High Tide Conditions Research Articles

Distinct molecular responses of mangrove plants to hypoxia and reoxygenation stresses contribute to their resilience in coastal wetland environment

Mangroves adapt to periodical submergence and constitute resilient ecosystems in coastal environments. The question is whether they can sustain long submergence stress when sea level rises as a consequence of climate change. To address this, seedlings of two representative mangrove species that acclimate to low to mid tide (Avicennia marina) and mid to high tide (Kandelia obovata) conditions were treated with continual submergence for 7 days as extended hypoxia, or semi-diurnal cyclic submergence and reoxygenation for 7 days. At specific time points, leaves were collected to construct RNA-Sequencing libraries for gene expression analysis. Through the lens of transcriptome, the initial response of A. marina to submergence was mild but more dramatic after prolong immersion. However, the initial response of K. obovata was drastic and reduced in latitude later, suggesting distinct species-specific responses. After adapting to diurnal cycles, both species minimized transcriptome fluctuations similarly. Metabolically, during initial response, sucrose and starch were converted into glucose for fermentation to increase glycolytic flux, coupled with regeneration of NAD+. The energy amelioration was accompanied by longer term phytohormone regulations where ethylene signal transduction pathway was enhanced, but abscisic acid biosynthesis was reduced. Notably, gibberellic acids biosynthesis increased in A. marina but decreased in K. obovata as a unique feature. Genomic level analysis indicated that only about 30 % of the conserved plant submergence responsive genes were expressed during submergence in these mangroves. The function of an ethylene responsive gene was validated in transgenic Arabidopsis. This research elucidates distinct molecular mechanisms and metabolic pathways that empower A. marina and K. obovata to endure prolonged submergence and hypoxia. By highlighting their unique adaptive strategies in response to rising sea levels, these findings enhance our understanding of mangrove resilience and provide insights for the conservation and management of these essential coastal ecosystems in the face of climate change.

Satellite-derived bathymetry using Sentinel-2 in mesotidal coasts

Coastal zones are strategic environments of high socioeconomic, political, and ecological value, with over half of the world’s population residing within 200 km of the coast. This proximity highlights their vulnerability to extreme events, which are exacerbated by global changes, leading to significant coastal impacts such as erosion, flooding, and ecosystem services deterioration. Consequently, efficient and operational methodologies for continuous monitoring are urgently needed to face these challenges. Bathymetric data are essential for understanding coastal dynamics, yet traditional data collection methods are often constrained by logistical challenges and high costs. Spaceborne remote sensing techniques offer significant advantages over traditional ground-based methods, particularly in terms of cost-effectiveness and operational efficiency. Over the last half-century, different Satellite-derived bathymetry (SDB) methodologies have been developed; however, challenges still persist. In this research, we applied a robust SDB methodology to three different study sites: Cíes Islands, Baiona Bay, and Vao beach within the Ría de Vigo, Galicia (NW Spain). These areas offer diverse and complex mesotidal environments to test for the very first time the methodology's efficacy. SDB was retrieved with a median absolute error (MedAE) ranging from 0.35 m to 1.55 m for depths up to 14 m. Results with different data source were evaluated, obtaining MedAE for nautical charts ranging from 0.46 m to 1.55 m. The precision between the data sources were quite close. In addition, multi-image composite was generated using images coinciding with both low tide (LT) and high tide (HT) conditions across the three zones. The lowest MedAE values were consistently obtained in images classified as LT (0.46 m) corresponding to Vao area. The results highlight the potential of nautical charts as a reliable source of calibration data for SDB, confirm the effectiveness of multi-image and switching models to correct artifacts and turbidity, considering tidal effects, improving single image approaches, and leverage visible bands for precise depth retrieval under varying conditions.

Numerical investigation for the influence of suspended sediment on salinity distribution in the Qiantang Estuary, China

