Hardgrounds Research Articles

Quantifying head and withers movement asymmetry in sound and naturally forelimb lame horses trotting on a circle on hard and soft surfaces

AbstractBackgroundReliable lameness thresholds for vertical head displacement for trotting on a circular path and on different surfaces have yet to be defined. Withers movement in lame horses could help improve the diagnostic accuracy of sensor technology.ObjectivesTo define head movement lameness threshold ranges and describe the relationship between head and withers movement during trotting under different circumstances in sound and forelimb lame horses.Study designRetrospective analysis of clinical data and comparison with control group.MethodsFifty‐five sound and thirty‐four naturally lame horses were trotted under field conditions on a hard surface on a straight line and on both directions on soft and hard surfaces. Movement asymmetry was analysed by measuring differences in displacement minima for head and withers using an inertial measurement unit sensor‐based gait analysis system. Receiver operating characteristic (ROC) analysis was performed to define threshold ranges. Relationships between head and withers data were identified by calculating the correlation with linear regression analysis.ResultsEstimated lameness threshold values for vertical head movement asymmetry ranged from 11.5 to 12.5 mm. On both surfaces, a head movement asymmetry threshold range from 24.5 to 26.5 mm could be found for the circle. Lame horses showed significant correlations between head and withers movement on hard ground straight line (R2 0.714, p < 0.001) and inner leg lame horses on the lunge (R2 0.915, p < 0.001).Main limitationsDifferent sources of lameness were not distinguished. Radius and speed during lungeing could not be perfectly controlled. Inclusion in the sound group was based on a subjective examination by one clinician and in the lame group two clinicians subjectively determined inner and outer leg lameness creating an extra amount of uncertainty.ConclusionsLameness thresholds for quantifying head movement asymmetry on the lunge were proposed. A significant correlation was observed between head and withers movement asymmetry under several conditions.

Robotic feet modeled after ungulates improve locomotion on soft wet grounds

Locomotion on soft yielding grounds is more complicated and energetically demanding than on hard ground. Wet soft ground (such as mud or snow) is a particularly difficult substance because it dissipates energy when stepping and resists extrusion of the foot. Sinkage in mud forces walkers to make higher steps, thus, to spend more energy. Yet wet yielding terrains are part of the habitat of numerous even-toed ungulates (large mammals with split hooves). We hypothesized that split hooves provide an advantage on wet grounds and investigated the behavior of moose legs on a test rig. We found that split hooves of a moose reduce suction force at extrusion but could not find conclusive evidence that the hoof reduces sinkage. We then continued by designing artificial feet equipped with split-hoof-inspired protuberances and testing them under different conditions. These bio-inspired feet demonstrate an anisotropic behavior enabling reduction of sinkage depth up to 46.3%, suction force by 47.6%, and energy cost of stepping on mud by up to 70.4%. Finally, we mounted these artificial feet on a Go1 quadruped robot moving in mud and observed 38.7% reduction of the mechanical cost of transport and 55.0% increase of speed. Those results help us understand the physics of mud locomotion of animals and design better robots moving on wet terrains. We did not find any disadvantages of the split-hooves-inspired design on hard ground, which suggests that redesigning the feet of quadruped robots improves their overall versatility and efficiency on natural terrains.

Evaluasi Kapasitas Pondasi Tiang Pancang Menggunakan Data Kalendering Pada ABT1-ABT 2 Underpass STA 2+550 Binjai-Stabat

