Tidal Patterns Research Articles

Crosstalk between the circatidal and circadian clocks mediates behavioral adaptation to tidal patterns.

The ability to anticipate tides is critical for a wide range of marine organisms, but this task is complicated by the diversity of tidal patterns on Earth. Previous findings suggest that organisms whose geographic range spans multiple types of tidal cycles can produce distinct patterns of rhythmic behavior that correspond to the tidal cycles they experience. How this behavioral plasticity is achieved, however, is unclear. Here, we show that Parhyale hawaiensis adapts its rhythmic behavior to various naturally occurring tidal regimens through the plastic contribution of its circatidal and circadian clocks. After entrainment to a tidal cycle that deviated only mildly from a regular 12.4h tidal cycle, animals exhibited strong circatidal rhythms. By contrast, following entrainment to more irregularly spaced tides or to tides that occurred every 24.8 h, a significant fraction of animals instead synchronized to the light/dark (LD) cycle and exhibited circadian behavior, while others showed rhythmic behavior with both circatidal and circadian traits. We also show that the circatidal clock, while able to entrain to various naturally occurring tidal patterns, does not entrain to an unnatural one. We propose that Parhyale hawaiensis's ecological success around the world relies in part on the plastic interactions between the circatidal and circadian clocks, which shape its rhythmic behavior appropriately according to tidal patterns.

Exploring environmental condition of silvofishery pond to support the sustainability of mangrove management in Berau Regency, Indonesia

The integration of mangrove management with aquaculture, termed the silvofishery pond system, has been implemented in Berau Regency, East Kalimantan Province, Indonesia. A detailed survey was conducted to assess the features of mangrove terrain surrounding silvofishery ponds, aiming to enhance the productive and sustainable management of these mangrove areas in Berau Regency. This survey focused on various land characteristics such as topography, tidal patterns, water quality, soil properties, climate, and the state of mangrove vegetation. The health of mangrove vegetation was assessed by calculating the Important Value Index (IVI) across different growth stages: trees, saplings, and seedlings. The findings reveal that the mangrove adjacent to the silvofishery ponds in Berau Regency are home to 14 species from 13 genera and 10 families. Rhizophora mucronata displayed the highest IVI scores across all growth stages: 75.17% for trees, 93.14% for saplings, and 66.98% for seedlings, the latter shared with Rhizophora apiculata. Soil quality emerged as a critical limiting factor for land use in silvofishery ponds, particularly due to high potential acidity (low pH) and low nitrogen (N) content. To enhance soil quality, it is recommended that soil management practices such as remediation (via drying, submerging, flushing, or liming) and N supplementation through fertilization be employed. Furthermore, given the sparse mangrove vegetation density at the tree level (1,012 trees/ha), efforts to promote natural mangrove regeneration and prevent deforestation and degradation are advised. Considering the unique characteristics of the mangroves, the implementation of the komplangan model—a silvofishery approach that segregates mangroves restoration pond from grow-out ponds—is recommended to boost productivity and ensure sustainability in the coastal region of Berau.

Development and prediction of scour around offshore wind turbine monopile foundations in ebb and flow tides

Monopile foundations are commonly used to support offshore wind turbines (OWTs) in nearshore shallow waters, where the periodic ebb and flow of tides can cause severe seabed erosion around these foundations. Accurately predicting the progression of scour depth under these tidal conditions is crucial for the safety of OWTs. While a few empirical formulas for equilibrium scour depth in periodic tides have been proposed, they often overlook the backfilling effects during their derivation. Consequently, these methods fail to predict the progression of scour depth characterized by recurring scouring and backfilling processes. In this study, the scour progression under different tidal patterns, including square tides, symmetrical sinusoidal tides, and asymmetrical sinusoidal tides with various periods, is investigated using numerical methods. It is indicated by the results that deeper scour depths are produced by symmetrical tides compared to asymmetrical tides, while the highest scour depth is observed under square tides, potentially slightly exceeding that under unidirectional currents. Additionally, asymmetric scour depths at the front and back sides of the pile can result from the asymmetry of tides. Although scour progression is affected by tide periods, their impact on the equilibrium scour depth is limited. Furthermore, a new concept called normalized cumulative effective flow intensity is introduced, which plays a primary role in governing equilibrium scour depth. Based on this concept, prediction methods for both equilibrium scour depth and scour progression under sinusoidal tides, which closely resemble natural tidal patterns, are proposed. The accuracy of these methods is validated by experimental data from previous studies. These findings not only provide a method to optimize the design of monopile burial depth but also aid in the development of appropriate maintenance measures to prevent scour-induced damage to OWT foundations over their long lifespans.

