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Understanding the factors shaping patterns of ecological resilience is critical for mitigating the loss of global biodiversity. Throughout aquatic environments, highly mobile predators are thought to serve as important vectors of energy between ecosystems thereby promoting stability and resilience. However, the role these predators play in connecting food webs and promoting energy flow remains poorly understood in most contexts. Using carbon and nitrogen isotopes, we quantified the use of several prey resource pools (small oceanic forage, large oceanics, coral reef, and seagrass) by 17 species of elasmobranch fishes (n = 351 individuals) in The Bahamas to determine their functional diversity and roles as ecosystem links. We observed remarkable functional diversity across species and identified four major groups responsible for connecting discrete regions of the seascape. Elasmobranchs were responsible for promoting energetic connectivity between neritic, oceanic and deep-sea ecosystems. Our findings illustrate how mobile predators promote ecosystem connectivity, underscoring their functional significance and role in supporting ecological resilience. More broadly, strong predator conservation efforts in developing island nations, such as The Bahamas, are likely to yield ecological benefits that enhance the resilience of marine ecosystems to combat imminent threats such as habitat degradation and climate change.

Any scientific career is a mix of planning and stochastic events, often with a fair share of the latter. I illustrate this by the evolution of my own career. Ecosystem studies of food webs under the impact of eutrophication (Master), and carbon cycling in DOC (Dissolved Organic Carbon)-rich lakes (PhD) led me to elemental ratios in organisms and the establishment of ecological stoichiometry. The role of phosphorus (P) in cellular processes again led to research on the evolution and regulation of genome size. As climate came higher on the agenda, it was time to apply the basic research on the C-cycle and climate in a wider context. As natural scientists, we should also engage in even wider contexts, and I have enjoyed discussions and co-operation with philosophers, psychologist, and social scientists. This helps seeing our own work in context. We should also reflect on why we do science. I have always felt that science should also add purpose to life by giving something back to society, and I have devoted much time to outreach, public talks, debates, and writing popular science books. It takes some time, but it is also rewarding and important—perhaps even more so than yet another paper. [ABSTRACT FROM AUTHOR]

Ecosystems are connected by flows of nutrients and organisms. Changes to connectivity and nutrient enrichment may destabilise ecosystem dynamics far from the nutrient source.We used gradostats to examine the effects of trophic connectivity (movement of consumers and producers) versus nutrient‐only connectivity on the dynamics of Daphnia pulex (consumers) and algae (resources) in two metaecosystem configurations (linear vs. dendritic).We found that Daphnia peak population size and instability (coefficient of variation; CV) increased as distance from the nutrient input increased, but these effects were lower in metaecosystems connected by all trophic levels compared with nutrient‐only connected systems and/or in dendritic compared with linear systems.We examined the effects of trophic connectivity (i.e. both trophic levels move rather than one or the other) using a generic model to qualitatively assess whether the expectations align with the ecosystem dynamics we observed.Analysis of our model shows that increased Daphnia population sizes and fluctuations in consumer‐resource dynamics are expected with nutrient connectivity, with this pattern being more pronounced in linear rather than dendritic systems.These results confirm that connectivity may propagate and even amplify instability over a metaecosystem to communities distant from the source disturbance, and suggest a direction for future experiments, that recreate conditions closer to those found in natural systems. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

In the context of ecological civilization, it is of great significance to explore the method of permanent basic farmland demarcate that takes into account the protection of arable land resources and the maintenance of ecosystems in order to build a new pattern of spatial development of the national territory.The study has been constructed a set of permanent basic farmland demarcate method considering ecosystem connectivity by combining land evaluation and site assessment method and future land use simulation model on the basis of identifying ecological sources, ecological corridors and "stepping stone" through the model of minimum cumulative resistance model and circuit theory, In order to provide some theoretical references for the demarcate of permanent basic farmland in Shiyan City. The results show: 1) Shiyan City has a total of 26 ecological sources, mainly forests and waters, distributed in the southern and central hilly areas; a total of 66 ecological corridors, centrally located in the territory of Zhuxi County, Zhushan County, Fang County, etc.; and a total of 121 "stepping stones". 2) According to the comprehensive evaluation score of land evalution and site assessment and the permanent basic farmland demand target of Shiyan City, the arable land with a comprehensive score ≥48.68 will be designated as permanent basic farmland, and the final area of permanent basic farmland is 167,800.23 hm2, which is mainly distributed in the southwestern part of Zhushan County, northern part of Zhuxi County, the central part of Fang County, and the central and northern part of Danjiangkou City, etc. However, there are serious conflicts with the important ecosystem connectivity land, including 1,772.64 hm2 with ecological sources, 4,274.19 hm2 with ecological corridors, and 391.86 hm2 with "stepping stones".3) Based on the FLUS model to simulate the process of permanent basic farmland demarcate in Shiyan City, the demarcated area is 167800.05 hm2, mainly located in the flat area of the river valley on the border of Zhushan County and Zhuxi County, the northern part of Danjiangkou City, the eastern part of Yunyang District, etc., with a high degree of centralization and contiguity; moreover, the demarcated permanent basic farmland effectively avoids encroachment on ecological source, ecological corridor and "stepping stone", realize the permanent basic farmland protection and ecosystem connectivity maintenance and coordinated development.4) Comparing the results of LESA with those of permanent basic farmland demarcate with consideration of ecosystem connectivity, it is found that permanent basic farmland demarcated based on the LESA method ignores the serious impact on ecosystem connectivity, while permanent basic farmland demarcated with consideration of ecosystem connectivity not only takes into account the impact on ecosystem connectivity, but also follows the historical pattern of urban expansion, realizing the harmonization of permanent basic farmland protection, ecosystem connectivity preservation and urban growth. In addition, the permanent basic farmland demarcated by the ecosystem connectivity approach is of higher quality, more concentrated and contiguous, and has a more regular shape, which is more conducive to mechanized farming, thus playing an important role in guaranteeing China's food security, advancing the structural reform of the agricultural supply side, and realizing the revitalization of the countryside. [ABSTRACT FROM AUTHOR]