A pile foundation is needed to support the building, if the hard soil layer is very deep. The pile foundation functions to move or transfer the load above it (superstructure) to deeper soil layers. For this purpose, it is necessary to evaluate the capacity of a single pile and the capacity of a group of piles that are capable of carrying the load above them. Evaluation of pile capacity requires calendaring data in the form of field driving data which is carried out when the pile reaches hard ground with penetration and rebound values taken for 10 strokes. Based on calendaring data, single pole capacity analysis was carried out using several methods. The results of the bearing capacity analysis from one method are compared with other methods and their relationship with pile penetration. The capacity value of the pile group is calculated based on the pile efficiency. Most of the pile capacities show almost the same single pile capacity values, such as the Hiley method (666.16 kN), Navy-Mckay (752.14 kN), Janbu (440.91 kN), except that the Sanders method gives results that are much different from The value of other methods is 1138.28 kN, this could be because this method only considers the weight of the pile. The relationship between single pile capacity and pile penetration shows that the smaller the pile penetration value, the greater the pile capacity. This is obtained in all methods used, although with different calculation methods and method.

Muscular Activation Levels of Subjects with Low Medial Longitudinal Arch During Single-Leg Squat and Single-Leg Balancing Exercises on Surfaces of Different Hardness

Background: The primary aim of this study is to examine the effect of the stiffness of rehabilitation material on muscle activation in individuals with low medial longitudinal arch. The secondary aim is to compare the effects of single-leg balancing and single-leg squat exercises on the activation of the muscles around the ankle in the same individuals. Methods: Twelve individuals with low medial longitudinal arch and 18 healthy control participants were included. Participants were asked to perform the single-leg balance and single-leg squat exercises on Theraband stability trainers of three different stiffness levels. Activation of the peroneus longus, peroneus brevis, tibialis anterior, medial and lateral gastrocnemius muscles during exercises was evaluated by surface electromyography. Results: The single-leg balancing exercise performed on soft and very soft ground was more effective than single-leg squat in increasing the activation of the lateral gastrocnemius muscle in participants with a low medial longitudinal arch. It was determined that performing single-leg squat exercise on a very soft surface instead of hard ground caused more muscular activation in the peroneus brevis, tibialis anterior, and medial gastrocnemius in the same individuals. Conclusions: The exercise progression to be applied on different surfaces to increase the activation of the muscles around the ankle in individuals with a low medial longitudinal arch and in healthy individuals without a low medial longitudinal arch was different.

The Impact of Eight Weeks of Aquatic Plyometric Training on the Explosive and Agility Capabilities of Swimmers

The objective of this study is to examine the impact of eight weeks of aquatic plyometric training on the explosive and agility abilities of swimmers. The following keywords were used: The objective of this study was to ascertain the impact of aquatic plyometric training (APT) on explosive power and agility. A training program incorporating APT was implemented on a sample of 20 swimmers. The findings revealed that utilizing APT at a depth up to the pelvis for 8 weeks and 3 times a week led to statistically significant differences and improvements in explosive power and agility. The effect size values for the two variables were 0.97 and 0.97, respectively. The researcher recommended the use of APT as a viable alternative to plyometric exercises on hard ground for enhancing explosive power and agility, while also reducing the risk of muscle and tendon injuries.

Inertial Sensor-Based Quantification of Movement Symmetry in Trotting Warmblood Show-Jumping Horses after "Limb-by-Limb" Re-Shoeing of Forelimbs with Rolled Rocker Shoes.

Hoof care providers are pivotal for implementing biomechanical optimizations of the musculoskeletal system in the horse. Regular visits allow for the collection of longitudinal, quantitative information ("normal ranges"). Changes in movement symmetry, e.g., after shoeing, are indicative of alterations in weight-bearing and push-off force production. Ten Warmblood show jumping horses (7-13 years; 7 geldings, 3 mares) underwent forelimb re-shoeing with rolled rocker shoes, one limb at a time ("limb-by-limb"). Movement symmetry was measured with inertial sensors attached to the head, withers, and pelvis during straight-line trot and lunging. Normalized differences pre/post re-shoeing were compared to published test-retest repeatability values. Mixed-model analysis with random factors horse and limb within horse and fixed factors surface and exercise direction evaluated movement symmetry changes (p < 0.05, Bonferroni correction). Withers movement indicated increased forelimb push-off with the re-shod limb on the inside of the circle and reduced weight-bearing with the re-shod limb and the ipsilateral hind limb on hard ground compared to soft ground. Movement symmetry measurements indicate that a rolled rocker shoe allows for increased push-off on soft ground in trot in a circle. Similar studies should study different types of shoes for improved practically relevant knowledge about shoeing mechanics, working towards evidence-based preventative shoeing.

