Seedling Development Responses of Avicennia marina (Forssk.) Vierh. in Aquaponics, Hydroponics, and Floating Raft Systems for Optimized Mangrove Propagation
Metadata
- Cite key: nuquiSeedlingDevelopmentResponses2025
- Item type: Journal Article
- Authors: R. Nuqui, M. Al Herbawi
- Affiliation: Marine Environment Research Centre, Ministry of Climate Change and Environment (MOCCAE), United Arab Emirates (UAE)
- Journal: International Journal of Scientific and Research Publications 15(11) (2025) 205-212
- Date: 11/2025
- Date added: 2026-07-13
- DOI: 10.29322/IJSRP.15.11.2025.p16719
- Funding: [not reported] — no formal grant/funding statement. Acknowledgment (p.8) thanks the UAE Ministry of Climate Change and Environment for “guidance, logistical assistance, and provision of essential resources,” which is not a funding number.
- URL: https://doi.org/10.29322/IJSRP.15.11.2025.p16719
- PDF:
Nuqui and Al Herbawi - 2025 - Seedling Development Responses of Avicennia marina (Forssk.) Vierh. in Aquaponics, Hydroponics, and.pdf
Opinion
An unusual and useful application of aquaponics — mangrove restoration nursery propagation rather than food production — with a genuinely fish-based aquaponic arm (live tilapia effluent, continuously circulated) compared against three alternatives. The stats are reported with real rigor (Welch’s ANOVA for heterogeneous variances, Bonferroni post hoc, normality tests), but the paper has a real internal defect: the Results-text height values and the Figure 1 caption’s height values disagree by a near-constant ~4.6 cm offset across all four systems, while both are internally consistent with the same pairwise-difference table (Table 2). That is exactly the kind of contradiction that would slip past a casual read — see Extraction notes. Fish-husbandry detail is minimal (no feed, growth, or survival data for the tilapia at all), which is fine given the paper’s stated scope but limits reuse for anything fish-side.
Abstract
The efficient propagation of Avicennia marina seedlings is vital for large-scale mangrove restoration, particularly amid increasing coastal degradation and climate change. This study evaluated the growth performance of A. marina seedlings over 90 days under four cultivation systems: aquaponics, hydroponics (including both drip irrigation and manual nutrient dosing), and floating raft systems. Each system received distinct nutrient sources, including aquaculture effluents from tilapia culture and organic plant-based nutrient extracts. Seedling growth was assessed through shoot height, root length, and leaf number. Statistical analysis using Welch’s ANOVA and Bonferroni post hoc tests revealed highly significant differences among treatments (p < 0.001). Aquaponics and floating raft systems consistently produced the tallest seedlings and greatest leaf counts, indicating enhanced above-ground biomass development. In contrast, hydroponic systems promoted greater root elongation, suggesting advantages in nutrient uptake or aeration. Notably, leaf production was highest with nutrient-rich tilapia effluents, highlighting the potential of integrated aquaculture for plant propagation. Furthermore, the floating raft system’s simulation of natural tidal flux supported superior foliar growth compared to the stable environmental conditions of indoor systems. These findings demonstrate that aquaponics and floating raft systems, particularly when coupled with aquaculture effluents, provide as sustainable and effective approaches to enhance mangrove seedling vigor in restoration initiatives.
Summary
The authors grew Avicennia marina (grey mangrove) propagules for 90 days under four soilless cultivation systems — aquaponics (tilapia effluent, continuous flow), hydroponics with drip irrigation (also tilapia effluent), hydroponics with manual dosing (seaweed/date-fruit extracts, rockwool substrate), and a floating raft over natural tidal mangrove canal water (control reference) — and measured final shoot height, root length, and leaf count on 325 seedlings in total. Using Welch’s ANOVA with Bonferroni-corrected post hoc tests (because variances were unequal across groups), they found highly significant differences among systems for all three traits (p < 0.001). Aquaponics and the floating raft produced the tallest, most leafy seedlings with no significant difference between the two; the hydroponic systems produced significantly shorter, less leafy seedlings but significantly longer roots, with aquaponics producing the shortest roots of all four systems. The paper argues this pattern reflects continuous nutrient/oxygen availability (aquaponics, floating raft) favoring shoot and leaf growth while intermittent/manual nutrient delivery (hydroponics) drives roots to forage further. No plant biochemical, mineral, or biomass (fresh/dry weight) data were collected — only the three morphological traits.
