Climate Change Vulnerability Assessment for the Major Habitats and Species in Lung Ngoc Hoang Nature Reserve, Vietnamese Mekong Delta

Stopping declines in biodiversity is critically important, but it is only a first step toward achieving more ambitious conservation goals. The absence of an objective and practical definition of species recovery that is applicable across taxonomic groups leads to inconsistent targets in recovery plans and frustrates reporting and maximization of conservation impact. We devised a framework for comprehensively assessing species recovery and conservation success. We propose a definition of a fully recovered species that emphasizes viability, ecological functionality, and representation; and use counterfactual approaches to quantify degree of recovery. This allowed us to calculate a set of 4 conservation metrics that demonstrate impacts of conservation efforts to date (conservation legacy); identify dependence of a species on conservation actions (conservation dependence); quantify expected gains resulting from conservation action in the medium term (conservation gain); and specify requirements to achieve maximum plausible recovery over the long term (recovery potential). These metrics can incentivize the establishment and achievement of ambitious conservation targets. We illustrate their use by applying the framework to a vertebrate, an invertebrate, and a woody and an herbaceous plant. Our approach is a preliminary framework for an International Union for Conservation of Nature (IUCN) Green List of Species, which was mandated by a resolution of IUCN members in 2012. Although there are several challenges in applying our proposed framework to a wide range of species, we believe its further development, implementation, and integration with the IUCN Red List of Threatened Species will help catalyze a positive and ambitious vision for conservation that will drive sustained conservation action.

Marsh terracing and coconut fiber mats are two restoration techniques currently being implemented at Sabine National Wildlife Refuge. We tested two hypotheses related to these restoration techniques: (1) marsh terracing enhances nekton assemblages, so that nekton use is similar to those at natural marsh edges, and (2) coconut matted marsh edges enhance SAV recruitment, so that nekton use is similar to those found at natural marsh edges. Samples from terraces and coconut matted marsh were compared to samples from the natural marsh and open water habitats. We measured the following variables at each habitat: (1) nekton density and abundance, (2) nekton biomass, (3) nekton size, (4) nekton diversity, and (5) nekton species composition. Using a collapsible throw trap with 3 mm mesh and a 3 x 2 m straight seine, 180 nekton samples were collected at four sampling dates from winter 2001 to fall 2002. Six habitat types were sampled: (1) natural marsh edge (< 1 m from marsh - water interface), (2) coconut matted marsh edge, (3) terrace edge, and (4), (5), (6) open water (50 m from marsh - water interface for all 3 edge types). Environmental variables that may be influenced by restoration status were also monitored at each habitat. Samples from terraces and coconut matted marsh were compared to samples from the natural marsh edge and open water habitat. Results indicated that nekton variables at coconut matted edge and open water, natural edge, and terrace edge were not significantly different (p > 0.332). Nekton density, biomass, and diversity were lower in open water habitats associated with natural marsh and terraces than in the other four habitats (p < 0.0001). Coconut matted and natural marsh edges had significantly higher numbers of some benthic dwelling species (e.g. blue crab Callinectes sapidus, white shrimp Litopaenaus setiferous, naked goby Gobiosoma bosc, clown goby Microgobius gulosus, Gulf pipefish Syngnathus scovelli) than terrace marsh edges (p < 0.0004), potentially due to differences in substrate caused by construction of the terraces. Researchers have suggested that decreased benthic habitat quality at dredged material marshes is related to an impaired infaunal community and differences in sediment texture. At Sabine NWR, terracing and coconut matting increased nekton utilization 4.5 times above that in open water habitat by enhancing and increasing marsh edge relative to open water. The value of terrace and coconut matted marsh habitat for individual species may vary depending on their niche requirements. Future

Extent of saltwater intrusion and freshwater exploitability in the coastal Vietnamese Mekong Delta assessed by gauging records and numerical simulations

