Coastal Salinity Research Articles

A Sustainable Methodological Approach for mitigation of Salt Stress of Rice Seedlings in Coastal Regions: Identification of Halotolerant Rhizobacteria from Noakhali, Bangladesh and their impact

Salinity hinders the growth of many crops common in the diet, such as rice, wheat and maize when cultivated in coastal salinity areas. Given the limited availability of cultivable land and the increasing growth of the population, it is necessary to enhance productivity. In this paper, we present an innovative approach to adopting Halotolerant Plant Growth Promoting Rhizobacteria (HPGPR) to enhance salt-tolerant rice varieties to solve salinity stress and enhance crop production. HPGPR has functions to overcome plant growth and development and is the most efficient bioinoculant for rice in saline environments. This approach can be considered a potential method because of the cost-effective and environmentally friendly impacts in agricultural production, which involves salt-affected areas.

The impact of acute low salinity stress on Antarctic echinoderms.

Climate change is causing increased coastal freshening in Antarctica, leading to reduced salinity. For Antarctica's endemic echinoderms, adapted to the stable polar environment, the impact of rapid reductions in coastal salinity on physiology and behaviour is currently unknown. Six common Antarctic echinoderms (the sea urchin Sterechinus neumayeri; the sea star Odontaster validus; the brittle star Ophionotus victoriae; and three sea cucumbers Cucumaria georgiana, Echinopsolus charcoti and Heterocucumis steineni), were directly transferred from ambient salinity (34.5‰) to a range of salinity dilutions (29-9‰) for 24 h. All species showed reduced activity and the establishment of a temporary osmotic gradient between coelomic fluid and external seawater. Most species exhibited a depression in oxygen consumption across tolerated salinities; however, at very low salinities that later resulted in mortality, oxygen consumption increased to levels comparable to those at ambient. Low salinity tolerance varied substantially between species, with O. victoriae being the least tolerant (24 h LC50 (lethal for 50% of animals) = 19.9‰) while E. charcoti and C. georgiana demonstrated the greatest tolerance (24 h LC50 = 11.5‰). These findings demonstrate the species-specific response of Antarctica's endemic echinoderms to short-term hypoosmotic salinity events, providing valuable insight into this phylum's ability to respond to an underreported impact of climate change.

Formation mechanisms and biogeochemical response of coastal salinity front in the central eastern Arabian Sea

This study investigates the formation mechanisms and impact of a coastal salinity front observed in the central eastern Arabian Sea (EAS) coast, particularly off Mangalore (∼13°N), during the peak summer monsoon in August 2018. The interplay of intense monsoon rainfall, river runoff and coastal upwelling created a dynamic frontal zone characterised by distinct physical and biogeochemical properties in the central EAS. The study revealed that observed salinity fronts are formed due to the breaking of freshwater lenses by strong upwelled waters and the subsequent offshore transport of low-salinity plumes by prevailing current and Ekman transport. The high nutrient concentrations enhanced the chlorophyll a concentration 15–20 times higher (10.12 mg/m3) in the frontal zone compared to the non-frontal station. The dominance of diatoms in the frontal zone indicates herbivorous control in the coastal food web. Accumulation of plastic debris and foam-like particles in the frontal zone poses ecological risks and threatens aquatic life.

Salt stress mitigation and improvement in fruit nutritional characteristics of tomato plants: New opportunities from the exploitation of a halotorelant Agrobacterium strain

Soil salinity is considered one of the most limiting factors in large agricultural areas, and tomato (Solanum lycopersicum L.) is highly sensitive to this abiotic stress, which exacerbates under drought. The use of halotolerant PGPR is a promising strategy to enhance tomato tolerance and productivity in saline soils. The present study tested the capability of the recently discovered bacterial strain PVr_9 to increase tolerance to salinity in tomato plants in vitro, greenhouse and open field conditions. When inoculated with PVr_9, in vitro seedlings showed a significant increase in primary root length, number of secondary roots and fresh weight both in absence of stress and when exposed to 150 mM NaCl. In plants exposed to salt treatment, PVr_9 upregulated the salt tolerance genes SOS1 and NHX1, and the enzyme prolyl aminopeptidase involved in proline metabolism. Proteins associated with resistance against pathogens were also upregulated by PVr_9 in absence of salt stress. In greenhouse, PVr_9-inoculated tomato plants treated for 1-week with 150 mM NaCl showed a significant increase in shoot fresh biomass, chlorophyll, proline content, and APX activity. Tomato fruits from PVr_9 inoculated plants, exposed in the field to salt stress during the flowering stage, showed higher levels of carotenoids, lycopene, and l-ascorbic acid, as well as an increased antioxidant capacity compared to fruits of uninoculated plants. These results indicate PVr_9 as a potential biostimulant in tomato for better tackling soil salinization in a context of climate change and expansion of coastal salinity, while there is large scope for the improvement of the nutritional characteristics of tomato fruits.