The Lower Silurian Visby Beds (ca. 430 Ma) exposed on the island of Gotland (Sweden) yield the oldest so far described MCE's (mesophotic coral ecosystems). Several basic questions concerning these ecosystems, including their extent, positioning, and particularly their spatial relation and affinity with the shallow water reefs, remain unanswered. We describe a deeply incised erosional channel infilled by redeposited detrital and biodetrital material including corals and stromatoporoids, which represents a unique example of a fossil depositional structure connecting shallow- and deep-water reef environments of that time. The mesophotic environment is embodied by limestones and marls, in which the channel is incised, while the shallow water habitats are represented by the redeposited material infilling the channel. The erosional channel contains material derived from hypothetical adjacent shallow-water reefal settings, which indicates that it served as an interconnecting zone between shallow- and deep-water benthic communities. The vertical connectivity of the shallow-water reefs and the adjacent mesophotic ecosystems results in a significant taxonomic overlap between these communities. This is especially important when taking into account that the Visby Beds are the oldest example of a fossil mesophotic ecosystem described so far. This indicates that the development of the earliest mesophotic ecosystems should not be attributed solely to gradual expansion of corals and stromatoporoids into greater depths, but probably took place also by means of redistribution of shallow water taxa during high-energy sedimentary events. [ABSTRACT FROM AUTHOR]

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Streams and forests are ecosystems connected through hydrology, but few studies have looked at the connectivity between streams and forests in the context of urban development. City-made decisions affect connections between streams and forests by isolating both ecosystems. Streams are often channelized or buried to increase potential development areas. Forests often become fragmented and may be removed unless protected. Historical choices in land usage affect the sites and sizes of current urban streams, forests, and development. This affects the distribution of impervious surfaces, which separates streams from forests. Despite these barriers to stream/forest interactions, cities can experience stream/forest connectivity. Seven Bloomington watersheds are ranked on their proportions of buried streams, channelized streams, forested hydrology, forested streams, urban forest patch cover, and impervious surface cover, along with the historical presence of urbanization. Watersheds demonstrate stream/forest connectivity, with five watersheds containing 50% or greater forested stream segments. Bloomington canopy cover reduces stormwater runoff by approximately 127 kiloliters per year. These forested areas reduce flooding, reduce nutrient loading, and reduce stream conditions associated with urban stream syndrome. Understanding urban stream/forest connectivity can improve green infrastructure design and green space design, which improve urban resilience and better connect residents to the environment. [ABSTRACT FROM AUTHOR]

The increase in climate-related extreme events and ecosystem degradation demands consistent and sustainable climate mitigation efforts. Seagrass playing a key role in nature-based carbon sequestration mitigation strategy. Here, we investigated the role of coral reef connectivity in blue carbon dynamics with seagrass meadows with coral reef connectivity (SC areas) and without coral reef connectivity (SG areas) in Palk Bay, India. The high sediment organic carbon was recorded in SC areas (90.26 ± 25.68 Mg org.C/ha) and lower in SG areas (66.96 ± 12.6 Mg org.C/ha). The maximum above-ground biomass (AGB) was recorded in Syringodium isoetifolium (35.43 ± 8.50) in SC areas and the minimum in Halophila ovalis (7.59 ± 0.90) in SG areas, with a similar trend observed in below-ground biomass (BGB). Our findings highlight the importance of coral reefs in enhancing the blue carbon potential of seagrass ecosystems and underscore the need for integrated conservation and restoration strategies for coral reefs and seagrasses. • Study reveals the site-specific habitat for SC & SG of carbon storage in Palk Bay • The mean above-ground biomass of Syringodium isoetifolim was 35.43 ± 8.50 g dwt/m2. • The sediment organic carbon stock of Cymodocea rotundata was 84.79 ± 1.37 Mg org.C/ha • Coral reef–seagrass habitat identified as potential climate change mitigation hotspot [ABSTRACT FROM AUTHOR]

Emerging aquatic insects constitute one of the main biological flows connecting aquatic and terrestrial ecosystems. In a landscape, there are many sources of emergence, which vary in space and time. Thus, they must be clearly defined when studying the inland dispersal of aquatic insects. In this study, we defined five types of hydrographic networks (including or not including ponds and ditches) on the basis of cartographic data of varying degrees of detail (from OpenStreetMap to field map) in order to explain the abundance of aquatic insects. We sampled Ephemeroptera, Plecoptera, Trichoptera, and Megaloptera (ETPM) with 64 sticky traps homogeneously covering a 75 ha agricultural landscape. The abundance of aquatic insects is logically better explained by the hydrographic networks recorded directly in the field than by the reference network, which is incomplete (OpenStreetMap). The results show that, depending on the sampling period, not all water bodies in the landscape are necessarily sources of emergence. To our knowledge, the issue of defining the sources of emerging aquatic insects has never been raised. Based on a practical example, this short note shows that, by refining the hydrographic network to better match the sources of emergence, the explanatory power of inland aquatic insect abundance can be greatly improved. [ABSTRACT FROM AUTHOR]