The secret lives of wedgefish: first insights into fine-scale behaviour and movement ecology of a globally imperilled ray

Wedgefishes have recently been recognised as one of the most imperilled marine fish families worldwide. However, many knowledge gaps about their biology and ecology hinder conservation efforts. Here we used a combination of acoustic telemetry and acceleration datalogger technology to gain fundamental insights into the fine-scale behaviour, habitat use, size of activity spaces, and residency of adult female bottlenose wedgefish (Rhynchobatus australiae) in the Ningaloo region of northwestern Australia. Acoustic tracking data over one year demonstrated that female bottlenose wedgefish continuously resided in a relatively small area of a productive coral reef lagoon. Acceleration data revealed that bottlenose wedgefish were nocturnal, with time of day having a greater influence on activity than tidal patterns. Bottlenose wedgefish also increased activity with seasonally increasing temperatures. We identified several discrete behavioural signatures in the acceleration data, inferred to correspond to chafing, settling/burying behaviour, foraging behaviour, and escape behaviour, based on their kinematics. Further observations are required to confirm these behaviours with certainty. Additionally, according to datalogger and acoustic data, tagged bottlenose wedgefish rarely inhabited areas greater than 2 m deep. Together, these first insights into behaviour and habitat use of adult female bottlenose wedgefish highlight the importance of nearshore habitats for this species and indicate that they may be highly resident to specific areas. Our findings provide important insight into the conservation of bottlenose wedgefish in northwestern Australia, including potential effectiveness of protected areas and interactions with specific anthropogenic threats such as shoreline development and recreational beach fishing.

Optimal distributed energy scheduling for port microgrid system considering the coupling of renewable energy and demand

The increased uptake of distributed renewable energy in port areas is facilitating the electrification and net zero transition of marine ports. Effective operation that considers unique characteristics of the port is critical to minimize the operating cost in the port microgrid (PMG). In this paper, we propose a joint scheduling method that considers the impact of tidal patterns on the period and intensity of port operations. The method takes advantage of the strong correlations between renewable energy (solar, wind and tidal) and multi-class load to support the PMG operator in determining the most cost-effective scheduling of energy supply and flexible loads during port activities. Additionally, the traditional centralized operation is vulnerable to local failures, and distributed operation for hundreds of energy units will result in significant computational burden, neither of which is suitable for the PMG operation. Our work decouples the PMG system based on the port functions and thus decomposes the PMG operation into a few subproblems. Then, we hierarchically solve the primal and dual problems by a distributed algorithm. Simulation results illustrate the benefits of tidal energy in the renewable generation mix. Furthermore, the proposed method achieves cost reductions of 12.4% and 21.7% under two different tidal patterns.

Pasang Surut dan Arus di Muara Sungai Kapuas Sepok Pangkalan, Teluk Bengkolan, Kalimantan Barat

Tides and currents influence the dynamics and biochemical circulation in a bay or estuary. This research aims to conduct an initial study of tides and currents in Bengkolan Bay, which is home to the mangrove ecosystem in West Kalimantan Province. Elevation and current measurements were carried out for 15 days at the mouth of the Kapuas River Sepok Pangkalan (north side of Bengkolan Bay) using tidal palms and drifters. The measurement results show that the pattern of water surface movement and currents at the research location is very dependent on ocean tidal patterns. Diurnal tides play a very large role (10 times) compared to semidiurnal tides. This big role causes the type of tides in Bengkolan Bay to be diurnal. Although semidiurnal tides have a small contribution, shallow water tidal constituent are actually caused by semidiurnal tidal energy dissipation.

