Settlement Plates Research Articles

Adapting Museum Workflows to Accommodate Omic-based, Multi-species Occurrences from Environmental Samples

Natural history museums play a critical role in curating global anthropological, biological and geological diversity. Museums host more than voucher samples for comparative identification purposes. They host a suite of derived products and associated information, which cascade from these records of diversity in time and space. Increasingly, museums capture whole communities through curation of environmental samples and their derived data. Environmental samples are defined as material samples that yield multi-species occurrence records that cannot be sorted into traditional independent lots and whose membership can only be determined by downstream analytical processes, usually based on the generation of DNA sequence profiles. These materials include samples such as filtered water; feces, gut dissections or gastric lavage; scraped and blended settlement plates; as well as sediment, ice or soil cores. Given the level of ongoing and predicted global change, through the curation of these environmental samples, museums provide time capsules of diversity and longitudinal breadth to examine temporal patterns in phenology, range shifts, species interactions and diversity loss or gain. The future of natural history museums is likely to expand from providing inventory-like services to more observatory functions. They should provide strategic windows to the past by partnering with place-based observatories or targeted regions of predicted change. Rather than individual specimens, environmental samples represent entire systems as events, defined by space and time. Thus, these environmental samples are explicitly event-centric. The cascade of derived information, protocols and handling steps, as well as analytical processes and their associated metadata, needs to be tracked via the minting of persistent identifiers at each material sample and derived data step. Efforts are underway through collaboratively funded programs like the iSamples Cyberinfrastructure group, funded by the US National Science Foundation, to semantically map these various material samples while capturing their parent-child relationships. Moreover, museums, such as the Smithsonian’s National Museum of Natural History, are scoping and examining existing systems of record, metadata models and mapping workflows, with particular emphasis on environmental samples. These event-based samples create new challenges for historically taxonomically-siloed departments pertaining to custodianship, permitting, versioning of biodiversity occurrence records based on improved reference libraries, and future use and reuse of these material samples. Management systems are being augmented or adopted to encompass these new workflows to ensure that today’s samples can support tomorrow’s science in service to a sustainable future.

Identifying knowledge gaps for successful restorative aquaculture of Ostrea edulis: a bibliometric analysis.

Background:Active restoration is necessary to enhance the recovery ofOstrea edulisreefs, which contribute to many ecosystem services. Restoration can be integrated within aquaculture practices, bringing positive environmental changes while maximising space utilisation. The restoration project MAREA (MAtchmaking Restoration Ecology and Aquaculture) aims to bring back O. edulisin the North-West Adriatic addressing the feasibility of its cultivation. Both successful restoration and sustainable aquaculture require a thorough understanding of the ecological needs, as the requirements of both activities need to be harmonized. Therefore, one of the preliminary activities before embarking on the pilot was the completion of a thorough literature review to identify research directions and gaps required for 'restorative aquaculture', aiming to gather the most up to dateO . edulisknowledge on a global and local scale. Methods:Internet (Web of Science, Scopus, Google scholar) and physical resources (libraries) were searched for all available global and local knowledge onO . edulis. Bibliometrixwas used to identify the main research topics using keywords, titles, and abstracts analyses. Studies were then manually screened and summarised to extract knowledge specific to restoration and aquaculture. Results:While restoration studies are recent, evidence for the loss of this species and potential causes (and solutions) have been discussed since the end of the 19 thcentury. While diseases were a leading cause for reef loss, substratum limitation appears to be one of the leading limiting factors for both restoration and aquaculture ofO . edulis, and was already mentioned in the early texts that were found. Conclusions:The review highlighted that restoration success and aquaculture feasibility depend upon the crucial stage of settlement. The project 'MAREA' will therefore increase its focus on this stage, both in terms of timing, location, and materials for settlement plates placement.