[Display omitted] Deep-sea environment, characterized by high pressures, extremely high/low temperatures, limited photosynthesis-generated organic matter, darkness, and high levels of corrosion, is home to flourishing special ecosystems in the world. Here, we illustrate how the deep-sea equipment offers insights into the study of life in the deep sea based on the work in the past five decades. We first describe how organisms in the deep sea are studied, even though it is highly difficult to get access to such extreme environments. We then explain the role of deep-sea technologies in advancing research on the evolution of organisms in hydrothermal vents, cold seeps, seamounts, oceanic trenches, and whale falls from the following perspectives: biological diversity, mechanisms of environmental adaptation, biological evolution, and ecosystem connectivity. Finally, to better understand the function and service of deep-sea organisms, and further conserve the special creatures under anthropologic activity and climate change, we highlight the importance of innovative deep-sea technologies to promote cutting-edge research on deep-sea organisms, and note the remaining challenges and developing directions for deep-sea equipment. [ABSTRACT FROM AUTHOR]

As biodiversity declines and climate change causes shifts in species distribution, the knowledge of species’ ecological needs is vital to conserve biodiversity. On Costa Rica’s Osa Peninsula and its adjacent forests, a rich mosaic of ecosystems hosting numerous threatened and endemic species, conservationists lack clarity on the basic habitat requirements of the endemic Black-cheeked Ant-Tanager (Habia atrimaxillaris). Numerous attempts have been made to understand its habitat requirements, resulting in contradictory conclusions. This study integrates new field data, thousands of community science observations, and comments in historical literature ranging over 50 years to complement the more localized studies. We explore the species’ habitat requirements, diet, and distribution in protected areas and biological corridors to better understand the species’ conservation needs and, in doing so, suggest a strategy to protect the Black-cheeked Ant-Tanager in a changing climate. We illustrate that Black-cheeked Ant-Tanagers occur in secondary forests, which they also use for foraging and nesting, suggesting that the conservation and restoration of secondary forests may help protect this range-restricted forest bird, especially through a targeted conservation strategy within biological corridors to build connectivity with higher elevations.

Ecological connectivity can influence the distributions of diversity and productivity among ecosystems, but relationships among multiple marine ecosystems remain relatively uncharacterized. Sandy beaches are recipient ecosystems that support coastal food webs through deposits of drift macrophytes (wrack), and serve as test cases for exploring within-seascape connectivity. We present results from the first comprehensive survey of geographic and temporal patterns of wrack cover and composition on beaches along the North Central Coast of California and test the role of local donor ecosystems and physical factors in predicting wrack distribution. We surveyed wrack at 17 beaches in August 2010, and monthly at a subset of 10 beaches for 13 months. We estimated explanatory variables of (1) local donor ecosystem cover (kelp forests, rocky intertidal, and bays and estuaries), (2) biomass transport, and (3) beach morphology. Regression analyses were used to evaluate relationships among the cover of six key wrack categories and the explanatory variables above, for two time periods. We found persistent geographic variation in wrack composition and detected significant relationships between wrack cover and cover of local donor ecosystems for five of the six wrack categories (Nereocystis, Zostera, Postelsia, mixed red algae, and mixed brown algae). Transport mechanisms (wind exposure, swell exposure) or attributes of the recipient ecosystem (beach width, beach slope) explained additional spatial variation for three of the six wrack categories (Zostera, Phyllospadix, and mixed red algae). Our results support the concept of considering ecological connectivity (particularly the role of donor ecosystems upon which recipient ecosystems rely) in the design and management of protected areas.

Emerging aquatic insects constitute one of the main biological flows connecting aquatic and terrestrial ecosystems. In a landscape, there are many sources of emergence, which vary in space and time. Thus, they must be clearly defined when studying the inland dispersal of aquatic insects. In this study, we defined five types of hydrographic networks (including or not including ponds and ditches) on the basis of cartographic data of varying degrees of detail (from OpenStreetMap to field map) in order to explain the abundance of aquatic insects. We sampled Ephemeroptera, Plecoptera, Trichoptera, and Megaloptera (ETPM) with 64 sticky traps homogeneously covering a 75 ha agricultural landscape. The abundance of aquatic insects is logically better explained by the hydrographic networks recorded directly in the field than by the reference network, which is incomplete (OpenStreetMap). The results show that, depending on the sampling period, not all water bodies in the landscape are necessarily sources of emergence. To our knowledge, the issue of defining the sources of emerging aquatic insects has never been raised. Based on a practical example, this short note shows that, by refining the hydrographic network to better match the sources of emergence, the explanatory power of inland aquatic insect abundance can be greatly improved.

