Coast Of Central Chile Research Articles

Chile Niño/Niña in the coupled model intercomparison project phases 5 and 6

The north and central coast of Chile is influenced by El Niño-Southern Oscillation (ENSO) through oceanic and atmospheric teleconnections. However, it also experiences episodic oceanic warmings off central Chile (30°S) lasting a few months that are not necessarily associated with ENSO. These episodes, called “Chile Niño” events, besides their ecological and socio-economical impacts, have also the potential to influence tropical Pacific variability. Here, we investigate how realistically the models in the Coupled Model Intercomparison Project (CMIP, Phases 5 and 6) simulate Chile Niño/Niña (CN) events, and quantify their changes under anthropogenic forcing. Despite limitations of the global models in simulating realistically coastal upwelling dynamics, we show that they simulate reasonably well the observed spatial pattern, amplitude and seasonal evolution of CN events. They however fail to properly represent the positive skewness from observations. The analysis of a sub-group of models (36) that simulate ENSO realistically reveals that CN events increase in amplitude and variance in the future climate with no changes in their frequency of occurence. This is interpreted as resulting from compensating effects amongst changes in remote drivers and local feedbacks. In particular, ENSO variance increases while that of the South Pacific Oscillation decreases. Conversely, we found that while the Wind-Evaporation-SST feedback tends to increase and the coupling between mixed-layer depth and SST weakens, favoring the development of CN events, the thermocline and wind-SST feedbacks decrease. However, only the change in the thermocline feedback is correlated to changes in CN variance amongst the models, suggesting a dominant role of local oceanic stratification changes in constraining the sensitivity of CN to global warming.

Oceanographical-driven dispersal and environmental variation explain genetic structure in an upwelling coastal ecosystem

The seascape comprises multiple environmental variables that interact with species biology to determine patterns of spatial genetic variation. The environment imposes spatially variable selective forces together with homogenizing and diverging drivers that facilitate or restrict dispersal, which is a complex, time-dependent process. Understanding how the seascape influences spatial patterns of genetic variation remains elusive, particularly in coastal upwelling systems. Here, we combine genome-wide SNP data, Lagrangian larval dispersal simulated over a hydrodynamic model, and ocean environmental information to quantify the relative contribution of ocean circulation and environmental heterogeneity as drivers of the spatial genetic structure of two congeneric intertidal limpets, Scurria scurra and S. araucana, along the central coast of Chile. We find that a genetic break observed in both limpet species coincides with a break in connectivity shown by the Lagrangian dispersal, suggesting that mean ocean circulation is an important seascape feature, in particular for S. scurra. For S. araucana, environmental variation appears as a better predictor of genetic structure than ocean circulation. Overall, our study shows broad patterns of seascape forcing on genetic diversity and contributes to our understanding of the complex ecological and evolutionary interactions along coastal upwelling systems.

Analysis of climate change and climate variability impacts on coastal storms induced by extratropical cyclones: a case study of the August 2015 storm in central Chile

ABSTRACT The projected increase in coastal risk requires a reevaluation of coastal risk reduction strategies. A multi-model approach is proposed to examine the variability of coastal storms influenced by climate change and El Niño Southern Oscillation (ENSO). To this end, the historic coastal storm of August 8 2015, resulting from a local extratropical cyclone (ETC) off the central Chilean coast, was analyzed through the coupling of the WRF atmospheric model, Delft3D FM (D-FLOW and D-WAVE modules), and EOT20 astronomical tide model. The results show that the characteristics of local ETCs are susceptible to regional temperature gradients associated with climate change and ENSO. The coastal storm of August 8 2015, presented a decrease in wave height and counterclockwise rotation of wave direction along the Chilean coast under the climate change scenario. Meanwhile, the ENSO scenarios under cold conditions generated a ETC track’s displacement toward the north, causing both an increase in wave height along the coast of the Antofagasta and Atacama regions and a decrease in wave height in the Valparaíso, O’Higgins, and Maule regions. Findings from this study emphasize the importance of considering dynamic design for coastal structures rather than traditional methods to adapt to changing storm patterns.

Morphological and Molecular Identification of Ulva spp. (Ulvophyceae; Chlorophyta) from Algarrobo Bay, Chile: Understanding the Composition of Green Tides.