The impact of sexual reproduction-induced vertical migration on the complexity of harmful algal blooms in Heterosigma akashiwo

Vertical migration behaviour, which is integral to marine energy circulation, is a prevalent trait among marine organisms. However, the behaviour of phytoplankton, particularly beyond diel vertical migration (DVM), remain underexplored compared to groups like zooplankton. Through the lens of the harmful alga Heterosigma akashiwo, which exhibits active vertical migrations and unique fluctuating bloom dynamics, this study aimed to explore the ecological intricacies and diverse benefits of phytoplankton vertical migration behaviours. During the bloom period of H. akashiwo, we unexpectedly observed a dense concentration of cells at bottom layer during daytime. This phase coincided with the emergence of cells related to this species' sexual reproduction. Laboratory experiments further showed an elevated frequency of sexual reproduction in the cell populations that migrated to deeper depths compared to those at the surface. This finding implies a connection between dense bottom accumulation (BA) and the life cycle transitions of the species. This BA phase persisted for two days, after which the populations returned to their standard DVM behaviour, providing insight into the unique fluctuating bloom dynamics of H. akashiwo. Our study suggests that phytoplankton vertical migrations are not strictly dictated by DVM, revealing diverse vertical migration behaviours that may contribute to the complexity of harmful algal bloom patterns.

Enhancing flow rate prediction of the Chao Phraya River Basin using SWAT–LSTM model coupling

Study regionChao Phraya River Basin—a major river with unique characteristics located in Thailand. Study focusThis study sought to simulate the flow rates in the Chao Phraya River Basin, which is a tidal river that poses challenges to traditional modeling approaches. The soil and water assessment tool (SWAT) is a hydrological model extensively employed for simulating flow rates. However, limitations arise in applying the SWAT model to the Chao Phraya River Basin due to its tidal nature, resulting in an unsatisfactory model performance. To address this, a long short-term memory (LSTM) model, i.e., the SWAT–LSTM model, was introduced to complement the SWAT model. New hydrological insights for the RegionThe collaborative coupling of hydrological information derived from the SWAT and LSTM notably enhanced the model performance. This improvement was assessed using the Nash-Sutcliffe efficiency (NSE), demonstrating an increase from 0.13 to 0.72. The incorporation of topographic static data in the coupling model was also investigated to provide the basic characteristics of the basin to the model. The results yielded an NSE exceeding 0.79. The shoreline water level was identified as a crucial input feature for indicating tidal patterns. The findings highlight the effectiveness of coupling the SWAT with LSTM for predicting tidal river flow rates, implying their applicability in similar scenarios across different basins.

Study on the Influence of Salinity, TDS, GWL and Land Use in the Coastal Region of Kebumen Regency with a Statistical Approach

This study investigates the impact of salinity levels, total dissolved solids (TDS), groundwater levels (GWL), and land use patterns in the coastal region of Kebumen Regency, employing a statistical approach. Coastal areas are often vulnerable to salinity variations, which can significantly affect the surrounding ecosystems and land utilization. The research aims to discern the correlation between TDS, salinity levels, GWL and land use practices in this specific region, employing statistical analysis as a means of quantifying and understanding these relationships. Total dissolved solids (TDS) represent the concentration of inorganic salts, minerals, and ions in water bodies and play a crucial role in the overall water quality of coastal areas. Salinity levels, on the other hand, directly affect TDS and are influenced by factors such as tidal patterns and freshwater input. Groundwater levels affect salinity and TDS. Land use practices, including agricultural, residential, and industrial activities, profoundly impact coastal ecosystems and are often influenced by salinity levels. This study utilizes statistical methods to analyze the complex interplay between TDS, salinity, GWL, and land use in the Kebumen Regency coastal region. By examining data related to TDS, salinity, GWL, and land utilization, this research seeks to contribute valuable insights into the sustainable management of coastal environments. The findings of this study are expected to inform decision-making processes for the benefit of local communities and ecosystems, guiding future policies and practices for the preservation and balanced development of coastal areas in Kebumen Regency

Development and Field Testing of the Technical Implementation Unit for Lowland Automatic Water Level Recorder (AWLR BTR) for Water Level Measurement in Jejangkit Lowland Irrigation Area, South Kalimantan