The St Lucia estuarine system on the east coast of South Africa is a declared World Heritage Site and Ramsar Site of International Importance. A major ecological feature of St Lucia during the last century was the annual spawning migration of the flathead mullet Mugil cephalus down the system in the first half of each year. Top predators, such as the African fish eagle Haliaeetus vocifer, white pelican Pelecanus onocrotalus, Nile crocodile Crocodylus niloticus and Zambezi shark Carcharhinus leucas, have made extensive use of adult M. cephalus as a food resource. With the advent of prolonged closure of the St Lucia mouth in the first decade of the 21st century, caused by the lack of St Lucia system connectivity with the Mfolozi River and a prolonged drought, this spawning migration has ceased to exist. The almost complete disappearance of M. cephalus was reinforced in the second decade of this century by a continued lack of any estuarine–marine connectivity. This loss of connectivity between Lake St Lucia and the sea for more than 12 years is longer than the normal life cycle of M. cephalus, and the possibility exists that the putative subpopulation of this species that occupied the system prior to the turn of the century may have been rendered locally extinct. In January 2021, the berm at the mouth of the estuary was artificially breached and the outflow of St Lucia estuarine waters into the sea occurred for the first time since 2002. However, it remains to be seen whether the recovery of the M. cephalus population to pre-2000 levels will occur over the short term (year) or longer term (decade). It is strongly recommended that an adaptive management strategy, rather than a fixed management approach, be adopted for the sake of future connectivity of the St Lucia system to the marine environment. [ABSTRACT FROM AUTHOR]

Throughout their life history, many animals transition among heterogeneous environments to facilitate behaviours such as reproduction, foraging and predator avoidance. The dynamic environmental and biological conditions experienced by mobile species are integrated in the chemical composition of their tissues, providing retrospective insight into movement.Here, we present a unique application of nitrogen stable isotope clocks ('isotopic clocks'), which integrate tissue turnover rates, consumer stable isotope ratios and habitat‐specific isotope baselines to predict time‐since‐immigration and the timing of habitat shifts in a migratory species. Nitrogen stable isotope values of blood plasma collected from juvenile sand tiger sharks Carcharias taurus, a species known to undertake seasonal movements between ocean and estuarine environments, were used to derive estimates of time‐since‐immigration and the timing of seasonal habitat shifts undertaken by this species.Nitrogen isotopic clocks estimated for 65 juvenile sand tiger sharks sampled across 6 years indicated that individual sharks predominantly arrived to estuarine habitats between June and July, with some individuals arriving as early as mid‐May. These estimates were validated by comparing isotope‐derived estuarine arrival times with those from acoustically tracked individuals. The median estuarine arrival day estimates from our isotopic approach aligned with estimates from acoustic telemetry for each sampling population.Sensitivity analyses indicated that isotopically inferred time‐since‐immigration and estuarine arrival estimates were robust to variation in isotopic turnover rate and diet tissue discrimination factors under multiple modelling scenarios. This suggests that parameterization of the nitrogen isotopic clock provides reliable estimates of time‐since‐immigration and day of arrival into new habitats if isotopic variation exists between origin and new locations.Our study presents a unique application of telemetry‐validated isotope clocks to derive retrospective estimates of time‐since‐immigration and timing of habitat shifts for animals that seasonally traverse heterogeneous environments. This approach can be readily applied across many temporal and spatial scales, and to other species and ecosystems, to facilitate rapid assessment of changes in animal habitat use and broader ecosystem structure. [ABSTRACT FROM AUTHOR]

The atmosphere is host to a complex electric environment, ranging from a global electric circuit generating fluctuating atmospheric electric fields to local lightning strikes and ions. While research on interactions of organisms with their electrical environment is deeply rooted in the aquatic environment, it has hitherto been confined to interactions with local electrical phenomena and organismal perception of electric fields. However, there is emerging evidence of coupling between large- and small-scale atmospheric electrical phenomena and various biological processes in terrestrial environments that even appear to be tied to continental waters. Here, we synthesize our current understanding of this connectivity, discussing how atmospheric electricity can affect various levels of biological organization across multiple ecosystems. We identify opportunities for research, highlighting its complexity and interdisciplinary nature and draw attention to both conceptual and technical challenges lying ahead of our future understanding of the relationship between atmospheric electricity and the organization and functioning of biological systems. [ABSTRACT FROM AUTHOR]

Autonomous Reef Monitoring Structures (ARMS) have been applied worldwide to characterize the critical yet frequently overlooked biodiversity patterns of marine benthic organisms. In order to disentangle the relevance of environmental factors in benthic patterns, here, through standardized metabarcoding protocols, we analyse sessile and mobile (<2 mm) organisms collected using ARMS deployed across six regions with different environmental conditions (3 sites × 3 replicates per region): Baltic, Western Mediterranean, Adriatic, Black and Red Seas, and the Bay of Biscay. A total of 27,473 Amplicon Sequence Variants (ASVs) were observed ranging from 1,404 in the Black Sea to 9,958 in the Red Sea. No ASVs were shared among all regions. The highest number of shared ASVs was between the Western Mediterranean and the Adriatic Sea (116) and Bay of Biscay (115). Relatively high numbers of ASVs (103), mostly associated with the genus Amphibalanus, were also shared between the lower salinity seas (Baltic and Black Seas). We found that compositional differences in spatial patterns of rocky‐shore benthos are determined slightly more by dispersal limitation than environmental filtering. Dispersal limitation was similar between sessile and mobile groups, while the sessile group had a larger environmental niche breadth than the mobile group. Further, our study can provide a foundation for future evaluations of biodiversity patterns in the cryptobiome, which can contribute up to 70% of the local biodiversity. [ABSTRACT FROM AUTHOR]