Green algae blooms of the genus Ulva are occurring globally and are primarily attributed to anthropogenic factors. At Los Tubos beach in Algarrobo Bay along the central Chilean coast, there have been blooms of these algae that persist almost year-round over the past 20 years, leading to environmental, economic, and social issues that affect the local government and communities. The objective of this study was to characterize the species that form these green tides based on a combination of ecological, morpho-anatomical, and molecular information. For this purpose, seasonal surveys of beached algal fronds were conducted between 2021 and 2022. Subsequently, the sampled algae were analyzed morphologically and phylogenetically using the molecular markers ITS1 and tufA, allowing for the identification of at least five taxa. Of these five taxa, three (U. stenophylloides, U. uncialis, U. australis) have laminar, foliose, and distromatic morphology, while the other two (U. compressa, U. aragoensis) have tubular, filamentous, and monostromatic fronds. Intertidal surveys showed that U. stenophylloides showed the highest relative coverage throughout the seasons and all intertidal levels, followed by U. uncialis. Therefore, we can establish that the green tides on the coast of Algarrobo in Chile are multispecific, with differences in relative abundance during different seasons and across the intertidal zone, opening opportunities for diverse future studies, ranging from ecology to algal biotechnology.

Antimicrobial Activity and Phytochemical Characterization of Baccharis concava Pers., a Native Plant of the Central Chilean Coast.

Few sclerophyllous plants from the central coast of Chile have been systematically studied. This work describes the phytochemical composition and antimicrobial properties of Baccharis concava Pers. (sin. B. macraei), a shrub found in the first line and near the Pacific coast. B. concava has been traditionally used by indigenous inhabitants of today's central Chile for its medicinal properties. Few reports exist regarding the phytochemistry characterization and biological activities of B. concava. A hydroalcoholic extract of B. concava was prepared from leaves and small branches. Qualitative phytochemical characterization indicated the presence of alkaloids, steroids, terpenoids, flavonoids, phenolic, and tannin compounds. The antimicrobial activity of this extract was assessed in a panel of microorganisms including Gram-positive bacteria, Gram-negative bacteria, and pathogenic yeasts. The extract displayed an important antimicrobial effect against Gram-positive bacteria, Candida albicans, and Cryptococcus neoformans but not against Gram-negatives, for which an intact Lipopolysaccharide is apparently the determinant of resistance to B. concava extracts. The hydroalcoholic extract was then fractionated through a Sephadex LH-20/methanol-ethyl acetate column. Afterward, the fractions were pooled according to a similar pattern visualized by TLC/UV analysis. Fractions obtained by this criterion were assessed for their antimicrobial activity against Staphylococcus aureus. The fraction presenting the most antimicrobial activity was HPLC-ESI-MS/MS, obtaining molecules related to caffeoylquinic acid, dicaffeoylquinic acid, and quercetin, among others. In conclusion, the extracts of B. concava showed strong antimicrobial activity, probably due to the presence of metabolites derived from phenolic acids, such as caffeoylquinic acid, and flavonoids, such as quercetin, which in turn could be responsible for helping with wound healing. In addition, the development of antimicrobial therapies based on the molecules found in B. concava could help to combat infection caused by pathogenic yeasts and Gram-positive bacteria, without affecting the Gram-negative microbiota.

Spatial distribution of lower intertidal decapods on the northern Patagonian coast (Pelluhuín beach, Puerto Montt, 41°29′S, Chile)

Abstract The decapod fauna of Chile’s intertidal shores in inner seas south of 40°S has relatively low diversity because of the presence of low-salinity waters due to river inputs and glacial smelts; nevertheless it is possible that the same decapods species are found as on the northern and central Chilean coast. The aim of the present study was to determine the spatial distribution patterns of lower intertidal decapods on Pelluhuín beach, a small beach south of Puerto Montt, northern Patagonia. Data were obtained by counting individuals from random quadrants in intertidal zones; to the obtained data the variance/mean ratio was applied to determine if the specimens have a random, aggregate or uniform distribution, which are associated with Poisson, negative binomial or positive binomial distributions respectively. Among four of the species observed, a uniform distribution (positive binomial) was reported, and one had an aggregated pattern (negative binomial). The sites correspond to rocky shores in semi-urban zones, and in a protected zone. Our results on the interpretative probabilistic models of aggregated distribution patterns agree with previously reported observations of decapods on the rocky shores of Northern and Central Chile, specifically in interpretative probabilistic models.

Environmental DNA reveals temporal variation in mesophotic reefs of the Humboldt upwelling ecosystems of central Chile: Toward a baseline for biodiversity monitoring of unexplored marine habitats.

