Transport of sediment in mangrove swamps

The transport of suspended sediment in mangrove swamps is controlled by three dominant processes. First, the transport processes in the estuaries and coastal waters draining the swamp, including flocculation, tidal pumping, baroclinic circulation, trapping of the smallest particles in the turbidity maximum zone, and the effect of the mangrove tidal prism. Second, the mechanical and chemical reactions in mangrove waters destroying flocs of cohesive sediment in suspension. Third, biological processes have a dominant influence on the ultimate fate of clay particles in mangroves.     

Physical processes in the Rufiji delta and their possible implications on the mangrove ecosystem

The physical processes such as coastal currents, estuarine circulation and monsoon winds prevailing in the Rufiji delta are discussed. The relationship between these processes and the occurrence of long-term trapping of the river discharge and the outflow of waters from the mangrove swamps into the nearshore zone has been observed. The trapped waters in the nearshore zone significantly reduce the mixing between the estuarine and offshore waters, leading to the two waters having distinctive properties. The existence of the trapped waters in the nearshore zone is supported by evidence from a satellite image and aerial photograph and measurements of salinity and suspended sediment concentration. The trapping phenomenon is discussed in the light of its possible implications on the ecology of mangrove ecosystems. Trapping may explain the enhanced growth of the mangrove in the delta compared to other areas. This trapping effect may be providing more time for nutrient retention in the mangrove zone, incorporation of the decomposed leaf litter and fine sediments in the substrate, and settling of fruits and seedlings in the swamps, thereby enhancing the regeneration of the mangrove.     

The estuarine character of the Gulf of Nicoya,an embayment on the Pacific coast of Central America

Hydrography and exchange processes in a tropical estuary, the Gulf of Nicoya, Costa Rica, are described from data collected in 1979 and 1980. The measurements and analyses were made in both the dry season and wet season and include temperature, salinity, and density at twenty locations in the gulf and currents (over a semi-diurnal tidal cycle) at five locations. These new results enlarge on the early study by Peterson (1958). Circulation in the lower gulf shows a marked east-west asymmetry due to the predominant runoff along its eastern shore from Rio Barranca and Tarcoles. The freshened surface water from the upper gulf combines with the runoff from these rivers and flows southward along the eastern side of the lower gulf. This flow is compensated by a northward flow of more saline water on the western side at all depths and on the eastern side along the bottom. The boundary between the southward and northward surface flow is marked by a strong salinity front in the rainy season. There is a rapid increase in tidal energy density toward the shoaling northern reaches of the lower gulf, between San Lucas Island and Puntarenas Peninsula. Enhanced mixing must accompany this increase, and direct measurements in the constriction between San Lucas and Puntaneras show that tidal mixing is dominant in transporting salt into the upper gulf against the freshwater runoff.     

Behavior of the groundwater in a riverine-type mangrove forest

The behavior of groundwater and physical properties of bottom sediment in a riverine-type mangrove forest which is composed of a tidal creek and fringing mangrove swamps were investigated through field observations at Iriomote Island, Japan. After the tidal water ebbed from the swamp surface to the creek, groundwater levels at swamp sites near the creek fell by up to 15 cm by the next flood tide, although the fall was negligible at sites far from the creek and at the open coast outside the mangrove forest. The amount of groundwater discharged to the creek from the swamp depended strongly both on the tidal range and the presence of the steep bank which separates the tidal creek from the fringing mangrove swamp. Based on the fall of groundwater level, the bulk hydraulic conductivity of the swamp was estimated to be 1.5×10⁻² cm/s. This value is two to three orders of magnitude larger than that measured in a laboratory using small scale sediment core samples collected in the swamp. These results suggest that the presence of crowded, intricate and large animal burrows as well as sediment layers rich in mangrove humus increases permeability in the mangrove swamp. Further, it is suggested that the mangrove topography with the steep bank of the tidal creek plays an important role which enhances material exchanges through groundwater between the mangrove swamp and the adjacent offshore waters.     