From Plates to Baits: Using a Remote Video Foraging System to Study the Impact of Foraging on Fouling Non-Indigenous Species

Marinas are a gateway for the introduction and establishment of non-indigenous species (NIS). In these habitats, competition and predation are crucial determinants for NIS establishment and invasiveness. However, fish trophic preferences and biotic effects inside marinas are poorly known. This study proposes a novel method that combines the deployment of settlement plates to recruit different assemblages, followed by their use as bait in remote underwater video systems. This combined approach, addressed as a remote video foraging system (RVFS), can record fish foraging behaviour, including feeding choices and their impacts on fouling assemblage composition. An experimental RVFS trial carried out in a marina of Madeira Island, Portugal (NE Atlantic), identified the Mediterranean parrotfish, Sparisoma cretense, as the most important fouling grazer in the area. S. cretense behaved as a generalist and increased the heterogeneity of fouling assemblages, which can hamper NIS dominance of the fouling and reduce the pressure of propagules from the marina to the natural environment. The RVFS tool was useful to understand the trophic links between foragers and fouling and has the potential to provide relevant information for the management of NIS introductions, establishment and spread.

PREDICTION OF ROAD CLEARANCE

One method of handling soil that can be done to speed up the consolidation process is to add a Pre-Loading embankment on top of the plan embankment. In addition, this handling is also carried out to achieve a reduction by the design load, so that the settlement of embankment after the construction period still meets the required criteria and standards. This study was conducted to obtain a comparison of the prediction of embankment settlement with the empirical method using CPT data and the prediction of settlement using the Asaoka Method. In addition, the results of the consolidation coefficient will also be compared which can be used to determine the right time for Pre-Loading excavation during the construction period. The data used are CPT test data in the field as well as laboratory test data and measurement data for the settlement plate settlement closest to the position of the CPT test. From the analysis carried out, it is obtained that the prediction of decline using the Asaoka method is smaller than the prediction of decline using the empirical method using CPT data. In addition, from the analysis, it was found that at locations HB-04 and SP 70, as well as HB-07 and SP 91, showed laboratory consolidation coefficient values (cv-Lab.) which were close to the consolidation coefficients of the Asaoka Method (cv-Asa.), while in HB -05 and SP 79 and HB-06 and SP 85 show a large difference in values. The average comparison of the cv-Lab. consolidation coefficients and CV-Asa. is 58.5%.

Detecting Rare Species With Passive Sampling Tools: Optimizing the Duration and Frequency of Sampling for Benthic Taxa

The choice of the duration and frequency of sampling to detect relevant patterns in field experiments or for environmental monitoring is always challenging since time and material resources are limited. In practice, duration and frequency of sampling are often chosen based on logistical constraints, experience, or practices described in published works but are rarely justified and almost never optimized before initiating sampling. Settlement plates are commonly used as a passive sampling tool to study recruitment patterns of fouling organisms (including non-indigenous species) and their deployment is amenable to experimentation with respect to manipulating duration and frequency of sampling. This study aimed to determine the optimal sampling strategy to detect rare species (e.g., a non-indigenous species early in the invasion process when its population size is still small). To do so, we deployed a series of settlement plates of various durations (1–32 days) and sampling frequencies (daily to biweekly) during the seasonal onset of recruitment, when larval supply was low, a situation that mimics the low propagule pressure of the early stages of the invasion process. We demonstrated that a combination of longer sampling duration and higher sampling frequency was the best strategy to maximize taxonomic richness. However, we found that an intermediate sampling duration of 1–2 weeks was optimal for detecting most species. These results can guide species-specific and assemblage-level sampling strategies using settlement plates. Additionally, this study can serve as a practical template for optimizing sampling of other taxonomic groups that were not examined in the present study as well as for the use of other methods.

Analysis of the Effect of Smear Zone on Consolidation Decline in the Tebing Tinggi-Kisaran Toll Road Project (Phase 1) Tebing Tinggi – Indrapura STA 102+700 Toll Road Project with 3D PLAXIS Modeling