Temperate mesophotic reef ecosystems (TMREs) are among the least known marine habitats. Information on their diversity and ecology is geographically and temporally scarce, especially in highly productive large upwelling ecosystems. Lack of information remains an obstacle to understanding the importance of TMREs as habitats, biodiversity reservoirs and their connections with better-studied shallow reefs. Here, we use environmental DNA (eDNA) from water samples to characterize the community composition of TMREs on the central Chilean coast, generating the first baseline for monitoring the biodiversity of these habitats. We analyzed samples from two depths (30 and 60 m) over four seasons (spring, summer, autumn, and winter) and at two locations approximately 16 km apart. We used a panel of three metabarcodes, two that target all eukaryotes (18S rRNA and mitochondrial COI) and one specifically targeting fishes (16S rRNA). All panels combined encompassed eDNA assigned to 42 phyla, 90 classes, 237 orders, and 402 families. The highest family richness was found for the phyla Arthropoda, Bacillariophyta, and Chordata. Overall, family richness was similar between depths but decreased during summer, a pattern consistent at both locations. Our results indicate that the structure (composition) of the mesophotic communities varied predominantly with seasons. We analyzed further the better-resolved fish assemblage and compared eDNA with other visual methods at the same locations and depths. We recovered eDNA from 19 genera of fish, six of these have also been observed on towed underwater videos, while 13 were unique to eDNA. We discuss the potential drivers of seasonal differences in community composition and richness. Our results suggest that eDNA can provide valuable insights for monitoring TMRE communities but highlight the necessity of completing reference DNA databases available for this region.

From risk assessment to land planning. The case of a trace element‐contaminated area in Chile

AbstractWhile abundant scientific literature focuses on diagnosing contaminated areas, solutions with a scientific base are far from balanced. This is the case of the Quintero‐Puchuncaví Bay, a widely known contaminated area in the central coast of Chile. Here, arsenic in soils surrounding the industrial complex has been reported as a threat to human health. However, land planning based on As contamination becomes a challenge since the whole area is identified as contaminated. Such a lack of land‐planning constrains the occupation and remediation of contaminated soil leading to a brownfield‐like landscape. To face this challenge, we proposed using a geospatial decision support system (S‐DSS) to integrate the contamination assessment, health and ecosystem risks, and potential land uses. When characterizing soil arsenic concentration thresholds for different land uses in a S‐DSS, we could categorize the land in suitable, caution, and unsuitable areas (based on human health risks). This way, we unravel areas with potential use in the current condition while also discerning caution and unsuitable categories, that can undergo extensive and intensive remediation techniques. Similarly, we took a conservational approach to estimate emerging risk from the industrial complex associated to explosions. Altogether, it highlights the potential of S‐DSS to integrate different geographic information. We finally feature two APPs regarding current land‐use suitability and a modeled one considering future arsenic emissions.

Oxidative damage associated with exposure to heavy metals present in topsoils in central Chile.

Exposure to heavy metals may cause the overproduction of reactive oxygen species, generating oxidative stress and consequently, various harms to human health. The soil surrounding the Ventanas Industrial Complex, in Puchuncaví and Quintero municipal districts on the central Chilean coast, contains heavy metal concentrations (As, Cu, Pb, Zn, among others) that far exceed the maximum permissible levels established by Italian soil standards (used as a reference). This study aimed to investigate the potential association between heavy metal exposure in humans and the levels of oxidative stress biomarkers in inhabitants of these locations. We took blood samples from 140 adults living in sites with high concentrations of heavy metals in the soil and compared them with blood samples from 140 adults living in areas with normal heavy metal concentrations. We assessed lipid peroxidation, damage to genetic material, and Total Antioxidant Capacity in these blood samples. Our results indicate an association between oxidative damage and heavy metal exposure, where the inhabitants living in exposed areas have a higher level of DNA damage compared with those living in control areas. Given that DNA damage is one of the main factors in carcinogenesis, these results are of interest, both for public health and for public policies aimed at limiting human exposure to environmental pollution.

