Next Article in Journal
Culture Collections for Conservation Ex Situ: Characterization and Biotechnological Application Potential of Saprotrophic Fungal Strains from Brazil
Previous Article in Journal
Environmental Drivers of Immature Whale Shark Surface Sightings in the Gulf of Tadjoura, Djibouti
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Conservation
Volume 5
Issue 4
10.3390/conservation5040069
conservation-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Flowing Towards Restoration: Cissus verticillata Phytoremediation Potential for Quebrada Juan Mendez in San Juan, Puerto Rico

by
Sofía Velázquez
1,
Keyla Soto Hidalgo
2,
Monica C. Rivas
1,
Sofía Burgos
3 and
Kelcie L. Chiquillo
1,*
1
Department of Biology, University of Puerto Rico, Rio Piedras, P.O. Box 23360, San Juan 00931, Puerto Rico
2
Department of Biological Sciences, College of General Studies, University of Puerto Rico, Rio Piedras, P.O. Box 23360, San Juan 00931, Puerto Rico
3
Estuario, San Juan, San Juan Bay Estuary Partnership, P.O. Box 9509, San Juan 00908, Puerto Rico
*
Author to whom correspondence should be addressed.
Conservation 2025, 5(4), 69; https://doi.org/10.3390/conservation5040069
Submission received: 18 September 2025 / Revised: 1 November 2025 / Accepted: 5 November 2025 / Published: 14 November 2025
Browse Figures
Versions Notes

Abstract

The detrimental effects of anthropogenic pollution are often magnified across ecosystems due to the interconnected nature of land, rivers, and oceans. Phytoremediation is an accessible technique that leverages the ability of plants to absorb and sequester pollutants and can potentially mitigate contaminants entering the ocean. It is a cost-effective and minimally invasive alternative to traditional water treatment methods. This study investigates the potential of the grapevine species Cissus verticillata (L.), a native plant from Puerto Rico, to be used in the phytoremediation of a creek in a highly urbanized site impacted by contaminated runoff due to heavy rainfall and sanitary waters. A mesocosm experiment was conducted using distilled water mixed with nutrients and known concentrations of cadmium (Cd) and lead (Pb) salts to assess whether C. verticillata could accumulate heavy metals in its tissues. Results showed that C. verticillata successfully absorbed heavy metals, with removal efficiencies of 80.13% (±0.16 SE) for Pb and 44% (±1 SE) for Cd. Results indicated a translocation factor <1 for both cadmium and lead, meaning C. verticillata is not a hyperaccumulator, but a metal stabilizer, as evident by the below detection limit (BDL) of the metals in Juan Mendez Creek. Despite evidence of new vegetative growth among individuals, no significant changes in total biomass or chlorophyll concentration were detected, indicating that C. verticillata maintained physiological stability under heavy metal exposure. Therefore, C. verticillata’s wide availability, adaptability to various environments, and climbing nature—which makes it less vulnerable to runoff and strong currents during rainy seasons—position it as a promising candidate for conservation initiatives and pollution management strategies.

1. Introduction

Understanding the effects of urbanization in the river basin is crucial, as these effects can be amplified by the interconnectedness of lands, rivers, and oceans [1,2,3]. Contaminants originating from urban, industrial, and agricultural activities can be transported by runoff into freshwater sources that eventually flow into the ocean, carrying various pollutants through multiple ecosystems [4]. Urban pollutants range from simple biodegradable substances [5] to complex biodegradable pollutants, as well as non-degradable pollutants, such as heavy metals [6,7]. Heavy metals are especially concerning due to their persistence, bioavailability, and ability to biomagnify as they move up the trophic levels in the food chain [8,9], posing threats to biodiversity and the stability of natural systems [10,11].
In particular, the heavy metals cadmium (Cd) and lead (Pb) are recognized for their severe public health implications [12]. Both are considered human carcinogens [13], disrupting cellular processes [14], even triggering apoptosis [15], and can alter physiological functions of the body even at low exposure [16,17]. These non-degradable pollutants have even been found within human fetuses [18] and breast milk [19] and can bioaccumulate within organisms, disrupting development [8]. These threats emphasize the urgent need to mitigate their impacts.
Phytoremediation has emerged as a promising strategy to reduce pollutants in water, soil, and air. This important process takes advantage of the ability of plants to absorb and concentrate elements from the environment in their tissues, or render them harmless [20,21], and has been widely applied for the remediation of soils and aquatic systems contaminated with heavy metals and other pollutants. Plants can uptake heavy metals through various mechanisms, depending on whether they act as “accumulators” or “excluders” [22,23]. Accumulator plants are often used in phytoextraction, a process that uses pollutant-accumulating species to remove metals from soil by concentrating them in harvestable parts of the plant [24,25,26]. Plants identified as “hyperaccumulators” of heavy metals are those that can translocate and accumulate especially high concentrations of metals not only in their roots but also in their aboveground tissues, like stems and leaves. In contrast, plants that act as excluders contribute to phytostabilization by immobilizing contaminants in the soil through absorption and retention within the root zone and restricting uptake in the rest of their biomass [27].
The use of native plants in phytoremediation has gained popularity for their efficiency in removing pollutants from and/or stabilizing them within soil, as they are better adapted to local conditions and can support broader biodiversity goals [28,29,30,31]. However, regions like Puerto Rico, characterized by heavy rainfall [32], present unique challenges to traditional phytoremediation approaches, as flooding events and strong currents can wash away large amounts of vegetation downstream [33]. Newly planted seedlings are especially vulnerable to the force of water currents, as they have not established a strong root system, compromising their ability to stabilize and carry out remediation. To overcome this obstacle, one possible solution is to utilize climbing plants attached to a support base with roots submerged in water.
Near bodies of water, vines can anchor themselves to stable surfaces using their tendrils while allowing their roots to hang freely [34] and grow actively in water [35]. In the tropics, vines are widely available. In Puerto Rico and the Virgin Islands alone, there are 385 climbing species; 247 of which are native [36]. However, the remediation potential of vines remains largely unknown. We hypothesize that Cissus verticillata will accumulate heavy metals primarily in its roots, thereby reducing translocation to aboveground tissues, similar to patterns reported in grapevines that retain copper and zinc in their root systems [37]. This study aims to assess the effectiveness of an abundant, native vine, Cissus verticillata, in sequestering heavy metals, specifically cadmium (Cd) and lead (Pb), to improve water quality.

