathered in 2020 from diverse sources, including medical records, Google Earth, and local statistical centers. The statistical analyses employed Chi-square and logistic regression techniques with the support of Predictive Analytics SoftWare (PASW) Statistics 18.

RESULTS

Both bivariate and multivariate analyses revealed two significant factors associated with the occurrence of bone and soft tissue cancer. Age exhibited a statistically significant influence (OR of 5.345 and a p-value of 0.000 < 0.05), indicating a robust connection between cancer development and age. Additionally, residing within a distance of less than 14 km from the sea significantly affected the likelihood of bone and soft tissue cancers OR 5.604 and p-value (0.001 < 0.05).

CONCLUSIONS

The study underscores the strong association between age and the development of these cancers, emphasizing the need for heightened vigilance and screening measures in older populations. Moreover, proximity to the sea emerges as another noteworthy factor influencing cancer risk, suggesting potential environmental factors at play. These results highlight the multifaceted nature of cancer causation and underscore the importance of considering socio-environmental variables when assessing cancer risk factors. Such insights can inform more targeted prevention and early detection strategies, ultimately contributing to improved cancer management and patient outcomes.

NOBEL-BOX: Development of a Low-Cost Ship-Based Instrument for Ocean Monitoring

This research aims to develop an inexpensive ocean observation instrument with the project name NOBEL (Nusantara Oceanography Backdoor Experiment Laboratory)-BOX. The device can be installed on all types of vessels for mapping the water conditions, providing accurate data for managing a marine area, particularly regarding water quality. The principle of NOBEL-BOX is to attach six sensors in a container connected to a microcontroller and then measure specific data directly and automatically. The methodology employed included experimental design, laboratory and field tests, and data evaluation to develop the necessary system and instruments. The design process encompassed the construction of the instrument and the fabrication, involving the creation of three-dimensional drawings and the design of microcontrollers and data transmission systems and power capacity. This instrument is box-shaped with a microcontroller, sensors, a battery, and cables located inside. The testing phase included data validation, testing of the device in the laboratory, and field testing showed that the device worked. The data provided from this instrument could meet the specific criteria for seawater analysis.

Aquaculture bacterial pathogen database: Pathogen monitoring and screening in coastal waters using environmental DNA

Increasingly diverse pathogen occurrence in coastal and mariculture areas demands improved monitoring platforms to prevent economic and public health implications. Accessible databases with up-to-date knowledge and taxonomy are critical for detecting and screening environmental pathogens. Condensed from over 3000 relevant reports in peer reviewed articles, we constructed an aquaculture bacterial pathogen database that provides specialized curation of over 210 bacterial pathogenic species impacting aquaculture. Application of the aquaculture bacterial pathogen database to environmental DNA metabarcoding monitoring data in Hong Kong coastal and mariculture waters effectively characterized regional pathogen profiles over a one-year period and improved identification of new potential pathogen targets. The results highlighted the increase in potential pathogen abundance related to aquaculture activity and the associated inorganic nitrogen load, which was chiefly due to the enrichment of Vibrio during the atypical dry winter season. The value of the aquaculture bacterial pathogen database for empowering environmental DNA-based approaches in coastal marine pathogen surveillance benefits water resource management and aquaculture development on a global scale.

Biogeochemical and physical drivers of hypoxia in a tropical embayment (Brunei Bay)

Dissolved oxygen is an ecologically critical variable with the prevalence of hypoxia one of the key global anthropogenic issues. A study was carried out to understand the causes of low dissolved oxygen in Brunei Bay, northwest Borneo. Hypoxia was widespread in bottom waters in the monsoonal dry season with dissolved oxygen < 2 mg/L throughout the coastal zone. This was a result of riverine nutrient input primarily from the Padas river driving excess primary production and its subsequent sinking into stratified bottom water where its decomposition consumed oxygen. Despite higher riverine nutrient input in the wet season hypoxia was less extensive due to the combination of turbidity reducing coastal primary production, the intrusion of oxygen-rich water from the South China Sea into offshore bottom layer waters and horizontal flushing increase advection of phytoplankton biomass out of the bay. Future investigation of hypoxia in shallow tropical regions therefore needs to consider the role of monsoonal season.