Coastal Salinity Management and Cropping System Intensification through Conservation Agriculture in the Ganges Delta

Soil salinity is the major constraint for cropping system intensification in the coastal region of the Ganges Delta. Salts build up on the soil surface, as well as in the crop root zone, due to the capillary rise in underground brackish water, hampering the growth and development of crops and resulting in mortality and low yields. We studied, for three years (2020–2021 to 2022–2023), the effect of conservation agricultural practices (zero tillage planting, crop residue recycling, and crop rotations) on the major soil properties (soil salinity and organic carbon status), crop performance (yield and economics), and water footprint. Conservation agricultural practices significantly reduce soil salinity, build soil organic carbon, reduce water footprint, and increase the profitability of cropping systems compared to tillage-intensive conventional practices. Under conventional agriculture, the sole cropping of rice is more profitable than double and triple cropping systems.

ASSESSMENT OF LIVELIHOOD SECURITY OF FARMERS IN COASTAL AREA

India is a developing nation where the vast majority of people rely on agriculture as their primary source of income. The means by which people maintain, thrive, and survive is known as their livelihood. A person’s ability to support himself is a result of how and why they organize to use labor, technology, power, knowledge, and social relationships to change their environment and meet their needs. In the state of Gujarat, coastal salinity is and will remain the biggest threat to sustainable crop production. The main causes of improved livelihood security are issues with the salinity of the soil and water. A study was conducted in Porbandar, Junagadh and Gir Somnath district to assess the livelihood security of coastal area farmers and to ascertain the relationship between livelihood security and profile of the coastal area farmers. A sample of 120 respondents were selected from 12 different villages on the basis of 5 km from the coastal belt of three districts by applying multistage purposively random sampling technique. Majority (61.67 per cent) of the farmers had medium level of overall livelihood security index, followed by 20.00 per cent of them had low level of livelihood security index and 18.33 per cent of them were with high level of livelihood security index.There was positive and highly significant relationship between education, size of land holding, occupation, annual income, economic motivation, resource use management behavior and their livelihood security and also had positively and significant relationship between management orientation and credit orientation with their livelihood security.

Intrinsic and extrinsic factors associated with the spatio-temporal distribution of infectious agents in early marine Chinook and coho salmon

Understanding the factors driving the spatial distribution of infectious agents in populations is key to predicting infectious agent distributions under future ecological and anthropogenic scenarios. We applied a geostatistical analysis to a data set of 59 infectious agents assayed in thousands of Chinook and coho salmon in their first marine year to identify intrinsic and extrinsic factors associated with the probability and density (infectious agent load) of infection. Meta-analysis of the pathogen-specific geostatistical models indicated that sea surface salinity was the extrinsic factor most frequently associated with infection probability and density for a majority of infectious agents. In addition, agents that were categorized as having a moderate risk of transmission from aquaculture to wild salmon were more likely to occur, and at higher infection densities, in fish collected closer to active aquaculture facilities. Although hypotheses pertaining to other intrinsic and extrinsic factors, including age at ocean entry, known hatchery origin, and sea surface temperature deviation, were not supported by the meta-analysis results, some individual agents demonstrated strong associations with these factors. Our results suggest that climate-change-driven shifts in coastal seawater salinity (and to a lesser extent, temperature) may result in changes to the infection dynamics of several infectious agents. In addition, our results contribute to existing evidence characterizing the risk of infectious agent transmission from netpen aquaculture to free-ranging salmon.

Effect of Salinity Intrusion and Coastal Erosion on Marawila Coastal Area, Sri Lanka

Coastal erosion has become a major threat to coastal areas all around the world while salinity intrusion has also become a problem due to erosion mitigation measures in coastal area. Coastal erosion (and accretion) in Marawila coastal area was investigated by analyzing satellite images using spatial analysis techniques. The effect of salinity intrusion on Marawila coastal area was identified by travelling along the coastline, conducting interviews and analyzing the reports. In this study it was identified that both coastal erosion and salinity intrusion are nexus problems in Marawila coastal area. This study highlights the effect of salinity intrusion and coastal erosion on Marawila coastal area.