2. Materials and Methods

2.1. Study Site of Local Watershed

Juan Méndez Creek (JMC), located in the municipality of San Juan, Puerto Rico, is part of the San Juan Bay Estuary. It drains from the Nuevo Milenio State Forest and flows into the San José Lagoon (Figure 1A). The creek spans approximately 6.75 km in length within a heavily urbanized watershed covering 8.2 square km (Figure 1B). Extensive hydrological modifications, including channelization, have left only minimal sections of the creek in its natural state [38].
Frequent pipeline breakages caused by an outdated sanitary system result in the influx of untreated sewage and illicit discharges into the creek, leading to poor water quality [39]. Additionally, JMC receives significant runoff from heavily trafficked avenues and surrounding communities. This area resembles riparian landscapes characterized by a mosaic of spontaneous plant communities. These include climbing vines such as Cissus verticillata, Ipomoea alba, and Passiflora suberosa, interspersed with wet meadows dominated by native herbaceous wetland species.
Water quality samples were collected from one site in JMC (Figure 1B) to characterize the site’s environmental conditions. We used a multiparameter EXO YSI probe to measure key water quality indicators, including temperature, pH, humidity, dissolved oxygen, conductivity, and salinity. Additionally, we collected water samples in sterile bottles for laboratory analysis of oil and grease concentrations (EPA 1664A [40]), total nitrate and nitrite (EPA 353.2 [41]), total phosphorus (Standard Methods 4500-P A, B, E [42]), total lead (EPA 200.7 [43]), and total cadmium (EPA 200.7 [43]). These procedures were repeated on three separate occasions to establish a comprehensive site profile.

2.2. Study Species Collection and Acclimation

The Bejuco de Caro (Cissus verticillata (L.)), native to Puerto Rico (Figure 1C), with widespread neotropical distribution, is an opportunistic, medicinal, non-woody vine that climbs using tendrils [36]. It has cultural significance due to its rapid growth. Due to its dense and entangled pattern of growth, it has been used as sun protection and insulation on shelters and/or worn as a shawl [44]. It grows over various substrates, including shrubs, trees, fences, old buildings, and electricity poles, often forming a thick canopy (Figure 1D). It reproduces through seeds and vegetatively, rooting from broken offshoots or fragments, and rapidly generates new shoots, with a growth rate of ~64 cm/day [45]. Although typically terrestrial, C. verticillata has been observed thriving in partially submerged environments [46], making it a promising candidate for aquatic phytoremediation in local waterways.
We collected C. verticillata samples from two primary locations: Juan Méndez Creek and the University of Puerto Rico-Rio Piedras campus. Our preparation process involved rinsing the harvested donor vines with water and creating uniform cuttings characterized by two leaves per individual. We randomly identified a total of twenty-five individuals and weighed the mass of each cutting. Then, the cuttings were placed in a growth tank with indirect sunlight, water, and 100 mg of 14-14-14 nitrogen: phosphorus: potassium (NPK) fertilizer (Evergreen Controlled Release Plant Food, SKU#174797, Owings Mills, MD, USA) per 10-gallon tank, resulting in roughly 2.7 mg/L of phosphorus and nitrogen, to encourage rooting. To increase oxygen and prevent stagnation for microbes to colonize, we added an aeration device (Penn-PlaxⓇ airPod™ aquarium air pump APB1, Hauppauge, NY, USA) and a supporting rack to provide structural stability for each cutting.
After an acclimation period of 30 days, the successfully rooted individuals were transferred to a controlled environmental chamber in the Soto lab at the University of Puerto Rico, Rio Piedras, from 7 October to 18 October 2024. This chamber allowed regulation of key conditions, including light, humidity, temperature, and air circulation. We randomly distributed the cuttings into five containers (Figure S1A–C), each equipped with an aeration device and supporting rack. Each container included five individual cuttings of C. verticillata with their roots submerged in water. The chamber was programmed to provide light between 6:00 a.m. and 6:00 p.m. for a consistent 12-h photoperiod. The cuttings were left to acclimate to these conditions for one week, during which observations were regularly recorded. Both rooting and acclimatization processes were conducted to minimize potential physiological shock in the cuttings and ensure their functionality remained effective before the experimental phase.

2.3. Phytoremediation Experiment

To investigate the potential nature of phytoremediation, we examined C. verticillata’s response to lead and cadmium exposure over two weeks. Prior to the experiment, plant tissue was collected from the leaf, stem, and root (n = 2) and sent to EQLAB for initial characterization. The samples underwent analysis using inductively coupled plasma (ICP-OES) to establish baseline heavy metal concentrations in roots, stems, and leaves.
Following acclimatization, the experimental phase began. C. verticillata cuttings were removed from the chamber to prepare the heavy metal solutions. To ensure phytoremediation potential was evident, stoichiometric calculations were made to have a final concentration of 3 mg/L of cadmium and lead (Figure S1). A previous study evaluated 5–15 mg/L and reported metal uptake efficiency decreased with increasing concentration, suggesting possible toxicity effects at higher levels [47]. Therefore, 3 mg/L was chosen as a detectable yet sub-toxic concentration for Pb and Cd exposures, allowing measurable uptake while minimizing phytotoxic stress. These measurements are significantly higher than the safe limits for drinking water established by the EPA—0.015 mg/L for lead (Pb) under the Lead and Copper Rule [48], and 0.005 mg/L for cadmium (Cd) under the National Primary Drinking Water Regulations [49]. After thoroughly mixing the prepared solutions, C. verticillata cuttings were evenly distributed among the five containers, initiating the exposure phase of the study.
We tracked temperature and humidity daily using an Acurite hygrometer (AcuRite, Lake Geneva, WI, USA) and thermometer within the chamber. Water pH was measured using an APERA instrument pH meter to detect changes in acidity. To monitor plant stress, we assessed chlorophyll content daily (Mon.-Fri.), which was determined indirectly using a SPAD-502Plus chlorophyll meter (Konica Minolta Inc., Tokyo, Japan), and expressed in SPAD units [50]. For each measurement, we analyzed two leaves per individual cutting and averaged the results.
Following two weeks of heavy metal exposure, we harvested the plants and recorded their final masses. The cuttings were separated into roots, stems, and leaves (only the blade was assessed for the leaf portion, with the petiole considered part of the stem), and were grouped by container. They were analyzed using ICP-OES to determine the total absorbed cadmium and lead concentrations in the different tissue types (n = 15). In addition to the tissue analysis, water samples from each container (A, B, C, D, and E; Figure S1A–C) were also analyzed using ICP-OES (Perkin Elmer, Waltham, MA, USA). This assessment tracked the residual heavy metal concentrations to evaluate the efficiency of lead and cadmium removal from the water.