Numerous studies have demonstrated that high suspended sediment concentration (SSC) can change density distribution and affect water mixing, but few scholars have investigated this impact on numerical simulations of estuarian salinity distribution. The Qiantang Estuary is a macro-tidal estuary with high SSC, which has a more significant influence on water density than that of salinity. Therefore, this paper established a three-dimensional (3D) numerical model coupling flow, salinity and SSC based on Delft3D and first analyzes the impact of SSC on salinity distribution under different runoff and tidal conditions in the Qiantang Estuary. The results indicated that simulated salinity generally decreases when considering the impact of SSC, suggesting a weakening effect on saltwater intrusion. The distribution of salinity difference (ΔS) and SSC show a strong spatial and temporal correlation, and ΔS peak increases and shifts upstream as the tidal range increases or runoff discharge decreases. The mechanism of SSC influencing saltwater intrusion can be summarized as follows: On the one hand, SSC increases the water density, which weakens the driving force for saltwater to move upstream, causing a decrease in flood current velocity and water level, and thereby diminishing the advective transport of salinity. On the other hand, SSC enhances density stratification, which weakens vertical turbulence and reduces the dispersive transport of salinity. These combined effects reduce both the advective and diffusive salinity fluxes during the flood tide, ultimately leading to a decrease in upstream salinity. Therefore, neglecting this effect in estuaries with high SSC can cause significant deviations in salinity simulation results, especially under low-flow and high-tide conditions.

Assessing sediment CO2 effluxes in the coastal ecosystem of North Sumatra, Indonesia

Coastal wetlands including mangrove play a vital role in regulating the local and global carbon cycle. Coastal areas contribute greatly to the carbon exchange process due to the complex interactions that occur between the atmosphere, land, and oceans. One of the important components in coastal carbon dynamics is CO2 gas exchange between soil, water and the atmosphere. This study aims to assess CO2 efflux across various land covers (namely natural mangrove, restored mangrove, and converted mangroves to oil palm and aquaculture pond) in the coastal areas of North Sumatra Province, and analyze the effect of sea tides and ebbs on the rate of CO2 efflux and their connection with the number and area of macrozoobenthos burrows. We applied direct sampling by using the static closed chamber method attached to portable CO2 analyzer. The mean of CO2 efflux in natural mangrove forest land covers was 866±585 mgCO2/m2/h during low tide conditions and 1137±792 mgCO2/m2/h during high tide conditions, followed by oil palm plantations at 760.71±341 mgCO2/m2/h, restored mangroves during low tide of 575.24±326 mgCO2/m2/h and 597.11±180 mg CO2/m2/h during high tide conditions, and the lowest was recorded in ponds at 588.55±358 mgCO2/m2/h. Further, we observed that tidal conditions affect the magnitudes of CO2 efflux in natural and restored mangrove forests, and we did not observe similar pattern in oil palms and ponds since these land covers were not influenced by regular tidal input. We also observed that no significant relationship between the number and area of macrozoobenthos burrows and CO2 efflux. Our findings suggest that CO2 effluxes in coastal wetlands are highly dynamic and presumably driven by complex factors and therefore, understanding their magnitudes and drivers requires extensive measurement covering large spatial and temporal scales.

Shoreline position trends in the Niger Delta: analyzing spatial and temporal changes through Sentinel-1 SAR imagery

Various natural and human-induced processes operating across different temporal scales contribute to the spatial and temporal evolution of shoreline alterations. Deltaic coasts, particularly dynamic geomorphic systems, experience continuous changes at various spatial and temporal dimensions. This investigation underscores the effectiveness of Sentinel-1 Synthetic Aperture Radar (SAR) data in assessing long-term shifts in shoreline positions, focusing on the Niger Delta region. Out of 255 images from 2015 to 2020, 36 were selected based on high tide conditions for each year. This study has pioneered a straightforward and systematic approach rooted in Geographic Information Systems (GIS). This approach offers an accessible pathway for evaluating coastal changes in regions with limited data availability. To better comprehend the heterogeneity of change processes along the shoreline and to pinpoint their causes and mechanisms, we divided the shoreline into distinct sediment cells. This division adheres to a convenient and well-established methodology. This study identifies prevailing erosion trends outweighing accretion, with specific areas showing distinct erosion (cells II, IV, VI, VII, and VIII) and accretion (cells I, III, and V) patterns. Furthermore, coastal areas near river mouths exhibit a higher susceptibility to change. This approach offers a pathway for evaluating coastal changes in data-limited regions and can establish an effective monitoring system benefiting coastal modellers, scientists, and government agencies. It lays the groundwork for comprehensive coastal zone frameworks, facilitating improved planning and management strategies.

