Buenaventura Bay Research Articles

Three-Dimensional Hydrodynamic and CFD Modeling of a Tidal Barrage Power Plant without Sluicing in Buenaventura, Colombia

Recent research revealed the potential of tidal energy in the central coastal region of the Colombian Pacific. Buenaventura City, located in the Valle del Cauca department in Colombia, has an important opportunity to develop tidal power technologies near its marine coastal areas. This research implemented a 3D hydrodynamic model for simulating the hydrodynamics of the Buenaventura Bay to provide data as input for evaluating the hydraulics of a tidal barrage without sluicing through CFD modeling. According to the results, the velocities across the gates during Syzygy (April 2021) showed impressive velocities between 9 and 11 m/s, which suggest a high possibility of producing electricity through tidal turbines. The mean behavior of velocities in the gates pointed to values of 3 and 5 m/s in most of the cases. The results during the Stoa condition were interesting because flow velocities higher than 1 m/s were not expected. This is promising because the plant might produce electricity even during the Stoa condition. For the first time, the results of this research suggest that there exists a high possibility of implementing tidal barrage plants in Buenaventura City, Colombia.

Effect of environmental variables on mercury accumulation in sediments of an anthropogenically impacted tropical estuary (Buenaventura Bay, Colombian Pacific)

Estuaries are the main entry areas of mercury to the marine environment and are important to understand the effect of this contaminant on marine organisms, since it accumulates in the sediments becoming available to enter the food trophic chain. This study aims to determine the environmental variables that mainly influence the spatiotemporal dynamics of total mercury accumulation in sediments of tropical estuaries. Sediment samples were collected from interior and exterior areas of the estuary during the dry and rainy seasons, representing the spatiotemporal gradients of the estuary. The grain size, organic matter content (OM), and total mercury concentration (THg) of the sediment samples were determined. In addition, salinity, temperature, dissolved oxygen, and pH of the water column associated with each sediment sample were assessed. The variations in environmental conditions, OM and THg in sediment were in accordance with a gradient which goes from conditions influenced by fresh water in the inner estuary to conditions influenced by sea water in the outer part of the estuary. The OM and THg in sediments presented similar variation patterns; they were higher in the rainy season than in the dry season and in the interior area of the estuary than in the exterior area. Despite the complex dynamic observed in the distribution and accumulation processes of mercury in sediments, these processes could be modeled from OM and salinity parameters. Due to the correlations found, in the process of accumulation of mercury in sediments the OM could represents the pathway of transport and accumulation of THg, and salinity could represent the influence of the hydroclimatic variations and environmental gradients of the estuary.

Effect of Sea Level Rise and Access Channel Deepening on Future Tidal Power Plants in Buenaventura Colombia

The evolution of tidal stream turbines is increasing the feasibility of future tidal plants in shallow depth areas with mid-tidal ranges (<5 m). However, extreme events such as changes in bathymetry due to the access channel deepening of coastal ports and sea level rise modify hydrodynamics and might affect the infrastructure and energy production of tidal energy converters. This research focused on Buenaventura Bay to analyze the effect of these extreme events on marine currents through calibrated-validated numerical modeling. Several monitored points were analyzed, and the results highlighted that the bay has potential for implementing tidal stream turbines because of the reported velocities between 0.25 and 2 m/s. The sea level rise increased 11.39% and access channel deepening reduced by 17.12% the velocity currents of the bay, respectively. These findings convert Buenaventura Bay to a candidate for implementing third generation tidal stream turbines and motivate future research for implementing tidal power systems in crucial areas such as the Colombian Pacific, where communities face restrictions in accessing affordable and clean energy.