2.4. Statistical Analyses

For the chlorophyll data, we applied the Shapiro–Wilk (using “shapiro.test”) test to assess whether the data followed a normal distribution in R version 4.2.3 [51]. Subsequently, the Bartlett test was used to evaluate homoscedasticity, or equal variances, across the data (“bartlett.test” in car package) [52]. Then, we performed an Analysis of Variance (ANOVA) to identify any statistically significant differences in chlorophyll levels across the different time frames. For plant biomass, we conducted the Shapiro–Wilk and Bartlett tests, and a paired t-test to compare the initial and final biomass of C. verticillata to evaluate plant growth. For the water samples, the removal efficiency (%) for cadmium and lead in each container was calculated:
Removal Efficiency (%) = (C0 − Cf)/C0 × 100
where C0 is defined as the initial metal concentrations (mg/kg) and Cf are final metal concentrations (mg/kg) in water samples. Finally, to assess the mechanisms of phytoremediation of C. verticillata, we applied a translocation factor (TF) technique to measure cadmium and lead translocation from root to shoot:
TF = Cshoot/Croot
where Cshoot and Croot are the measured metal concentrations (mg/kg) in shoots and roots, respectively. We performed a t-test to determine differences between the removal efficiencies and translocation factors of each metal.
To detect if metal concentrations were different between tissue types, we used a Linear Mixed-Effects model for final internode length using the “lme” function from the “nlme” stats package [53], as this analysis is robust to violation of assumptions of normality [54]. We used Tukey’s multiple comparison test to determine which treatments were significantly different from each other using the package and function “lsmeans” in R ver. 4.2.3 [55]. Tukey’s post hoc values less than 0.05 were considered to be significantly different between treatments.

3. Results

3.1. Water Quality in Juan Mendez Creek (JMC)

Water quality analyses in Juan Mendez Creek (JMC) revealed that heavy metal concentrations of cadmium (Cd) and lead (Pb) were below the detection limit (BDL) (Table 1). Additionally, total phosphorus was 0.19 mg/L (±0.03 SE), indicating eutrophication in the watershed. All other parameters were within the limits accepted by the EPA [56].

3.2. Plant Growth and Stress

Biomass measurements of C. verticillata individuals showed no statistically significant difference between initial and final sampling points (p = 0.7, df = 48) (Figure 2A). Chlorophyll levels remained consistent throughout the experiment, with no significant differences observed between days (p = 0.8, df = 224) (Figure 2B). However, despite the lack of significant growth, a total of 38 new leaves were recorded across all 25 individuals.

3.3. Mechanisms of Translocation of Cadmium and Lead

Prior to heavy metal exposure, ICP-OES analysis revealed that cadmium (Cd) and lead (Pb) were below the detection limit (BDL) of concentration in the roots, stems, and leaves of C. verticillata.
After two weeks of heavy metal exposure, ICP-OES analyses in roots, stems, and leaves revealed that C. verticillata effectively accumulates cadmium (Cd) and lead (Pb). We found significant differences in the amount of Cd between different tissue types (p = 0.0041) (Table 2a). Concentration of Cd in tissues was observed to be the highest in roots (avg 1100 mg/kg ± 400 mg/kg SE), with moderate concentrations in stems (avg 46 mg/kg ± 14 mg/kg SE) and lower levels in leaves (avg 1.6 mg/kg ± 0.3 mg/kg SE) (Figure 2). Significant pairwise differences in Cd transference showed that leaves differed from roots (p = 0.0073) and roots differed from stems (p = 0.0094), but no difference was observed from stems to leaves (Table 2b).
Similarly to Cd, we found significant differences in concentration of Pb between different tissue types (p = 0.0001) (Table 3a). We found that the concentration of lead in tissues was the highest in roots (avg 870 mg/kg ± 160 SE), markedly lower in stems (avg 19 mg/kg ± 5 mg/kg SE), and falling below the detection limit in leaves (Figure 3). Significant pairwise differences in Pb transference showed differences between leaves and roots and stems (p = 0.0001), but no difference was observed from stems to leaves (Table 3b).

3.4. Phytoextraction of Cadmium and Lead

Phytoremediation experiments with C. verticillata resulted in different removal efficiencies for cadmium (Cd) and lead (Pb) from water. The study demonstrated a notably higher removal efficiency for lead, reaching 80.13% (±0.16 SE), compared to 44% (±1 SE) for cadmium (p = 0.046) (Figure 4A). Translocation factors for both elements were low (Figure 4B), and we found no significant difference.

4. Discussion and Conclusions

We found that C. verticillata showed a remarkable capacity for phytoextraction of heavy metals from water, and an ability to adapt under exposure to a heavily contaminated environment. This is the first study demonstrating C. verticillata’s ability to sequester cadmium (Cd) by 44% (±1 SE) and lead (Pb) by 80.13% (±0.16 SE) from water. Previous studies support our findings, as C. verticillata has been identified as a promising candidate for metal stabilization and retention, and an accumulator of cadmium in soil experiments [57]. Additionally, C. verticillata maintained growth and stable chlorophyll levels despite high heavy metal exposure, indicating minimal stress and highlighting its potential as an effective phytoextraction plant. Similarly, no significant differences in chlorophyll content were found in black mangroves, indicating their ability to remove heavy metals without affecting physiology [58].
The native vine C. verticillata acts as a cadmium excluder in water by specifically accumulating the highest concentration of metals in its roots. Similarly, other studies found that the highest concentrations of cadmium accumulated in the roots of Phragmites australis [59] and Eichhornia crassipes (water hyacinth) when extracted from water [60], with some transference to aerial tissue.
We found that C. verticillata is also an effective lead excluder. Lead has been identified as notoriously difficult to remove from soil [21], and even in plants identified as hyperaccumulators such as Brassica juncea (Indian mustard), only a small amount of lead is transferred from roots to shoots [61]. Additionally, Pistia straitotes (water lettuce) and E. crassipes (water hyacinth) were found to accumulate lead mainly in the root system from water [62,63]. Similar results were reported with the highest concentrations of lead immobilized in the roots of red beet [64].
For a plant to effectively translocate metals from its roots to its shoots, the translocation factor (TF) must be greater than 1 [21]. C. verticillata had a TF < 1 for both the cadmium and lead treatments, revealing that this species is not a hyperaccumulator in water. Although we found some concentrations of cadmium in our leaves and stems, limited accumulation could also reflect the plant’s maturity or short treatment period, warranting further study on saturation thresholds.
Future studies should examine longer-term accumulation dynamics, as well as using individuals with more biomass and more replicates to identify a saturation threshold and assess how quickly this threshold is reached. Additionally, this study aimed to isolate the removal potential for cadmium and lead, but C. verticillata may be able to remove other pollutants from water, such as other heavy metals (e.g., Cu, Zn, Cr) and/or organic pollutants (e.g., pesticides). Investigating how multiple pollutants act in tandem, along with manipulating variables such as pH and salinity, would provide valuable insight into how these variables affect plant health to inform potential field applications.
In potential urban applications, coordinated management by local environmental organizations (i.e., the San Juan Bay Estuary Partnership) would be necessary to ensure proper handling. The use of C. verticillata in restoration efforts should focus on its role as a metal stabilizer by retaining metals within the root zone. For effective decontamination and complete removal of heavy metals from the environment, total plant removal is necessary. Plant material may be harvested and incinerated, or composted to recycle the metals, in accordance with hazardous waste disposal standards set by the EPA [65], and dependent upon additional local regulations. C. verticillata also holds cultural importance in its native range, having been traditionally used for various medicinal purposes, such as treating diabetes, abscesses, hemorrhages, fevers, indigestion, and epilepsy [66]. While this familiarity could facilitate community interest in restoration and remediation efforts, its capacity to accumulate heavy metals necessitates caution. Therefore, any harvesting or disposal should be conducted under the supervision of trained personnel, who could play a key role in educating the public about both the ecological benefits and safe handling of this species.
Complementing its metal-accumulation capacity, C. verticillata can quickly colonize new areas and is often found growing on stable structures such as fences, bridges, buildings, culverts, trees, and powerlines. This natural self-anchoring ability allows its submerged root systems to remain in contact with the water column, allowing continued uptake of metals and nutrients, even during high-flow events [46], which are frequent in Puerto Rico following hurricanes. These characteristics, combined with its widespread abundance, suggest that C. verticillata could serve as a cost-effective species for future restoration and phytoremediation efforts.
Vines, in general, have been proven effective in the remediation of contaminated water sources. For example, Ipomea aquatica removes cadmium, zinc, copper [43], chromium, and manganese [67] from water, and decreases the toxicity of treated textile wastewater [68], while Ipomea batatas has been used to remediate motor oil in contaminated soil [69]. As a helophytic group of organisms, vines have evolved to grow vertically, climbing onto existing infrastructure to obtain support for their stems [34]. The high density of C. verticillata and other vine species in contact with water observed at Juan Mendez Creek may explain why water quality analyses revealed heavy metal presence below detection limits (BDL), as these vines could be aiding in metal sequestration. However, cadmium has been known to naturally precipitate out of water and settle in sediments; conversely, lead is not able to precipitate out of water naturally. Given the presence of multiple vine species at our site, we propose that hanging vines may offer a promising phytoremediation strategy in tropical climates.
The phytoremediation potential of vine species could take advantage of this adaptation, yielding a solution for mitigating contamination in rapidly changing urbanized environments while safeguarding drinking water and supporting healthy ecosystems. This study identifies C. verticillata as a fast-growing, widely distributed species capable of removing heavy metals from water, highlighting its potential use in phytoremediation. However, it is important to note that these findings are based on a short experimental duration and a limited range of metals tested, which constrains the generalization of the results and may underestimate the plant’s long-term accumulation capacity. Future studies with extended monitoring and broader metal analyses will be essential to fully assess its remediation potential.