Compensatory shell thickening in corrosive environments varies between related rocky-shore and estuarine gastropods

Few studies have considered the capabilities of gastropods living in minerally-deficient acidified coastal waters to compensate for outer shell corrosion or compromised growing edge shell production. We compared inner shell thickening between pristine shells (control) and corroded shells (experiment) of two related intertidal neritid gastropod species from reduced salinity and acidified environments. We predicted that the rocky-shore, Nerita chamaeleon, which has greater access to shell building biomineralization substrates, should better control shell thickness than the estuarine, Neripteron violaceum. Accordingly, N. chameleon was found to compensate perfectly for variation in the thickness of the outer calcitic blocky layer (BL). Optimal shell thickness (OST) was maintained by selective reabsorption of the aperture ridge of the distal shell (aragonitic crossed-lamellar layer, CL) and by increased internal deposition of proximal (older) shell (aragonitic protocrossed lamellar, PCL). Despite greater exposure to acidification and hyposalinity, N. violaceum showed no significant compensatory shell thickening. These findings reveal that shell thickening capability may vary greatly among intertidal gastropods and that this may be constrained by environmental biomineralization substrate availability. Such environmentally-related responses carry implications for predicted future reductions in coastal water pH and salinity.

Formation and Dynamics of a Coherent Coastal Freshwater Influenced System

AbstractOn the Northwest European Shelf rivers provide freshwater to the coastal seas. This coastal freshwater can be misrepresented in ocean models without effective coastal resolution. This leaves an unanswered question; is freshwater retained around Scotland and what affects its variability? Here, we deploy and run an unstructured model with enhanced coastal resolution to simulate the Northwest European Shelf from 1993 to 2019, the Scottish Shelf Water‐Reanalysis Service (SSW‐RS) long‐time run. The unstructured nature of the model grid means it more accurately captures a “bubble” of Coastal Water than a 7 km structured grid model (the Atlantic Margin Model 7 km). Surface salinity in the SSW‐RS shows salinity fronts within 80 km of the coast around west and north Scotland that disintegrates east of Orkney. There are periods characterized by high coastal salinity when freshwater is more actively advected away from the coast. Empirical orthogonal function statistical analysis shows the first two modes in surface salinity account for 66% of the variance. The first mode correlates with North Atlantic Oscillation and the salinity driven velocity variability which change the salinity through advection and diffusion. The second mode correlates with Ekman transport variability where the north of Scotland acts as a wedge causing bipolar dynamics either side. Freshwater is trapped in the west, while saline water from the north reduces the freshwater pathway to the North Sea. This is important for salinity distribution, stratification in the North Sea, marine habitats and frontal transport.

Climate Change Driving Salinity: An Overview of Vulnerabilities, Adaptations, and Challenges for Indonesian Agriculture

Abstract Climate change has negatively affected agricultural productivity in Indonesia. This study conducted a bibliometric analysis of the literature on soil salinity caused by climate change, discussed the impact of soil salinity on Indonesian agriculture, examined various strategies for adaptation to salinity, and delivered some ideas for future research. An analysis of 39 identified Scopus articles related to farmers’ vulnerability, adaptation, and practices was carried out. This study was performed in November 2022 and employed Bibliometrix R package and VOSviewer software. Findings show that salinity has left Indonesia’s agriculture vulnerable to reduced food production, especially for small-scale farmers losing crop yields and land. Various adaptation measures have been initiated, such as restoring soil fertility and using saline-resistant varieties. Irrigation facilities improvements have also been carried out to reduce the risks of soil salinity expansion. Farmers also try social action measures, such as selling assets, borrowing money for daily needs, and even changing jobs. However, for farmers to survive and sustain their businesses, any such measures need to produce satisfactory results. A review of the existing literature reveals a lack of soil salinity studies in Indonesia, which simultaneously points to research gaps not only on the issue of the impact of salinity on income and the vulnerability of small farmers but also on the development of adaptation strategies to address salinity due to climate change. Significance Statement Soil salinization caused by climate change is a disastrous problem in Indonesia’s coastal areas that presents a major challenge to the productivity of rice agriculture and difficulties in addressing sustainable food security. To provide researchers with a clear understanding of the current emphasis and future trends in climate change–induced salinity research, systematically analyzing the relevant literature in the existing research area is necessary. The bibliometric analysis in this study shows that research on salinity due to climate change in Indonesia still needs to be completed. Further comprehensive studies to find a focus for managing coastal soil salinity are urgently required to reduce vulnerability and increase adaptation to salinity due to climate change.