Evaluation of Wastewater Discharge Reduction Scenarios in the Buenaventura Bay

Buenaventura Bay is facing severe pollution due to the direct discharge of untreated wastewater from 695 outlets along the coast, which serves 500,000 people. To address this issue, a study was conducted using the RMA11 water quality model, which was previously calibrated and validated, coupled with the RMA10 3D hydrodynamic model to assess sanitation scenarios in the bay. Five effluent reduction scenarios were proposed and compared based on fecal coliform concentration as an indicator, with evaluation also based on areas where fecal coliform concentrations exceeded the standard for primary contact. The model results revealed poor water quality in the bay, indicating that immediate action was necessary to prevent further deterioration. The proposed staged reduction in discharges would initially have more severe effects than the current situation, but this would improve when the treatment plant became operational. However, even with the plant in operation, the complete sanitation of the bay cannot be achieved, and further measures are required. This study emphasizes the urgent need for effective and sustainable measures to improve water quality in Buenaventura Bay and demonstrates the usefulness of the modeling approach in identifying effective sanitation scenarios to achieve this goal. The results highlight the need for a comprehensive management strategy to tackle pollution in the bay and provide insights for other regions facing similar challenges.

Assessment of mercury and lead contamination using the bivalve Anadara tuberculosa (Arcidae) in an estuary of the Colombian Pacific

Buenaventura Bay is considered the main estuary on the Pacific coast of Colombia, because of port and industrial activities. Mining and agriculture are major sources of contamination in the estuary. This study used the bivalve Anadara tuberculosa to evaluate the presence of mercury and lead in the Dagua River estuary (Colombia), one of the main tributaries coming into the bay. Five samplings for sediments and six for tissues of A. tuberculosa were carried out between 2016 and 2017. Additionally, a series of bioassays were conducted to determine its ability to bioaccumulate metals. A mean mercury concentration of 0.57 ± 0.74 mg*kg−1 and lead concentration of 0.87 ± 0.68 mg*kg−1 in sediment were found. Bioassays allowed us to conclude that at low mercury exposure concentrations (0.25 mg*kg−1), lesions are generated in animal tissue, mainly in sexual cells. The high concentrations of mercury found in organisms exceed the maximum permitted concentration established in Colombia. In addition, the contamination factors for mercury and lead were considered very high. This research aims at contributing to the use of Anadara tuberculosa, as prospective bioindicator for pollution biomonitoring in mangrove coastal ecosystems.

Influence of environmental variables on the spatiotemporal dynamics of water quality in Buenaventura Bay, Colombian Pacific.

Tropical estuaries are productive dynamic ecosystems where water quality is mediated by physicochemical and biological processes and by fluvial and anthropogenic discharges. The objective of the study was to determine the influence of environmental variables on the spatiotemporal dynamics of water quality in Buenaventura Bay, which is a highly impacted estuary. Sampling was carried out during the dry and rainy season, at three depths, in four stations that represent the environmental gradient of the bay. Temperature, total dissolved solids, salinity, dissolved oxygen, and pH were determined for each sample. In addition, alkalinity, phosphates, nitrites, and nitrates as indicators of water quality were also measured. The estuary was classified as meso- and polyhaline, with appropriate oxygen and pH conditions and spatiotemporal gradients of temperature and solids mediated by river discharges. Significant variations were found in the physicochemical variables by season, with maximum salinity, pH, and solids in the dry season and oxygen and temperature in the rainy season. Likewise, most of these environmental variables were higher in the outer zone of the estuary and lower in the inner stations. Alkalinity and nitrite values were within the permitted ranges, while phosphates and nitrates indicated low water quality. There was a significant direct influence of temperature and oxygen on alkalinity and nitrites. However, for phosphates, no significant influence of environmental variables was found, suggesting a greater influence by fluvial and anthropogenic discharges, which produce a decrease in the environmental quality of the estuary.

Influence of water quality on the macroinvertebrate community in a tropical estuary (Buenaventura Bay).