Supplementary Materials

The following supporting information can be downloaded at https://www.mdpi.com/article/10.3390/conservation5040069/s1. Acclimation and chamber setup are depicted in Figure S1: Acclimation and chamber setup. (A) Rooting process setup with support rack (picture taken by S. Velázquez, 12 September 2024). (B) Acclimation process setup, 25 tagged C. verticillata cuttings, five per container (picture taken by S. Velázquez, 1 October 2024). (C) Tagged C. verticillata in cadmium and lead solutions, new growth depicted (picture taken by S. Velázquez, 8 October 2024).

Author Contributions

Conceptualization, S.V., S.B. and K.L.C.; Methodology, K.S.H. and K.L.C.; Validation, K.L.C., S.V. and K.S.H.; Formal Analysis, S.V., K.L.C. and K.S.H.; Investigation, S.V., K.L.C., M.C.R. and K.S.H.; Resources, K.S.H. and K.L.C.; Data Curation, K.L.C. and S.V.; Writing—Original Draft Preparation, S.V., K.L.C. and M.C.R.; Writing—Review & Editing, S.V., S.B., M.C.R., K.L.C. and K.S.H.; Visualization, S.V., K.L.C. and M.C.R.; Supervision, K.L.C. and K.S.H.; Project Administration, M.C.R., S.V. and K.S.H.; Funding Acquisition, S.V., K.S.H. and K.L.C. All authors have read and agreed to the published version of the manuscript.

Funding

This work was supported by Isla Mar Seed Fund; KSH was funded by NSF-CREST Center for Innovation, Research and Education in Environmental Nanotechnology (CIRE2N) under Grant Number NSF-HRD-1736093; KLC was funded by UPR Rio Piedras Start Up Funds and RaMP-UP: Research and Mentoring for Postbaccalaureates in Biological Sciences at the University of Puerto Rico, NSF DBI: 2216584.

Institutional Review Board Statement

Cissus verticillata was used in this study. The wild sample, which included fruits and flowers, was collected from the University of Puerto Rico, Rio Piedras (18°24′13.23″ N, 66°2′47.58″ W) on 28 October 2025, in the municipality of San Juan, Puerto Rico. This plant was hanging from a woody tree with thicker, brown branches resembling a Psidium species in an urban, semi-shaded, disturbed area. Voucher specimens have been deposited at the Herbarium of the University of Puerto Rico at Río Piedras (UPRRP, Rio Piedras, 17 Avenida Universidad, Suite 1701, San Juan, Puerto Rico 00925-2537), founded in 1966, which houses approximately 70,000 accessioned specimens of mycological, algal, and vascular plant taxa from Puerto Rico and the Caribbean. The Cissus specimen associated with this study is cataloged under accession number 63751 and barcode UPRRP32707. It can be cited as “Chiquillo s.n. (UPRRP acc. no. 63751, barcode UPRRP32707)”. Specimens were identified and verified by Dr. Fabiola Areces Berazain (Department of Biology, University of Puerto Rico, Río Piedras).

Data Availability Statement

The data that support the findings of this study are openly available and accessible via OSF. Link for peer review: https://osf.io/tpqhy/?view_only=de1d7f553e274885b1d751f170052d89 (accessed on 4 June 2025).