The Salinity of Coastal Waters as a Bellwether for Global Water Cycle Changes

AbstractWhile the global water cycle has been studied previously based on land and open ocean studies, here we use coastal satellite sea surface salinity (SSS) data to show that in global aggregate, SSS variations near coasts are strongly correlated with global water cycle variability driven by El Niño Southern Oscillation (ENSO). This is a significant finding as we demonstrate that open ocean SSS variability is not as sensitive to ENSO and global water cycle variability as the coastal oceans at interannual timescales. Aggregated global coastal SSS could therefore be used as a proxy for detection of changes in the large‐scale cycling of water between the oceans and continents. Moreover, we identify major potential “hotspots” on land and in the coastal ocean that tend to drive global coastal salinity variability, and which may consequently be most sensitive to future physical and biological impacts of water cycle changes on the coastal oceans.

Assessing spatial impacts of historical pulp mill effluent on trophic dynamics in a coastal marine ecosystem using stable isotope (δ13C and δ15N) analysis

Boat Harbour, Nova Scotia was a tidal estuary that was converted into a wastewater treatment facility for pulp mill effluent in 1967. Treated effluent from Boat Harbour was discharged into the coastal Northumberland Strait, contributing significant nutrient and freshwater inputs into the coastal environment, potentially impacting local biogeochemistry and ecosystem structure. This study used stable isotope analysis of carbon (δ13C) and nitrogen (δ15N) of representative taxa to assess spatial variability in nutrient sources and trophic dynamics. Results identified stable isotope variation with depleted δ13C and δ15N values in taxa near Boat Harbour. Blue mussel (Mytilus edulis) and mummichog (Fundulus heteroclitus) were the most suitable bioindicators for identifying variation in nutrient sources. Stable isotope signatures in this study may be reflective of residual pulp mill effluent-derived nutrients, differences in marine versus terrestrial nutrient sources, and a pronounced coastal salinity gradient. The present study defined the baseline nutrient conditions of the Northumberland Strait and will be useful in assessing the effectiveness of remediation activities.

Modeling the interannual variability in Maipo and Rapel river plumes off central Chile

Abstract. River plumes have a direct influence on coastal environments, impacting coastal planktonic and benthic communities, including fishery resources. In general, the main drivers of river plume dynamics are the river discharge and the alongshore wind stress, whereas the tides and topography play a secondary role. In central Chile, rivers flowing into the eastern Pacific have a relatively short path on land, with a high slope and a mixed snow–rain regime. This study aims to understand the interannual variability in the plumes of the Maipo and Rapel rivers in the coastal/shelf area off central Chile and their influence on local ocean dynamics. We used the Coastal and Regional Ocean Community (CROCO) model, with 1 km horizontal resolution and 20 sigma levels, to simulate the ocean dynamics for the period 2003–2011. The results show that the plume's area coverage and coastal ocean salinity are strongly correlated with the river discharges. The predominant northeastward winds control the plumes' orientation toward the northwest. However, episodes of southeastward winds in winter can reverse the plumes' direction, promoting their attachment to the coast and southward transport. Results also show a salification trend linked to the severe droughts hitting central Chile during the studied period. This salification determines a change in local dynamics which could be more frequent in future scenarios of climate change with a significant lack of rain and river discharges along central Chile.

Evaluating multi-hazard risk associated with tropical cyclones using the fuzzy analytic hierarchy process model