Salinity intrusion in the Vietnamese Mekong Delta (VMD) has been exacerbated significantly in recent years by the changing upstream inflows, sea level rise resulting from climate change, and socioeconomic development activities. Despite significant damage to agricultural production and freshwater supplies, quantitative assessments of future flows and salinization remain limited due to lack of observation data and modelling tools to represent a highly complex hydraulic network. In this study, we combine 1D-MIKE 11 and 2D-MIKE 21 hydrodynamic models to simulate future flows, water level and salinity intrusion in the Hau River—one main river branch in the Mekong Delta. Future hydrological changes are simulated under multiple scenarios of upstream inflow changes, climate change and sea level rise for the 2036–2065 period. We first use the 1D-MIKE 11 to simulate the flow regime throughout the whole VMD using upstream discharges, outlet water levels and rainfall data as boundary conditions. Output from this step is then used to force the 2D-MIKE 21 model to estimate flow velocity, water level and salinity concentration in the Hau River, focusing on the salinization-prone section between Can Tho, Dinh An, and Tran De estuaries. Simulation results show that salinization will increase substantially, characterized by (1) higher salinity intrusion length under spring tide from 6.78% to 7.97%, and 8.62% to 10.89% under neap tide; and (2) progression of the salinity isohalines towards the upper Mekong Delta, from 3.29 km to 3.92 km for 1 practical salinity unit (PSU) under spring tide, and 4.36 km to 4.65 km for 1 PSU concentration under neap tide. Additionally, we found that salinity intrusion will make it more difficult to re-establish the freshwater condition in the estuary in the future. In particular, the flushing time required to replace saltwater with freshwater at the estuaries tends to increase to between 7.27 h for maximum discharge of 4500 m3/s and 58.95 h for discharge of 400 m3/s under the most extreme scenario. Increasing salinization along the Hau River will have important consequences for crop production, freshwater supplies and freshwater ecosystems, therefore requiring timely adaptation responses.

Lakes integrate the signals of changing hydroclimate in their surrounding basin, which substantially influence gross primary production (GPP), respiration (R), and net ecosystem production (NEP). Most research focuses only on the changes to the open water habitat despite the littoral habitat's importance to lakes and its sensitivity to hydroclimatic variability. We analyze how years with different ice‐out dates and snow water equivalent (SWE) triggered different metabolism responses in the open water and littoral habitats of a subalpine lake. The dry (early ice‐out date and low SWE) and wet (late ice‐out date and high SWE) years had lower GPP and R rates in both habitats compared to the average hydroclimatic year. Furthermore, consumer biomass decreased during dry and wet years. GPP and R reduced the most in the littoral habitat. Consequently, the relative contribution to total lake GPP and R of the littoral habitat decreased, and the contribution of the open water habitat increased during the dry and wet years. We demonstrate that hydroclimatic conditions affect productivity and consumer biomass and show that within‐lake habitats do not experience equivalent responses to climate forcing. Our study has implications for how ecosystem scientists and managers quantify the absolute and relative contributions of the littoral habitat to whole lake production in the context of climate variation.

Nature reserves are a means of conserving natural and cultural treasures which if lost, can never be restored for its importance. Several international organizations cater for nature reserves.&nbsp; In 1966, the Tourism and Conservation Authority was established. It belongs to the International Union for Conservation of Nature (IUCN) which caters for nature reserves and their management.&nbsp; With the growing attention being paid to the environment, the year 2002 was declared the &#39;International Year of Tourism and Environment&#39;, in accordance with a decision taken by the Economic and Social Council of the United Nations in 1998.&nbsp; Later on, this decision was approved of by the General Assembly of the United Nations. The problem expounded in this study is the wide gulf between theory and practice when a certain area is declared &#39;protected&#39;.&nbsp; An example is the &#39;Nile Islets&#39; which were declared a nature reserve in accordance with a political decree that was not based on any environmental survey or study of the area.&nbsp; Moreover, the classification of protected areas in Egypt is not accurately defined.&nbsp; There is considerable overlap between protected areas, and it is evident that most of them suffer from lack of organization, management and protection. Many important historical, archaeological and rich cultural heritage sites in Egypt suffer remarkable deterioration.&nbsp; Some have completely fallen apart, and some have vanished or have being sacrificed to the bulldozer. This research aims at: (1) deciding the criteria and considerations required to declare a certain area &#39;a nature or cultural reserve&#39; and the comprehensive tourism development needed; (2) evaluating the current condition (status quo) in the protected area of Al-Moez Street in Cairo. The methodology used in this research work includes: (1) The descriptive analytical method, (2) case study method, (3) survey method, (4) deductive method, and (5) analysis of the primary and secondary data related to the field of study using the statistical program SPSS - V - 11. Research findings have revealed that the criteria and principles of the sustainability of urban and tourism development of Al-Moez Street have been taken into consideration to a reasonable extent.&nbsp; This is also confirmed by the findings of the statistical analysis and the positive and negative aspects that have been observed by a team who paid frequent visits to the area. &nbsp; Key words:&nbsp;Cultural&nbsp;tourism, protected area, criteria of protected area.