Acknowledgments

First, we are grateful to the Chiquillo Lab for all the support and guidance throughout the semester. Special thanks to José Radames Fuentes from EQLAB and Rebeca Rivera from Estuario for their unwavering support and guidance throughout this project. To agronomist Zuleiris A. Rodríguez Reyes for their guidance on the plant growth process. And finally, to Cristina Martinez Benito and the students of the Scientific Writing course of UPR Rio Piedras for their assistance in reviewing and refining this work.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Freeman, L.A.; Corbett, D.R.; Fitzgerald, A.M.; Lemley, D.A.; Quigg, A.; Steppe, C.N. Impacts of urbanization and development on estuarine ecosystems and water quality. Estuaries Coasts 2019, 42, 1821–1838. [Google Scholar] [CrossRef]
  2. Ren, L.; Cui, E.; Sun, H. Temporal and spatial variations in the relationship between urbanization and water quality. Environ. Sci. Pollut. Res. 2014, 21, 13646–13655. [Google Scholar] [CrossRef] [PubMed]
  3. Xiong, W.; Ni, P.; Chen, Y.; Gao, Y.; Li, S.; Zhan, A. Biological consequences of environmental pollution in running water ecosystems: A case study in zooplankton. Environ. Pollut. 2019, 252, 1483–1490. [Google Scholar] [CrossRef] [PubMed]
  4. GESAMP. Protecting the Oceans from Land-Based Activities: Land-Based Sources and Activities Affecting the Quality and Uses of the Marine, Coastal and Associated Freshwater Environment (GESAMP Reports and Studies No. 71); United Nations Environment Programme: Nairobi, Kenya, 2001; Report No.: 71; Available online: http://www.gesamp.org/publications/protecting-the-oceans-from-land-based-activities (accessed on 8 May 2025).
  5. Mallin, M.A.; Williams, K.E.; Esham, E.C.; Lowe, R.P. Effect of human development on bacteriological water quality in coastal watersheds. Ecol. Appl. 2000, 10, 1047–1056. [Google Scholar] [CrossRef]
  6. Carle, M.V.; Halpin, P.N.; Stow, C.A. Patterns of watershed urbanization and impacts on water quality. J. Am. Water Resour. Assoc. 2005, 41, 693–708. [Google Scholar] [CrossRef]
  7. Shafi, S.M. Environmental Pollution; Atlantic Publishers & Distributors: New Delhi, India, 2005; Available online: https://books.google.com.pr/books?hl=en&lr=&id=bd8UxaeRFmgC&oi=fnd&pg=PA1&dq=land+contamination+shafi+2005&ots=fbJJOahos-&sig=oYus661i9Qz8N9CDg3lxpTKtSU0&redir_esc=y#v=onepage&q&f=false (accessed on 15 May 2025).
  8. Ali, H.; Khan, E.; Ilahi, I. Environmental chemistry and ecotoxicology of hazardous heavy metals: Environmental persistence, toxicity, and bioaccumulation. J. Chem. 2019, 2019, 6730305. [Google Scholar] [CrossRef]
  9. Saidon, N.B.; Szabó, R.; Budai, P.; Lehel, J. Trophic transfer and biomagnification potential of environmental contaminants (heavy metals) in aquatic ecosystems. Environ. Pollut. 2024, 340, 122815. [Google Scholar] [CrossRef]
  10. Jeffries, T.C.; Schmitz Fontes, M.L.; Harrison, D.P.; Van-Dongen-Vogels, V.; Eyre, B.D.; Ralph, P.J.; Seymour, J.R. Bacterioplankton dynamics within a large anthropogenically impacted urban estuary. Front. Microbiol. 2016, 6, 1438. [Google Scholar] [CrossRef]
  11. Quero, G.M.; Cassin, D.; Botter, M.; Perini, L.; Luna, G.M. Patterns of benthic bacterial diversity in coastal areas contaminated by heavy metals, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs). Front. Microbiol. 2015, 6, 1053. [Google Scholar] [CrossRef]
  12. Tchounwou, P.B.; Yedjou, C.G.; Patlolla, A.K.; Sutton, D.J. Heavy metal toxicity and the environment. EXS 2012, 101, 133–164. [Google Scholar] [CrossRef]
  13. International Agency for Research on Cancer. Agents Classified by the IARC Monographs; World Health Organization: Lyon, France, 2025; Volume 1–138, Available online: https://monographs.iarc.who.int/agents-classified-by-the-iarc/ (accessed on 12 May 2025).
  14. Shalan, M.G.; Mostafa, M.S.; Hassouna, M.M.; El-Nabi, S.E.H.; El-Refaie, A. Amelioration of lead toxicity on rat liver with vitamin C and silymarin supplements. Toxicology 2005, 206, 1–15. [Google Scholar] [CrossRef]
  15. Pham, T.N.D.; Marion, M.; Denizeau, F.; Jumarie, C. Cadmium-induced apoptosis in rat hepatocytes does not necessarily involve caspase-dependent pathways. Toxicol. In Vitro 2006, 20, 1331–1342. [Google Scholar] [CrossRef]
  16. Gurer-Orhan, H.; Sabır, H.U.; Özgüneş, H. Correlation between clinical indicators of lead poisoning and oxidative stress parameters in controls and lead-exposed workers. Toxicology 2004, 195, 147–154. [Google Scholar] [CrossRef] [PubMed]
  17. Joseph, C.L.M.; Havstad, S.; Ownby, D.R.; Peterson, E.L.; Maliarik, M.; McCabe, M.J.; Barone, C.; Johnson, C.C. Blood lead level and risk of asthma. Environ. Health Perspect. 2005, 113, 900–904. [Google Scholar] [CrossRef] [PubMed]
  18. Caserta, D.; Graziano, A.; Lo Monte, G.; Bordi, G.; Moscarini, M. Heavy metals and placental fetal-maternal barrier: A mini-review on the major concerns. Eur. Rev. Med. Pharmacol. Sci. 2013, 17, 2198–2206. [Google Scholar] [PubMed]
  19. Al-Saleh, I.; Shinwari, N.; Mashhour, A. Heavy metal concentrations in the breast milk of Saudi women. Biol. Trace Elem. Res. 2003, 96, 21–37. [Google Scholar] [CrossRef]
  20. Salt, D.E.; Smith, R.D.; Raskin, I. Phytoremediation. Annu. Rev. Plant Biol. 1998, 49, 643–668. [Google Scholar] [CrossRef]
  21. Alkorta, I.; Hernández-Allica, J.; Becerril, J.; Amezaga, I.; Albizu, I.; Garbisu, C. Recent findings on the phytoremediation of soils contaminated with environmentally toxic heavy metals and metalloids such as zinc, cadmium, lead, and arsenic. Rev. Environ. Sci. Biotechnol. 2004, 3, 71–90. [Google Scholar] [CrossRef]
  22. Sinha, R.K.; Herat, S.; Tandon, P.K. Phytoremediation: Role of Plants in Contaminated Site Management. In Environmental Bioremediation Technologies; Singh, S.N., Tripathi, R.D., Eds.; Springer: Berlin/Heidelberg, Germany, 2007; pp. 315–330. [Google Scholar] [CrossRef]
  23. Tangahu, B.V.; Abdullah, S.R.S.; Basri, H.; Idris, M.; Anuar, N.; Mukhlisin, M. A review on heavy metals (As, Pb, and Hg) uptake by plants through phytoremediation. Int. J. Chem. Eng. 2011, 939161. [Google Scholar] [CrossRef]
  24. Kumar, P.B.A.N.; Dushenkov, V.; Motto, H.; Raskin, I. Phytoextraction: The use of plants to remove heavy metals from soils. Environ. Sci. Technol. 1995, 29, 1232–1238. [Google Scholar] [CrossRef]
  25. Alaboudi, K.A.; Ahmed, B.; Brodie, G. Phytoremediation of Pb and Cd contaminated soils by using sunflower (Helianthus annuus) plant. Ann. Agric. Sci. 2018, 63, 123–127. [Google Scholar] [CrossRef]
  26. Zhuang, P.; Yang, Q.W.; Wang, H.B.; Shu, W.S. Phytoextraction of heavy metals by eight plant species in the field. Water Air Soil Pollut. 2007, 184, 235–242. [Google Scholar] [CrossRef]
  27. U.S. Environmental Protection Agency. Introduction to Phytoremediation; National Risk Management Research Laboratory: Cincinnati, OH, USA, 2000; Report No.: EPA/600/R-99/107. Available online: http://www.clu-in.org/download/remed/introphyto.pdf (accessed on 10 May 2025).
  28. Futughe, A.E.; Purchase, D.; Jones, H. Phytoremediation using native plants. In Phytoremediation; Shmaefsky, B., Ed.; Springer: Berlin/Heidelberg, Germany, 2020. [Google Scholar] [CrossRef]
  29. Lam, E.J.; Cánovas, M.; Gálvez, M.E.; Montofré, Í.L.; Keith, B.F.; Faz, Á. Evaluation of the phytoremediation potential of native plants growing on a copper mine tailing in northern Chile. J. Geochem. Explor. 2017, 182 (Pt B), 210–217. [Google Scholar] [CrossRef]