Experiment data
- Location: UAE coastal mangroves (propagule source) and Marine Environment Research Centre facilities, UAE (system location not further specified)
- Design: 4-arm comparison (Aquaponics; Hydroponics–Drip; Hydroponics–Manual Nutrient Dosing; Floating Raft/control reference), single nutrient-source/salinity regime per arm as described in Table 1, no stated randomization scheme or block design
- Replicates / n: 325 seedlings total across the four systems (no stated per-system breakdown) — [unclear]
- Duration: 90 days
- Organisms: Avicennia marina propagules / Tilapia (Oreochromis sp.) fingerlings, 25–30 per 50 L tank
- Statistics: Welch’s ANOVA (unequal-variance correction) with Bonferroni-adjusted post hoc pairwise comparisons; normality checked via Kolmogorov-Smirnov, Shapiro-Wilk, Anderson-Darling; alpha = 0.05
- Plant height: Aquaponics 19.57 ± 3.65 cm; Floating Raft 20.37 ± 3.97 cm; Hydroponics–Drip 12.40 ± 2.13 cm; Hydroponics–Manual 15.74 ± 3.12 cm (Results text, p.3-4) — ⚠️CHECK against Figure 1 caption, see Extraction notes
- Leaf count: Floating Raft 5.3 ± 0.65; Aquaponics 5.12 ± 1.16; Hydroponics–Manual 3.85 ± 0.8; Hydroponics–Drip 3.19 ± 0.92
- Root length: Hydroponics–Manual 20.11 ± 6.67 cm; Hydroponics–Drip 18.35 ± 5.01 cm; Floating Raft 17.11 ± 4.89 cm; Aquaponics 10.38 ± 4.10 cm (shortest)
Seedling height
This paper: Aquaponics (19.57 ± 3.65 cm) and Floating Raft (20.37 ± 3.97 cm) were significantly taller than Hydroponics–Drip (12.40 ± 2.13 cm) and Hydroponics–Manual (15.74 ± 3.12 cm) after 90 days (Welch’s ANOVA F(3, 109.36) = 47.96, p < 0.001). No significant difference between Aquaponics and Floating Raft (p = 1.000). See ⚠️CHECK in Extraction notes — Figure 1’s caption gives different absolute numbers for the same comparison.
Compared with:
- todo Somerville et al. 2014 — cited repeatedly for the mechanism (oxygenated, nutrient-rich aquaponic effluent supporting vigorous shoot development)
- todo Budiadi et al. 2022 — A. marina seedling growth under controlled salinity in an ex situ nursery, cited for tidal/salinity-driven growth response
- todo Heo et al. 2024 — crop growth comparison between hydroponics and aquaponics under different light inputs
Leaf count
This paper: Floating Raft (5.3 ± 0.65) and Aquaponics (5.12 ± 1.16) produced significantly more leaves than Hydroponics–Manual (3.85 ± 0.8) and Hydroponics–Drip (3.19 ± 0.92) (Welch’s ANOVA F(3, 108.6) = 89.71, p < 0.001). Authors attribute the hydroponic systems’ lower counts partly to low light intensity (~221 lux) limiting photosynthesis.
Compared with:
- todo Chen et al. 2023 — effects of light intensity on growth/quality of lettuce and spinach, cited to support the low-light explanation for reduced hydroponic leaf counts
Root length
This paper: Hydroponics–Manual (20.11 ± 6.67 cm) and Hydroponics–Drip (18.35 ± 5.01 cm) produced the longest roots; Aquaponics (10.38 ± 4.10 cm) the shortest (Welch’s ANOVA F(3, 111.55) = 70.86, p < 0.001). Authors attribute this to continuous nutrient/oxygen access in aquaponics reducing the need for root foraging, versus intermittent/manual nutrient delivery in hydroponics driving root elongation; rockwool substrate porosity is also cited as a contributing factor for the manual-dosing arm.