Identificación del riesgo en la Quebrada Jaime, Valparaíso, Chile

The commune of Valparaíso, located on the central coast of Chile, represents a territory of interest for the study of the impacts derived from socio-natural risks and the discussion about its due inclusion in the current territorial planning instruments. Particularly, the Jaime ravine (quebrada Jaime), located in the foothills of the coastal mountain range, represents an interesting study site due to its physical configuration and the level of anthropic intervention that occurs. In this sector, part of the community's low-income population has been forced to migrate, due to the scarcity of urban land in safe areas, facing a series of risks that jeopardize their quality of life. This research uses multicriteria analysis based on physical and social variables to identify and territorially express the risk scenarios for the population of this stream. Forest fires and mass removal processes are presented as the most complex events with the greatest impact and that until now have not been properly integrated into the Valparaíso Metropolitan Regulatory Plan (PREMVAL), thus allowing the intensive use of the territory in risk areas, a situation that must be reanalyzed based on the natural dynamics of the ravine and the progressive occupation of the land, to avoid future impacts on the population

Phylogenetic position and reinstatement ofGayella(Sapotaceae), a monotypic genus endemic to Chile with an Eocene origin in continental Australia

AbstractPouteria splendensis the only native species of Sapotaceae in Chile, a species once placed in the monotypic genusGayellaand known asG. valparadisaea, but for a long time treated as aPouteria. In a phylogenetic analysis, this species was placed in an Australasian clade, not with its presumed relatives in South America. We used Bayesian inference under a relaxed molecular clock in BEAST, nuclear ribosomal DNA (ETS, ITS), the nuclear geneRPB2, indel information, and 201 terminals to find the closest relative ofP. splendensand to estimate the age of the disjunction between Australasia and South America. The taxon has an isolated phylogenetic position, being part of the cladeʼs backbone, and is placed with weak support as sister toVan‐royena, another monotypic genus, but endemic to Australia. Our results justify reinstatement ofGayellawith its single speciesG. valparadisaea.Gayellahas a unique combination of morphological features including alternate, opposite or 3‐whorled leaves, often on the same plant, a usually 6‐lobed, rotate corolla with revolute corolla lobes giving the flower a star‐like appearance, lacerate to dentate staminodes, and yellow‐orange‐red fruit with plano‐convex cotyledons and an exserted radicle below the cotyledon commissure. The split betweenGayellaandVan‐royenais estimated to the late Eocene at about 40.0 Ma (50.5–25.3 Ma). The hypothesis that the presence ofGayellain South America is a result of vicariance is consistent with the timing of the geological splits of southern Gondwana, as well as with evidence from fossil pollen, but long‐distance dispersal is an alternative explanation that cannot be excluded.Gayellais restricted to an area with a Mediterranean‐type climate in coastal central Chile, where it occurs in rocky places, ravines, and gullies, usually below 100 m altitude within reach of sea mist.Gayella valparadisaeais a rare plant, listed as Endangered (EN) in Chile, but it does not occur in any protected area. Considering the isolated phylogenetic position of this old lineage, we urge the Chilean authorities to increase the efforts towards protection of this species.

A modeling study of hydrographic and flow variability along the river-influenced coastal ocean off central Chile

The coast of central Chile has multiple rivers with a marked seasonal discharge variability. Few studies have addressed primarily the seasonal variability of river plume extension and vertical structure. Here, we have analyzed the effects of multiple river outflows on the hydrography (salinity and density) and meridional transports off central Chile. This study is focused on synoptic and intraseasonal scales of variability using eight years of semi-realistic model outputs. Our results reveal that the plume spreading is much broader during winter than spring. Wind-driven changes in plume shapes modulate the geostrophic component of the flow field off Biobío and Itata rivers in winter (spring) after downwelling (upwelling) favorable winds. The geostrophic flow was important off Mataquito and Maule rivers after upwelling-favorable winds, primarily in spring. The stratification in winter was mostly associated with the freshwater content in all coastal regions and showed a rapid response to the wind stress forcing. The mixing through wind stress decreased in spring, modifying the stratification and uncoupling the wintertime variability between stratification and freshwater.

INTEGRATING EXPERIMENTS WITH SUBTIDAL DEATH ASSEMBLAGES TO UNVEIL THE PREDATORY HABITS OF MURICID GASTROPODS FROM THE SOUTHEASTERN PACIFIC