  30. Mousavi Kouhi, S.M.; Moudi, M. Assessment of phytoremediation potential of native plant species naturally growing in a heavy metal-polluted saline–sodic soil. Environ. Sci. Pollut. Res. 2020, 27, 10027–10038. [Google Scholar] [CrossRef]
  31. Salazar, M.J.; Pignata, M.L. Lead accumulation in plants grown in polluted soils: Screening of native species for phytoremediation. J. Geochem. Explor. 2014, 137, 29–36. [Google Scholar] [CrossRef]
  32. Keellings, D.; Hernández Ayala, J.J. Extreme rainfall associated with Hurricane Maria over Puerto Rico and its connections to climate variability and change. Geophys. Res. Lett. 2019, 46, 2964–2973. [Google Scholar] [CrossRef]
  33. Edmaier, K.; Burlando, P.; Perona, P. Mechanisms of vegetation uprooting by flow in alluvial non-cohesive sediment. Hydrol. Earth Syst. Sci. 2011, 15, 1615–1627. [Google Scholar] [CrossRef]
  34. Penfound, W.T. The role of vines in plant communities. Adv. Front. Plant Sci. 1966, 17, 187–192. [Google Scholar]
  35. Gökbayrak, Z.; Dardeniz, A.; Arıkan, A.; Kaplan, U. Best duration for submersion of grapevine cuttings of rootstock 41B in water to increase root formation. J. Food Agric. Environ. 2010, 8, 607–609. [Google Scholar]
  36. Acevedo-Rodríguez, P. Vines and climbing plants of Puerto Rico and the Virgin Islands. In Contributions from the United States National Herbarium; Smithsonian Institution: Washington, DC, USA, 2005; Volume 51, pp. 396–401. [Google Scholar]
  37. Hummes, A.P.; Bortoluzzi, E.C.; Tonini, V.; da Silva, L.P.; Petry, C. Transfer of copper and zinc from soil to grapevine-derived products in young and centenarian vineyards. Water Air Soil Pollut. 2019, 230. [Google Scholar] [CrossRef]
  38. San Juan Bay Estuary Partnership. Juan Mendez Creek Restoration Project; Estuario: San Juan, Puerto Rico, 2024; Available online: https://estuario.org (accessed on 23 May 2025).
  39. Estuario de la Bahía de San Juan. Monitoreo Bacteriológico de Playas y Lagunas; Estuario de la Bahía de San Juan: San Juan, Puerto Rico, 2025; Available online: https://estuario.org/enterococos/ (accessed on 5 May 2025).
  40. EPA Method 1664A; Oil and Grease, n-Hexane Extractable Material (HEM) by Extraction and Gravimetry. U.S. Environmental Protection Agency: Washington, DC, USA, 2010. Available online: https://www.epa.gov/sites/default/files/2015-08/documents/method_1664a_1999.pdf (accessed on 13 May 2025).
  41. EPA Method 353.2; Determination of Nitrate-Nitrite Nitrogen by Automated Colorimetry. U.S. Environmental Protection Agency: Cincinnati, OH, USA, 1993. Available online: https://www.epa.gov/sites/default/files/2015-08/documents/method_353-2_1993.pdf (accessed on 13 May 2025).
  42. Standard Methods 4500-P A, B, E; Phosphorus. American Public Health Association, American Water Works Association, Water Environment Federation: Washington, DC, USA, 2012.
  43. EPA Method 200.7; Determination of Metals and Trace Elements in Water and Wastes by Inductively Coupled Plasma–Atomic Emission Spectrometry. U.S. Environmental Protection Agency: Cincinnati, OH, USA, 1994. Available online: https://www.epa.gov/esam/method-2007-determination-metals-and-trace-elements-water-and-wastes-inductively-coupled (accessed on 13 May 2025).
  44. Chiquillo, K.L. (University of Puerto Rico, Rio Piedras, San Juan, Puerto Rico). Personal communication, 26 July 2024.
  45. Valderrama-Landeros, L.; Camacho-Cervantes, M.; Velázquez-Salazar, S.; Villeda-Chávez, E.; Flores-Verdugo, F.; Flores-de-Santiago, F. Detection of an invasive plant (Cissus verticillata) in the largest mangrove system on the eastern Pacific coast—A remote sensing approach. Wetl. Ecol. Manag. 2025, 33, 13. [Google Scholar] [CrossRef]
  46. Burgos, S. (Estuario, San Juan, Puerto Rico); Chiquillo, K.L. (University of Puerto Rico, Rio Piedras, San Juan, Puerto Rico). Personal communication, 25 March 2024.
  47. Badrul Hisam, N.I.; Zakaria, M.Z.; Azid, A.; Abu Bakar, M.F.; Samsudin, M.S. Phytoremediation process of water spinach (Ipomoea aquatica) in absorbing heavy metal concentration in wastewater. J. Agrobiotechnol. 2022, 13, 131–144. [Google Scholar] [CrossRef]
  48. U.S. Environmental Protection Agency. Lead and Copper Rule; U.S. Environmental Protection Agency: Washington, DC, USA, 2024. Available online: https://www.epa.gov/dwreginfo/lead-and-copper-rule (accessed on 10 April 2025).
  49. U.S. Environmental Protection Agency. National Primary Drinking Water Regulations; Environmental Protection Agency: Washington, DC, USA, 2024. Available online: https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations (accessed on 23 May 2025).
  50. Percival, G.C.; Keary, I.P.; Noviss, K. The potential of a chlorophyll content SPAD meter to quantify nutrient stress in foliar tissue of sycamore (Acer pseudoplatanus), English oak (Quercus robur), and European beech (Fagus sylvatica). Arbor. Urban. For. 2008, 34, 89–100. [Google Scholar] [CrossRef]
  51. R Core Team. R: A Language and Environment for Statistical Computing; R Foundation for Statistical Computing: Vienna, Austria, 2025; Available online: https://www.r-project.org/ (accessed on 15 March 2023).
  52. Fox, J.; Weisberg, S. Visualizing fit and lack of fit in complex regression models with predictor effect plots and partial residuals. J. Stat. Softw. 2018, 87, 1–27. [Google Scholar] [CrossRef]
  53. Pinheiro, J.C.; Bates, D.M. Nonlinear mixed-effects models: Basic concepts and motivating examples. In Mixed-Effects Models in S and S-PLUS; Statistics and Computing; Springer: New York, NY, USA, 2000; pp. 273–304. [Google Scholar] [CrossRef]
  54. Schielzeth, H.; Dingemanse, N.J.; Nakagawa, S.; Westneat, D.F.; Allegue, H.; Teplitsky, C.; Réale, D.; Dochtermann, N.A.; Garamszegi, L.Z.; Araya-Ajoy, Y.G. Robustness of linear mixed-effects models to violations of distributional assumptions. Methods Ecol. Evol. 2020, 11, 1141–1152. [Google Scholar] [CrossRef]
  55. Lenth, R.V. Least-squares means: The R package lsmeans. J. Stat. Softw. 2016, 69, 1–33. [Google Scholar] [CrossRef]
  56. Government of Puerto Rico, Department of Natural and Environmental Resources. Puerto Rico Water Quality Standards Regulation, as Amended in August 2022. Resolution No. 9079. 2022. Available online: https://www.epa.gov/sites/default/files/2014-12/documents/prwqs.pdf (accessed on 13 May 2025).
  57. Orosco, M.; Merley, P. Evaluación de Plantas Arvenses de Reproducción Asexual Adaptadas al Cultivo de Cacao Para uso en Programa de Fitorremediación; Universidad UTE, Facultad de Ciencias de la Ingeniería a Industrias, Carrera De Ingeniería Ambiental y Manejo de Riesgos Naturales: Santo Domingo, Dominican Republic, 2022; 65p, Available online: https://repositorio.ute.edu.ec/entities/publication/cc6480c5-b589-4784-8444-bfdde29b148a (accessed on 28 April 2025).
  58. Soto Hidalgo, K.T.; Carrión-Huertas, P.J.; Kinch, R.T.; Betancourt, L.E.; Cabrera, C.R. Phytonanoremediation by Avicennia germinans (black mangrove) and nano zero valent iron for heavy metal uptake from Cienaga Las Cucharillas wetland soils. Environ. Nanotechnol. Monit. Manag. 2020, 14, 100363. [Google Scholar] [CrossRef]
  59. Iannelli, M.A.; Pietrini, F.; Fiore, L.; Petrilli, L.; Massacci, A. Antioxidant response to cadmium in Phragmites australis plants. Plant Physiol. Biochem. 2002, 40, 977–982. [Google Scholar] [CrossRef]
  60. Liao, W.S.; Chang, L.W. Heavy metal phytoremediation by water hyacinth at constructed wetlands in Taiwan. J. Aquat. Plant Manag. 2004, 42, 60–68. [Google Scholar]
  61. Liu, D.; Jiang, W.; Liu, C.; Xin, C.; Hou, W. Uptake and accumulation of lead by roots, hypocotyls and shoots of Indian mustard (Brassica juncea L.). Bioresour. Technol. 2000, 71, 273–277. [Google Scholar] [CrossRef]