Compared with:
- todo Shivani et al. 2024 — root system exploration in hydroponic agriculture, cited for the nutrient-foraging root elongation mechanism
Study design detail — aquaponics vs. hydroponics–drip share the same nutrient source
Both the Aquaponics and Hydroponics–Drip arms use tilapia effluent as the sole nutrient input and the same stated salinity range (0–35 ppt, matched per Table 1’s footnote). The only stated difference between these two arms is delivery method: continuous circulated immersion (Aquaponics) vs. scheduled drip irrigation at 30–100 mL/hr (Hydroponics–Drip). This means the Aquaponics-vs-Hydroponics-Drip contrast in this paper isolates irrigation/delivery method, not nutrient source — worth flagging for anyone using this row as a generic “fish effluent vs. no fish effluent” comparison. The Hydroponics–Manual arm is the one genuinely non-fish nutrient source (seaweed/date-fruit extracts).
Linked claims
- Continuous nutrient delivery favors shoot and leaf growth over root elongation
- Aquaponic effluent can substitute for synthetic nutrient solution in mangrove seedling propagation
- Floating raft tidal exposure enhances foliar development relative to stable indoor systems
Citations to chase
- todo Somerville et al. (2014) — FAO small-scale aquaponic food production technical paper, repeatedly cited as the mechanistic basis for oxygenated/nutrient-rich effluent benefits
- todo Budiadi et al. (2022) — Avicennia marina seedling growth/quality under controlled salinity in an ex situ nursery (Forests)
- todo Heo et al. (2024) — crop growth comparison, hydroponics vs aquaponics with different light inputs (Frontiers in Horticulture)
- todo Chen et al. (2023) — light intensity effects on lettuce/spinach growth and quality (Plants)
- todo Shivani et al. (2024) — root systems in hydroponic agriculture (J. Experimental Agriculture International)
- todo Syakir et al. (2021) — mangrove growth rate using hydroponic installation with MOL nutrient (IOP Conf. Series)
Extraction notes
⚠️CHECK Plant height (Aquaponics and all three comparison arms): Results text (p.3-4) states Aquaponics 19.57 ± 3.65 cm, Floating Raft 20.37 ± 3.97 cm, Hydro Drip 12.40 ± 2.13 cm (printed with unit “m”, clear typo — see MINOR below), Hydro Manual 15.74 ± 3.12 cm (also printed “m”). These four values reproduce Table 2’s pairwise mean differences exactly, e.g. 19.57 − 12.40 = 7.17 = Table 2’s “Aquaponics vs Hydro Drip +7.17”; 19.57 − 20.37 = −0.80 = Table 2’s “Aquaponics vs Floating Raft −0.80”. Figure 1’s caption (p.5) instead states “aquaponics and floating raft culture systems exhibited the greatest average height (14.96–15.77 cm)… hydroponics drip (7.79 cm)… manual nutrient dosing (11.14 cm).” These figure values also reproduce Table 2’s differences exactly (14.96 − 7.79 = 7.17; 14.96 − 15.77 = −0.81 ≈ −0.80; 7.79 − 11.14 = −3.35, matching “Hydro Drip vs Hydro Manual −3.35”). Both value sets are therefore internally consistent with the same difference table, but offset from each other by a near-constant ~4.60–4.61 cm across all four groups (19.57−14.96=4.61; 20.37−15.77=4.60; 12.40−7.79=4.61; 15.74−11.14=4.60). This constant-offset pattern suggests the two sets could represent different bases (e.g. final absolute height vs. a height increment/growth measured from an unstated baseline such as initial propagule length) — but the paper never states or explains this, and it is equally possible one set is simply a transcription slip when the figure was drafted. Not resolvable as error-vs-definition from the text alone. Recorded: 19.57 ± 3.65 cm (Results text value) for the trials.csv Plant height cell, because it carries a reported SD (the Figure 1 caption gives none) and is the value referenced in the paper’s own Discussion section. Figure 1’s 14.96 cm recorded as the candidate alternative. Does not affect Leaf count (Figure 2’s caption numbers match the Results text exactly: 5.3, 5.12, 3.19, 3.85) or Root length (Figure 3’s caption gives no numeric values to compare).