Observation of water levels using tide gauge is typically conducted by designated personnel or observers. However, its on-field implementation is deemed to be less effective due to the relatively low accuracy of readings. Additionally, hourly water level readings are necessary to generate detailed tidal patterns. Hence, Automatic Water Level Recorder (AWLR) plays a crucial role as an alternative to tide gauge. The utilization of AWLR is considered more practical, yielding more accurate reading data. Furthermore, readings can be conducted continuously, ensuring data acquisition in all conditions. The development of the AWLR BTR system involved literature reviews, software development, hardware assembly, device testing, field trials, and data comparison with the Valeport Tide Gauge. Field trials were conducted at DIR Jejangkit, South Kalimantan. The conducted trials involved operating the AWLR BTR and comparing it with the Valeport AWLR data for validation. Through calculations, the comparison of data between AWLR BTR and AWLR Valeport demonstrates similar water level values, where the average value from AWLR BTR data is 39,69 and Valeport is 39,55. Meanwhile, the Pearson correlation coefficient between the water levels of AWLR BTR and AWLR Valeport is found to be 0,9976, indicating a strong positive correlation between these two data variables.

PENGEMBANGAN ARDUINO DATA LOGGER MENGGUNAKAN TDR H3CR UNTUK SIMULATOR PASANG SURUT

Tides, crucial natural phenomena, significantly impact various aspects of life. Recognizing their importance, this study presents the development of a tidal simulator leveraging Arduino data logging and TDR H3CR technology. The simulator aims to mimic tidal processes, crucial for educational and research purposes. Traditional methods of acquiring tidal data are time-consuming and expensive. Thus, a simulator proves advantageous in reducing research time and costs. At Raja Ali Haji Maritime University, a tidal simulation model exists but with manual operation and limited data capture capabilities. To address these limitations, this study designed a new simulator utilizing H3CR, DC Water Pump, and DC Selenoid Valve for automated tidal circulation. The research method involved system design, component integration, and laboratory experiments. Calibration of components like the ultrasonic sensor HC-SR04 ensured accurate data collection. The overall system experiment validated the simulator's functionality, demonstrating its ability to replicate tidal processes effectively. Results indicated that the simulator produced tidal patterns resembling sinusoidal waves, with slight noise attributed to sensor limitations. The designed simulator serves as an efficient learning tool for understanding tidal phenomena, exhibiting comparable results to natural tidal data. This study contributes to the advancement of tidal simulation technology, offering a cost-effective and accessible solution for educational and research purposes.

Characteristics of sea surface current during the second transitional monsoon in the Bangka strait, North Sulawesi, Indonesia

Understanding the dynamics of surface currents in the Bangka Strait is crucial for various maritime and coastal activities. This strait connects Likupang, a super-priority tourism destination, with other islands in North Sulawesi. These activities include navigation safety, inter-island transportation, fisheries, search and rescue operations, and marine pollution control. This study investigated the characteristics of currents in the strait using a hydrodynamic model called Delft3D. The result revealed that the currents exhibit a tidal pattern, with dominant westward flow during floods and eastward flow during ebb. Maximum sea current velocity during spring tide in the second transition monsoon occurred in September 2022, with an average speed of 102.67 cm/s. Current ellipse analysis confirmed the tidal type of the currents.

Influence of Fluvial Discharges and Tides on the Salt Wedge Position of a Microtidal Estuary: Magdalena River

The linkage between the salt wedge, tidal patterns, and the Magdalena River discharge is established by assessing the ensuing parameters: stratification (ϵ), buoyancy frequency (β), potential energy anomaly (φ), Richardson number by layers (RL), and bottom turbulent energy production (P). The salinity, temperature, density, and water velocity data utilized were derived from MOHID 3D, a previously tailored and validated model for the Magdalena River estuary. To grasp the dynamics of the river, a flow regime analysis was conducted during both the wet and dry climatic seasons of the Colombian Caribbean. The utilization of this model aimed to delineate the estuary’s spatial reach, considering flow rates spanning from 2000 to 6500 m3/s across two tidal cycles. This approach facilitates the prediction of the position, stability, and stratification degree of the salt front. Among the conclusions drawn, it is highlighted that: 1. The river flow serves as the principal conditioning agent for the system, inducing a strong estuary response to weather stations; 2. The extent of wedge intrusion and the river discharge exhibit a non-linear, inversely correlation; 3. Tidal waves cause differences of up to 1000 m in the horizontal extent of the wedge; 4. Widespread channel erosion occurs during the rainy season when the salt intrusion does not exceed 2 km; 5. Flocculation processes intensify during the transition between the dry and wet seasons; 6. The stability of the salt layering and the consolidation of the FSI–TMZ are contingent upon the geometric attributes of the channel.