The anthropogenic discharges of inorganic nutrients impact water quality, affecting the macroinvertebrate assemblage and food safety. The main objective of this study was to examine the seawater quality and macroinvertebrate dynamics in muddy habitats of Buenaventura Bay, Colombian Pacific. Macroinvertebrates were captured using artisanal trawl nets during different seasons and along four sampling sites. Multivariate analyses (canonical correspondence analysis and generalized additive model) were used to assess the effects of variations in nitrite, nitrates, phosphate concentrations, and physicochemical variables (salinity, pH, dissolved oxygen [DO], temperature, and total dissolved solids [TDS]) of water on the macroinvertebrate assemblage. Richness was the highest at sites with high salinity and temperature and low concentrations of nitrites and TDS. The densities of the commercial shrimp species Xiphopenaeus riveti and Rimapenaeus byrdi were the highest at sites with higher DO and alkalinity, and lower nitrate concentrations. The swimming crab Callinectes arcuatus was dominant at sites with low water quality. In summary, in the transitional season and at the inner sites of Buenaventura Bay, it was observed the lowest water quality due to high nitrate concentration. High nitrate concentration was highlighted as the main anthropogenic factor that could decrease the capture of target macroinvertebrate species for food and livelihoods of artisanal fishermen and their families. Thus, macroinvertebrate communities may be vulnerable to increased inorganic nutrient inputs, which could affect estuarine water quality and ecosystems services. Integr Environ Assess Manag 2022;18:796–812. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Spatial distribution and increase of microplastics over time in sediments of Buenaventura Bay, Colombian Pacific

The increase in production, consumption and inadequate disposition of plastics has generated an accumulation of these elements in marine ecosystems, which have become important microplastics sinks (< 5 mm). The objective of this research was to determine the temporal and spatial differences in the density, distribution, and type of microplastics in the sediments of Buenaventura Bay. For this purpose, sediment samples were collected in the internal estuary (close to the rivers) and in the external estuary (with a greater marine influence). Samples were obtained in the dry, transition, and rainy season for the years 2015 and 2019. Microplastics were extracted by density separation method, each particle was classified and measured by optical microscopy. Density ranged from 11 to 1,354 particles/kg, with averages of 194.9 ± 51.3 and 359.6 ± 88.0 particles/kg for the years 2015 and 2019, respectively, reporting an increase of 84.4 %. The internal estuary presented a higher density in both years and the fibers constituted the most common form of microplastic particles, with 63.7 % for 2015 and 56.03 % for 2019. The presence and increasing accumulation of microplastics generates risks and adverse effects for the marine communities; additionally it coul compromise the food safety for coastal human populations.

Spatial distribution and increase of microplastics over time in sediments of Buenaventura Bay, Colombian Pacific

The increase in production, consumption and inadequate disposition of plastics has generated an accumulation of these elements in marine ecosystems, which have become important microplastics sinks (< 5 mm). The objective of this research was to determine the temporal and spatial differences in the density, distribution, and type of microplastics in the sediments of Buenaventura Bay. For this purpose, sediment samples were collected in the internal estuary (close to the rivers) and in the external estuary (with a greater marine influence). Samples were obtained in the dry, transition, and rainy season for the years 2015 and 2019. Microplastics were extracted by density separation method, each particle was classified and measured by optical microscopy. Density ranged from 11 to 1,354 particles/kg, with averages of 194.9 ± 51.3 and 359.6 ± 88.0 particles/kg for the years 2015 and 2019, respectively, reporting an increase of 84.4 %. The internal estuary presented a higher density in both years and the fibers constituted the most common form of microplastic particles, with 63.7 % for 2015 and 56.03 % for 2019. The presence and increasing accumulation of microplastics generates risks and adverse effects for the marine communities; additionally it coul compromise the food safety for coastal human populations.