Repairing of soft clay Embankment loading method with PVD is a soil improvement system consisting of Embankment loading work, installation PVD, installation PHD, and geotechnical instruments. Preload serves to compress the subgrade. PVD serves to speed up the process of soil compaction. Horizontal drains serves to drain pore water taken from the PVD in a horizontal direction to the outside of the location that improved. Geotechnical instruments function to monitor and record the process and determine the performance of the result improving soil that have been carried out. Embankment loading and PVD (Prefabricated Vertical Drain) are technologies that are often used in the construction world to increase shear strength and speed up consolidation time of soft soils. However, during the installation of PVD using a mandrel it can affected the surrounding soil, causing the soil to become disturbed. The disturbed area is called by Smearzone. Due to the presence of a smear area, analysis and calculations are needed to obtain a consolidation time that is in accordance with field conditions. This analysis aims to compare the decrease of displacement in the settlement plate (SP-124) with modeling in PLAXIS 3D considering using with or without taking into account the effect of the smearzone. The method used in this thesis is the analytical method using Terzaghi theory and the finite element method using PLAXIS 3D. From the results obtained analytically the magnitude of the decrease is 15.252 cm while the results from the PLAXIS 3D analysis without the effect of the smear zone is 15.15 cm and with the effect of the smear zone being, 2 times the dimensions of the mandrel the results obtained are 15.131 cm, 15.133 cm and 15.134 cm, with 3 times the dimensions of the mandrel the results obtained are 15,142 cm, 15,141 cm and 15,14 cm and with 4 times the dimensions of the mandrel the results obtained are 15,144 cm, 15,143 cm and 15,143 cm. The decrease that occurs in the settlement plate 124 in the field is 15.10 cm. So it can be concluded that the calculation of consolidation decrease using analytical theory is relatively close to the decrease in actual results in the field with a percentage difference of 1% decrease. There are differences in settlement due to laboratory data not representing the entire soil layer. Due to the decrease that occurred 15.10 cm, the result of the effect of the smear effect 2 times the mandrel dimension and half of the coefficient of permeability of the original soil with a reduction ratio of 0.2% is the result that is closest to the results of field observations compared to without a smear effect of 0.331%.

Deterioration Analysis and Consolidation Time Using Terzaghi 1-D Method and 3D Plaxis Modeling: A Case Study of the Tebing Tinggi Toll Road Development Project - Indrapura STA. 103 + 200

Land transportation has an important role in the transportation sector. Road infrastructure is growing rapidly to meet basic human needs which increasingly require rapid movement for distribution of basic needs and other logistics. Soil has the characteristics of a relatively low bearing capacity and relatively large compression and lasts a relatively long time. One of the factors that cause soft soil to have a low bearing capacity is having a high water content. The high level of compressibility in soft soils is caused by the high void ratio. The development of preloading and vertical drainage methods is also combined with the use of horizontal drainage. Preloading works to compress the subgrade. PVD (Prefebricate Vertical Drain) serves to accelerate the process of soil compaction. PHD (Prefebricate Horizontal Drain) works to drain pore water from the PVD in a horizontal direction to the outside of the embankment. Located on the Tebing Tinggi Toll Road Construction Project – Kisaran (Phase 1), the Tebing Tinggi Inderapura Toll Road in zone 3 Sta 103 +200. The purpose of writing this thesis is to analyze the magnitude of the settlement and consolidation time using analytical methods and using modelling in PLAXIS 3D. Analyzing the effect of the smear zone due to PVD erection using a mandrel. Analyzing the effectiveness of using PHD as horizontal drainage. Knowing the pore water pressure that occurs. Comparing the results of PLAXIS 3D modelling with data settlement in the field. The calculation of the consolidation settlement using the 1-dimensional Terzaghi method was obtained at 102,46 mm. This result is relatively close to the conditions that occur in the field, where the decrease in the SP-132 settlement plate in the field is 103 mm and the decrease in Asaoka is 102 mm. The consolidation time required when there is a decrease of 100 mm in PLAXIS 3D modelling with a smear zone effect is 243 days and without a smear, the zone effect is 240 days. The required consolidation time without the use of PHD is 242 days and the consolidation time from the data settlement plate 132 (SP-132) is 239 days. Calculation of settlement and consolidation time using PLAXIS 3D modelling by taking into account the effect of the smear zone gives results that are close to the situation in the field. From the results of the PLAXIS 3D modelling, it is found that the minimum pore water pressure occurs until the end of the stockpiling activity for 248 days. The use of PVD in combination with PHD is effectively applied in the field, indicated by the minimum pore water pressure that occurs is smaller than without using PHD. From the percentage of pore water pressure that occurs in the soil, 64,4% is greater by using PHD, meaning that the percentage of water that comes out is faster by using PHD. Keywords: Preloading, PVD, PHD, consolidation, PLAXIS 3D.