The present study comprises the first systematic analysis of the limits of upstream movement by some fish species that use the estuarine area of the Patos Lagoon basin in southern Brazil. The Sinos River sampling program included 86 sites, sampled from 1998 to 2014, covering lowland stretches and headwater streams. The Guaíba sampling program was conducted from February 2011 to March 2013 and comprised 59 independent samples. Six fish species using estuarine areas occur in the upper Patos basin, 250–500 km from the Patos Lagoon outlet to the Atlantic Ocean. Parapimelodus nigribarbis specimens ranged from 11.3 to 18.9 cm (median = 13.3 cm) in length, i.e., were adults (Sinos, n = 459; Guaíba, n = 149). The species was captured almost 500 km from the Patos outlet, as far as 180 km upstream in the Sinos main channel. In Guaíba Lake, the species was captured mainly in autumn, although it was more abundant in winter and spring in the Sinos River. Lycengraulis grossidens was captured in the Sinos Basin, restricted to the lower stretches in spring and summer months (n = 7). In Guaíba Lake (n = 134) the species occurred throughout the lake and year-round, and was ten times more abundant in spring. Most specimens were adult (8.2–26.9 cm, median = 20.0 cm). Most Micropogonias furnieri individuals (n = 63) were juveniles (10.7–33.4 cm, median = 14.2 cm). The species was not captured in the Sinos Basin. In Guaíba Lake M. furnieri occurred predominantly in the southernmost part (downstream) and was more abundant (>10×) in winter. Genidens genidens (n = 27) was captured only in summer in the southern part of Guaíba Lake (closest to the outlet). Most individuals were adults (24.5–34.0 cm, median = 27.8 cm). Genidens barbus (n = 7) was restricted to spring and summer months and was captured only in southern (near-outlet) parts of Guaíba Lake, comprising mainly large juveniles and adults (31.5–68.0 cm, median = 37.9). Mugil liza (n = 13) appeared in spring in relatively low abundances but was widespread throughout Guaíba Lake during the summer. The species was not captured in the Sinos sampling program. The size profile comprised specimens nearing maturity (34.3–45.5 cm, median = 38.9 cm). Finally, we suggest possible biological cycles for these species that combine these new distribution data with published information.

Saltmarshes provide a broad range of high-value ecosystem services and can be sensitive to eutrophication, but elucidating such impacts at broad spatial scales demands a better understanding of the underlying nutrient linkages between saltmarsh soil and tidal waters. We used existing water quality data and field surveys of 15 saltmarshes across a broad trophic gradient of coastal waters, but similar biogeographic setting (in Ireland) to investigate if phosphorus and nitrogen pools in saltmarsh soils are related to those in tidal water across saltmarshes. We also investigated if the strength of such relationships is inversely related to ground elevation, which approximates the degree of tidal inundation. Plant-available phosphorus and nitrogen pools in soil were related to water nutrients, albeit only weakly. We did not find any support for the moderating influence of elevation, indicating that it may be obscured by internal cycling and external sources. We also found evidence for effect of birds on the saltmarsh nutrient pool. Saltmarsh soils are unlikely to serve as general sentinels of nutrient conditions in their corresponding water bodies and may need separate assessment criteria and management tools, which in turn require disentangling localised and whole-saltmarsh sources of variation in nutrient concentrations. [ABSTRACT FROM AUTHOR]

Abstract Water-to-air carbon dioxide fluxes from tropical coastal waters are an important but understudied component of the marine carbon budget. Here, we investigate drivers of carbon dioxide partial pressure (p CO 2) in a relatively pristine mangrove-seagrass embayment on a tropical island (Bali, Indonesia). Observations were performed over eight underway seasonal surveys and a fixed location time series for 55 h. There was a large spatial variability of p CO 2 across the continuum of mangrove forests, seagrass meadows and the coastal ocean. Overall, the embayment waters surrounded by mangroves released CO 2 to the atmosphere with a net flux rate of 18.1 ± 5.8 mmol m−2 d−1. Seagrass beds produced an overall CO 2 net flux rate of 2.5 ± 3.4 mmol m−2 d−1, although 2 out of 8 surveys revealed a sink of CO 2 in the seagrass area. The mouth of the bay where coral calcification occurs was a minor source of CO 2 (0.3 ± 0.4 mmol m−2 d−1). The overall average CO 2 flux to the atmosphere along the transect was 9.8 ± 6.0 mmol m−2 d−1, or 3.6 × 103 mol d−1 CO 2 when upscaled to the entire embayment area. There were no clear seasonal patterns in contrast to better studied temperate systems. p CO 2 significantly correlated with antecedent rainfall and the natural groundwater tracer radon (222Rn) during each survey. We suggest that the CO 2 source in the mangrove dominated upper bay was associated with delayed groundwater inputs, and a shifting CO 2 source-sink in the lower bay was driven by the uptake of CO 2 by seagrass and mixing with oceanic waters. This differs from modified landscapes where potential uptake of CO 2 is weakened due to the degradation of seagrass beds, or emissions are increased due to drainage of coastal wetlands. Highlights • An aquatic CO 2 source in the mangrove dominated upper embayment waters was associated with delayed groundwater inputs. • A shifting CO 2 source-sink in the lower embayment bay was driven by the uptake of CO 2 by seagrass and mixing with oceanic waters. • This more pristine system differs to modified landscapes, where potential uptake of CO 2 is weakened due to the degradation of seagrass beds, or emissions are increased due to drainage of coastal wetlands. • Antecedent rainfall and radon were found to be the best predictors of CO 2 dynamics, with no clear seasonality observed, in contrast to better studied seasonal temperate systems. • Extended delays of groundwater-derived CO 2 in the coastal waters compared to mangrove forest waters highlight the importance of comparative studies with more modified systems which are known to have more rapid delivery of carbon to coastal waters. • This study may assist when determining anthropogenic modification buffer zones in mangrove forest embayments. [ABSTRACT FROM AUTHOR]