Telmatometropsis fredyi gen. nov., sp. nov.: a new water strider from the Colombian Pacific region (Insecta, Hemiptera, Gerridae)

A new genus of Gerridae (Insecta, Hemiptera, Heteroptera) in the subfamily Trepobatinae, Telmatometropsisgen. nov., with a single included species, T. fredyisp. nov., is described from the Colombian Pacific region. Representatives of the new genus were collected in mangrove lagoons of Buenaventura Bay, Valle del Cauca Department. The new genus can be diagnosed by the relative proportions of the antennomeres, the shape of the male fore tarsus, and by the black markings on the head, thorax and abdomen.

Identification of Synergies and Conflicts in Coastal and Marine uses in Colombian Pacific: a Spatial Multi-Criteria Analysis

The increasing demands for physical space towards diverse maritime activities call for coherent planning and scientific knowledge to support the management of the marine the environment. Using secondary multi-scale geographic information gathered from national institutions, expert judgment and a multi-criteria analysis integrated with GIS tools, we aimed to identify potential synergies and conflicts between human activities occurring in the jurisdiction of the master harbor of Buenaventura in the Valle del Cauca department (CP01) in the Colombian Pacific coast. We identified 105 overlaps in which 5.04% were categorized with high CNI (Conflict Normalized Index), while 13 interactions were evaluated with the highest conflict value, representing 14 sectors/groups. Additionally, 12.97% of the overlaps were categorized with a medium number of overlaps (4-6 overlays use), specifically distributed inside the Buenaventura Bay. Conservation uses (Protected Areas – SINAP in Colombia) was consistent within all 13 incompatibilities and conflicts distribution along the study area was not homogenous. The methodological approach used in this study can be used to identify conflicts and synergies in human uses and activities in the marine and coastal environment through the implementation of a methodology adapted to the context of the area. It presents a technical contribution to future processes of Marine/Maritime Spatial Planning and the Integrated Management of the Coastal Zone of Colombia.

Tsunami hazard assessment for the central and southern pacific coast of Colombia

ABSTRACT Highly destructive tsunamis occurred near the Pacific coast of Colombia in 1906 and 1979. Recent studies have established asperities within the subduction zone in this area, which can cause megathrust earthquakes triggering highly destructive tsunamis. In this study we assess the tsunami hazard in the main populated areas of Colombia Pacific coast by calculating the inundation depth and the maximum tsunami height from major scenario. A deterministic method is applied using slip deficit models and broadband slip models as tsunami sources. Result suggest that, for the worse-case scenario, the maximum deformation of the seafloor is 6.0 m within the Esmaraldas segment ; the maximum height of the tsunami is 4.66 m, 4.34 m and 0.53 m around. Tumaco Island, Morro Island, and Cascajal Island (Buenaventura Bay), respectively. Two to five meters inundation depth were calculated in over 11% and 10% of the total areas of the islands of Tumaco and Morro, respectively. Based on these result, tsunami hazard maps were alaborated and will serve to create tsunami mitigation plans in these areas.

Effect of water quality variation on fish assemblages in an anthropogenically impacted tropical estuary, Colombian Pacific

In tropical estuaries, fish diversity varies spatially and temporally due to behavioral processes such as reproductive migrations, predator avoidance, and foraging, which are affected by water quality. Eutrophication is one of the main factors affecting water quality in estuaries. The objective of this study was to determine variation in fish assemblage explained by fluctuating water quality in the Buenaventura Bay. Fish were captured using artisanal trawl nets during the wet, dry, and transitional seasons at four sampling sites. Additionally, alkalinity; phosphate, nitrite, and nitrate concentrations; dissolved oxygen; pH; temperature; and suspended solids were measured. Multivariate analysis was used to assess the effect of water quality on fish assemblage. In Buenaventura Bay, the assemblage composition of Pseudupeneus grandisquamis, Daector dowi, and Citharichthys gilberti was affected by nitrate concentration. Moreover, large fish biomasses were associated with high nitrite concentration, intermediate salinity, and low dissolved oxygen, suggesting that these estuaries are dominated by species tolerant to poor water quality. Species richness was associated with low nitrate and phosphate concentrations, more suitable water quality indicators, and intermediate temperatures. These results suggest that the deteriorating water quality of estuaries as a result of the anthropogenic impact could increase dominance and decrease richness, resulting in structural changes of fish assemblages.