Mangrove density and delta formation in Segara Anakan Lagoon as an impact of the riverine sedimentation rate

Abstract. Cahyo TN, Hartoko A, Muskananfola MR, Haeruddin, Hilmi E. 2024. Mangrove density and delta formation in Segara Anakan Lagoon as an impact of the riverine sedimentation rate. Biodiversitas 25: 1276-1285. Segara Anakan Lagoon (SAL) is in Southwestern of Central Java Province, Indonesia. The Western Part of SAL (WP-SAL) gets its sediment load from the Citanduy River. This research aimed to determine the temporal pattern of the shoreline, water body area, depth, delta formation, and mangrove density at WP-SAL. Shoreline data were extracted from a base map and the satellite imagery. Overlapping analysis of several shorelines and depth maps showed different results in terms of values or patterns. The western part of SAL had silted up and reached more than 85% in 161 years. The sediment accretion impacted the shoreline (between 177 ha yr-1 in 1999-2003), and the average decrease of the water bodies speed was 61 ha yr-1. The Pelawangan Barat waters (PBW) and the main lagoon had a decreasing depth because of the sediment deposits. The sedimentation also greatly impacts mangrove species distribution, clustering and association, and density and mangrove affinity. Mangrove density growth-based and the delta formation were formed and developed following the tidal pattern during floods and ebbs. It can be used to predict the future morphology of WP-SAL. The WP-SAL will be sediment filled and left the waterways channels, it was reached within 13.6 years from 2018, which would be in 2032.

Tidal Analysis and Implementasion of an Internet of Things (IoT) Sea Level Monitoring Device in Coastal Region

Monitoring the sea level is crucial for the protection of coastal communities and infrastructure. Instruments that can record and transmit the sea level in real time are essential for preventing potential disasters. This study presents the design, construction, and evaluation of an instrument for measuring sea level using a pressure sensor, a microcontroller, and a GSM module. The sea level analyzed using T Tide analysis. The instrument's accuracy was established through a calibration process, resulting in a sensor reading accuracy of 96.76% and a low root mean square error of 3.24 cm. The linear regression model confirmed the strong correlation between sensor readings and actual water depth, with a coefficient of determination of 0.999. The instrument achieved an accuracy of 96.76% and a low root mean square error of 3.24 cm. Field testing over three days showed the instrument's reliability in measuring sea levels, with an accuracy rate of 91.93% and an root mean square error of 8.07 cm with a packet loss of 7.86%. The study area had mixed semidiurnal characteristics, with water levels ranging from 60.1 cm to 209.55 cm. Significant constituents such as principal lunar diurnal constituent (K1) and Principal lunar semidiurnal (M2) dominate the tidal patterns, each with distinct frequencies, amplitudes, and signal-to-noise ratios. This research provides a precise and cost-effective instrument for measuring water depth, which is suitable for coastal management, environmental monitoring, and scientific investigation.

Verification of tidal trends in Cananeia (SP) and Santos (SP)

Recent studies indicate an imminent global rise in mean sea level. However, comprehending variations in tidal patterns is imperative before analyzing the scenario of extreme events, typically associated with the combination of high tides and intense meteorological influences. This study presents local trends in sea level, amplitude, and phase of the two main tidal components in Cananeia (SP) and Santos (SP), utilizing tide gauge data from records of sufficient length to avoid the need for nodal correction in the tide components. Using more up-to-date tide gauge data allowed the investigation of observed trends. Long-term tidal data series revealed an upward trend in mean level of approximately 4,324 mm/year in Cananeia and 0,538 mm/year in Santos. Both locations were affected by human activities along their estuaries, with Santos experiencing significant variations in the amplitude and phase values of the tidal constituents annually.