Sound pressure level determination around the transformer using coherent and incoherent analytical summation methods

In this paper, coherent and incoherent analytical summation methods from elementary sound sources on the transformer’s tank are presented. They aim to determine a one-third-octave spectrum of sound pressure levels (SPL) in points around the transformer. Each part of the transformer’s surface is treated as a separate plane source so the analytical calculation can be applied to find SPL in the surroundings. Reflections from the ground are also considered by putting an image of the plane sources on the other side of the reflecting plane and adding its contributions to the total pressure in the desired points. Grid-like vibration measurements of vibration velocity on the tank surfaces are used as input parameters. Vibrations and sound pressure levels are measured to validate the method on the 5 MVA transformer experimental object. The SPL around the transformer in short-circuit (SC) and open-circuit (OC) tests is measured in the semi-anechoic chamber to compare it with theoretical results. By analyzing the results, the coherent calculation with reflection provided the most accurate results. In the SC operating condition, the normalized root mean square error (NRMSE) is 17.2%, and in the OC operating condition, it is 10.9%. The novelty of the presented method is that it considers complicated transformer geometry where each surface is calculated as a separate noise source. It calculates noise at a distance from the elementary vibration sources, considering phase and reflection from the hard ground, and provides detailed noise maps that can be used for noise modeling around the substations.

Ichnology and Main Types of Trace Fossils

Ichnology studies the traces of activities left by modern and ancient animals. The advantage of trace fossils of biological activity and solid fossils is that the trace fossils are not modified by late diagenesis. They are the original deposits of organisms on the sedimentary environment and can directly reflect the living habits of animals and their living environment. According to the sedimentary substrate in which animals live, trace fossils can be divided into tracks, traceways, trails, crawling traces, resting traces, burrows on the soft ground, and erosion traces made by animals on the hard ground.

Outcomes of Surgical Management of Turf Toe: 12-Year Results.

Background "Turf toe" is a classical capsuloligamentous injury to the plantar surface of the metatarsophalangeal (MTP) joint of the great toe. The name is synonymous with injuries sustained on artificial turf or hard grounds. The classical injury pattern is a hyperdorsiflexion injury with an axial load. The outcomes of these injuries are unpredictable and there are no clear guidelines for the management of these injuries. These injuries are debilitating and can lead to long-term problems and inability to return to pre-injury activity level if missed. We present a long-term surgical follow-up of severe grade 3 turf toe injuries. Methods In the period from 2011 to 2022, we treated 20 patients with turf toe/MTP joint instability. There were 10 football injuries (50%), six running injuries (30%), two gymnastic injuries (10%), one motorcycle injury (0.5%), and one was a ballet dancer (0.5%). All the grade 1 and 2 injuries were treated conservatively with rest, ice application, and splinting of the toe. Grade 3 injuries were treated surgically and strict rehabilitation protocol was followed. Results The mean age at surgery was 32.7 years and the average patient follow-up was 7.5 months after surgery. The Manchester-Oxford Foot Questionnaire (MOXFQ) score showed a statistically significant improvement from a mean of 73.0 (median = 75) preoperatively to 28.1 (median = 28.6) postoperatively (median improvement = 46.4, P = 0.022). Similarly, there was a significant improvement in pain score, which showed an improvement from a mean of 72.9 (median = 70.0) preoperatively to a mean of 22.9 (median = 25.0) postoperatively (median improvement = 51.3, P = 0.022). Conclusion Turf toe is a serious injury that may prevent a high percentage of patients from resuming their previous physical activities. The correct identification, classification, and grading of the first MTP joint instability helps in decision-making and achieving good surgical outcomes.