Abstract As quantitative tools, drill holes have been used to calculate predation frequencies in time and space. These traces can also inform predator preference and some strategies predators use to drill on prey (e.g., edge drilling, site stereotypy, or alternative modes of predation when there is no drill hole). In this study, our goal was to leverage the informative power of drill holes to characterize the predatory habits of muricid gastropods from the central coast of Chile. We integrated information from experiments and death assemblages (DAs) to unveil the predatory strategy of Ancathina monodon, Crassilabrum crasilabrum, and Concholepas concholepas on the mobile gastropod Tegula tridentata and the sessile bivalve Perumytilus purpuratus. Experiments supported previous findings for predatory strategies (basal spine for Ancathina and alternative modes of predation for Concholepas), and showed the stereotypic predation of Crassilabrum on Tegula—a herbivore that is devastating subtidal kelp forests. Based on drill holes from DAs, at least 11 molluscan families are consumed by muricids in these communities. DAs also helped validate the stereotypic predation of Crassilabrum on Tegula, as drill holes were found in the same position both in experiments and DAs. Despite their thinner shells, mytilids were well represented in DAs and were found with drill holes in the five locations sampled. We describe for the first time the predatory strategy of Crassilabrum in Chile and confirm that muricids other than Concholepas are active predators on subtidal rocky habitats from the southeastern Pacific Ocean, a region that is still understudied.

When material science meets microbial ecology: Bacterial community selection on stainless steels in natural seawater

The passive film depends on the alloy's composition and the exposure conditions. How the surface composition affects the selection of microbial biofilms though, has not been fully elucidated or incorporated into the analysis of corrosive biofilms. The degradation of stainless steel (SS) exposed to natural seawater was studied to understand how the oxide layer composition of SS could affect the selection and variability of the bacterial community. To accomplish this goal, austenitic and superferritic SS grades were exposed to natural seawater on the central coast of Chile. The deterioration of steel and qualitative description of biofilm formation was monitored at different exposure periods. Biofilms were evaluated based on massive sequencing analysis of the bacterial community and subsequent ecological studies. The results revealed that variability of the calculated corrosion rate correlated with the similarity of the bacterial community within samples from each SS and its corrosion inferred capacity. The associated bacterial families showed a higher representation in SSs with a more significant increase in the Fe/Cr ratio over the exposure time. These findings revealed that iron content in the oxide layer represents a key feature of the surface composition for selecting bacterial assemblages in marine environments.

Size overlap in intertidal decapod communities on a central Chilean rocky beach (El Quisco, 32°24′S, Valparaiso region, Chile)

Abstract The intertidal crustaceans on the Chilean coast are characterized by high diversity and niche specialization. The present study applied a size-overlap null model analysis for intertidal decapod communities in a central Chilean rocky beach (El Quisco, 32°24′S). The application of six models simulations revealed that there is a size overlap, confirmed by the results of all those six simulations. This means that the reported species would share their ecological niches. The results agree with the first classical ecological descriptions for Chilean intertidal decapods at a local scale and support the observations for similar species on the southern Pacific and southern Atlantic coasts, and the results of the null model agree with a first comparative study of decapods in the north and on the central Chilean rocky coast.

Prevalence and molecular identification of zoonotic Anisakis and Pseudoterranova species in fish destined to human consumption in Chile

Zoonotic larvae of the family Anisakidae found in several fish species represent a serious risk in public health since they may cause food-borne anisakidosis in humans. Chile has culinary preferences including eating raw fish in many traditional preparations. In the present study, a total of 180 fish specimens representing three different fish species, i.e., Chilean hake (Merluccius gayi), snoek (Thyrsites atun), and sea bream (Brama australis), were caught at central coast of Chile. Parasitological examination was performed on musculature and abdominal cavity for subsequent extraction and quantification of anisakid larvae. Estimation of infection parameters, such as prevalence, was performed indicating 100% (CI: 0.94–1.0) prevalence of anisakid L3 in Chilean hakes and snoeks. Moreover, sea breams reached a prevalence of 35% (CI: 0.23–0.48). Prevalence of anisakid larvae in muscle was also analyzed showing values of 18.6% (CI: 0.097–0.309) in Chilean hakes, 15% (CI: 0.07–0.26) in snoeks, and 1.7% (CI: 0–0.089) in sea breams. Meanwhile, prevalence of anisakid larvae in internal organs showed highest values for peritoneum (100% and 83.3%) for snoeks and Chilean hakes, respectively, for liver (96.7%) and gonads (86.6%) in Chilean hakes, and for intestine (98.3%) in snoeks. Molecular analysis of collected anisakid L3 unveiled presence of two potentially zoonotic nematode species, i.e., Pseudoterranova cattani and Anisakis pegreffii. P. cattani was found in Chilean hakes and snoeks being the first molecular host species report for Chilean snoeks. Besides, A. pegreffii was also identified in these species being the first molecular report on this regard. These findings are relevant for better understanding of epidemiology of anisakiasis in Chilean coasts and for public health issues considering potential risk of human population due to its culinary preferences in eating raw fish.