Influences of environmental conditions in the fish assemblage structure of a tropical estuary

Three fish assemblages (functional groups according to estuary use) were examined, which presented different responses to environmental variations, mainly associated to the dry and rainy seasons and high and low salinities and temperatures in the Buenaventura Bay estuary, Colombia, Tropical Eastern Pacific. In total, 4674 individuals were collected, belonging to 69 species of 29 families. The most abundant species was Sphoeroides trichocephalus (35% of the total density). The assemblage of estuarine-resident fishes showed high tolerance to environmental variations since these were present all along the estuary and throughout the year. The assemblage of marine estuarine–dependent species was associated with the rainy season and low salinities and temperatures. The assemblages of marine estuarine opportunist fishes were associated with areas of higher environmental variability in both seasons, dry and rainy. Fish species belonging to the same functional group showed variations in their response to environmental changes which evidenced complex spatial and temporal dynamics. Understanding these changes is necessary to generate effective management plans based on scientific ecological knowledge, which include environmental impacts present in this estuary such as microplastics, heavy metals, and effects of dredging, and their effects on the ecosystem.

Mercury dynamics in macroinvertebrates in relation to environmental factors in a highly impacted tropical estuary: Buenaventura Bay, Colombian Pacific

The environmental health of Buenaventura Bay, a highly impacted tropical estuary, is influenced by numerous human activities, including mining upstream. Large- and small-scale fishing plays an important role in the local economy, so we investigated the dynamic processes of bioaccumulation of mercury at basal trophic levels. Four samples were taken at each of the four locations in Buenaventura Bay during each of the four seasons of 2015. We measured the total mercury content (T-Hg, dry weight) in sediments and in muscle tissue across 17 macroinvertebrate species. The most abundant were the blue crab (C. arcuatus) and the mantis shrimp (S. aculeata aculeata). Blue crab showed an average muscle T-Hg value ​​exceeding the limit of 0.2 g·g-1, which is the maximum T-Hg level suggested for food consumption by vulnerable humans and populations: pregnant women, children, and the community that feeds from this source of protein on a daily basis. It was found that, 6.22% of individuals exceeded the 0.5 g·g-1 level, which is the maximum T-Hg level suggested for food consumption by the general population: the population that consumes it sporadically. Significantly high values ​​of T-Hg in blue crab and mantis shrimp occurred during low salinity conditions in the estuary, suggesting that Hg mainly originates from river runoff during the rainy season. Nevertheless, the biota-sediment accumulation factor (BSAF) was favored in high salinity, which could mean greater availability of Hg for higher levels of the estuarine food web in the dry season and in marine waters. In general, the T-Hg levels in some samples exceeded 0.2 g·g−1. Therefore this pollutant must be monitored due to its biomagnification potential and as a threat to human health, especially that for the local population of fishermen and their families.

Effect of bathymetric changes on residence time in Buenaventura bay (Colombia)

In order to study the effects of dredging on the residence time of the water in Buenaventura Bay, a 2D finite elements hydrodynamic model was coupled with a particle tracking model. After calibrating and validating the hydrodynamic model, two scenarios that represented the bathymetric changes generated by the dredging process were simulated. The results of the comparison of the simulated scenarios, showed an important reduction in the velocities fields that allow an increase of the residence time up to 12 days in some areas of the bay. In the scenario without dredging, that is, with original bathymetry, residence times of up to 89 days were found.