TEMPORAL PATTERN OF AEDES SOLLICITANS AND AEDES TAENIORHYNCHUS IN AN INTERTIDAL WETLAND SYSTEM, NORTHEASTERN FLORIDA: A LITERATURE REVIEW

Temporal and spatial patterns of mosquito species distributions are influenced by weather conditions and climate, changes in water quality, and many other factors. Aedes taeniorhynchus and Aedes sollicitans are common salt marsh mosquitoes that cause many nuisance problems for human populations. St. Johns County (north-eastern Florida) has, over the past decades, been one of the fastest growing counties in the U.S.A. This is related to changes in land use and land cover, and local climate variations. It has been recently noticed that two species, Ae. taeniorhynchus and Ae. sollicitans, switch their temporal pattern in St. Johns County. To explore factors influencing potential changes between the temporal distribution of the two species of salt marsh mosquitoes, a literature search was conducted. Based on the literature, there are many factors influencing the potential species switch or temporal patterns of the two species. These include meteorological and tidal patterns as well as land use and land cover changes. The results of the literature analysis indicate that the switch and change in temporal pattern between the two species needs to be further explored, especially with respect to temperature, tidal flooding, water quality (especially salinity), sea level rise and land use/cover.

Diel and tidal cycles in summer habitat use by St. Lawrence Estuary Belugas through a pluriannual passive acoustics monitoring network

A network of 10 passive acoustics monitoring stations is used to examine patterns of habitat use at diel and tidal timescales by St. Lawrence Estuary beluga during summer 2018 and 2019. An occurrence index of vocal activity within the preferred frequency band of communications for belugas is used as a proxy for presence at the stations. Diel and tidal patterns of activity and mean residency time are extracted from statistics of hourly occurrence timeseries at the 10 stations. Spatially, diel and tidal occurrence levels of beluga communication sounds show patterns of variation that differ among the stations, but tend to be locally stable from one summer to next. Mean residency time at the 9 Estuary stations vary between 4 to 15 hours and most have an occurrence maximum during early morning. The Saguenay fjord station shows a distinct profile, with a mean residency time of 30 hours and high level of activity at evening and night. This work underlines the ability of passive acoustics, through continuous monitoring at high spatio-temporal resolution, to reveal the complexity of the habitat use by this confined marine mammal population and understand its responses to diel and tidal forcings of the ecosystem.

Numerical simulation study on hydrodynamics of Xisha Islands and Reefs driven by tide levels, sea surface heights and ocean currents

This study employs the FVCOM numerical model to investigate tide flow and hydrodynamics in the marine region surrounding Yongxing Island. The HYCOM model is utilized to obtain sea surface height and ocean current data at the boundary. Additionally, the astronomical tide level predicted by the TPXO9 global tide model is incorporated into the analysis. Through numerical simulation research, the paper aims to examine the aforementioned phenomena. The findings indicate a strong concurrence between the outcomes of the FVCOM numerical simulation and the observed data. The winter and summer tidal patterns in the seas around Yongxing Island exhibit a high degree of similarity. In winter, the current speed of rapid flood and ebb process, exhibits somewhat higher than that in summer. The maximum current speed occurs in the northern marine region of Yongxing Island, during the rapid flood process, whereas it occurs in the northwest marine region of Yongxing Island during the rapid ebb process.

Hybrid Intelligence for Marine Biodiversity: Integrating Citizen Science with AI for Enhanced Intertidal Conservation Efforts at Cape Santiago, Taiwan

Marine biodiversity underpins the formation of marine protected areas (MPAs), necessitating detailed surveys to account for the dynamic temporal and spatial distribution of species influenced by tidal patterns and microhabitats. The reef rock intertidal zones adjacent to urban centers, such as Taiwan’s Cape Santiago, exhibit significant biodiversity, yet they are increasingly threatened by tourism-related activities. This study introduces an artificial intelligence (AI)-empowered citizen science (CS) approach within the local community to address these challenges. By integrating CS with AI, we establish a hybrid intelligence (HI) system that conducts in situ biological surveys and educational programs focused on reef ecological conservation. This initiative not only facilitates the collective gathering and AI-assisted analysis of critical data but also uses machine-learning outputs to gauge data quality, thus informing subsequent data collection and refinement strategies. The resulting collectivity and iterative enhancement foster a mutual and continuous HI learning environment. Our HI model proves instrumental in fostering community engagement and public involvement in CS endeavors, cultivating the skills necessary for documenting rocky intertidal biodiversity shifts. These efforts are pivotal for informing the design and governance of future MPAs, ensuring their efficacy and sustainability in marine conservation.