  62. Abbas, Z.; Arooj, F.; Ali, S.; Zaheer, I.E.; Rizwan, M.; Riaz, M.A. Phytoremediation of landfill leachate waste contaminants through floating bed technique using water hyacinth and water lettuce. Int. J. Phytoremediation 2019, 21, 1356–1367. [Google Scholar] [CrossRef]
  63. Tin Win, D.; Myint Myint, T.; Sein, T. Lead removal from industrial waters by water hyacinth. AU J. Technol. 2003, 6, 187–192. [Google Scholar]
  64. Sêkara, A.; Poniedziaek, M.; Ciura, J.; Jêdrszczyk, E. Cadmium and lead accumulation and distribution in the organs of nine crops: Implications for phytoremediation. Pol. J. Environ. Stud. 2005, 14, 509–516. [Google Scholar]
  65. U.S. Environmental Protection Agency. Phytoremediation Resource Guide; U.S. Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory: Cincinnati, OH, USA, 2000. Available online: https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=10002SEE.TXT (accessed on 22 August 2025).
  66. Drobnik, J.; Barroncas de Oliveira, A. Cissus verticillata (L.) Nicolson and C.E. Jarvis (Vitaceae): Its identification and usage in the sources from 16th to 19th century. J. Ethnopharmacol. 2015, 171, 317–329. [Google Scholar] [CrossRef] [PubMed]
  67. Haokip, N.; Gupta, A. Phytoremediation of chromium and manganese by Ipomoea aquatica Forssk. from aqueous medium containing chromium–manganese mixtures in microcosms and mesocosms. Water Environ. J. 2020, 35, 438–448. [Google Scholar] [CrossRef]
  68. Rane, N.R.; Swapnil, M.P.; Vishal, V.C.; Suhas, K.K.; Rahul, V.K.; Jyoti, P.J.; Sanjay, P.G. Ipomoea hederifolia rooted soil bed and Ipomoea aquatica rhizofiltration coupled phytoreactors for efficient treatment of textile wastewater. Water Res. 2016, 96, 1–11. [Google Scholar] [CrossRef]
  69. Izinyon, C.; Rawlings, A. Assessment of sweet potato (Ipomoea batatas) for phytoremediation of motor oil contaminated soil. Niger. J. Technol. 2013, 32. [Google Scholar]
Conservation 05 00069 g001
Figure 1. Overview of sampling location in a highly urbanized area. (A) Map with Juan Méndez Creek highlighted in blue, which flows into San José Lagoon. The map highlights the main channel; tributaries and headwater portions are not shown. (B) Blue pin indicates the sampling location at 18°23′53″ N, 66°02′31″ W. (C) C. verticillata growing in Juan Mendez Creek site (photo taken by S. Velázquez, 26 August 2024). (D) C. verticillata forming a thick canopy over fences and powerlines (photo taken by S. Velázquez, 5 September 2024).
Figure 1. Overview of sampling location in a highly urbanized area. (A) Map with Juan Méndez Creek highlighted in blue, which flows into San José Lagoon. The map highlights the main channel; tributaries and headwater portions are not shown. (B) Blue pin indicates the sampling location at 18°23′53″ N, 66°02′31″ W. (C) C. verticillata growing in Juan Mendez Creek site (photo taken by S. Velázquez, 26 August 2024). (D) C. verticillata forming a thick canopy over fences and powerlines (photo taken by S. Velázquez, 5 September 2024).
Conservation 05 00069 g001
Conservation 05 00069 g002
Figure 2. C. verticillata biomass and chlorophyll levels during the experiment. (A) Initial and final averaged biomass of C. verticillata individuals (n = 25). (B) Averaged chlorophyll levels of C. verticillata individuals across the experiment (n = 25).
Figure 2. C. verticillata biomass and chlorophyll levels during the experiment. (A) Initial and final averaged biomass of C. verticillata individuals (n = 25). (B) Averaged chlorophyll levels of C. verticillata individuals across the experiment (n = 25).
Conservation 05 00069 g002
Conservation 05 00069 g003
Figure 3. Average (mg/kg) of Cd and Pb concentrations in root, stem, and leaf tissues of C. verticillata (n = 15). BDL = below detection limit. Different letters (a, b) indicate significant differences (p < 0.05).
Figure 3. Average (mg/kg) of Cd and Pb concentrations in root, stem, and leaf tissues of C. verticillata (n = 15). BDL = below detection limit. Different letters (a, b) indicate significant differences (p < 0.05).
Conservation 05 00069 g003
Conservation 05 00069 g004
Figure 4. Removal efficiency and translocation factor of C. verticillata for cadmium and lead. The white bar indicates the Cadmium (Cd) treatment, and the striped bar indicates the Lead (Pb) treatment. Error bars show standard error (SE). (A) Removal efficiency calculated from initial and final metal concentrations (mg/kg) in water samples after two weeks of cadmium and lead treatments (n = 5). Different letters (a, b) indicate significant differences. (B) Translocation factors for cadmium and lead in C. verticillata, averaged across all containers, calculated from the metal concentrations (mg/kg) in plant tissues, specifically shoots and roots (n = 25).
Figure 4. Removal efficiency and translocation factor of C. verticillata for cadmium and lead. The white bar indicates the Cadmium (Cd) treatment, and the striped bar indicates the Lead (Pb) treatment. Error bars show standard error (SE). (A) Removal efficiency calculated from initial and final metal concentrations (mg/kg) in water samples after two weeks of cadmium and lead treatments (n = 5). Different letters (a, b) indicate significant differences. (B) Translocation factors for cadmium and lead in C. verticillata, averaged across all containers, calculated from the metal concentrations (mg/kg) in plant tissues, specifically shoots and roots (n = 25).
Conservation 05 00069 g004
Table 1. Water quality parameters collected from Juan Méndez Creek during September 2024. n = 3. BDL = below detection limit. a EPA standards for use of public water supply, propagation and maintenance, as well as primary and secondary contact recreation [56].
Table 1. Water quality parameters collected from Juan Méndez Creek during September 2024. n = 3. BDL = below detection limit. a EPA standards for use of public water supply, propagation and maintenance, as well as primary and secondary contact recreation [56].
ParameterEPA Limit aAverageStandard Error
Temperature (°C)-28.70±0.39
pH6.0–9.07.00±1.81
Humidity (%)-68.63±2.82
Dissolved Oxygen (mg/L)>5.05.29±0.32
Conductivity (SPC)<10000.23±0.04
Salinity (PPT)<5000.11±0.02
Oil and Grease (mg/L)50 2.60±0.20
Nitrate and Nitrite (mg/L)1.71.22±0.31
Total Phosphorus (mg/L)0.160.19±0.03
Lead—Total (mg/L)0.009BDLBDL
Cadmium- Total (mg/L)0.008BDLBDL
Table 2. Statistical results of cadmium testing. (a) Results of LME and (b) post hoc analyses of cadmium. p-values in bold are significant.
Table 2. Statistical results of cadmium testing. (a) Results of LME and (b) post hoc analyses of cadmium. p-values in bold are significant.
(a) Response variable: Cadmium
Numerator DFDenominator DFF-valuep-value
Intercept11210.1941750.0077
Tissues2129.0093380.0041
(b) Tukey’s post hoc test: Cadmium
estimateSEdfT-ratiop-value
Leaves–Roots−1130.430212−3.7470.0073
Leaves–Stems−44.330212−0.1470.9882
Roots–Stems1086.1302123.6010.0094
Table 3. Statistical results of lead testing. (a) Results of LME and (b) post hoc analyses of lead. p-values in bold are significant.
Table 3. Statistical results of lead testing. (a) Results of LME and (b) post hoc analyses of lead. p-values in bold are significant.
(a) Response variable: Lead
Numerator DFDenominator DFF-valuep-value
Intercept11232.485940.00001
Tissues21230.421340.0001
(b) Tukey’s post hoc test: Lead
estimateSEdfT-ratiop-value
Leaves–Roots−86812712−6.8290.0001
Leaves–Stems−1930212−0.1500.9878
Roots–Stems848302126.6790.0001
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Share and Cite