Ichnological response to the Middle Eocene Climatic Optimum (MECO) in the Bartonian deposits of Kutch Basin, India

The Middle Eocene Climatic Optimum (MECO) represents a short-lived interval of global warming that disrupted the long-term cooling episode extending from the middle to late Eocene time. Biostratigraphically the MECO corresponds to the upper interval of planktic foraminiferal zones E11–E12 and the shallow benthic zone 17. Both the planktic and benthic foraminiferal zones are well-documented within the Bartonian mixed siliciclastic‑carbonate sequence of the Kutch Basin in western India. This case study aims to investigate the impact of MECO on the endobenthic community using ichnology as a proxy. The studied sequence comprises the underlying Harudi Formation, consisting of the marine green and grey shale and bioclastic limestone beds, and the overlying Fulra Limestone characterized by benthic foraminifera-rich limestones. The Harudi Formation is bereft of trace fossils except in one bioturbated firmground and two bioeroded hardground horizons. The MECO corresponds to the thin carbonate packstone, the middle green shale, and the Nummulites obtusus rudstone occurring at the middle to upper part of the Harudi succession, established earlier by a concurrent negative δ13Corg isotopic excursion. The shelly limestone or bivalve coquina bed deposited immediately prior to the beginning of the MECO consists of a monospecific firmground ichnofabric characterized by Balanoglossites triadicus. Out of two bioeroded beds, the lower one coincides with the earliest MECO interval and is marked by a brown carbonate hardground colonized with two ichnospecies of Gastrochaenolites. The upper bioeroded horizon corresponding to the end of the MECO is characterized by a series of top- and side-bioeroded (with Gastrochaenolites, Entobia, and Oichnus) carbonate nodules containing multigenerational septarian cracks. The upper hardground demarcates the top of the Nummulites obtusus coquina bed and the starkest basin-wide sediment starvation, making it a major condensed horizon that developed following a steady glacio-eustatic rise during the warming event. The MECO prompted the subsequent deposition of shallow-marine platform carbonates of the Fulra Limestone by accelerating a sharp rise in the sea-level and proliferation of diverse Larger Benthic Foraminifera in a warm oligotrophic seawater.

Immersive virtual reality and computer vision for heritage: visual evaluation and perception of the industrial heritage sites along the Yunnan–Vietnam railway (Yunnan section)

The visual composition and human perception are found to relate to the reuse and tourism of heritage railways. Previous studies have used either environmental audits and on-site interviews that have limitations in terms of cost, time, and measurement scale, or virtual perception base on two-dimension images but with gaps in interactivity, virtual immersion and field of view. This study developed an “objective + subjective” visual evaluation and perception framework integrating Computer Vision (CV) and Immersive Virtual Reality (IVR) to assess the visual quality of industrial heritage sites along the Yunnan-Vietnam Railway (Yunnan Section). The stepwise multiple linear regression models were carried out to investigate the relationship between objective evaluation and subjective perception. The results showed that 16 landscape elements of the heritage sites were successfully segmented. According to the visual perception score bands, the 120 industrial heritage sites were classified as 39 high-score sites, 66 medium-score sites, and 15 low-score sites. In general, although the sky and hard ground accounted for a higher proportion, they had little effect on the sum scores, while the vegetation, water, and buildings played a significant role in the perception of visual quality. The results can help researchers, planners, and government departments clarify the visual quality to scientifically specify bottom-up planning and management solutions for railway industrial heritage sites. Moreover, the simplicity, accuracy, and effectiveness of this framework make it suitable for large-scale visual evaluation of other railway industrial heritage sites and linear heritage sites.