Analysis of Soil Subscription on Soil Lack Combination of PVD and PHD With Analytical and Numerical Methods Using 3D Plaxis in STA 103 + 550 Construction of High Click Toll Road Range, Stage 1

The construction of transportation facilities on soft soil will cause problems where the bearing capacity of soft soil is low and the process of land subsidence will require a long period of time. As is known, the land subsidence factor causes many problems in the process of building transportation facilities, besides that, there will also be problems at the level of service (serviceability). Therefore, this problem must be anticipated before the transportation facility begins to function. There are many methods that can be done. Where in the selection of methods, the efficiency and effectiveness factors are very dominant. One method that can be done is to fill the soil combined with vertical drain and horizontal drain. This method was chosen to be one of the most widely used methods because it is easy to do and quite efficient. The purpose of writing this thesis is to analyze thereduction of settlement each layer of soft soil that is repaired using the soil filling method combined with prefabricated vertical drain and prefabricated horizontal drain using the PLAXIS 3D program. The results of this calculation will then be compared with observations made in the field using a settlement plate for later analysis. Calculation of the size of the consolidation settlement using the Terzaghi 1 dimension consolidation method obtained a decrease of 16.09 cm. This result is relatively close to the results of observations made in the field of 16.3 cm. In the PLAXIS 3D modeling approach using 1 PVD line and 1 PHD line, the result is a decrease of 16.52 cm without taking into account the effect of the smear zone and 16.22 cm taking into account the effect of the smear zone. In the PLAXIS 3D modeling approach using 2 PVD lines and 2 PHD lines, the result is a decrease of 16.54 cm without taking into account the effect of the smear zone and 16.28 cm by taking into account the effect of the smear zone. And when modeling without using PHD the value of the decrease obtained is 9.7 cm. When modeling using sand blanket as a substitute for PHD, the decrease value is 13.3 cm

Identifying knowledge gaps for successful restorative aquaculture of Ostrea edulis: a bibliometric analysis

Background: Active restoration is necessary to enhance the recovery of Ostrea edulis reefs, which contribute to many ecosystem services. Restoration can be integrated within aquaculture practices, bringing positive environmental changes while maximising space utilisation. The restoration project MAREA (MAtchmaking Restoration Ecology and Aquaculture) aims to bring back O. edulis in the North-West Adriatic addressing the feasibility of its cultivation. Both successful restoration and sustainable aquaculture require a thorough understanding of the ecological needs, as the requirements of both activities need to be harmonized. Therefore, one of the preliminary activities before embarking on the pilot was the completion of a thorough literature review to identify research directions and gaps required for ‘restorative aquaculture’, aiming to gather the most up to date O. edulis knowledge on a global and local scale. Methods: Internet (Web of Science, Scopus, Google scholar) and physical resources (libraries) were searched for all available global and local knowledge on O. edulis. Bibliometrix was used to identify the main research topics using keywords, titles, and abstracts analyses. Studies were then manually screened and summarised to extract knowledge specific to restoration and aquaculture. Results: While restoration studies are recent, evidence for the loss of this species and potential causes (and solutions) have been discussed since the end of the 19th century. While diseases were a leading cause for reef loss, substratum limitation appears to be one of the leading limiting factors for both restoration and aquaculture of O. edulis, and was already mentioned in the early texts that were found. Conclusions: The review highlighted that restoration success and aquaculture feasibility depend upon the crucial stage of settlement. The project ‘MAREA’ will therefore increase its focus on this stage, both in terms of timing, location, and materials for settlement plates placement.

Interpretation of Cone Penetration Test Data of an Embankment for Coupled Numerical Modeling

The Nerang Broadbeach Roadway (NBR) embankment in Australia is founded on soft clay deposits. The embankment sections were preloaded and surcharged-preloaded to limit the post-construction deformation and to avoid stability failure. In this paper, we discuss the NBR embankment’s geology, geotechnical properties of the subsurface, and long-term field monitoring data from settlement plates and piezometers. We demonstrate a comparison of cone penetration test (CPT) and piezo cone dissipation test (CPT-u) interpreted geotechnical properties and the NBR embankment’s foundation stratification with laboratory and field measured data. We also developed two elasto-viscoplastic (EVP) models for long-term performance prediction of the NBR embankment. In this regard, we considered both the associated and the non-associated flow rule in the EVP model formulation to assess the flow rule effect of soft clay. We also compared EVP model predictions with the Modified Cam Clay (MCC) model to evaluate the effect of viscous behavior of natural Estuarine clay. Both EVP models require six parameters, and five of them are similar to the MCC model. We used the secondary compression index of clay in the EVP model formulations to include the viscous response of clay. We obtained numerical models’ parameters from laboratory tests and interpretation of CPT and CPTu data. We observed that the EVP models predicted well compared with the MCC model because of the inclusion of soft clay’s viscosity in the EVP models. Moreover, the flow rule effect in the embankment’s performance predictions was noticeable. The non-associated flow rule EVP model predicted the field monitoring settlement and pore pressure better compared to the MCC model and the associated flow EVP model.