The expanding economical activities have accelerated losses of biodiversity and ecosystem services, which are especially pronounced in Asia. To find solutions to stop these losses, a group of scientists studying both ecological and social sciences has launched an interdisciplinary research network, entitled TSUNAGARI (Trans-System, UNified Approach for Global and Regional Integration of social-ecological study toward sustainable use of biodiversity and ecosystem services). The project is based on two main perspectives: (1) integrating different disciplines of environmental research across multiple spatial scales, and (2) evaluating the importance of ecosystem connectivity between land and ocean for biodiversity and ecosystem services. The integrative studies have been started as follows: (1) integrating global-scale analyses of biodiversity and economy by developing GIS-based footprint analysis, (2) establishing the link between the studies of local good practices of ecosystem management and life cycle assessment on ecosystem good and services, (3) linking local-scale ecosystem studies to decision making processes for sustainable society by multiple stakeholders, and (4) upscaling local analyses of ecosystem processes to broad-scale analyses of ecosystem patterns. The proposed approaches are considered effective to solve problems that impede conservation of biodiversity and sustainable use of multiple ecosystem services in various situations although we also find some gaps such as regional biases in biodiversity data and involvement of different types of stakeholders. By overcoming the major bottlenecks, we believe the new integrated approaches will promote conservation and sustainable management of biodiversity and ecosystem services research, and contribute to advance decision-making processes from local communities to international levels. [ABSTRACT FROM AUTHOR]

Cross-ecosystem movements of mobile consumers are a primary mechanism by which energy and nutrients are exchanged between disparate ecosystems. While factors influencing variation in bottom-up subsidies between ecosystems have been well studied, much less is known regarding how biotic and abiotic factors influence the dynamics of mobile consumer-driven connectivity. In a literature survey, we found only 14% of studies examined factors contributing to variation in cross-ecosystem marine foraging by freshwater-adapted consumers. Here, we examine the relationships between abiotic factors and cross-ecosystem movements of a highly mobile freshwater-adapted top predator, Alligator mississippiensis (American alligator). As alligators lack physiological adaptations to survive in marine environments, we predict this linkage would be affected by factors that modify the ability to cope with high salinities. Our results reveal that multiple abiotic factors (e.g., relative humidity, temperature, total precipitation) are key explanatory variables of the duration of cross-ecosystem foraging trips by alligators, and that the absence of salt glands does not preclude them from performing long forays into marine environments. More broadly, our results expand our understanding of mobile consumer-driven ecosystem connectivity at the land-sea interface by demonstrating connectivity is highest when physical stressors are relaxed, and access to and availability of resources are maximized. [ABSTRACT FROM AUTHOR]

Understanding the factors shaping patterns of ecological resilience is critical for mitigating the loss of global biodiversity. Throughout aquatic environments, highly mobile predators are thought to serve as important vectors of energy between ecosystems thereby promoting stability and resilience. However, the role these predators play in connecting food webs and promoting energy flow remains poorly understood in most contexts. Using carbon and nitrogen isotopes, we quantified the use of several prey resource pools (small oceanic forage, large oceanics, coral reef, and seagrass) by 17 species of elasmobranch fishes ( n = 351 individuals) in The Bahamas to determine their functional diversity and roles as ecosystem links. We observed remarkable functional diversity across species and identified four major groups responsible for connecting discrete regions of the seascape. Elasmobranchs were responsible for promoting energetic connectivity between neritic, oceanic and deep-sea ecosystems. Our findings illustrate how mobile predators promote ecosystem connectivity, underscoring their functional significance and role in supporting ecological resilience. More broadly, strong predator conservation efforts in developing island nations, such as The Bahamas, are likely to yield ecological benefits that enhance the resilience of marine ecosystems to combat imminent threats such as habitat degradation and climate change.

The use of nature-like fishways to increase ecosystem connectivity has increased in recent years, but their effectiveness has rarely been evaluated. A rock ramp was constructed in the Shiawassee River in 2009, and post-construction effects (2011-2012) were evaluated on the summer fish assemblage by comparing fish assemblage composition to a nearby free-flowing river and a nearby river with a dam. Patterns of fish species richness, mean catch-per-unit-effort and proportional abundance in reaches upstream and downstream of the rock ramp, dam and comparable sites in the free-flowing river were evaluated. Overall, species richness by site and proportional abundance in the rock-ramp river were more similar to the free-flowing river, while species richness by reach was more similar to the dammed river. These findings suggest that the rock ramp has improved connectivity for the summer fish assemblage, but has not fully restored conditions to the level observed in a free-flowing river. [ABSTRACT FROM AUTHOR]