Potential risks of heavy metals in green mussels (Perna viridis) harvested from Cilincing and Kamal Muara, Jakarta Bay, Indonesia to human health

This study investigates Pb, Cd, and Cr in the suspended particulate matter (SPM), sediments, and green mussels from Cilincing and Kamal Muara, Jakarta Bay and estimates their potential human health risks. The results showed that the metal levels in SPM from Cilincing ranged from 0.81 to 1.69 mg/kg for Pb and 2.14 to 5.31 mg/kg for Cr, while in Kamal Muara ranged from 0.70 to 3.82 mg/kg for Pb and 1.88 to 4.78 mg/kg dry weight for Cr. The levels of Pb, Cd, and Cr in sediments from Cilincing ranged from 16.53 to 32.51 mg/kg, 0.91 to 2.52 mg/kg; and 0.62 to 1.0 mg/kg whereas in Kamal Muara ranged from 8.74 to 8.81 mg/kg; 0.51 to 1.79 mg/kg, and 0.27 to 0.31 mg/kg dry weight, respectively. The levels of Cd and Cr of green mussels in Cilincing ranged from 0.014 to 0.75 mg/kg and 0.003 to 0.11 mg/kg; while in Kamal Muara ranged from 0.015 to 0.073 mg/kg and 0.01 to 0.04 mg/kg wet weight, respectively. Pb was not detected in all samples of green mussels. The Pb, Cd, and Cr levels in the green mussels were still below the permissible limits set by international standards. However, the Target Hazard Quotient (THQ) for adult and children in several samples were higher than one indicating potential noncarcinogenic effects to consumers due to Cd accumulation. To reduce the detrimental effects of metals, we suggest maximum mussel consumption of 0.65 kg for adults and 0.19 kg for children in a week based on the highest level of metals.

Accumulation of Plastics and Trace Elements in the Mangrove Forests of Bima City Bay, Indonesia

Pollution with microplastics (MPs), nanoplastics (NPs) and trace elements (TEs) remains a considerable threat for mangrove biomes due to their capability to capture pollutants suspended in the water. This study investigated the abundance and composition of plastics and TEs contained in the soil and pneumatophores of Avicennia alba sampled in experimental areas (hotel, market, river mouth, port, and rural areas) differentiated in anthropopressure, located in Bima Bay, Indonesia. Polymers were extracted and analyzed with the use of a modified sediment isolation method and Fourier transform infrared spectroscopy. Trace elements were detected by inductively coupled plasma optical emission spectrometry. The lowest and highest quantities of MPs in soil were recorded in rural and hotel areas, respectively. The rural site was characterized by distinct MP composition. The amounts of sediment-trapped MPs in the tested localities should be considered as high, and the recognized polymers partly corresponded with local human activity. Concentrations of seven plastic types found in plant tissues did not entirely reflect sediment pollution with nine types, suggesting a selective accumulation (particularly of polyamides and vinylidene chloride) and substance migration from other areas. Very low concentrations of non-biogenic TEs were observed, both in sediments and pneumatophores. The results highlight the relevance of environmental contamination with plastics.

The identification of the new species Nitratireductor thuwali sp. nov. reveals the untapped diversity of hydrocarbon-degrading culturable bacteria from the arid mangrove sediments of the Red Sea

Introduction

The geological isolation, lack of freshwater inputs and specific internal water circulations make the Red Sea one of the most extreme-and unique-oceans on the planet. Its high temperature, salinity and oligotrophy, along with the consistent input of hydrocarbons due to its geology (e.g., deep-sea vents) and high oil tankers traffic, create the conditions that can drive and influence the assembly of unique marine (micro)biomes that evolved to cope with these multiple stressors. We hypothesize that mangrove sediments, as a model-specific marine environment of the Red Sea, act as microbial hotspots/reservoirs of such diversity not yet explored and described.

Methods

To test our hypothesis, we combined oligotrophic media to mimic the Red Sea conditions and hydrocarbons as C-source (i.e., crude oil) with long incubation time to allow the cultivation of slow-growing environmentally (rare or uncommon) relevant bacteria.

Results and discussion

This approach reveals the vast diversity of taxonomically novel microbial hydrocarbon degraders within a collection of a few hundred isolates. Among these isolates, we characterized a novel species, Nitratireductor thuwali sp. nov., namely, Nit1536^T. It is an aerobic, heterotrophic, Gram-stain-negative bacterium with optimum growth at 37°C, 8 pH and 4% NaCl, whose genome and physiological analysis confirmed the adaptation to extreme and oligotrophic conditions of the Red Sea mangrove sediments. For instance, Nit1536^T metabolizes different carbon substrates, including straight-chain alkanes and organic acids, and synthesizes compatible solutes to survive in salty mangrove sediments. Our results showed that the Red Sea represent a source of yet unknown novel hydrocarbon degraders adapted to extreme marine conditions, and their discovery and characterization deserve further effort to unlock their biotechnological potential.