The role of marinas in the establishment and spread of non-indigenous species in Baltic Sea fouling communities

The study included the sampling of 12 marinas across six areas of the Baltic Sea with settlement plates and scraping of submerged structures to assess the role of marinas in the spread of non-indigenous species (NIS) via biofouling. 15 NIS were detected in the marinas and secondary spread of previously introduced NIS was detected in five out of six sea areas. Salinity and sea area significantly affected the composition of the fouling assemblages. Settlement plates appeared as the more efficient sampling method over scraping, while the seasonal analyses revealed that the monitoring effort should span over the summer and early autumn in the south-eastern, central, and northern Baltic Sea. The present findings indicate that marinas contribute to the spread of non-indigenous fouling organisms, and there is an increasing demand for the monitoring of marinas and stricter regulations regarding the biofouling management of leisure boats in the Baltic Sea.

Dropping plates to pick up aliens: towards a standardised approach for monitoring alien fouling species

Biological invasions pose a major threat to biodiversity and significant investment is required to prevent the introduction of alien species, contain introduced populations and mitigate associated impacts. The implementation of standardised long-term monitoring programmes enables the early identification of new alien species, the tracking of spread, the assessment of the effectiveness of management interventions, and an understanding of temporal and spatial trends. Globally, fouling species are known to cause economic losses through accumulation on vessel hulls and port infrastructure and via the disruption of aquaculture activities. Additionally, fouling taxa can have ecological impacts in recipient systems, most often driven by their dominance in biological interactions. In South Africa, this group accounts for the majority of marine alien taxa. Accordingly, this study tested an approach for monitoring fouling biota using open and caged PVC settlement plates deployed in marinas. After 16 weeks, plates were removed, biota identified, and relative abundance captured as percentage cover. This method proved to be effective, logistically simple and cost-efficient. Twenty-four taxa were recorded, of which 58% were invasive species. It is recommended that this monitoring approach be implemented around the South African coast as a first step to providing key information to inform management and research.

Prediksi Penurunan Konsolidasi Menggunakan Preloading dan Prefabricated Vertical Drain dengan Software Metode Elemen Hingga

Consolidation is the process of removing water from the pores of the soil which causes changes in the volume of the soil which results in damage to the construction above it. This is more fatal if the decline that occurs is local. Nowadays the use of vertical drains is increasingly in demand, especially with the Prefabricated Vertical Drain (PVD) system which can reduce the time of the soil consolidation process significantly from several years to a matter of months and with technological advances, software is created that can make it easier to calculate construction work with computer programs, one of which is the only finite element method software (Plaxis) to calculate the consolidation settlement process. This study aims to analyze using Finite Element Method software with the help of 2D and 3D plaxis programs to get the consolidation settlement size. The results of 2D and 3D modeling will be compared so that the results that are closest to the field conditions are obtained. From the results of the analysis, it can be concluded that the magnitude of the decrease in Plaxis 3D is closer to the settlement plate data S29 with a decrease of 6.956m or a difference of -0.234m, while the magnitude of the decrease in Plaxis 2D is 7.491 with a difference of decrease of 0.301m.