⚠️MINOR Height units, hydroponic arms: Results text (p.3) prints “hydroponics drip (12.40 ± 2.13 m)” and “hydroponics manual nutrient dosing (15.74 ± 3.12 m)” — unit given as metres, impossible for a 90-day seedling and inconsistent with every other height figure in the paper (all in cm: Table 2, Figure 1, Discussion). Read as cm (typo). No cell impact.
[unclear] Whether the Aquaponics “0–35 ppt” salinity range reflects the as-run design or a post-hoc harmonization: Table 1’s footnote states the range “was standardized to 0–35 ppt… to align with the experimental design of the Hydroponics – Drip system,” which could mean the arms were run in parallel across matched salinity levels, or that the table was reconciled for comparability after the fact. Results/Discussion never break the Aquaponics results down by salinity subgroup (a single pooled Aquaponics value is reported throughout), so this does not change any recorded cell but affects how the salinity manipulation within the Aquaponics arm should be interpreted.
[not reported] Fish husbandry beyond species, life stage, stocking count (25–30/tank), tank volume (50 L), and “aerated conditions”: no feed type, feed rate, growth, weight, or survival data for the tilapia anywhere in the paper — this is a plant-propagation study using fish effluent as a nutrient source, not a fish-production trial.
[not reported] grouped — Fish Category, Plant Category (paper does not formally categorize the fish or the mangrove propagules beyond species name/life stage), Initial Stock density (given as headcount/tank volume, not a density), Fish trial duration (distinct from the 90-day seedling assessment window), Replicates (n) per system (only the pooled total of 325 across all four systems is given), Plants/m², SPAD, Lat/Long, Aq pH, Dissolved Oxygen, EC, TAN/NH4-N, NO2-N, NO3-N, Plant fresh weight, Plant dry matter.
NO COLUMN: relative humidity 42–76% (indoor systems, p.2); salinity gradients as ppt for each arm (Aquaponics/Hydro-Drip 0–35 ppt incl. pure seawater; Hydro-Manual 15–20 ppt) — EC (dS/m) is the schema’s water-salinity column but the paper reports salinity in ppt, not EC, and converting ppt→EC requires an empirical relationship rather than an exact unit conversion, so EC is left NR per the no-derivation rule rather than estimated.
Source: Nuqui and Al Herbawi - 2025 - Seedling Development Responses of Avicennia marina (Forssk.) Vierh. in Aquaponics, Hydroponics, and.pdf
Data Tables
Structured data extracted from this paper into the vault's
trials.csv/plant_measurements.csvdatasets. Fields the paper didn't report are omitted. Download the full datasets (measurements).
Trial Parameters
nuquiSeedlingDevelopmentResponses2025-T1
Fish
| Field | Value |
|---|---|
| Fish | Tilapia (Oreochromis sp.), fingerlings |
Water
| Field | Value |
|---|---|
| Water volume in the system | 50 |
| Water type | Tilapia effluent (polycarbonate tanks) (Table 1) |
| Water classification | Saline/brackish gradient, 0-35 ppt including pure seawater (Table 1) |
Plant
| Field | Value |
|---|---|
| Plant | Avicennia marina (Forssk.) Vierh. (grey mangrove), propagule/seedling |
| Details | Propagules 2-4 cm, washed 3x freshwater, soaked 24h freshwater pretreatment; sown one hole apart on seedling trays, ~10-15% of propagule submerged, no substrate (p.2) |
| Days Plant after transplant | 90 |
| Plant height | ⚠️CHECK 19.57 +/- 3.65 (cm) — see Experimental Remarks / note Extraction notes |
| Leaf count | 5.12 +/- 1.16 |
System & Setup
| Field | Value |
|---|---|
| System type | Aquaponics — seedling trays floated directly in continuously circulated, aerated tilapia effluent, no substrate (Table 1, p.2) |
| Media Details | None (no substrate; seeds floated directly in water column) (Table 1) |
