Meet Conservation Objectives Research Articles

Integration approaches for overlapping protected areas in the Qinghai-Xizang Plateau, China

Overlapping protected areas, where the same land is designated as more than one type of protected area, is a widespread issue that complicates the management and effectiveness of the protected area network. Systematically assessing the extent of overlap, along with their effective integration, is crucial for enhancing the effectiveness of protected areas in meeting conservation objectives. We take the Qinghai- Xizang Plateau as a case study, conducting a quantitative assessment of the spatial relationships among six distinct categories of protected areas. We compare the efficacy of two scenarios aimed at integrating overlapping protected areas. Scenario 1 is based on the protection level and categories of protected area and Scenario 2 considers the conservation objectives in addition to Scenario 1. Our findings reveal that 240 (45.6%) protected areas on the Qinghai-Xizang Plateau experience overlap, encompassing about 6.6% of the total area of the protected areas. Notably, over 50% of geo-parks, scenic spots, and forest parks are affected by overlap. While both scenarios yielded comparable outcomes in terms of the overall number and area of integrated protected areas, they differed in their effectiveness across different categories. Compared to Scenario 1, Scenario 2 is more effective in 31 overlapping protected areas that match the conservation objectives. This study offers valuable insights and a reference for China and other nations grappling with the challenges of overlapping protected area designations, which will ultimately improve the efficiency of the protected area network.

Ecological quality assessment: A framework to report ecosystems quality and their dynamics from reference conditions

AbstractWorldwide, ecosystems are suffering important taxonomic and functional modifications in response to anthropogenic disturbances, operating at multiple spatial and temporal scales. Awareness on biodiversity losses has led to the adoption of conservation policies and the development of programs devoted to the conservation and the restoration of terrestrial, freshwater, and marine ecosystems. The assessment of the ecological health of ecosystems requires measuring and characterizing restoration or degradation dynamics and their consequences on the ecological quality with respect to reference conditions defined pragmatically as conservation targets. Methodological innovations, in terms of data collection, analysis, and visualization, have an important influence on the ability of ecologists to understand biodiversity changes. The assessment of the quality of ecosystems with respect to reference conditions requires to address, notably, three main challenges: the definition of reference conditions, the assessment of the degree of achievement of conservation objectives, and the qualitative and quantitative characterization of recovering and departing patterns. We propose here the ecological quality assessment (EQA) framework as a data‐driven approach to track ecological quality focusing on the distance of the tested stations with respect to a chosen reference envelope using fuzzy logic and trajectory analysis. We take advantage of those analytical tools to propose a general and flexible multivariate framework by quantifying the achievement of reference conditions, measuring restoration and degradation dynamics when temporal series are available, and representing and synthesizing this information. To take into account the natural spatiotemporal variability of sites considered as reference, we gave two variants to our framework: a state‐based variant when no temporal replications are available and a trajectory‐based variant specially devoted to compare whole trajectories to a trajectory reference envelope defined by a set of reference trajectories. These two complementary approaches were illustrated through two terrestrial and marine ecological applications using the R package “ecotraj” in order to evidence ecological observations that meet conservation objectives from those that do not meet them. EQA constitutes a flexible framework for the assessment and reporting of ecosystem quality, including restoration and degradation dynamics adaptable to multiple questions in the different fields of ecology and conservation.

Assessing Community Readiness for Payments for Ecosystem Service Schemes for Tropical Primary Forest Protection in the Democratic Republic of Congo

Primary forest conservation is essential for limiting climate change, for meeting conservation objectives, and the Sustainable Development Goals. Schemes that compensate communities for forgone extractive uses are important policy tools, but effective deployment demands an understanding of local deforestation drivers and host communities’ preferences. We use Q-methodology to reveal discourses present in three communities in the Democratic Republic of Congo. Our results reveal three factors with a common emphasis on forest conservation and preferences for compensation in the form of social investments, rather than cash. The main contrasts were in attitudes towards farming. The first discourse, we call conservationist—open to ideas, displayed a commitment to learning better practices for community material benefit in service of forest conservation. The second discourse, which demonstrated greater confidence in their capacity to support livelihoods from farming, we call aspirational artisans. The third, which was acutely aware of the impact of their farming on forest conservation, we called passive, conflicted farmers. We also demonstrate an aspiration for the continued development of farming amongst participants, which although still correlated with preferences for forest conservation, may lead to compensation schemes inadvertently stirring future land use tensions if design does not reconcile agricultural development and conservation.