Tidal Characteristic Analysis Utilizing Radar Tide Gauge in Cirebon Seawater

Radar-based tide gauges are one approach in measuring water level offering easier installation and maintenance. Tidal data recording that has been done commonly applies tide staff or pressure tide gauge. In this study, a radar tide gauge was installed at Cirebon port, northern part of Java island, to determine the tidal characteristics in Cirebon seawaters. Water elevation data was recorded every 15 minutes from July 2022 to November 2023. The tidal component is calculated using least squares method while the tidal type is determined using the Formzahl number. The dominant tidal component known consists of semidiurnal component i.e. M2, S2, N2, K2, 2N2; diurnal component, K1, O1, P1, Q1, J1, TAU1; and shallow water component SSA components with a height of 11.98, 5.58, 2.91, 2.11, 1.45, 11.80, 3.89, 6.11, 2.08, 1.56 and 3.11 (in cm), respectively. Tidal type in the study area is mixed type prevailing Semidiurnal. The tidal range is around 0.8-1 m high with high tide conditions at 6.00-9.00 and 18.00 - 21.00, while low tide conditions are within 11.00 - 14.00 and 01.00 - 04.00. Elevation height calculation based on datum is done by combining the tidal components. Tidal measurement data using radar can be an alternative data to support and complement data recorded in Cirebon and may become a consideration for development and other maritime activities.

Kajian Kualitas Air Laut dan Sebaran Indeks Pencemaran di Pesisir Utara Kecamatan Palang-Tuban pada Musim Kemarau

The northern coastal area of ​​Palang Sub-District is a densely populated area in the Tuban district with high differentiation of economic activities. The large population and heterogeneous community activities on the northern coastal of Palang Sub-District have the potential to become a source of pollution which results in a decrease in seawater quality. The research aim is to analyze seawater quality on the north coast of Palang Sub-District based on seawater quality parameters and the spatial distribution of the pollution index. It is hoped that this research can help local governments to monitor and control water pollution in the area. Sea water sampling was carried out in the dry season for 2 days at high and low tide conditions. This research analyzes the concentration values ​​of BOD, COD, NO3-, TSS, detergent, oil & grease, pH, temperature, and Total coliform compared to seawater quality standards of PP RI No. 22 of 2021 Appendix VIII on Marine Biota. The spatial distribution of the water quality pollution index is the result of interpolation using the Inverse Distance Weighted (IDW) method from the results of measuring test parameters. The Pearson Correlation statistical test was carried out to determine the level of correlation between the parameters selected in determining water quality. The results of the research show a decline in the quality of the northern coastal waters of Palang-Tuban District with several parameter concentration average values ​​exceeding the quality standards, namely pH = 6.9 (QS = 7.0-8.5); TSS = 29.2 ppm (QS= 20 ppm); Nitrate = 0.4 ppm (QS = 0.06 ppm), BOD5 = 54.8 ppm (QS= 20 ppm), COD = 112.5 ppm (QS= 100 ppm). The water quality status shows that the water conditions are moderately polluted (ST1A), lightly polluted (ST1B-ST5B), and good conditions (ST4C & ST5C). Controlling and reducing the pollution load entering coastal waters needs to be carried out to prevent the quality of coastal waters from decreasing further. One of them is by creating wastewater treatment at every fishing port and fish auction.

Modelling of ocean currents and distribution of total suspended solids in Citarum River estuary

The Citarum River is an important river in West Java, which empties into the Java Sea carrying large suspended sediment concentrations. The purpose of this study is to examine the interaction of current patterns and distribution of total suspended solids (TSS) in the Northwest and Southeast Monsoons using hydrodynamic Modelling. The flow model and TSS used were 2-dimensional models with the OpenFlows FLOOD software. The ocean tide model results were validated using the Root Mean Square Error (RMSE) method with a value of 0.10. The current velocity in the West and East monsoons ranges from 0.07 - 0.35 m/s. Currents flow north and northeast during high-tide conditions and move south and southwest during low-tide conditions in both seasons. The movement of TSS was influenced by the current patterns. The highest concentration of TSS is in the Northwest Monsoon at low tide, which was in the range of 560–575 mg/L. The lowest TSS concentration was in the Southeast Monsoon during high tide conditions, ranging from 80 to 120 mg/L. The high concentration of TSS in the Northwest Monsoon was influenced by higher rainfall, with an average in January and only 23.2 mm/day while in the Southeast Monsoon it is only 7.8 mm/day.

Application of Simple Refraction Correction Method for Shallow Coastal Bathymetric Mapping Based on UAV-Photogrammetry

Shallow coastal bathymetric data has an important role in various applications, especially in maritime and coastal management fields. Various survey techniques to produce such data have been carried out by several researchers, one technique that is cheap, covers the wide area, flexible, and produces high-resolution bathymetric data is UAV-photogrammetry. However, this technique is affected by refraction effects that cause the estimated depth of underwater objects to be shallower than fact, thus reducing the accuracy of the bathymetric model. Therefore, the objective of this study is to present a simple refraction correction method based on the Least-Square method. To test the reliability of the method, the accuracy of the model is compared with two other methods (without correction and using a correction factor = 1.34). In addition, the effectiveness of the method was also tested through its application in various survey conditions. Overall, the proposed method outperforms the two existing methods. It is also very effective in reducing the error value during high tide conditions by up to 70%. The height of the UAV does not significantly affect the accuracy of the correction model, so in this case it is recommended to use an altitude of 100 m for survey efficiency.