| Air supplement | Y (Tilapia tank maintained ‘under aerated conditions’ (p.2); aeration systems referenced generally for oxygenated effluent (p.3)) |
| Climate control | Y (Indoor cultivation (incl. Aquaponics) held at room temp 22.20-27.00 degC, RH 42-76%, light ~221 lux, 10-12h light/12-14h dark photoperiod (p.2); Floating Raft exposed to ambient/natural conditions, not climate-controlled) |
| Artificial Lighting | Y (~221 lux maintained indoors, 10-12h light / 12-14h dark photoperiod (p.2)) |
| Equipment | 50 L polycarbonate tilapia tanks; seedling propagation trays; aeration equipment (type unspecified); indoor climate-controlled room (p.2) |
| Control Parameters | Room temp 22.20-27.00 degC, RH 42-76%, light ~221 lux, 10-12h/12-14h light:dark photoperiod (indoor systems) (p.2) |
| Combination | Tilapia (Oreochromis sp.) x Avicennia marina mangrove propagules; Aquaponics compared against Hydroponics-Drip, Hydroponics-Manual Nutrient Dosing, and Floating Raft (natural tidal, control reference) (p.2-3) |
Site
| Field | Value |
|---|---|
| Region | Middle East |
| Country | United Arab Emirates |
| Average room Temperature | 22.20-27.00 |
Results & Statistics
| Field | Value |
|---|---|
| Measured Unit | cm (height, root length); count (leaves) |
| Statistic Details | Welch’s ANOVA (unequal-variance correction) with Bonferroni-adjusted post hoc pairwise comparisons; normality checked via Kolmogorov-Smirnov, Shapiro-Wilk, Anderson-Darling tests; alpha=0.05 (p.3) |
| Statistically analysed | Y |
Experimental Remarks: TRIAL DEFINITION: T1 = Aquaponics arm (tilapia effluent, continuous flow, no substrate, salinity 0-35 ppt incl. pure seawater, per Table 1). Only one aquaponic treatment in this paper — Results/Discussion report a single pooled Aquaponics group, never broken down by salinity level — so one row. Comparison arms (not extracted as AP rows, recorded here for reference): Hydroponics-Drip (tilapia effluent via drip 30-100 mL/hr, 0-35 ppt, height 12.40+/-2.13 cm [printed ‘m’ in text, typo, see WARN-MINOR], leaves 3.19+/-0.92, root 18.35+/-5.01 cm); Hydroponics-Manual Nutrient Dosing (seaweed/date-fruit extracts, rockwool/jiffy substrate, 15-20 ppt, height 15.74+/-3.12 cm [printed ‘m’, typo], leaves 3.85+/-0.8, root 20.11+/-6.67 cm); Floating Raft/control reference (natural tidal mangrove canal water, Hydrostone medium, height 20.37+/-3.97 cm, leaves 5.3+/-0.65, root 17.11+/-4.89 cm). | WARN-CHECK Plant height (Aquaponics): Results text p.3-4 states Aquaponics 19.57+/-3.65 cm, Floating Raft 20.37+/-3.97 cm, Hydro Drip 12.40+/-2.13 cm, Hydro Manual 15.74+/-3.12 cm; these reproduce Table 2’s pairwise mean differences exactly (19.57-12.40=7.17 = Table 2’s ‘Aquaponics vs Hydro Drip +7.17’; 19.57-20.37=-0.80 = Table 2’s ‘Aquaponics vs Floating Raft -0.80’). Figure 1 caption p.5 instead states ‘aquaponics and floating raft… (14.96-15.77 cm)… hydroponics drip (7.79 cm)… manual nutrient dosing (11.14 cm)’; these ALSO reproduce Table 2’s differences exactly (14.96-7.79=7.17; 14.96-15.77=-0.81; 7.79-11.14=-3.35). Both sets are internally consistent with the same difference table, offset from each other by a near-constant ~4.60-4.61 cm across all four groups (19.57-14.96=4.61; 20.37-15.77=4.60; 12.40-7.79=4.61; 15.74-11.14=4.60). Suggests the two sets may represent different bases (e.g. final absolute height vs. a height increment/growth from an unstated baseline) but the paper never states this and a simple transcription slip is equally possible. Not resolvable as error-vs-definition from the text. Recorded: 19.57+/-3.65 cm (Results text, has SD, matches Discussion narrative) as the Plant height cell. Figure 1’s 14.96 cm recorded as the candidate alternative. Affects Plant height only — Leaf count (Figure 2 caption matches Results text exactly: 5.3, 5.12, 3.19, 