MDPI and ACS Style

Velázquez, S.; Hidalgo, K.S.; Rivas, M.C.; Burgos, S.; Chiquillo, K.L. Flowing Towards Restoration: Cissus verticillata Phytoremediation Potential for Quebrada Juan Mendez in San Juan, Puerto Rico. Conservation 2025, 5, 69. https://doi.org/10.3390/conservation5040069

AMA Style

Velázquez S, Hidalgo KS, Rivas MC, Burgos S, Chiquillo KL. Flowing Towards Restoration: Cissus verticillata Phytoremediation Potential for Quebrada Juan Mendez in San Juan, Puerto Rico. Conservation. 2025; 5(4):69. https://doi.org/10.3390/conservation5040069

Chicago/Turabian Style

Velázquez, Sofía, Keyla Soto Hidalgo, Monica C. Rivas, Sofía Burgos, and Kelcie L. Chiquillo. 2025. "Flowing Towards Restoration: Cissus verticillata Phytoremediation Potential for Quebrada Juan Mendez in San Juan, Puerto Rico" Conservation 5, no. 4: 69. https://doi.org/10.3390/conservation5040069

APA Style

Velázquez, S., Hidalgo, K. S., Rivas, M. C., Burgos, S., & Chiquillo, K. L. (2025). Flowing Towards Restoration: Cissus verticillata Phytoremediation Potential for Quebrada Juan Mendez in San Juan, Puerto Rico. Conservation, 5(4), 69. https://doi.org/10.3390/conservation5040069

Article Metrics

Back to TopTop