Sensory physiology and behavior of blue crab (Callinectes sapidus) postlarvae during horizontaltransport

Adult blue crabs (Callinectes sapidus) live in estuaries and release larvae near the entrances to estuaries. Larvae are then transported offshore to continental shelf areas where they undergo development. Postlarvae, or megalopae, remain near the surface and undergo reverse diel vertical migration. The behaviors underlying this migration pattern are responses to light and a solar day rhythm in activity, in which megalopae are active during the day and inactive at night. Onshore transport probably occurs by wind‐generated surface currents. Once in the vicinity of an estuary, megalopae move up the estuary by selective tidal stream transport, in which they swim in the water column on rising tides at night and are on or near the bottom at all other times. Light inhibits swimming during the day. The ascent into the water column on nocturnal rising tides does not result from a biological rhythm in activity, but rather is cued by the rate of increase in salinity during rising tides. Megalopae have separatebehavioural responses in coastal/shelf areas and in estuaries, which are induced by chemical cues in offshore and estuarine waters.     

Solute dynamics in a North Brazilian mangrove: the influence of sediment permeability and freshwater input

Although water in mangrove sediments influences nutrient cycling in both, mangrove forest and estuary, little information exists on seasonal and vertical distribution of dissolved organic and inorganic compounds in the sediment column. We studied the influence of sediment texture and chemistry, permeability (K), tides, and rainfall on dissolved organic carbon (DOC) and nitrogen (DON), dissolved inorganic phosphate (DIP) and salinity in creek and sediment waters of a mangrove in Pará, Brazil. Water samples were taken from boreholes and piezometers in the mangrove forest and from an adjacent tidal creek at neap and spring tides, during the dry and rainy season. Forest sediment was analysed for carbon (C), nitrogen (N), salinity and permeability. Clay, C and N decreased with depth. Sediment permeability (K) was lowest (<0.1 m day⁻¹) in the upper, clay-rich and crab-burrow-free mud layer. In the deeper, fine sand strata, K ranged from 0.7 to 1.8 m day⁻¹. Tidal range in the creek was 3.5 and 5.5 m for neap and spring tides, respectively. Salinity, DOC, DON and DIP in creek water were inversely related to tidal height. Piezometer data revealed significant water level changes in deeper, sandy sediment layer, which followed, time-lagged, the tidal fluctuations. In contrast, tide did not affect the water level in the upper sediment due to low permeability. Compared with creek water, sediment water was enriched in DOC, DON and DIP because of organic matter input and mineralization. In deeper layers, solute concentration was most likely affected by sorption processes (DOC and DIP) and reduction reactions (DIP). During the rainy season, DOC and DON in creek and sediment water were higher than in the dry season. DIP appeared invariant to seasonal changes. In the rainy season, salt flushing from surface sediments resulted in higher salinities at intermediate sediment depths, while in the deeper layers salinity was lower due to exchange with water from the tidal creek.     

Adaptive significance of hatching rhythms and dispersal patterns of estuarine crab larvae: avoidance of physiological stress by larval export?