International Union for Conservation of Nature (IUCN) Red List assessments rely on published data and expert inputs, and biases can be introduced where underlying definitions and concepts are ambiguous. Consideration of climate change threat is no exception, and recently numerous approaches to assessing the threat of climate change to species have been developed. We explored IUCN Red List assessments of amphibians and birds to determine whether species listed as threatened by climate change display distinct patterns in terms of habitat occupied and additional nonclimatic threats faced. We compared IUCN Red List data with a published data set of species' biological and ecological traits believed to infer high vulnerability to climate change and determined whether distributions of climate change-threatened species on the IUCN Red List concur with those of climate change-threatened species identified with the trait-based approach and whether species possessing these traits are more likely to have climate change listed as a threat on the IUCN Red List. Species in some ecosystems (e.g., grassland, shrubland) and subject to particular threats (e.g., invasive species) were more likely to have climate change as a listed threat. Geographical patterns of climate change-threatened amphibians and birds on the IUCN Red List were incongruent with patterns of global species richness and patterns identified using trait-based approaches. Certain traits were linked to increases or decreases in the likelihood of a species being threatened by climate change. Broad temperature tolerance of a species was consistently related to an increased likelihood of climate change threat, indicating counterintuitive relationships in IUCN assessments. To improve the robustness of species assessments of the vulnerability or extinction risk associated with climate change, we suggest IUCN adopt a more cohesive approach whereby specific traits highlighted by our results are considered in Red List assessments. To achieve this and to strengthen the climate change-vulnerability assessments approach, it is necessary to identify and implement logical avenues for further research into traits that make species vulnerable to climate change (including population-level threats).

Interplay between land-use dynamics and changes in hydrological regime in the Vietnamese Mekong Delta

Background: Understanding abundance, diversity and density of waterbird species along with detailed description of habitat utilization pattern is significant to understand species ecology and consequently for management and conservation. Waterbird density and their utilisation pattern of different habitats in Wular lake was investigated during study period from 2017-2019. Methods: Population estimation of waterbirds was carried out by point count and line transect method. Length of the transect varied from 50-100 meters. Waterbird density was estimated using Reynolds formula in a circular plot. Radius of circle varied from 45- 50 meters. Pattern of habitat utilisation was calculated by Ivlev’s index. Findings: Twenty-five (25) species of waterbirds belonging to eighteen (18) genera, seven families (7) and six orders (6) were recorded. Mean population of 628193874.20 during mid-winter and 420.58142.10 individuals during post winter was observed. Mean density of 810.81387.3 birds ha-1 during mid-winter and 71.291.33 birds ha-1 during post winter was recorded. Of all the habitats, open water had highest waterbird density (630.3258.32 birds ha-1) while as paddy fields had lowest waterbird density (0.440.08 birds ha-1) during mid-winter. During post winter also open water habitat was the most densely populated habitat (30.24.85 birds ha-1) but marshes were least densely populated habitat (0.410.05 birds ha-1) during this season. Open water habitat was most preferred habitat and peatlands the most avoided one. Variation in densities among different habitats was statistically significant (p<0.05). Novelty: Anthropogenic threats like agricultural conversion, habitat degradation and pollution greatly affect the utilisation of different habitats by waterbirds. Knowledge indicating the density and diversity of waterbirds along with their preference and avoidance towards different habitats will help in managing those habitats as well as framing conservation policies for survival of waterbirds inhabiting them. Keywords: Habitat utilisation; Density; Population; Ramsar; Waterbirds; Wetlands; Wular