A new genus and species of cornulitid tubeworm from the Hirnantian (Late Ordovician) of Estonia

AbstractA new cornulitid genus and species, Porkuniconchus fragilis new genus and species, is here described from the Ärina Formation (Hirnantian, Porkuni Regional Stage) of northern Estonia. This new taxon differs from most cornulitids by having a fusiform ornamentation pattern that is somewhat similar to that of Kolihaia. All studied specimens are attached to a carbonate hardground. The hardground fauna is by abundance and encrustation area dominated by cornulitids. Other encrusters are represented only by a single sheet-like cystoporate bryozoan. The cornulitid specimens represent different growth stages, which suggest that the hardground was continuously colonized by cornulitid larvae. The high encrustation density indicates that the studied hardground may have represented a high-productivity site in the Hirnantian of the Baltic Basin.UUID: http://zoobank.org/623afcc3-ab32-4e8f-be14-a1093cba4ae6

Energy-optimal trajectories for skid-steer rovers

This paper presents the energy-optimal trajectories for skid-steer rovers on hard ground, without obstacles. We obtain 29 trajectory structures that are sufficient to describe minimum-energy motion, which are enumerated and described geometrically; 28 of these structures are composed of sequences of circular arcs and straight lines; there is also a special structure called whirls consisting of different circular arcs. Our analysis identifies that the turns in the trajectory structures (aside from whirls) are all circular arcs of a particular turning radius, R′, the turning radius at which the inner wheels of a skid-steer rover are not commanded to turn. This work demonstrates its paramount importance in energy-optimal path planning. There has been a lack of analytical energy-optimal trajectory generation for skid-steer rovers, and we address this problem by a novel approach. The equivalency theorem presented in this work shows that all minimum-energy solutions follow the same path irrespective of velocity constraints that may or may not be imposed. This non-intuitive result stems from the fact that with this model of the system the total energy is fully parameterized by the geometry of the path alone. With this equivalency in mind, one can choose velocity constraints to enforce constant power consumption, thus transforming the energy-optimal problem into an equivalent time-optimal problem. Pontryagin’s Minimum Principle can then be used to solve the problem. Accordingly, the extremal paths are obtained and enumerated to find the minimum-energy path. Furthermore, our experimental results by using Husky UGV provide the experimental support for the equivalency theorem.

Prediction of ground vibration under combined seismic and high-speed train loads considering earthquake intensity and site category

Based on a two-and-half-dimensional finite element model (2.5D FEM), the layered ground vibration under combined seismic and high-speed train loads was investigated. On this basis, the effect of site category and earthquake intensity on ground vibration under the combined action of two dynamic loads was analyzed. Numerical examples indicated that ground vibration displacement due to combined loads decreases with the increase of soil stiffness, while the influence of soil stiffness on the ground vibration is small when the hardness of the subsoil is large. The peak ground displacement (PGD) is a reasonable seismic intensity index for predicting the ground vibration displacement at the track center under the combined loads, which has a higher accuracy for hard ground. In view of this, an equivalent shear wave velocity and PGD-based prediction formula was proposed to estimate the ground vibration under combined seismic and high-speed train loads. Reliability of the prediction formula was verified through comparison with results of numerical tests, indicating that the prediction formula has good applicability to different site conditions and seismic events. Compared with the previous study, it demonstrated that the prediction method provided an effective means for estimating ground vibration caused by a high-speed train load during earthquakes.

Investigation on the Rock-Fragmentation Process of Conical-Shaped TBM Cutterhead in Extremely Hard Rock Ground