Effects of harvesting on subtidal kelp forests (Lessonia trabeculata) in central Chile

AbstractThe systematic degradation of marine ecosystems is a global phenomenon that has important and diverse consequences including biodiversity loss and reduced ecosystem service provisions. In temperate regions, subtidal kelp forests are dominant ecosystems in rocky coasts, subjected to the influence of local‐scale stressors and regional environmental variation. For example, kelps within the Humboldt Current System are at risk of degradation from live‐harvesting by fisheries. However, limited information exists regarding the long‐term consequences of kelp harvesting, which, in turn, limits the ability to provide effective management and conservation efforts. Here, we examined the ecosystem‐level consequences of the artisanal subtidal Lessonia trabeculata fishery along the coast of central Chile during a 2‐year period, assessing (1) the change in adult and juvenile L. trabeculata density within harvested and nonharvested (control) plots (~90 m2), (2) the impact of L. trabeculata harvesting on reef fish and macroinvertebrate assemblages, and (3) the change in density of the most abundant L. trabeculata‐associated species. The experiment was conducted over a 2‐year period, from December 2016 to May 2019. Approximately 90% of L. trabeculata was removed by an experienced kelp fisherman in experimental plots. After 2 years, L. trabeculata and its associated community showed a lack of recovery in the harvested plots. Within these plots, the average abundance of the rock shrimp, Rhynchocinetes typus, and the herbivorous snail, Tegula tridentata, was greater than in nonharvested plots and the pattern persisted over the study period. The difference in abundance of associated species may be key to the (lack of) recovery of L. trabeculata forests. Our study highlights the impact of L. trabeculata harvesting on associated fauna; however, significant knowledge gaps remain regarding the capacity and time frame to reestablish the original biomass of L. trabeculata, as well as its associated fauna. The management of L. trabeculata fisheries needs to account for ecosystem‐wide impacts in order to better manage and protect vital coastal ecosystems.

Growth of Crassostrea gigas (Thunberg, 1793) cultivated in different cultivation devices deployed in sheltered and non‐sheltered sites of central Chile

We cultivated the Pacific oyster (Crassostrea gigas) simultaneously in three types of cultivation device sets deployed in two sites: a sheltered site and a non-sheltered site in the coast of the central area of Chile. Oysters were cultivated in polypropylene trays, nylon cones and lanterns suspended at 2, 5 and 8 m depth from long-lines. Organism sampling was performed monthly from June, 2014 to May, 2015, measuring temperature, salinity and chlorophyll a. Growth was measured by shell length, wet meat weight and meat yield. At the end of cultivation, there were significant differences in the growth of oysters with higher growth in lanterns at 2 m at Punta Lobería (non-sheltered site). Higher growth was also found at 2 m in Coliumo bay (sheltered site). Better growth seems associated with the stability of salinity and chlorophyll a. This is the first study that demonstrates the viability of oyster cultivation in non-sheltered environments on the coast of central Chile.

Draft Genome Sequence of Marinobacter sp. Strain AL4B, a Marine Bacterium Isolated from Quintero Bay, Chile.

ABSTRACTQuintero Bay, located along the central coast of Chile, has suffered different oil spills during the past 10 years, impacting its marine ecosystems. Here, we report the genome sequence of Marinobacter sp. strain AL4B, a marine bacterium isolated from Quintero Bay, Chile.

Optimization of Low Head Axial-Flow Turbines for an Overtopping BReakwater for Energy Conversion: A Case Study

Overtopping-type wave power conversion devices represent one of the most promising technology to combine reliability and competitively priced electricity supplies from waves. While satisfactory hydraulic and structural performance have been achieved, the selection of the hydraulic turbines and their regulation is a complex process due to the very low head and a variable flow rate in the overtopping breakwater set-ups. Based on the experience acquired on the first Overtopping BReakwater for Energy Conversion (OBREC) prototype, operating since 2016, an activity has been carried out to select the most appropriate turbine dimension and control strategy for such applications. An example of this multivariable approach is provided and illustrated through a case study in the San Antonio Port, along the central coast of Chile. In this site the deployment of a breakwater equipped with OBREC modules is specifically investigated. Axial-flow turbines of different runner diameter are compared, proposing the optimal ramp height and turbine control strategy for maximizing system energy production. The energy production ranges from 20.5 MWh/y for the smallest runner diameter to a maximum of 34.8 MWh/y for the largest runner diameter.