Seasonal gross primary production in response to environmental drivers from arid mangroves in the Gulf of California

Mangrove ecosystems provide multiple services, because of their Carbon (C) storage capacity they are recognized as blue carbon ecosystems. Gross Primary Productivity (GPP) is an important component of the C cycle, however is challenging to measure at multiple time and spatial scales, providing opportunity for novel and practical research using remote sensing. In northwestern Mexico mangroves find their northern most distribution in Sonora, were the North American Monsoon System that occurs from June to September is an important driver of ecosystem processes. The aim of this research was to changes of GPP at “Estero El Sargento” using remote sensing (MOD17A2H V6) and modeling (SPL4CMDL) products, and further explore environmental drivers that influence such change, for a period of three-year period (2014–2016). Our results show that in this mangrove site, GPP was not limited by precipitation, producing high values during the Pre-Monsoon season (385–490 gC m−2) than in the Monsoon season (260–311 gC m−2). Furthermore, high tide conditions, air temperature (T), and vapor pressure deficit (VPD) strongly drive GPP during the Monsoon (r2 = 0.4) and Post Monsoon (r2 = 0.6) seasonswhich was not the case for the Pre-Monsoon season. There is a clear seasonality that influences ecosystem processes, with T and VPD being the most relevant environmental drivers. The increase in T and VPD limits GPP, which is of vital importance under the current climate change conditions. This type of studies is important to the Comcaac (Seri) Nation especially with their ongoing conservation efforts.

WAVE TRANSMISSION AND DISSIPATION BY HYBRID (VEGETATED WITH MANGROVE) BREAKWATERS

In recent years a group of studies for coastal protection (Hashim and Catherine (2013), Maza et al. (2018), Tomiczek et al. (2020), among others) have been carried out to determine drag coefficients in mangrove forests due to ocean waves. Following the mangrove hybrid platform concept by Tagaki (2019), and actual projects such as the mangrove rehabilitation site in the Jakarta Fishing Port, the main objective of this study was to propose and test a hybrid structure capable of controlling wave energy via breaking and dissipation. The experimental tests focused on determining the rates of the wave energy distribution (reflection, transmission and dissipation) due to the presence of an afforested mangrove zone in the upper part of the breakwater. A fixed-bottom small-scale model was tested under normal and extreme marine regimes. The prototype dimensions of the breakwater are total height 5.70 m, crest width 10 m, seaside slope 2:1 (H:V) and leeward slope (1.5:1). The barrier is composed of a rigid bottom built of artificial elements (cubipods) and a long crown intended to be vegetated (with red mangroves, for example). The rationale behind this configuration is to provide ecosystem services by an artificially built mangrove forest protected by the rigid bottom. The experimental program consisted of 54 experiments divided into 7 groups corresponding to regular and irregular waves, mean and extreme and high and low tide conditions. Other variables of interest were the density and spatial distribution of mangroves, such as core materials.

Monitoring Water Quality in Ballona Lagoon, Los Angeles, California: Nitrate Level Fluctuation in Low and High Tide Condition

Monitoring Water Quality in Ballona Lagoon, Los Angeles, California: Nitrate Level Fluctuation in Low and High Tide Condition

ANALYSIS OF CHEMICAL CONTENTS IN RAW MATERIAL OF RICH MINERALS SEA SALT

The mineral content of seawater is a natural raw material to produce rich mineral sea salt. Rich mineral sea salt is a consumption salt with a NaCl content of <50% used to live a low sodium diet for a healthy lifestyle. In general, traditional sea salt was produced with the multistage evaporation method to obtain a NaCl content of ≥ 94.7%, whereas the production of rich mineral sea salt uses a total evaporation method and then removes the salt flower at a certain concentration to get low sodium chlorine and contain other natural minerals. This study aims to analyze the chemical content of the raw material of rich mineral sea salt. The location of seawater used as raw material for rich mineral sea salt is Camplong District, Sampang Regency. Samples were obtained from sea level with a distance of ± 400 m from the coastline and carried out during high tide conditions. The chemical analysis of seawater samples consists of Na, Mg, Ca, K, Fe, Cl− dan SO42−. The analysis method is based on the Indonesian National Standard of environmental quality test. The results of the major mineral analysis showed that the largest mineral content of seawater was calcium (Ca2+) at 492.350±10.395 mg/L and Sodium (Na+) at 482,000±1.979 mg/L. In contrast, the smallest mineral content is iron mineral (Fe2+) of < 0.08 mg/L. These results will be used for preliminary data before producing naturally rich mineral sea salt.