3.85) and Root length (Figure 3 caption has no numeric values to compare) are unaffected. | WARN-MINOR Height units for hydroponic arms: Results text p.3 gives ‘hydroponics drip (12.40 +/- 2.13 m)’ and ‘hydroponics manual nutrient dosing (15.74 +/- 3.12 m)’ — unit printed as metres, impossible for a 90-day seedling (12.4 m) and inconsistent with every other height value in the paper (all cm: Table 2, Figure 1, Discussion). Read as cm, a typo. No cell impact. | NOT DERIVED, left NR: Initial Stock density (paper gives 25-30 individuals per 50 L tank — a headcount and volume, not a density in kg/m3, per schema rule); Fish trial duration (paper states seedlings were assessed ‘after 90 days’ and effluent was ‘continuously circulated’ but never states a fish-rearing/trial duration distinct from the 90-day seedling window); Replicates (n) (paper states ‘325 seedlings across the systems’ in aggregate, p.3, with no per-system breakdown; 325/4 is not an integer so arms were not necessarily equal-n, and no table gives per-arm n); SGR, FCR, feed data (routine/regime/total), fish size initial/final, survival rate, weight gain (fish husbandry beyond species/stocking count/salinity/aeration is not reported at all in this plant-propagation-focused study). | UNCLEAR: whether the Aquaponics ‘0-35 ppt’ salinity range reflects the as-run design or a post-hoc harmonization for presentation — Table 1’s footnote states the range ‘was standardized to 0-35 ppt… to align with the experimental design of the Hydroponics-Drip system,’ ambiguous between ‘run in parallel across matched salinity levels’ and ‘table reconciled for comparability after the fact.’ Results/Discussion never break Aquaponics results down by salinity subgroup (single pooled AP value throughout), so this does not change any recorded cell but affects interpretation of the AP arm’s actual salinity manipulation. | Fish Category and Plant Category left NR — paper does not formally categorize the fish or the plant beyond species name and life stage. | Water volume in the system = 50 L is the stated PER-TANK volume (‘50L polycarbonate tank’, p.2, ‘25-30 individuals per 50L polycarbonate tank’); number of tanks and total water volume across trays/system not stated, so this is tank-only, not total system volume. | EC (dS/m) left NR: the paper reports salinity as ppt (0-35 ppt gradient incl. pure seawater for Aquaponics/Hydro-Drip; 15-20 ppt for Hydro-Manual) rather than EC; converting ppt to EC requires an empirical relationship, not an exact unit conversion, so it was not attempted per the no-derivation rule. NO COLUMN: relative humidity 42-76% (indoor systems, p.2) — no column fits humidity. | DESIGN NOTE: the Aquaponics and Hydroponics-Drip arms share the identical nutrient source (tilapia effluent) and identical salinity range (0-35 ppt); they differ only in delivery method (continuous circulated immersion vs. scheduled drip irrigation, 30-100 mL/hr). The Aquaponics-vs-Hydroponics-Drip comparison in this paper therefore isolates irrigation/delivery method, not nutrient source — worth noting for anyone using this row to represent a generic ‘aquaponics vs hydroponics nutrient source’ contrast. The Hydroponics-Manual arm used a genuinely different, non-fish nutrient source (seaweed/date-fruit extracts). | AP / HYD generic columns left NR: this paper’s headline outcomes (height, leaf count, root length) already have dedicated columns above; no separate generic ‘yield’ metric is reported that would populate these fields without duplicating Plant height/Leaf count. | Funding: no formal grant/funding statement in the paper; Acknowledgment (p.8) thanks the UAE Ministry of Climate Change and Environment for guidance/logistical assistance/resources, recorded in the note’s Metadata section, not a grant number.