Multi-hazard events have received attention globally due to their increasing frequency and severity in recent years. The coastal region of Bangladesh is particularly vulnerable to multi-hazard events induced by tropical cyclones (TC), including coastal flooding, extreme precipitation, extreme winds, and salinity intrusion. These events inflict substantial damage on human lives and property, yet there has been limited effort to quantitatively assess the associated risks. This study aims to investigate the spatial distribution of multi-hazard risks stemming from TC events, employing a Fuzzy Analytic Hierarchy Process (FAHP) approach. Risk is assessed in relation to hazard, exposure, vulnerability, and mitigation capacities in the study area. Various indicators are selected to define each of these four risk components, with weights determined through expert input for FAHP modeling. The results indicate that more than 50% of the area faces multi-hazard risks, with the hazard component exhibiting the highest degree of risk association, followed by exposure, vulnerability, and adaptive capacity. Storm surge-induced flooding is identified as the most prominent hazard during TC events, followed by intense precipitation, extreme winds, and salinity intrusion. Areas characterized by high population density, a large number of vulnerable populations (e.g., those under 15 years or over 65 years), low elevation, and underdevelopment are found to be the most risk prone. Notably, the presence of hospitals, cyclone centers, and effective warning systems in proximity to an area enhances its potential to withstand multi-hazard impacts. Among the 19 coastal districts, Cox's Bazar and Feni are identified as the most risk prone. The framework and findings presented in this study offer valuable insights for the development and prioritization of multi-hazard risk mitigation policies by identifying the most vulnerable zones and the associated risk factors.

Marker-assisted enhancement of bacterial blight (Xanthomonas oryzae pv. oryzae) resistance in a salt-tolerant rice variety for sustaining rice production of tropical islands.

Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae is a major disease of rice, specially in the tropical regions of the world. Developing rice varieties with host resistance against the disease is the most effective and economical solution for managing the disease. Pyramiding resistance genes (Xa4, xa5, xa13,and Xa21) in popular rice varieties using marker-assisted backcross breeding (MABB) has been demonstrated as a cost-effective and sustainable approach for establishing durable BB resistance. Here, we report our successful efforts in introgressing four resistance genes (Xa4, xa5, xa13, and Xa21) from IRBB60 to CARI Dhan 5, a popular salt-tolerant variety developed from a somaclonal variant of Pokkali rice, through functional MABB. Both BB and coastal salinity are among the major challenges for rice production in tropical island and coastal ecosystems. Plants with four, three, and two gene pyramids were generated, which displayed high levels of resistance to the BB pathogen at the BC3F2 stage. Under controlled salinity microplot environments, the line 131-2-175-1223 identified with the presence of three gene pyramid (Xa21+xa13+xa5) displayed notable resistance across locations and years as well as exhibited a salinity tolerance comparable to the recurrent parent, CARI Dhan 5. Among two BB gene combinations (Xa21+xa13), two lines, 17-1-69-334 and 46-3-95-659, demonstrated resistance across locations and years, as well as salt tolerance and grain production comparable to CARI Dhan 5. Besides salinity tolerance, five lines, 17-1-69-179, 46-3-95-655, 131-2-190-1197, 131-2-175-1209, and 131-2-175-1239, exhibited complete resistance to BB disease. Following multilocation testing, potential lines have been identified that can serve as a prospective candidate for producing varieties for the tropical Andaman and Nicobar Islands and other coastal locations, which are prone to BB and coastal salinity stresses.

Estuarine salinity extremes: Using the Coastal Salinity Index to quantify the role of droughts, floods, hurricanes, and freshwater flow alteration

In the face of accelerating climate change, advancing understanding of how extreme climatic events influence estuarine salinities can help to inform resource management. Extreme salinities driven by droughts, hurricanes, floods, and freshwater flow alterations can lead to ecological transformations in estuarine ecosystems. Here, we applied the Coastal Salinity Index (CSI; Conrads and Darby 2017) to 22 years (1998–2020) of salinity data in a Louisiana estuary (Barataria Estuary, USA) to elucidate the impacts of extreme events on estuarine salinities. The CSI is an index to quantify salinity patterns at a specific location through long-term averages and deviations from historical average conditions. We calculated and compared CSI values for four stations distributed along an estuarine salinity gradient. We identified 10 events between 1998 and 2020 that produced extreme salinities, including two droughts, four hurricanes, three floods, and one freshwater diversion. The droughts of 2000 and 2006 caused surface water salinities to increase substantially throughout the estuary. The effects of hurricanes were highly variable, with some storms leading to elevated salinities throughout the entire estuary (e.g., Hurricanes Katrina and Rita in 2005), whereas other storms led to elevated salinities for some but not all stations (e.g., Hurricanes Gustav and Ike in 2008 or Hurricane Isaac in 2012). The opening of a freshwater river diversion in 2010 contributed to fresher conditions throughout the estuary and appeared to reduce or eliminate the increases in salinity that normally occur during the summer, although these effects were short-lived. Mississippi River floods in 2008, 2011, and 2019 reduced salinities throughout the estuary, but the effects were most pronounced in the lower estuary compared to the upper estuary. Collectively, our results advance understanding of the influence of extreme events on estuarine salinity regimes. Our analyses also highlight the value of the CSI for identifying periods with extreme salinities (i.e., extreme high or low salinities) via calculations that place salinity levels within and across estuaries within a historical context.