Hatchery supplementation increases potential spawning stock of Rio Grande Silvery Minnow after population bottlenecks

AbstractObjectiveSupplementation of imperiled wild fish stocks with captively raised fish is a commonly used conservation tool. Programs designed to maintain or improve fish populations through supplementation should be evaluated to determine whether they are meeting conservation objectives. The Rio Grande Silvery Minnow Hybognathus amarus is a small‐bodied, endangered minnow endemic to the Rio Grande basin of the southwestern United States. The wild population of Rio Grande Silvery Minnow has been supplemented with captive‐reared fish since 2002. Our objective was to determine whether supplementation measurably increases the number of spawning fish after years of population bottlenecks; this objective was simplified because nearly all hatchery‐released fish have been given identifying markings.MethodsWe leveraged a long‐term fish sampling data set (18 years) covering the species' contemporary range and a single‐season, high spatial coverage fish sampling data set to determine whether the number of potential spawners was increased by the addition of hatchery fish.ResultHatchery‐reared fish increased the catch rates of spawners by up to an order of magnitude in some years. We also observed that most hatchery‐reared fish were recaptured near the point of release. We were able to determine that supplementation with hatchery fish increased the abundance and distribution of Rio Grande Silvery Minnow and provided the desired demographic boost after severe population bottlenecks.ConclusionReleasing hatchery‐reared fish may be a useful tool for conservation of imperiled freshwater fishes. However, there is a need for spawning and rearing infrastructure that matches the life‐history of the species and sufficient postrelease monitoring to evaluate the effectiveness of hatchery supplementation. Use of hatchery‐reared fish has been beneficial for improving population resiliency of Rio Grande Silvery Minnow following recruitment bottlenecks; however, natural recruitment can greatly exceed hatchery supplementation and conditions promoting natural recruitment should be restored.

Comparing translocated beavers used as passive restoration tools to resident beavers in degraded desert rivers

AbstractWildlife translocation facilitates conservation efforts, including recovering imperiled species, reducing human–wildlife conflict, and restoring degraded ecosystems. Beaver (American, Castor canadensis; Eurasian, C. fiber) translocation may mitigate human–wildlife conflict and facilitate ecosystem restoration. However, few projects measure outcomes of translocations by monitoring beaver postrelease, and translocation to desert streams is relatively rare. We captured, tagged, and monitored 47 American beavers (hereafter, beavers) which we then translocated to two desert rivers in Utah, USA, to assist in passive river restoration. We compared translocated beaver site fidelity, survival, and dam‐building behavior to 24 resident beavers. We observed high apparent survival (i.e., survived and stayed in the study site) for eight weeks postrelease of resident adult beavers (0.88 ± 0.08; standard error) and lower but similar apparent survival rates between resident subadult (0.15 ± 0.15), translocated adult (0.26 ± 0.12), and translocated subadult beavers (0.09 ± 0.08). Neither the pre‐ nor the post‐translocation count of river reaches with beaver dams were predicted well by the Beaver Restoration Assessment Tool, which estimates maximum beaver dam capacity by river reach, suggesting beaver‐related restoration is not maximized in these rivers. Translocated beavers exhibited similar characteristics as resident subadult beavers during dispersal; they were more vulnerable to predation and many emigrated from the study sites. High mortality and low site fidelity should be anticipated when translocating beavers, but even so, translocation may have contributed to additional beaver dams in the restoration sites, which is the common goal of beaver‐assisted river restoration. Multiple releases at targeted restoration sites may eventually result in establishment and meet conservation objectives for desert rivers.