The KwaZulu-Natal Bight comprises the only sizeable shelf region on the eastern coast of South Africa, and is influenced by both the Agulhas Current on its seaward side and rivers and estuaries on its landward side. Established knowledge of the effect of the Agulhas Current includes the influence on nutrient concentrations in the bight of a semi-permanent upwelling cell at its northern border (St Lucia) and, to a much lesser extent, of a semi-permanent eddy feature at its southern extremity. Current modelling efforts, however, point to a very important role of land-derived nutrients, which supplement the productivity of food webs of the bight. This connectivity of the bight to its adjacent ecosystems has various implications. First, its productivity has traditionally been viewed via phytoplankton growth, whereas ecosystem modelling efforts point to a very high reliance on imported detritus (mainly land-derived) in order to sustain especially the rich benthic food web. The benthos in the bight dominates the food web, and is in marked contrast to the upwelling system of the west coast of South Africa (Atlantic Ocean) where water-column productivity dominates. Second, the importance of the connectivity of the Thukela Bank prawn-trawling ground to estuarine nursery areas, which has been modelled quantitatively, highlights the significance of this particular ecosystem connectivity for fisheries and also for the Thukela Bank food web. Heterogeneity across the bight is apparent for nutrient turnover rates (carbon, nitrogen, phosphorus), CNP content and stoichiometry, whereas nitrogen is a limiting nutrient across the entire bight. The food web near the Thukela River is richer in nutrient content and more active (higher turnover rates) compared to the northern and southern parts of the bight. This environmental heterogeneity was also apparent from the CNP content and stoichiometry of the various species and species groups in the bight. Requirements to take the hydrodynamic, biogeochemical and first ecosystem modelling efforts towards a meaningful predictive capability are discussed. The importance of adopting a system-level view of the bight and its connected systems for realistic exploration of global change scenarios is highlighted. [ABSTRACT FROM AUTHOR]

While recent research has provided evidence that the emergence of merolimnic insects (species with an aquatic larval stage) provides a considerable energy subsidy to riparian food webs, it has also shown that merolimnic insects may serve as a vector for contaminants. Therefore, riparian food webs may be at risk from either an aquatic-terrestrial transfer of contaminants or from the contaminant-driven reductions of emerging merolimnic insects. The objective of the present study was to develop an integrated stream mesocosms test design capable of identifying these inter-ecosystem boundary effects and to provide a comprehensive approach as a basis for ecotoxicological testing. We chose the widely distributed web-building spider Tetragnatha extensa as a representative species for riparian predators. Trophic aspects of riparian food webs were investigated by stable isotope analysis of carbon (δC) and nitrogen (δN). Utilization of stable isotope ratios provided detailed information on the riparian food web structure and the dietary composition of T. extensa. Merolimnic invertebrates (mainly Cloeon spp. and Chironomidae) were found to contribute up to 71 % of T. extensa's diet, demonstrating their importance in riparian food webs in ecotoxicological mesocosm testing. This study provides a conceptual and methodological basis for assessing aquatic insect emergence-related pollutant transfer or effect translation from aquatic to adjacent terrestrial systems. [ABSTRACT FROM AUTHOR]

Coastal marine and estuarine ecosystems are highly productive and serve a nursery function for important fisheries species. They also suffer some of the highest rates of degradation from human impacts of any ecosystems. Identifying and valuing nursery habitats is a critical part of their conservation, but current assessment practices typically take a static approach by considering habitats as individual and homogeneous entities. Here, we review current definitions of nursery habitat and propose a novel approach for assigning nursery areas for mobile fauna that incorporates critical ecological habitat linkages. We introduce the term 'seascape nurseries', which conceptualizes a nursery as a spatially explicit seascape consisting of multiple mosaics of habitat patches that are functionally connected. Hotspots of animal abundances/productivity identify the core area of a habitat mosaic, which is spatially constrained by the home ranges of its occupants. Migration pathways connecting such hotspots at larger spatial and temporal scales, through ontogenetic habitat shifts or inshore-offshore migrations, should be identified and incorporated. The proposed approach provides a realistic step forward in the identification and management of critical coastal areas, especially in situations where large habitat units or entire water bodies cannot be protected as a whole due to socio-economic, practical or other considerations. [ABSTRACT FROM AUTHOR]

Rivers in tropical Australia are largely pristine, and ecosystem connectivity is intact, but water resources in northern Australia are under increasing development pressure. A better understanding of the role and life histories of key migratory species is urgently needed to manage the risks posed by development. We investigated the life history of Macrobrachium spinipes (Schenkel, 1902) in the Daly River of the Northern Territory, Australia. We carried out a 13-mo trapping program (2011-2012) at 7 sites along the river between 92 and 405 km from the estuary. We provide the first detailed account of spatial and temporal changes in relative abundance and reproduction, and present information on length at first maturity and Fulton's body condition factor. Reproduction was strongly seasonal and was restricted to the wet-season months of November to April, followed by a recruitment pulse 3 to 4 mo later during the early dry season. Length at first maturity declined as the reproductive season progressed but did not vary significantly with distance from the estuary. Condition was temporally variable and peaked for both sexes immediately after the wet season before declining throughout the dry season. Relative abundance patterns followed a similar pattern. Contrary to results for other Macrobrachium species in rivers of comparable length, we found an increase in the relative abundance of females throughout the river's length during the reproductive season and reproductive effort occurring far upstream, over a restricted time period. This result highlights the importance of maintaining connectivity for reproductive success of this species and further recruitment into these upstream reaches. [ABSTRACT FROM AUTHOR]