Despite the oligotrophic conditions of the southeastern Levantine Sea and northern Red Sea, six lobster species—five slipper lobsters (Scyllaridae) and one spiny lobster (Palinuridae)—maintain permanent, reproducing populations in the study area. Additionally, there are isolated records of four other sporadic lobster species. In the southeastern Mediterranean, permanent species include the Mediterranean slipper lobster,Scyllarides latus, small European locust lobster, Scyllarus arctus, and pygmy locust lobster, Scyllarus pygmaeus. In the northern Red Sea, they include the clamkiller slipper lobster, Scyllarides tridacnophaga, Lewinsohn locust slipper lobster, Eduarctus lewinsohni, and pronghorn spiny lobster, Panulirus penicillatus. This review synthesizes current knowledge of their biology and ecology, including distribution, habitat, reproduction and development, feeding, predators and anti-predatory adaptations, behavior, sensory modalities, environmental impacts, threats, and conservation. Recent advances focus mainly on larger, commercially valuable species (S. latus, S. tridacnophaga, P. penicillatus), while major gaps remain for oceanic post-embryonic stages and the nektonic nisto postlarva, as well as for smaller, often cryptic species (S. arctus, S. pygmaeus, E. lewinsohni). Addressing these gaps will require targeted research, using modern methodologies, in coastal, deep, and open waters, coupled with citizen-science surveys. While many Indo-Pacific decapods have been established in the Mediterranean, no immigrant lobster species have successfully colonized Levant waters, despite rare records of three non-indigenous species (NIS). However potential NIS predators and shifts in mollusk compositions, the main prey of some native lobsters, may affect the latter. Large lobsters remain targeted by fisheries despite protective regulations, which are not always effective or obeyed. No-take marine protected areas (MPAs) or nature reserves can be effective if sufficiently large and well-managed. Habitat loss from marine construction can be partly compensated by stable, environmentally safe artificial reefs tailored to lobster behavioral ecology. The categories of the studied lobsters’ species in the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, last updated over fifteen years ago, should be re-evaluated.

We performed a preliminary evaluation of a mobile sampling platform with adjustable push net and live box (Platform) against two common methods for sampling small-bodied fish (i.e., 10–100 mm) in two distinct lentic habitats. Nearshore (NS) littoral habitat was sampled by Platform and beach seine, and open water (OW) pelagic habitat by Platform and Kodiak trawl. Our goal was to evaluate the Platform’s ability to describe fish assemblage structure across habitat types in contrast to common techniques restricted to single habitat types that are less comparable due to gear-specific bias. Platform sample speed had a significant positive effect on recapture efficiency of both nearly neutrally buoyant objects and marked fish. Marked fish recapture efficiencies were similar for Platform in NS and OW, indicating similar efficiency across habitat types. Platform capture efficiency was similar to beach seine and greater than Kodiak trawl. With similar sampling time, the Platform collected more individuals and taxa in NS relative to beach seine and in OW relative to Kodiak trawl. Greater taxa detection by the Platform suggests that it may be effective at detecting species that are numerically rare in specific habitats when compared to these methods. Fish CPUE was significantly greater NS regardless of technique. However, by using the Platform, there is greater confidence that this difference was reliable and not a gear selectivity artifact. Overall, this preliminary study demonstrates the Platform’s potential to collect standardized data across NS and OW habitats, track ontogenetic habitat shifts, and detect differences in small-bodied fish taxa richness, relative abundance, and density between NS and OW habitats. Continued experimentation beyond a single reservoir and fish size range is required before consensus can be established regarding the utility of this new push net design.

Marine protected areas (MPAs) are a primary tool for the stewardship, conservation, and restoration of marine ecosystems, yet 69% of global MPAs are only partially protected (i.e., are open to some form of fishing). Although fully protected areas have well‐documented outcomes, including increased fish diversity and biomass, the effectiveness of partially protected areas is contested. Partially protected areas may provide benefits in some contexts and may be warranted for social reasons, yet social outcomes often depend on MPAs achieving their ecological goals to distinguish them from open areas and justify the cost of protection. We assessed the social perceptions and ecological effectiveness of 18 partially protected areas and 19 fully protected areas compared with 19 open areas along 7000 km of coast of southern Australia. We used mixed methods, gathering data via semistructured interviews, site surveys, and Reef Life (underwater visual census) surveys. We analyzed qualitative data in accordance with grounded theory and quantitative data with multivariate and univariate linear mixed‐effects models. We found no social or ecological benefits for partially protected areas relative to open areas in our study. Partially protected areas had no more fish, invertebrates, or algae than open areas; were poorly understood by coastal users; were not more attractive than open areas; and were not perceived to have better marine life than open areas. These findings provide an important counterpoint to some large‐scale meta‐analyses that conclude partially protected areas can be ecologically effective but that draw this conclusion based on narrower measures. We argue that partially protected areas act as red herrings in marine conservation because they create an illusion of protection and consume scarce conservation resources yet provide little or no social or ecological gain over open areas. Fully protected areas, by contrast, have more fish species and biomass and are well understood, supported, and valued by the public. They are perceived to have better marine life and be improving over time in keeping with actual ecological results. Conservation outcomes can be improved by upgrading partially protected areas to higher levels of protection including conversion to fully protected areas.