A global assessment of research on urban ecology of reptiles: patterns, gaps and future directions

AbstractGlobal urban expansion has multiple impacts on biodiversity and ecosystem functioning. Still, urban centres may play an important role in the conservation of reptiles, an undersampled, megadiverse and unevenly distributed group especially vulnerable to anthropogenic impacts. However, major gaps in research on the urban ecology of reptiles and species responses to urbanisation persist, which may limit our capacity to guide suitable conservation policies. We conducted a global systematic literature review to evaluate biogeographic, taxonomic and ecological research biases in the urban ecology of reptiles and ultimately to detect major gaps and steer future sampling efforts. Our database comprised 278 articles dealing with biological responses to urbanisation of 493 species across 45 countries, comprising 658 cases between a given species and specific biological response. Research on the urban ecology of reptiles was geographically and taxonomically biased. Developed countries within temperate regions were better sampled, whereas developing tropical and megadiverse countries were mostly undersampled or neglected. Among reptile orders, Testudines and Crocodylia were proportionally more studied than Squamata. Across lower groups within Squamata, lizards were present in most studies and were the biological model most commonly used. Studies evaluating biological responses associated with landscape‐level processes, behaviour and/or population dynamics were prevalent, whereas conservation, human–reptile conflicts and wildlife management were the least considered topics. Our results show that research on urban ecology of reptiles is unevenly distributed across regions and lineages. Overcoming these major gaps is an important step towards the improvement of the conservation of reptiles worldwide under the upcoming biodiversity loss scenario. Beyond spreading sampling efforts across undersampled countries, taxa and research topics to meet conservation objectives, we recommend more multidisciplinary approaches to evaluate and compare the actual performance of reptiles in urban environments and to achieve the equilibrium between human well‐being and species conservation.

A systematic review of artificial reefs as platforms for coral reef research and conservation.

Artificial reefs (ARs) have been used on coral reefs for ecological research, conservation, and socio-cultural purposes since the 1980s. We examined spatio-temporal patterns in AR deployment in tropical and subtropical coral reefs (up to 35° latitude) and evaluated their efficacy in meeting conservation objectives, using a systematic review of the scientific literature. Most deployments (136 studies) were in the North Atlantic and Central Indo-Pacific in 1980s – 2000s, with a pronounced shift to the Western Indo-Pacific in 2010s. Use of ARs in reef restoration or stressor mitigation increased markedly in response to accelerating coral decline over the last 2 decades. Studies that evaluated success in meeting conservation objectives (n = 51) commonly reported increasing fish abundance (55%), enhancing habitat quantity (31%) or coral cover (27%), and conserving target species (24%). Other objectives included stressor mitigation (22%), provision of coral nursery habitat (14%) or source populations (2%) and addressing socio-cultural and economic values (16%). Fish (55% of studies) and coral (53%) were the most commonly monitored taxa. Success in achieving conservation objectives was reported in 33 studies. Success rates were highest for provision of nursery habitat and increasing coral cover (each 71%). Increasing fish abundance or habitat quantity, mitigating environmental impacts, and attaining socio-cultural objectives were moderately successful (60–64%); conservation of target species was the least successful (42%). Failure in achieving objectives commonly was attributed to poor AR design or disruption by large-scale bleaching events. The scale of ARs generally was too small (m2 –10s m2) to address regional losses in coral cover, and study duration too short (< 5 years) to adequately assess ecologically relevant trends in coral cover and community composition. ARs are mostly likely to aid in reef conservation and restoration by providing nursery habitat for target species or recruitment substrate for corals and other organisms. Promoting local socio-cultural values also has potential for regional or global impact by increasing awareness of coral reef decline, if prioritized and properly monitored.