Large-bodied, top-predators are often highly mobile, with the potential to provide important linkages between spatially distinct food webs. What biological factors contribute to variation in cross-ecosystem movements, however, have rarely been examined., Here, we investigated how ontogeny (body size), sex and individual-level behaviour impacts intrapopulation variation in cross-ecosystem foraging (i.e. between freshwater and marine systems), by the top-predator Alligator mississippiensis., Field surveys revealed A. mississippiensis uses marine ecosystems regularly and are abundant in estuarine tidal creeks (from 0·3 to 6·3 individuals per km of creek, n = 45 surveys). Alligator mississippiensis captured in marine/estuarine habitats were significantly larger than individuals captured in freshwater and intermediate habitats., Stomach content analysis (SCA) showed that small juveniles consumed marine/estuarine prey less frequently (6·7% of individuals) than did large juveniles (57·8%), subadult (73%), and adult (78%) size classes. Isotopic mixing model analysis ( SIAR) also suggests substantial variation in use of marine/estuarine prey resources with differences among and within size classes between sexes and individuals (range of median estimates for marine/estuarine diet contribution = 0·05-0·76)., These results demonstrate the importance of intrapopulation characteristics (body size, sex and individual specialization) as key determinants of the strength of predator-driven ecosystem connectivity resulting from cross-ecosystem foraging behaviours. Understanding the factors, which contribute to variation in cross-ecosystem foraging behaviours, will improve our predictive understanding of the effects of top-predators on community structure and ecosystem function. [ABSTRACT FROM AUTHOR]

As the world's population increases, settled areas expand, agricultural areas become more intensively managed, and ecosystems become increasingly fragmented as habitat elements are removed to make way for agricultural production. Reversal of fragmentation by enhancing ecosystem connectivity is a key step in halting biodiversity loss in agricultural areas. One way to decrease fragmentation is by maintaining habitat areas on farms and compensating farmers for the loss of the income that could have been earned if these areas were used for agricultural production. The implementation of ecological compensation schemes requires public funds, and governing bodies will only be willing to carry out this task if it is in accordance with the wishes of the public. This study sought to assess the attitudes of the public in Switzerland to ecosystem connectivity measures in rural areas, known as ecological compensation areas, and to measure whether attitudes could be influenced by the provision of ecological information. A revealed preference choice experiment was conducted using manipulated photographs of typical farmland, with various habitat elements added to an ‘empty’ agricultural landscape. Information treatments were given to half the respondents, while a control group received no further information. Approximately, half of the respondents showed no clear preferences for any particular landscapes. The remainder expressed preferences for more complex landscapes with half preferring landscapes containing ecosystem-connecting elements. This result challenges what has previously been considered to be an almost universal preference for complexity in landscapes. Provision of information was found to be not a significant influence on attitudes, although this result may be due to the complexity of the information that was delivered. Those seeking to influence landscape preferences, for example by reaching the disengaged majority, would be well advised to use simple emotional messages rather than complex ecological arguments. [ABSTRACT FROM AUTHOR]

The notion that the conservation of wetlands in the world is too limited has gained a universal consensus because of the conflicts between their great value and the drastic decline in their quantity and quality. To mitigate these conflicts, ecological networks have integrated the hydrologic and biological connectivity of ecosystems. The basic elements of ecological networks, patches, and corridors, have been extracted to reflect the attributes of the hydrologic and biological connectivity of ecosystems. This paper reviews recent applications of network approaches to ecological conservation, focusing on their application in wetland ecosystems, and proposing a new perspective for wetland conservation. This review is limited to four aspects: first, the linkages between wetlands and ecological networks are determined by reviewing the development both of them; second, the two types of connectivity and their application that can be obtained from graphs or network models are discussed; third, common network analysis approaches, which can provide a theoretical basis to explore the optimal relationship between network structure and function, are summarized; finally, this paper presents the configuration and convergence characteristics of different types of wetland networks at multiple spatial scales. At the conclusion, suggestions for further work are presented. [ABSTRACT FROM AUTHOR]

Resource subsidies between habitats are common and create the potential for the propagation of. environmental impacts across system boundaries. However, recent understanding of the potential for subsidy-mediated cross-system impact propagations is limited and primarily based on passive flows of nutrients and detritus or short-term effects. Here, we assess the effects of sustained alterations in aquatic insect emergence (active subsidy pathway), due to chronic stream pollution, for riparian spiders. The sustained reduction in aquatic insect densities at the polluted reaches resulted in a marked decline in web spider population density and a shift in spider community composition. Our results provide the first evidence that stream pollution can control populations and community structure of terrestrial predators via sustained alterations in aquatic subsidies, emphasizing the role of subtle trophic linkages in the transmission of environmental impacts across ecosystem boundaries. [ABSTRACT FROM AUTHOR]

Herring ( Clupea harengus) and sprat ( Sprattus sprattus) are the key prey resources of common terns ( Sterna hirundo) breeding in the Wadden Sea. Breeding success of the terns has been below average since 2002, coinciding with exceptionally low herring recruitment and sprat abundance. Time series of herring and sprat abundance in the North Sea and in the Wadden Sea were analyzed to explain long-term breeding success and chick development at two common tern breeding colonies. North Sea herring recruitment and sprat abundance in the Wadden Sea explained the largest part of common tern breeding success, both as single variables and in a multiple regression approach. Breeding success showed stronger correlations with herring recruitment indices derived from the North Sea region compared to the Wadden Sea. Also, herring and sprat abundance data explained more variability in breeding success than of more directly responding measures such as growth rate and maximum weight of chicks. Despite spatial and temporal incoherences between fish surveys and the common tern breeding season, breeding success of common terns reflected the abundance of their key prey fish beyond their foraging range and breeding season. We argue that the ecological connectivity between large- and small-scale herring abundance and the responsiveness of common tern breeding success is strong enough to establish a fish-seabird indicator system to be potentially valuable in monitoring and conservation. [ABSTRACT FROM AUTHOR]