Estuarine crabs commonly display two larval dispersal patterns in which larvae are either exported from or retained within estuaries. The semiterrestrial fiddler crab Uca minax (LeConte, 1855) hatches on nocturnal spring high tides in the upper estuary and larvae are rapidly transported downstream. The mud crab Rhithropanopeus harrisii (Gould, 1841) hatches on nocturnal high tides of any amplitude and larvae are retained behaviorally in the upper estuary throughout development. If larvae are exported from the estuary to avoid environmental stress, then exported larvae should be less tolerant of high temperatures and low salinities than retained larvae. Larvae of these two species of estuarine crabs were hatched at 20‰ and 25 °C and subjected to salinities of 0, 5, 10,20, and 30‰, temperatures of 25 and 35 °C, and exposure times of 2, 6, 12, and 48 h. Larvae of both species reared at 30 or 20‰ survived well, while those reared in fresh water all died within 2 h regardless of temperature. Mud crab larvae reared at 5 and 10‰ survived better at the lower temperature (25 °C), higher salinity, and shorter exposure times. There was no significant effect of temperature or salinity on the survival of fiddler crab larvae, although survival decreased with increasing exposure time. Thus, the hypothesis that fiddler crab larvae are exported into stable coastal waters to reduce physiological stress is not supported. However, fiddler crab larvae may have evolved to be very tolerant of extreme temperature and salinity stress because they, unlike mud crabs, often release their larvae into shallow creeks. Most fiddler crab larvae are released on nocturnal spring high tides, which facilitates dispersal from tidal creeks. However, freshwater runoff and heat transferred from the marsh surface to flooding waters may still create stressful conditions for larvae soon after they are released. Larval release on spring high tides may facilitate dispersal from tidal creeks.     

Watershed Deforestation and Down-Estuary Transformations Alter Sources,Transport, and Export of Suspended Particles in Panamanian Mangrove Estuaries

We identified eight Panamanian watersheds in which conversion from wet tropical forest to pastures differed and assessed the effects of degree of deforestation, and down-estuary transformations, on the suspended particulate matter discharged from the watersheds, entering, traversing through mangrove estuaries, and emerging into coastal waters. Deforested watersheds discharged larger concentrations of suspended particulate matter, with lower % C and N, higher mineral content, and heavier isotopic signatures into fresh reaches of estuaries. Down-estuary, sediment entrainment increased non-organic content of particulates, and watershed-derived imprints of deforestation on composition of particulate matter were mostly erased by within-estuary transformations. Isotopic signatures of C, N, and S in particulate matter demonstrated strong land-sea couplings, and indicated that the direction of the coupling was asymmetrical, with terrestrial and estuarine sources delivering particulate materials to coastal waters and sediments. Mangrove estuaries therefore both act as powerful modulators of human activities on land, while also exporting particulate materials to sea.     

Palynomorph distribution in a mangrove ecosystem along environmental and salinity gradient: a tool for palaeoecological reconstruction

Pollen assemblages closely reflect the local vegetation that characterizes the salinity status, providing useful analogs for paleoecologxical reconstruction in regional deposits. Palynological evidences of surface sediments from the Coringa mangrove wetland were correlated with the physicochemical and sediment salinity records to observe the relationship between them. The statistical analysis of the data obtained here revealed a marked horizontal salinity gradient from north to south.. In this study, ordination (detrended correspondence analysis) of palynomorph groups has identified a salinity gradient of 1.1 to 3.0 PSU from the north to the south in the wetland. High palynomorph deposition and lower salinity are observed along channel margins due to the mixing of estuarine water during the rainy season. The mudflats along the transects show a lower diversity of plants in the pollen record and high total dissolved solids (TDS) than commonly found in the coastal wetlands. The presence of scrubby halophytic vegetation in the upper saltmarsh and oligohaline-freshwater vegetation in the low tidal saline marshes is a zonation pattern related to the localized influence of freshwater conditions. Palynomarine Index (PMI) reveals the highest freshwater/tidal inundation along Ramannapalem due to the presence of numerous riverine channels while the remaining part of the wetland has restricted tidal inundation leading to the conversion of mangrove forests to salt pans and paddy fields. Thus, the health and productivity of the mangrove ecosystem are also governed by hydrodynamics, catchment land use, water discharge in the channels, and tidal flushing.