Salinity intrusion, exacerbated by climate change and anthropogenic activities, poses a significant global threat to agricultural productivity, particularly in coastal and deltaic regions. Rice, a staple crop critical for food security and economic stability in many developing nations, is highly susceptible to salt stress, which reduces yields and threatens livelihoods. In the Vietnamese Mekong Delta (VMD), a key rice-producing region, recurrent drought-induced salinity events have caused substantial damage to agriculture, and the economic well-being of millions of residents. These events highlight the urgent need for sustainable solutions to maintain rice production under adverse environmental conditions. Plant-Growth-Promoting Rhizobacteria (PGPR) have emerged as a promising eco-friendly approach to enhance plant salt tolerance, offering potential to mitigate salinity stress in rice crops. Here we review the role of PGPR in alleviating salinity stress in rice farming in the VMD, highlighting its potential as a sustainable agricultural approach. The review synthesizes existing research to assess the causes of salinity intrusion, the efficacy of PGPR, and the limitations of current studies in this region. The major points are the following: 1) Saline intrusion in the VMD is driven by multiple factors, including sea-level rise, land subsidence, upstream dams’ operation, and excessive sand mining, which exacerbate agricultural challenges; 2) PGPR enhance rice salt tolerance through mechanisms such as osmotic regulation, improved nutrient uptake, and activation of stress-responsive genes, as evidenced in controlled and field studies; 3) Research in Vietnam is constrained by a lack of long-term investigations and a reliance on publications in Vietnamese-language scientific journals, which may limit international attention and rigorous peer-review processes, necessitating further studies to support scalability and adoption by VMD farmers, and also enlarge international collaboration in this important field of study.

ABSTRACTThe Vietnamese Mekong Delta (VMD) is one of the world’s most vulnerable deltas to climate change and sea level rise. Adequate understandings of future hydrological changes are crucial for effective water management and risk-proofing, however, this knowledge body is currently very limited. This study quantifies the responses of the VMD’s river flow regime to multiple stimuli, namely future upstream inflow variation, local climate change, and sea level rise. The one-dimensional hydrodynamic model MIKE 11 was used to simulate discharges and water levels across the delta. We developed four scenarios to represent changes in the upstream discharges, precipitation changes and sea level rise, covering the 2036–2065 period. We downscaled climate data and applied three bias-correction methods for five General Circulation Models (GCM), and two Representative Concentration Pathways (RCPs). The climate change projections show similar trends of increasing wet season precipitation and decreasing dry season precipitation. However, cross-scenario variations are sometimes large, depending on the individual GCMs, the RCPs and specific locations. The hydraulic simulation results indicate that, under discharge changes between −20% and +10%, combined with in-delta precipitation variations during the dry season, river discharges at the four representative stations could reduce substantially from −2.5% to −100.2%. During the wet season, the calculated river discharges show increase between 7.3% and 46.7% under four considered scenarios. Substantial changes in the VMD’s river flow regime could have potentially serious implications for water management, especially saltwater intrusion, and therefore calling for timely adaptation measures.

Ladybirds (Coleoptera: Coccinellidae) provide services that are critical to food production, and they fulfill an ecological role as a food source for predators. The richness, abundance, and distribution of ladybirds, however, are compromised by many anthropogenic threats. Meanwhile, a lack of knowledge of the conservation status of most species and the factors driving their population dynamics hinders the development and implementation of conservation strategies for ladybirds. We conducted a review of the literature on the ecology, diversity, and conservation of ladybirds to identify their key ecological threats. Ladybird populations are most affected by climate factors, landscape composition, and biological invasions. We suggest mitigating actions for ladybird conservation and recovery. Short-term actions include citizen science programs and education, protective measures for habitat recovery and threatened species, prevention of the introduction of non-native species, and the maintenance and restoration of natural areas and landscape heterogeneity. Mid-term actions involve the analysis of data from monitoring programs and insect collections to disentangle the effect of different threats to ladybird populations, understand habitat use by taxa on which there is limited knowledge, and quantify temporal trends of abundance, diversity, and biomass along a management-intensity gradient. Long-term actions include the development of a worldwide monitoring program based on standardized sampling to fill data gaps, increase explanatory power, streamline analyses, and facilitate global collaborations.