Finite Element Simulation of Vacuum Preloading at Palembang – Indralaya Toll Project

Methods for the prediction of soil behavior during the application of vacuum preloading are available but have not been used precisely and have not been proven yet in Indonesia. There are two common approaches to vacuum preloading simulation, based on the application of a uniform external load to the vacuum area, and based on suddenly lowering the groundwater level to create vacuum conditions, respectively. This affects the settlement, lateral deformation, and pore pressure predictions. The objective of this research was to improve the prediction of soil behavior based on high-quality field data by using state of the art vacuum preloading simulations. The results were compared with those of a series of instrumentation equipment, i.e. a settlement plate, an extensometer, and a piezometer. This research used data from the Palembang-Indralaya Toll Road, a section of the Trans Sumatera Toll Road that is approximately 22 km long and has an embankment height of about 4 m to 9 m. It was built over a swampy soft soil area, using vacuum preloading to improve the soil. Axisymmetric analysis of vacuum preloading was conducted for a single-drain system, plane-strain analysis was conducted for single- and multiple-drain systems, and 3D analysis was conducted for single-drain, multiple-drain, and cluster-drain systems. The results show that the proposed method produced a good correlation between the predicted data and the recorded monitoring data.

The "Little MonSta" Deep-Sea Benthic, Precision Deployable, Multi-Sensor and Sampling Lander Array.

The “Little MonSta” benthic lander array consists of 8 ROV-deployable (remotely operated vehicle) instrumented lander platforms for monitoring physical and chemical oceanographic properties and particle sampling developed as part of the MMMonKey_Pro program (mapping, modeling, and monitoring key processes and controls in cold-water coral habitats in submarine canyons). The Little MonStas offer flexible solutions to meet the need to monitor marine benthic environments during a historically unprecedented time of climate-driven oceanic change, develop an understanding of meso-scale benthic processes (natural and man-made), and to calibrate geological environmental archives. Equipped with acoustic Doppler current profilers (ADCPs), sediment traps, nylon settlement plates and homing beacons, the compact and upgradable lander platforms can be deployed by ROVs to precise locations in extreme terrains to a water depth of 3000 m. The array allows cluster-monitoring in heterogeneous environments or simultaneous monitoring over wider areas. A proof-of-concept case study was presented from the cold-water coral habitable zone in the upper Porcupine Bank Canyon, where the Little MonStas collected 868.8 h of current speed, direction, temperature, and benthic particulate flux records, as well as 192 particle samples subsequently analyzed for particular organic carbon (POC), lithic sediment, live foraminifera, and microplastics. The potential to upgrade the Little MonStas with additional sensors and acoustic releases offers greater and more flexible operational capabilities.

Artificial Light at Night (ALAN) negatively affects the settlement success of two prominent intertidal barnacles in the southeast Pacific

Many coastal processes are regulated by day/night cycles and are expected to be altered by Artificial Light at Night (ALAN). The goal of this study was to assess the influence of ALAN on the settlement rates of intertidal barnacles. A newly designed settlement plate equipped with a small central LED light source was used to quantify settlement rates in presence/absence of ALAN conditions. “ALAN plates” as well as regular settlement plates were deployed in the mid rocky intertidal zone. Both ALAN and control plates collected early and late settlers of the barnacles Notochthamalus scabrosus and Jehlius cirratus. Early settlers (pre-metamorphosis cyprids) were not affected by ALAN. By contrast, the density of late settlers (post-metamorphosis spats) was significantly lower in ALAN than in control plates for both species, suggesting detrimental ALAN impacts on the settlement process. The new ALAN plates represent an attractive and alternative methodology to study ALAN effects.

Spatial and Temporal Variation of Scleractinian Coral Recruitment in Balok Coastal Waters and Bidong Island, Malaysia

Understanding coral recruitment is important as increasing of regional decline of coral reef worldwide. This study aimed to investigate the spatial and temporal coral recruitment patterns around reef sites in Balok coastal waters and Bidong Island, Malaysia. Recruitment density was determined by quantifying number of coral recruits settled on the terra-cotta tiles and artificial reef settlement plates. In Balok coastal waters, a total of 159 coral recruits were counted with 0.09 ± 0.03 n/m2 mean recruitment density per plate, while in Bidong Island, a total of 319 coral recruits were counted with 0.19 ± 0.02 n/m2 mean recruitment density per plate. Coral recruits were dominated by genus Pocillopora followed by Stylopora and Seriatopora in Bidong. Meanwhile in Balok, genus Platygyra was dominant coral recruits followed by Porites and Fungia. Additionally, minor spawning event was predicted in Balok coastal waters in September due to increase number of Platygyra coral. Recruitment density varied significantly between locations, types of settlement plates and plate’s orientation at both study areas. Current findings highlighted the significant use of artificial reef plates to increase the chances of larval settlement. This research also provides important information in assessing coral resilience towards different environmental conditions between coastal and sheltered reef areas.