Relationships between Organic Matter Content in Seawater and Sediment in the East Coast of Bengkalis Island, Riau

Organic matter is one of indicators of environmental fertility in both land and aquatic ecosystem. In the coastal area, the content of organic matter in a certain amount can be useful for aquatic biota, but it can also cause a disturbance if the amount exceeds the assimilation capacity of the waters. This study aims to determine the organic matter content in the water column and sediment at high and low tide conditions in the waters of the East coast of Bengkalis Island as well as to determine their relationships. The study was carried out by survey method where samples and data were collected directly in the field and then were taken to the laboratory for further analysis. The results showed that the mean organic matter content in the seawater was lower at high tide (17.38 mg/L – 25.28 mg/L) than at low tide (29.63 mg/L – 35.55 mg/L), whilst in sediments the organic matter content at high tide conditions was also lower (2.28% - 5.37%) compared to low tide (3.46% - 8.62%). The sediment of the east coast of Bengkalis Island was dominated by mud type (53.62 - 93.94 %). The organic matter content in seawater and sediment showed a strong correlation with r value of 0.730 both during high tide (Y= -1.423 + 0.271X) and also during low tide (Y= -14.912 + 0.615X with r value of 0.844), respectively. Further study is still needed to provide a comprehensive understanding on the sustainable environmental condition of the east coast of Bengkalis Island as it is one of the important fishing ground.

Factors Affecting Water Quality and Surface Sediment at the Port of Tanjung Emas Semarang during the East Asian Monsoon

Port plays an important role in provisioning commodity needs for the society in a region. Port of Tanjung Emas Semarang (PTES) is the major port on the north coast of Java Island and serves as a port for liquid and solid goods, passengers, and fuel. This descriptive research applied a random sampling technique whose samples were taken from the port basin and control station. The research was carried out at ten stations at both high and low tides during the East Asian Monsoon. This research was aimed: a) to test the correlation of physical-chemical parameters at both high and low tide using Pearson correlation, b) to test the correlation of heavy metals (Pb, Cd, Cu, Zn) in seawater and sediment at both high and low tide, c) to perform cluster analysis on the stations at both high and low tide, d) to determine port waters Index of Pollution (IP), e) to identify factors that affect the port water pollution using PCA (Principal Component Analysis). The findings showed that in waters, Pb was found as the most dominant pollutant at both high and low tides (Pb>Cd>Cu>Zn). In sediment, Zn was the most dominant of all (Zn>Cu>Pb>Cd). Igeo value indicated that the contamination level in the sediment was moderate. Heavy metals accumulate differently at high and low tides, at low tide heavy metals accumulate on the outside toward the port, while at high tide they accumulate at the mouth of the Kali Baru River. This is caused by differences in the flow of tidal or ebb currents. All research stations were classified as having heavy pollution. Both control stations (Siangker and BKT estuaries) showed differences with stations inside the port, including physico-chemical variables, namely: a) TSS, phosphate, nitrate during high tide conditions; b) pH, DO, TDS, turbidity, TSS at low tide.

Wave overtopping at near-vertical seawalls: Influence of foreshore evolution during storms

This work presents the results of an investigation on how wave overtopping at a near-vertical seawall at the back of a sandy foreshore is influenced by sequences of erosive storms. The experiments were carried out in the Large Wave Flume (GWK) at Leibniz University, Hannover (Germany). The tested layout consisted of a near-vertical 10/1 seawall and a sandy foreshore with an initial 1/15 slope. Three sequences of idealised erosive storms were simulated. Within each storm both the incident wave conditions and still water level were varied in time to represent high and low tide conditions. Each sequence started from a 1/15 configuration and the beach was not restored in between storms. The measurements included waves, beach profile, wave overtopping volumes. The profile of the beach was measured after each sea state tested.Wave overtopping at each stage of the tested storms was significantly influenced by bed changes. This was linked to the measured evolution of the beach. Measurements showed that a barred profile developed quickly at the start of each sequence, and scour developed at the toe of the structure during high water level conditions, while accretion or partial backfilling developed during low water level conditions. Due to these processes, the position of a sea state in the tested sequence is shown to be an important factor in determining the wave overtopping volume. Remarkably, when a weaker idealised storm followed a more energetic one, nearly the same level of overtopping was recorded. This is explained by the foreshore erosion, leading to increased water depths and wave heights at the toe of the structure. This finding allows to quantify and to explain the variability of wave overtopping in storms following one another at intervals shorter than the recovery time of the foreshore.