     

Ecology and distribution of diatoms in Biscayne Bay,Florida (USA): Implications for bioassessment and paleoenvironmental studies

The spatial and temporal distribution of planktonic, sediment-associated and epiphytic diatoms among 58 sites in Biscayne Bay, Florida was examined in order to identify diatom taxa indicative of different salinity and water quality conditions, geographic locations and habitat types. Assessments were made in contrasting wet and dry seasons in order to develop robust assessment models for salinity and water quality for this region. We found that diatom assemblages differed between nearshore and offshore locations, especially during the wet season when salinity and nutrient gradients were steepest. In the dry season, habitat structure was primary determinant of diatom assemblage composition. Among a suite of physicochemical variables, water depth and sediment total phosphorus (STP) were most strongly associated with diatom assemblage composition in the dry season, while salinity and water total phosphorus (TP) were more important in the wet season. We used indicator species analysis (ISA) to identify taxa that were most abundant and frequent at nearshore and offshore locations, in planktonic, epiphytic and benthic habitats and in contrasting salinity and water quality regimes. Because surface water concentrations of salts, total phosphorus, nitrogen (TN) and organic carbon (TOC) are partly controlled by water management in this region, diatom-based models were produced to infer these variables in modern and retrospective assessments of management-driven changes. Weighted averaging (WA) and weighted averaging partial least squares (WA-PLS) regressions produced reliable estimates of salinity, TP, TN and TOC from diatoms (r² = 0.92, 0.77, 0.77 and 0.71, respectively). Because of their sensitivity to salinity, nutrient and TOC concentrations diatom assemblages should be useful in developing protective nutrient criteria for estuaries and coastal waters of Florida.     

Marine and estuarine gradients — An overview

The Proceedings of the ECSA 21 symposium on Marine and Estuarine Gradients are reviewed. It is emphasised that this is probably the first time that a full set of papers on the tidal freshwater sections of estuaries has appeared. There is however some ambiguity in the terminology applied to such waters, and a more consistent terminology is proposed. In particular the estuary is defined as reaching upstream as far as the tidal limit, irrespective of salinity. A wide variety of gradients within estuaries and coastal waters are considered, but it is apparent that the crucial spatial gradients are based on salinity, oxygen and turbidity, and that many other gradients are co-variables with these parameters. Temperature is also important for temporal gradients.     

Selection of phytoplankton associations in Lake Balaton,Hungary, in response to eutrophication and restoration measures,with special reference to the cyanoprokaryotes

Seasonal and spatial patterns of aquatic primary production were compared in a tidal creek (Estero Pargo) bordered by mangroves and open waters of Terminos Lagoon, Mexico. Comparisions were made during a 17-month period in 1990–91 that spanned dry, rainy, and storm or 'Norte' seasons. Annual net primary productivity was 478 g C m-2 yr-1 in the lagoon and 285 g C m-2 yr-1 in the tidal creek. In some months, there were significant differences in primary production between the two sites. In both areas, the highest productivity occurred in summer at the start of the rainy season (June 1991), and the lowest production occurred during the dry season from February to May. Aquatic primary production was lower during the dry season of 1991 in comparison to 1990, possibly related to unusually low precipitation during 1991. Seasonal changes in water column productivity were correlated to variations in light and precipitation. The effect of runoff from mangrove forests was assessed by serial additions of surface water from a fringe forest to bottle incubations of lagoon water. Small additions of mangrove water stimulated primary production in lagoon waters during all seasons. The net productivity was extremely sensitive to aliquot volume; small amounts (0.3 and 1.7% of total volume) were stimulatory, increasing rates by > 50% in 7 of 12 experiments. The greatest effect occurred in September, 1990, when productivity tripled after an amendment with 1 ml (0.3% by volume) of mangrove water. Additions greater than 3% of total volume generally led to reduction in net productivity probably due to the inhibitory effect of humic substances. In many tropical systems, tidal exchange of estuarine waters with mangrove forests is likely to be important to enhancing water column productivity by exporting organic nutrients and other growth-enhancing substances to the estuary. This revised version was published online in July 2006 with corrections to the Cover Date.     