Carbon stocks in mangrove forests of the Colombian Pacific

Mangrove forests occupy less than 1% of tropical forest areas, but they represent approximately 3% of worldwide tropical forest carbon capture. The present study quantified carbon stocks in mangrove forests in two bays in the Colombian Pacific, and evaluated the effect of forest structure on variations of carbon storage in the different ecosystem compartments. Significant differences were found in carbon stocks between the stations of Málaga Bay (a national marine park) and Buenaventura Bay (the main harbor area). Belowground biomass and sediment represented the greatest carbon stocks in the forest. Carbon reserves in mangroves in the Colombian Pacific were similar compared with other tropical mangrove areas. These results highlight the importance of evaluating carbon storage in these ecosystems and of formulating conservation and management strategies integrated with the mangrove forest in the Colombian Pacific.

Dinámica de la estructura y composición de macroinvertebrados y su relación con las variables ambientales en la bahía de Buenaventura

Buenaventura bay is characterized by a great dynamic of environmental variables. There is descriptive information concerning the distribution of macroinvertebrates in the bay and its habitat, however it is necessary to document on its dynamics in relation to environmental variables. The objective of the present work was to determine the espatio-temporal variation in the structure and composition of macroinvertebrates and their relationship with the environmental variables. Four sampling (April-June-September-November) were carried out throughout 2015, in four stations (Estuary River-Internal Estuary-External Estuary-Marine Estuary). At each station three samples of sediments, physicochemical variables of the water and macroinvertebrates were collected. A total of 532 individuals were found in 17 species and 9 families. The abundance varied from 0.7±1.2 to 29.7±7.4 individuals per trawl and the richness varied from 0.3±1.2 to 4.7±1.2 species per trawl. The multiple regression analysis suggests an influence of the variables salinity and percentage of clayson the structure and composition of macroinvertebrates in the bay. The abundance and richness of macroinvertebrates was higher when the salinity conditions prevailed in the estuary.

Ampliación de distribución y récord de talla de Daector gerringi (Actinopterygii, Batrachoididae, Thalassophryninae) especie endémica colombiana

La familia Batrachoididae cuenta con cuatro subfamilias, 23 géneros y 83 especies en todo el mundo, de las cuales quince están presentes en aguas colombianas. La especie Daector gerringi, endémica en el Pacífico oriental colombiano, se ha registrado en el departamento del Chocó, específicamente en los ríos San Juan, Baudó y recientemente en el departamento del Valle del Cauca en bahía Málaga. Este trabajo documenta el primer registro para la especie en la bahía de Buenaventura, Valle del Cauca, y representa el récord de talla para la especie.

DINÁMICA ESPACIAL Y TEMPORAL DE LA BIOMASA ALGAL ASOCIADA A LAS RAÍCES DE MANGLE EN LA BAHÍA DE BUENAVENTURA, COSTA PACÍFICA DE COLOMBIA

The spatial and temporal variation of biomass of mangroveassociated macroalgae growing on roots of Rhizophora. mangle and pneumatophores of Avicennia. germinans were studied at three sampling stations in Buenaventura bay, Colombia, between November 1999 and September 2003. Eighteen species of algae were collected including nine Rhodophyceae, five Chlorophyceae and four Cyanophyta (Cyanobacteria). Four species dominated the algal flora and collectively contributed with 90 % of the total algal biomass. Bostrychia calliptera was the most dominant with 32 % of the total biomass, followed by Boodleopsis verticillata (26 %), Catenella impudica (18 %), and Caloglossa leprieurii (12 %). Algal biomass between seasons showed significant differences, with higher biomass found during the dry season compared to those of the rainy season. The algal biomass at the mouth of the estuary was significantly higher than that found in the inner areas of the estuary (annual means of 30.7 ± 10.8 vs. 13.8 ± 4.1 g m-2 respectively).Three well-defined vertical zones were observed, based on algal biomass: A narrow upper zone, dominated by B. calliptera; a wide middle zone, with mixed populations of C. impudica and B. calliptera, registering annual mean of 86.8 ± 24.1 g m-2, and a bottom zone, dominated by C. leprieurii and B. verticillata. The results indicated that water level inundation and the vertical position along the roots seem to be the most important factors influencing the algal biomass.