Spatio-temporal variation and seasonal dynamics of stranded beach anthropogenic debris on Indonesian beach from the results of nationwide monitoring

The first stranded macrodebris study on a national scale in Indonesia was conducted on 18 beaches from February 2018 to December 2019. The average weight and abundance of beach debris were higher between October and February (rainy season). The highest stranded macrodebris was located in Ambon, Manado, Takalar, and Padang. Plastic (46.38 %) was the most prevalent type of debris across all macrodebris categories, with single-use plastics such as plastic sachets, plastic bags, and plastic bottles being the dominant macroplastic debris (64.64 %). Based on CCI, HII, and BGI, 18 beaches are "moderately clean," with few hazardous items observed, and "Good." This anthropogenic macrodebris is thought to be more localized (55 %) than transboundary macrodebris. Litter control and environmental quality of this Indonesian coastal region should be improved through a proactive and flexible approach. Finally, extensive stranded beach debris monitoring is recommended to better understand the distribution of macrodebris in the region.

A half-century record of coral skeletal P/Ca reveals late 20th century nutrient pollution in Port Dickson, Malaysia

Anthropogenic nutrient pollution has been identified as one of the key stressors of coastal ecosystems. However, the paucity of long-term nutrient records limits our understanding of both the extent of nutrient pollution as well as of the ecological impacts. Here, using coral skeletal phosphorus (P/Ca), we reconstructed a half-a-century record of seawater phosphate at Port Dickson, Malaysia. The P/Ca in the coral revealed an up to 8-fold increase in coral P/Ca from the late 1970s to 2000s, likely linked to increases in fertilizer use (R² = 0.47) and variabilities in rainfall (R² = 0.17). The rise in coral P/Ca in coincided with a contemporaneous 18 % decrease in coral skeletal density, suggesting phosphate enrichment may impact the growth and structural integrity of reef-building corals. Given the importance of both agriculture and heavy reliance on coral reefs by populations in Southeast Asia, our study highlights continue the need to develop environmental management upstream of coastal zones.

Microbiological assessment of marine and estuarine ecosystems using fecal indicator bacteria, Salmonella, Vibrio and antibiotic resistance pattern

Marine and estuarine environments are often affected by microbiological contamination that adversely affects their use and severely impacts human health. To examine the influence of anthropogenic activities, this study used two different ecosystems in Agadir Bay, to compare fecal indicator bacteria (FIB) and bacterial pathogen profiles over two years. Vibrio target pathogens were detected at a high frequency (49.3%), while a low percentage (5.5%) was noted for Salmonella. Apart from those mentioned above, several other pathogenic bacteria were detected such as Cronobacter sakzakii, Pseudomonas fluorescens, and Aeromonas hydrophila. We also investigated the antimicrobial resistance of the pathogenic bacteria isolated. Salmonella strains were sensitive to all the antibiotics used, except ampicillin, amoxicillin + Ac clavulanic and chloramphenicol. And Vibrio strains were resistant to ampicillin, cephalothin, amikacin, and ciprofloxacin. This study highlights the limitations of FIB in assessing the microbiological quality and the importance of environmental surveys in understanding the distribution of pathogens.

Beach debris quantity and composition around the world: A bibliometric and systematic review

Anthropogenic pollution of marine ecosystems caused by beach debris has become a serious environmental concern in the last few decades. Regarding the raising production of beach debris, the present work aimed to summarize the quantity and quality of beach debris reported from different beach areas of the world. Also, a bibliometric analysis was used to analyze research trends and upgrade knowledge in this research area. Using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), the eligible papers reviewed regarding beach debris abundance along with their composition from 2010, which were extracted from the Scopus database. The results of the study showed that plastic items represented the dominant material (61.25%), followed by food (5.88%), wood (5.78%), metals (5.2%), and glass (5%). Further, the beaches studied were classified into three degrees, including highly polluted (31.5 items/m2), moderate polluted (3.47 items/m2), and low polluted (0.37 items/m2), based on the average abundance of debris.