A modelling investigation of the distribution of stratification and phytoplankton abundance in the Irish Sea

Thermal stratification and phytoplankton abundance are modelledon a 5 km grid covering the Irish Sea. The water column is approximatedby three layers. The top layer is uniformly mixed by wind stirringand the bottom by tidal energy, while linear gradients can occurin the middle layer. The model is forced with hourly meteorologicaldata and mean tidal energies. Primary production is representedby a model with a single nutrient and a single phytoplanktonpopulation. The results from the model show good agreement withdata collected on a Ministry of Agriculture, Fisheries and Food(MAFF) cruise in May 1992 and with historical data. When advectionis included, driven by depth-averaged currents, the surfacetemperature patterns are improved but bottom temperatures indeep water are raised and high concentrations of chlorophyllare carried offshore from coastal regions. This indicates alimitation of using depth-averaged currents and a need to accountfor differences in phytoplankton species composition in coastaland offshore waters. Calculations demonstrate the importanceof salinity variations to stratification and phytoplankton growth.Smoothing the wind mixing energy has the effect of delayingthe onset of the spring bloom in areas where wind mixing issignificant. Removing the diurnal cycle of solar heating alsodelays the spring bloom. The chlorophyll gradient in the middlelayer has a large impact on the response of the model to short-termvariability in the meteorological forcings.     

Flux of organic carbon in a riverine mangrove wetland in the Florida Coastal Everglades

Short-term (daily) and seasonal variations in concentration and flux of dissolved organic carbon (DOC) were examined over 15 tidal cycles in a riverine mangrove wetland along Shark River, Florida in 2003. Due to the influence of seasonal rainfall and wind patterns on Shark River’s hydrology, samplings were made to include wet, dry and transitional (Norte) seasons. We used a flume extending from a tidal creek to a basin forest to measure vertical (vegetated soil/water column) and horizontal (mangrove forest/tidal creek) flux of DOC. We found significant (p < 0.05) variations in surface water temperature, salinity, conductivity, pH and mean concentration of DOC with season. Water temperature and salinity followed seasonal patterns of air temperature and rainfall, while mean DOC concentration was highest during the dry season (May), followed by the wet (October) and ‘Norte’ (December) seasons. This pattern of DOC concentration may be due to a combination of litter production and inundation pattern of the wetland. In contrast to daily (between tides) variation in DOC flux between the mangrove forest and tidal creek, daily variations of mean water quality were not significant. However, within-tide variation of DOC flux, dissolved oxygen content and salinity was observed. This indicated that the length of inundation and water source (freshwater vs. saltwater) variation across tidal cycles influenced water quality and DOC flux in the water column. Net DOC export was measured in October and December, suggesting the mangrove forest was a source of DOC to the adjacent tidal creek during these periods. Net annual export of DOC from the fringe mangrove to both the tidal creek and basin mangrove forest was 56 g C m⁻² year⁻¹. The seasonal pattern in our flux results indicates that DOC flux from this mangrove forest may be governed by both freshwater discharge and tidal range.     

The Nutrient Status of Mgazana,a Warm Temperate Mangrove Estuary in the Transkei,Eastern Cape,South Africa

Mgazana, a rural southern African mangrove system, was visited monthly from August, 1995 to February, 1997 to collect water samples for nutrient analysis. Surface and bottom samples were taken during spring low tide at seven stations along the estuary and the following physico-chemical parameters measured: river flow, temperature, salinity, oxygen, transparency, ammonia, nitrite, nitrate, phosphate, inorganic carbon (IC), organic carbon (OC), total carbon (TC), soluble nitrogen (SN), particulate nitrogen (PN) and total nitrogen (TN). Using correlation matrix analysis and ANOVA, river flow was found to affect estuarine salinity, transparency and stratification, which influenced nutrient dynamics. Significant seasonal (winter and summer) differences were found for temperature, river flow, nitrate, SN, TN, IC and OC. Most nutrients were significantly correlated with river flow showing gradients down the estuary, indicating allochthonous input from the catchment. OC levels within the estuary were high, probably due to autochthonous mangrove leaf-fall processing by the various in-fauna, but high levels measured at the head of the estuary during high river flow suggested additional allochthonous input from coastal forest litter. Conversely, IC was negatively correlated with river flow suggesting that autochthonous faunal and microbial mineralisation of organic matter occurs within creeks, which is then diluted by increased stream-flow. An N:P ratio of 2.7:1 was obtained for this rural mangrove system, which was low compared with Spartina-based East Cape estuaries subject to urban, industrial and agricultural pollution.     