Managing coastal aquifer salinity under sea level rise using rice cultivation recharge for sustainable land cover

Study regionThe coastal aquifer of Nile Delta, Egypt is used to develop the current study. Study focusExcess water from rice irrigation is a source of incidental recharge to mitigate seawater intrusion. This paper numerically explores the optimal location of rice cultivations by subdividing the delta domain into three distinct recharging regions (north, central and south). Additionally, SEAWAT code was simulated under a combination of rice cultivation relocation and sea level rise (SLR). New hydrological insights for the regionThe study findings revealed significant variations in salt volume reduction depending on the location of rice cultivation in the delta. Placing rice cultivation in the northern region resulted in the highest reduction of salt volume (19 %). In contrast, locating the recharge in the central region yielded a salt volume reduction of 0.50 %, while rice cultivation in the southern region produced a 15 % increase. Considering the projected SLR of 61 cm by 2100, there was an overall salt volume increment of 3 %. However, when accounting for both SLR and rice cultivation recharge in the northern region, a substantial salt volume reduction of 17 % was observed. The results demonstrated that incidental recharge by rice cultivation in coastal aquifers is an effective method for enhancing saltwater intrusion control. Moreover, this study improves our understanding of hydrological processes and expected responses in the delta under future climate scenarios.

On-farm agronomic manipulations to improve rice (Oryza sativa L.) production in the saline coastal zone of the Red River Delta in Vietnam

ABSTRACT Sporadic salinity caused by seawater intrusion is a serious concern for rice (Oryza sativa L.) production in the Red River Delta (RRD) of Vietnam, and guidance for on-farm agronomic management is needed. Three sets of on-farm experiments – namely, trials of (1) nitrogen (N) fertilizer use (replicated trials and surveys of farmer fields, including plots receiving zero N), (2) resistant varieties, and (3) shallow irrigation management – were conducted from 2015 to 2017 in three communes in Nam Dinh province in the RRD, to assess technologies adaptable by farmers. Yield response to N fertilizer in the farmer fields was generally low and greatly variable, associated with variable N recovery efficiency and internal efficiency, particularly in fields at risk of high salinity in one commune during summer 2015. In the replicated trials, N fertilizer applied at 120–180 kg N ha−1 in spring and 100–150 kg N ha−1 in summer generally produced better yields with higher N use efficiencies than the current high N application rates (219 and 189 kg N ha−1, respectively). Recently developed salinity-resistant varieties M2 and M14 produced almost 50% higher yield than the conventional varieties in very saline at-risk fields. Shallow water-depth management (<5 cm) resulted in grain yields similar to the higher conventional-depth management in the less saline fields, but significantly reduced yields in the more saline fields. These results indicate potential resource-use efficiencies in rice production to better cope with coastal salinity in the RRD.

Some like it salty: Spatio‐temporal dynamics of salinity differentially affect anurans and caudates in coastal wetlands

Abstract Coastal wetlands are naturally subjected to salinity, which is expected to increase through global climate changes. Most species will be affected by these changes, leading to major consequences for community structure and ecosystem functioning. We investigated variation of salinity of temporary wetlands across spatial (1,000 m from the ocean) and temporal (across three breeding season) scales relevant to coastal biodiversity and used amphibians (six species, sampled across one breeding season) as a model to investigate the consequences of the spatio‐temporal variation of salinity in 24 ponds situated on the Atlantic coast of France. We show that salinity is a highly dynamic environmental variable that varies widely both across spatial and temporal scales. The spatio‐temporal dynamics of salinity are a critical factor structuring amphibian communities that affect the main amphibian phylogenetic groups (caudates vs. anurans) differently. Temporal variation in salinity disrupts the match between salinity selected by reproductive adults and those experienced later by their developing offspring, which negatively affect reproductive success. Future changes in coastal salinity are likely to affect the structure and functioning of these ecosystems, excluding salt‐intolerant species and eventually leading to less diverse communities of salt‐tolerant species.