Osmotik Word Level Teredo navalis Linnaeus 1758 in the Mangrove Root Habitat in East Halmahera, Indonesia

This study aims to analyze the osmotic work level and pattern of osmoregulation at mollusc Teredo navalis Linnaeus 1758 in mangrove root habitats from different salinities. Case study was performed with the purposive sampling method. The research data were analyzed descriptively and quantitatively. The sampling technique is based on tidal conditions of seawater. Two locations was designated, namely station I and II in the north and the south respectively. Teredo navalis samples were taken from 2 types of mangrove roots. Analysis of the level of osmotic work using Automatic Micro Osmometer Roebling Type 13/13 DR. Salinity was measured using a refractometer. The results showed that the osmotic level of Teredo navalis in the root habitat of Rhizophora sp. and Avicennia sp. at high and low tide conditions varied, specifically 523 mOsm/l H2O, 123 mOsm/l H2O, and 32 mOsm/l H2O. This varying level of osmotic action results in three patterns of osmoregulation, viz. hyperosmotic, hypoosmotic, and isosmotic. The highest salinity was found in Avicennia sp. mangrove at station II and the lowest in Rhizophora sp. at low tide at station II, with the value was 31‰ and 10‰ respectively. Differences in salinity determine the osmoregulation pattern of Teredo navalis L in different habitats.

Improvement of Dissolved Oxygen in Perlis River based on Various Aeration Systems

Water pollution is closely related to the Water Quality Index (WQI). One of the parameters in classifying WQI is dissolved oxygen (DO) that can be improved by introducing the surface and subsurface aerations. Herein, the Perlis River’s water quality was investigated by evaluating the DO’s improvement based on various aeration systems. The changes of DO (mg/L) and DO improvement (%) were evaluated during both low and high tide conditions. A total of 9 sets of data collection had been studied by comparing base DO (without running of aeration) and measured DO (with running of aeration) of river. The DO sensor was used to measure the changes of DO in the aeration measurement system. Results found that the DO improvement managed to achieve 74.89%, 10.18%, 35.58%, and 52.45% for water jet, air compressor, commercial venturi, and DIY venturi, respectively. Besides, different behaviour of DO’s improvement was observed during low and high tide conditions.

Water Quality and Its Relationship to Tides and Ebbs on the Sail River, Pekanbaru City, Riau Province, Indonesia

The Sail River flows through the Pekanbaru City area which functions as a hydrological reservoir and main drainage channel. This river is affected by tides. Development along the Sail River Basin may affects the aquatic ecosystems. The research was conducted to determine the quality of the Sail River water and how it relates to the tides. Sampling was carried out two times during June-July 2021 in high and low tide conditions. The water quality parameters measured were temperature, TSS, pH, dissolved oxygen, BOD, COD, oil and fat, and Pb metal. Results showed that the temperature, COD, and Pb were significantly different at high tide and low tide conditions. On the other hand, during low and high tides condition, the value of TSS, pH, dissolved oxygen, BOD, oil, and fat were not significantly different. Dissolved oxygen levels during high and low tide ranged from 2.00 -3.00 mg/l and 1.00 -1.70 mg/l respectively. The Pb content during high and low tides ranged from 0.12-0.16 mg/l. In the present study, the values of dissolved oxygen and Pb content does not meet the water quality standards of Government Regulation No. 22/2021 (Class III).

Floating macro marine debris trends in the Banda Aceh estuary environment

Banda Aceh is a city at the western tip of Indonesia and is one of the provinces that has a coastal area that can contribute plastic waste to the sea. The source of plastic waste comes from land and human activities which are then carried through river mouths to end up in the sea. The purpose of this study was to determine the characteristics of marine debris at the mouth of the Krueng Aceh River. Data collection is determined based on the time of the tide. The research was carried out using a boat mounted with a marine debris trap. The results showed that plastic waste dominated the mouth of the river by 90 percent, both during high and low tide conditions. There is a difference in the amount of waste that accumulates at high and low tide in the Krueng Aceh estuary.