Dynamic compaction of crushed concrete fill, full-scale test at Jätkäsaari, Helsinki

Concrete waste in the form of crushed concrete can be utilized in street and road structures. Today, a significant amount of concrete waste generated by various demolition and other activities is not fully utilized in infrastructure projects within Helsinki; as a result, a portion of concrete waste generated in the city is be transported to other sites outside the Helsinki metropolitan area. In Helsinki, large-scale land reclamation projects have been implemented, and this trend will continue in the near future. Utilization of concrete waste as fill material in land reclamation projects will reduce the need to transport concrete waste outside the Helsinki metropolitan area, with a concurrent reduction in need to transport blasted rock to the land reclamation sites. This will promote reuse and recycling of waste and will reduce heavy traffic and CO2 emissions. Crushed concrete has not been previously tested in Finland as a fill material in land reclamation projects subjected to deep compaction methods. In 2018-2019 suitability of crushed concrete for land reclamation purposes was tested in a full-scale dynamic compaction test. The objective of the test was to assess the degree of compaction produced by dynamic compaction, determine the compression rate of compacted layers under pre-loading embankment, and measure environmental impacts of the fill material. The pilot structure was implemented in Tritoninpuisto (Triton Park) located in the southern part of Jatkasaari. Crushed concrete with varying grain size was compacted using the dynamic compaction method. All materials compacted well. Results of the pilot study indicate that dynamic compaction can be applied to densify crushed concrete fill material for land reclamation. Settlement plates on the top and the bottom of the pilot structure were used to monitor short-term settlement during dynamic compaction and long-term settlement after completion of the work. Long-term settlement was minor after compaction and placement of a pre-loading embankment. Implemented study has indicated that compacted crushed concrete is a suitable material for land reclamation in street and park areas.

Fouling communities and non-native species within five ports along the Bristol Channel, South Wales, UK

Non-native species (NNS) are widely regarded to be one of the major threats to the loss of biodiversity worldwide. Maritime trade is the primary pathway for the transport and introduction of aquatic NNS around the world, and ports are central to this network. Our knowledge of port communities and the NNS they contain is limited, with ports often remaining unsurveyed for decades, which was the case within the studied region. Settlement plates were deployed for 10–11 months at five commercial ports along the Bristol Channel and Severn Estuary in South Wales, UK. We report unique communities in each of the ports with salinity being the main driver for differences among locations. Eleven NNS were identified across all ports with non-native to native species proportions ranging from 0.13 to 0.33 in each port. Most of these NNS are known to exist in the region and are ‘established’ species within the UK. High variation in community structure and NNS composition among all ports independent of geographic proximity highlights the importance of monitoring individual ports with a view to implementing bespoke, effective NNS management strategies.

Artificial light at night alters the settlement of acorn barnacles on a man-made habitat in Atlantic Canada

Human growth has caused an unprecedented increase in artificial light at night (ALAN). In coastal habitats, many species rely on day/night cycles to regulate various aspects of their life history and these cycles can be altered by this stressor. This study assessed the influence of ALAN on the early (cyprid) and late (spat) settlement stages of the acorn barnacle Semibalanus balanoides, a species widely distributed in natural and man-made coastal habitats of the North Atlantic. A newly designed settlement plate, originally for studies in rocky intertidal habitats in the southeast Pacific, was adapted to measure settlement rates on man-made habitats -wharf seawalls- located in Atlantic Canada. Plates equipped with a small LED diode powered by an internal battery (ALAN plates) were used to quantify settlement rates in comparison to plates lacking a light source (controls). These plates were deployed for 6 d in the mid-intertidal levels, where adult barnacles were readily visible. ALAN and control plates collected large number of settlers and showed to be suitable for this type of man-made habitats. The number of early settlers (cyprids) did not differ between plates but the number of late settlers (spat) was significantly lower in ALAN plates than in controls. These results suggest that light pollution has little influence on the early stages of the acorn barnacle settlement but is clearly detrimental to its late stages. As barnacles dominate in many natural and man-made hard substrates, it is likely that ALAN also has indirect effects on community structure.