Saltmarsh Boundary Modulates Dispersal of Mangrove Propagules: Implications for Mangrove Migration with Sea-Level Rise

Few studies have empirically examined the suite of mechanisms that underlie the distributional shifts displayed by organisms in response to changing climatic condition. Mangrove forests are expected to move inland as sea-level rises, encroaching on saltmarsh plants inhabiting higher elevations. Mangrove propagules are transported by tidal waters and propagule dispersal is likely modified upon encountering the mangrove-saltmarsh ecotone, the implications of which are poorly known. Here, using an experimental approach, we record landward and seaward dispersal and subsequent establishment of mangrove propagules that encounter biotic boundaries composed of two types of saltmarsh taxa: succulents and grasses. Our findings revealed that propagules emplaced within saltmarsh vegetation immediately landward of the extant mangrove fringe boundary frequently dispersed in the seaward direction. However, propagules moved seaward less frequently and over shorter distances upon encountering boundaries composed of saltmarsh grasses versus succulents. We uniquely confirmed that the small subset of propagules dispersing landward displayed proportionately higher establishment success than those transported seaward. Although impacts of ecotones on plant dispersal have rarely been investigated in situ, our experimental results indicate that the interplay between tidal transport and physical attributes of saltmarsh vegetation influence boundary permeability to propagules, thereby directing the initial phase of shifting mangrove distributions. The incorporation of tidal inundation information and detailed data on landscape features, such as the structure of saltmarsh vegetation at mangrove boundaries, should improve the accuracy of models that are being developed to forecast mangrove distributional shifts in response to sea-level rise.     

Young Mangrove Stands Produce a Large and High Quality Litter Input to Aquatic Systems

Mangrove swamps are key ecosystems along the Vietnam coast. Although mangrove litter is thought to represent an important input of organic matter and nutrients to the coastal aquatic systems, the factors determining the quality and size of this litter flux have not been studied so far. We monitored leaf, stipule, twig, and reproductive litter monthly in monocultures of Rhizophora apiculata mangrove forests of 7, 11, 17 and 24 years old in the Camau province, Mekong Delta, Vietnam. Litter traps were used to measure litter fall production from June 2001 till May 2002. Total litter fall was in the range of 8.86–14.16 t DW ha⁻¹ year⁻¹. Leaves were the main component, and represented 70% of litter fall production in all stands. Total litter fall was lower in the older stands but the amount of reproductive litter was significantly higher in these stands (17 and 24 years). Biomass of leaf litter was highest between the end of the wet season and the beginning of the dry season. Phosphorus and nitrogen levels in leaf litter were significantly higher in younger than in older stands. Overall, our study indicated that young stands produced the highest input of litter and particularly of nitrogen and phosphorus to the surrounding aquatic system. Consequently, these stands contribute significantly to the fisheries.     

Temporal variability of particulate organic carbon,nitrogen and phosphorus in the Northern Adriatic Sea

The particulate organic carbon (POC), nitrogen (PN) and phosphorus (PP) vertical distribution along the water column and temporal variability in coastal and offshore waters of the Northern Adriatic Sea were related to the hydrodynamic conditions and biological processes. Fresh water inputs from the Po and Adige rivers enhance primary production, resulting in high POC, PN and PP concentrations at the surface. In offshore waters, POC and PN concentrations were about 3–4 times less than in the coastal waters, while PP were up to 10 times lower, highlighting a marked phosphorus depletion. In the bottom layer, the POC content decreases due to the strong density gradients which separate bottom waters with prevailing degradation processes. Short term 48 h-variability of POC, PN and PP in the coastal waters was determined to a great extent by variations in the spreading of river plumes at the surface and by nepheloid layers and resuspension processes in the bottom waters. The particulate matter in the Adriatic offshore waters is extremely depleted as regards particulate phosphorus and is characterised by C_org:P and N:P ratios higher than the Redfield ratio.     