Conical-shaped cutterhead is one type of tunnel boring machine (TBM) cutterhead which may have advantage of high rock-breaking efficiency in extremely hard rock ground. This study investigated the rock-fragmentation process of disc cutters on the conical-shaped cutterhead via a series of numerical simulations that had been verified by laboratory rock-fragmentation tests. Firstly, the rock-fragmentation numerical model of the six cutters in the 'flat-cone' contiguous part was built based on cutting mode analysis of the conical-shape cutterhead. The rock sample in the numerical model was synthesized using a grain-based discrete element method (GB-DEM) and the reliability of this approach was verified via scaled rock-fragmentation tests conducted on a self-developed linear cutting machine (LCM). Then, a series of numerical simulations were conducted to study the influence of cutterhead cone angle, cutter spacing, and cutter installation angle on the rock-fragmentation performance. The results were as follows: 1) the nature of rock fragmentation in the cone area is the rock fragmentation under side free-face condition; 2) the penetration specific energy can be reduced and thus the rock-fragmentation efficiency can be improved by appropriately increasing the conical angle, reducing the cutter spacing, and increasing the cutter installation angle; 3) for the studied granite, the optimal conical angle is 25°, the cutter spacing is suggested to be no more than 70 mm, and the cutter tilt angle is suggested to be no more than 3°. The results obtained in this paper can be used as guidance for the design of the conical-shaped cutterhead.

Dynamic Responses of Concrete-Face Rockfill Dam to Different Site Conditions under Near-Fault Earthquake Excitation

The western region of China is rich in hydropower resources and characterized by unique geological conditions. For the construction or planned construction of high dams in this region, different types of cover layers are formed due to special geological structures, most of which are located in high seismic intensity zones. This study focuses on four different site conditions: hard ground, medium–hard ground, medium–soft ground, and weak ground. By simulating the dynamic response of concrete-face rockfill dams under near-fault earthquake excitation, the vertical settlement of the dam and the attenuation of seismic motion under different site conditions are analyzed. The research findings reveal a consistent trend where the vertical settlement of the dams progressively escalates with increasing dam height across all four site conditions. This settlement phenomenon is especially pronounced in weak ground conditions, posing a potential risk of failure. Furthermore, when subjected to near-fault pulse-type earthquake motions, the existence of weak soil layers significantly dampens the seismic forces experienced by the dam. This finding suggests that the weaker the geological conditions of the site, the more pronounced the attenuation effect of the seismic motion. Additionally, the overburden layers have a noticeable amplification effect on near-fault pulse-type earthquake motion. However, this amplification effect is not significant in weak ground, possibly due to the presence of weak soil layers restricting the propagation and amplification of seismic motion. In conclusion, these research findings have practical significance for the dynamic response of high dam construction in different site conditions in the western region of China. They provide a scientific basis for the design and construction of high dams and serve as a reference for the implementation of seismic mitigation measures and earthquake disaster prevention in engineering projects.

The influence of different horseshoes and ground substrateson mid-stance hoof orientation at the walk.

Horseshoes with modified contact surfaces combined with deformable ground substrates are used to change hoof orientation during mid-stance, for example, for therapeutic reasons. To measure the effect of horseshoes and ground substrates on sagittal and transverse plane hoof orientation at mid-stance using a dorsal hoof wall mounted triaxial accelerometer. In vivo experiment, randomised crossover design. Differences in sagittal and transverse plane angles between standing and mid-stance of the left front hoof of six horses walking with regular horseshoes, egg bar, toe-wide, medial-wide, lateral-wide and three-degree egg bar shoes on turf, sand and hard ground substrates were assessed with linear mixed models with horseshoe and substrate type as fixed factors (p < 0.05) for each animal. Hoof angles were significantly affected by horseshoe (p < 0.001), surface (p < 0.001) and the combination (p < 0.001). The sagittal plane angle increased in deformable ground substrates at walk-in mid-stance on turf [mean (±standard deviation): 2.6° (±3.8°)] and on sand [2.6° (±4.1°)] across all shoes. The greatest increase was observed with egg bar shoes [turf: 4.37° (±3.82°); sand 4.69° (±3.83°)]. There was a tendency for the hoof to sink laterally into deformable ground substrates among all shoes [turf: 1.11° (±1.49°); sand: 0.93° (±1.93°)]. Medial-wide shoes increased the lateral sinking [turf: 2.00° (±1.63°); sand: 1.79° (±1.58°)]. Lateral-wide shoes reduced the lateral sinking on turf [0.62° (±1.26°)] and induced a marginal medial sinking on sand [-0.007° (±2.03°)]. The substrate properties were not quantitatively assessed, and observations were limited to front hooves at the walk. A larger sample size would be preferable. Mid-stance hoof orientation changes with specific combinations of shoes and ground substrates in the walking horse.

Investigation of disc cutter wear during shield tunnelling in weathered granite: A case study

Wear characteristics of disc cutter can vary significantly during shield tunnelling in different geological formations. This paper presents a case study on disc-cutter wear experienced during earth pressure balance shield tunnelling of the Guang-Fo intercity railway in Guangzhou, China. During excavation of the 2.8 km tunnel, 149 cutter inspections were conducted and 1163 cutters were consumed. Cutter wear morphology and cutter consumption was investigated. Cost-effectiveness of cutter replacement under different ground conditions was evaluated regarding time consumption. Field data revealed that cutter consumption varied with ground conditions, cutter mounting radii, and boring parameters. During mixed ground tunneling, it was noticed that the tips of cutter rings had been sharpened. An approximate estimation of when to inspect cutters during tunnelling can be determined using the field penetration index. Cutter replacement in hard rock ground was more cost-effective than in other ground conditions. The wear data provided here can serve as a reference for future operations in similar geological conditions.

Comparison of static and dynamic balance ability according to gender in athletes- a cross sectional study

The aim of the present study was to compare the balance ability between genders in elite athletes. A total of 152 athletes, 76 female and 76 male, from 10 different branches with similar demographic characteristics included to the study. A computerized balance platform (BT4, HUR Labs Oy, Tampere, Finland) was used to determine balance ability of the athletes. Static balance measurement, with eyes open and closed stability test on hard and soft ground; dynamic balance measurement was evaluated with forward, backward, left and right functional reach test and Romberg values calculated by the device. It was determined that the Romberg value of female athletes was higher than that of male athletes (p= 0.025). It was determined that the area scanned by female athletes in static balance ability on fixed ground with eyes open was less than that of male athletes (p= 0.025); the length drawn by female athletes in static balance ability on soft ground with eyes open was less (p= 0.010) and their scanning speed was slower (p= 0.007). Static balance ability of female athletes were significantly better than male athletes, and female athletes interpreted visual inputs better than male athletes in static balance ability. We recommend training with visual inputs and visual exercises in order to increase balance performance, especially in female athletes.

Hidden Depths: A Unique Biodiversity Oasis in the Persian Gulf in Need of Further Exploration and Conservation

The Persian Gulf, a young and shallow epicontinental sea, is known for its unique geological and oceanographic characteristics that foster its diverse and productive marine ecosystems. A substantial portion of the Gulf’s seafloor consists of unconsolidated soft sediments, making it unsuitable for colonization by many sessile organisms. Consequently, relatively few hard grounds and submerged banks provide suitable habitats for benthic and substrate dwellers. This study documents a unique marine habitat on an offshore submerged bank, likely a raised salt dome, south of Qeshm Island, Iran. This area is home to a high concentration of ahermatypic coral species and remains relatively sheltered from human activities. The bank’s geographic location allows inflow currents from the Strait of Hormuz to transport larvae and nutrients, providing suitable substrates for various sessile invertebrates. Moreover, it causes the formation of Taylor columns, which affect fluid dynamics and circulation patterns, indirectly enhancing biodiversity. Despite facing risks from large-scale regional and localized threats, the bank’s remoteness from the main coast and its depth provide some protection. This study emphasizes the need for continued exploration and the implementation of effective conservation measures in the region, along with additional research to clarify the ecological and physical parameters supporting its diversity. It also presents the first in situ photographic evidence for the occurrence of some octocoral genera in the Gulf. Future research should investigate how the species compositions of hidden banks and shoals contribute to the overall biodiversity of the Persian Gulf.