Runoff from tomato cultivation in the estuarine environment: biological effects of farm management practices

The use of plastic row covers (plastic mulch) on vegetable farms increases runoff of pesticides after rainfall events and has been linked to toxic events in adjacent tidal waters. In coastal Virginia, USA, runoff from tomato fields with plastic mulch was suspected of causing mortality of commercial hard clam larvae at a hatchery located downstream of farming operations. Concern about the putative impacts of this practice on local waters resulted in a collection of studies to: (1) determine the sensitivity of early life stages of bivalves to copper, a commonly used fungicide; (2) examine acute and chronic biological effects of runoff on tidal creeks; and (3) examine the efficacy of management practices designed to reduce the delivery of pesticides to adjacent creeks. Laboratory bioassays revealed that 48-h LC₅₀ values for embryonic clams Mulinia lateralis and Mercenaria mercenaria were 38 and 20 μg/l, respectively. In situ bioassays with Palaemonetes pugio showed that pulsed toxic conditions sometimes occur downstream of some tomato farms in plastic mulch following rainfall events. Growth, mortality rates and bioaccumulation of copper and organic pesticides in oysters were not correlated with the use of plastic mulch in watersheds. Sediment bioassays indicated potential toxicity in sediment collected downstream of some tomato fields in plastic mulch, but the effects were not consistent between years. Closer examination of management practices on the farms suggests that controlling runoff can prevent toxic impacts. Elevated levels of crop protectants measured at the outflow of farm ponds suggested that they may do little to reduce loadings of some pesticides. However, forested buffer zones and ephemeral sedimentation basins appeared to be effective in reducing pesticide concentrations in runoff and pulsed toxicity in tidal creeks.     

Recognition of co-existence pattern of salt marshes and mangroves for littoral forest restoration

Climate-change driven sea level rise causes a increase in salinity in coastal wetlands accelerating the alteration of the species composition. It triggers the gradual extinction of species, particularly the mangrove population which is intolerant of excessive salinity. Thus despite being crucial to a wide range of ecosystem services, mangroves have been identified as a vulnerable coastal biome. Hence restoration strategy of mangroves is undergoing rigorous research and experiments in literature at an interdisciplinary level. From a data-driven perspective, analysis of mangrove occurrence data could be the key to comprehend and predict mangrove behavior along different environmental parameters, and it could be important in formulating management strategy for mangrove rehabilitation and restoration. As salt marshes are the natural salt-accumulating halophytes, mitigating excessive salinity could be achieved by incorporating salt-marshes in mangrove restoration activities. This study intends to find a novel restoration strategy by assessing the frequent co-existence status of salt marshes, with the mangroves, and mangrove associates in different zones of degraded mangrove patches for species-rich plantation. To achieve this, we primarily design a novel methodological framework for the practice of knowledge discovery concerning the coexistence pattern of salt marshes, mangroves, and mangrove associates along with environmental parameters using a data mining paradigm of association rule mining. The proposed approach has the capability to uncover underlying facts and forecast likely facts that could automate the study in the field of ecological research to comprehend the occurrence of inter-species relationships. Our findings are based on published data gathered on the Sundarban Mangrove Forest, one of the world’s most important littoral forests. The existing literature reinforces the findings that include all the sets of frequently co-occurring mangroves, their associates, and salt marshes along the salinity gradient of coastal Sundarbans. A detailed understanding of the occurrence patterns of all these, along with the environmental variables, would be able to promote decision-making strategy. This framework is effective for both academia and stakeholders, especially the foresters/ conservation planners, to regulate the spread of salt marshes and the restoration of mangroves as well.