Conservation Implications of Spatiotemporal Variation in the Terrestrial Ecology of Western Spadefoots

ABSTRACTConservation of species reliant on ephemeral resources can be especially challenging in the face of a changing climate. Western spadefoots (Spea hammondii) are small burrowing anurans that breed in ephemeral pools, but adults spend the majority of their lives underground in adjacent terrestrial habitat. Western spadefoots are of conservation concern throughout their range because of habitat loss, but little is known about the activity patterns and ecology of their terrestrial life stage. We conducted a radio‐telemetry study of adult western spadefoots at 2 sites in southern California, USA, from December 2018 to November 2019 to characterize their survival, behavior, and movements from breeding through aestivation to refine conservation and management for the species. Western spadefoot survival varied seasonally, with risk of mortality higher in the active season than during aestivation. The probability of movement between successive observations was higher during the winter and spring and when atmospheric moisture was high and soil water content at 10‐cm depth was low. The amount of rain between observations had the strongest effect on the probability of movement between observations; for every 20 mm of rainfall between observations, western spadefoots were 2.4 times more likely to move. When movements occurred, movement rates were highest when both relative humidity and soil water content at 10‐cm depth were high. The conditions under which western spadefoots were likely active on the surface, likely to have moved, and moved at the highest rates are conditions that reduce the risk of desiccation of surface‐active spadefoots. Western spadefoot home range areas varied between study sites and were mostly &lt;1 ha, although 1 individual's home range area was &gt;6 ha. Western spadefoots rapidly dispersed from the breeding pools, and asymptotic distances from the breeding pool were generally reached by June. The asymptotic distance from the breeding pool varied between sites, with the 95th percentile of the posterior predictive distribution reaching 486 m at 1 site and 187 m at the other. Western spadefoots did not select most habitat components disproportionately to their availability, but at Crystal Cove State Park, they avoided most evaluated vegetation types (graminoids, forbs, and shrubs). Spatial variation was evident in most evaluated western spadefoot behaviors; context‐dependent behavior suggests that site‐specific management is likely necessary for western spadefoots. Furthermore, comparison with an earlier study of western spadefoots at Crystal Cove State Park indicated substantial temporal variation in western spadefoot behavior. Therefore, basing management decisions on short‐term studies might fail to meet conservation objectives. Better understanding the influences of spatial context and climatic variation on western spadefoot behavior will improve conservation efforts for this species. © 2021 This article is a U.S. Government work and is in the public domain in the USA. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.

Tracking the response of industrial fishing fleets to large marine protected areas in the Pacific Ocean.

Large marine protected areas (MPAs) of unprecedented size have recently been established across the global oceans, yet their ability to meet conservation objectives is debated. Key areas of debate include uncertainty over nations' abilities to enforce fishing bans across vast, remote regions and the intensity of human impacts before and after MPA implementation. We used a recently developed vessel tracking data set (produced using Automatic Identification System detections) to quantify the response of industrial fishing fleets to 5 of the largest MPAs established in the Pacific Ocean since 2013. After their implementation, all 5 MPAs successfully kept industrial fishing effort exceptionally low. Detected fishing effort was already low in 4 of the 5 large MPAs prior to MPA implementation, particularly relative to nearby regions that did not receive formal protection. Our results suggest that these large MPAs may present major conservation opportunities in relatively intact ecosystems with low immediate impact to industrial fisheries, but the large MPAs we considered often did not significantly reduce fishing effort because baseline fishing was typically low. It is yet to be determined how large MPAs may shape global ocean conservation in the future if the footprint of human influence continues to expand. Continued improvement in understanding of how large MPAs interact with industrial fisheries is a crucial step toward defining their role in global ocean management.

Dynamics of canopy development of Cunninghamia lanceolata mid-age plantation in relation to foliar nitrogen and soil quality influenced by stand density

It has been generally accepted that different silvicultural practices affect the forest canopy morphology and structure. During forest establishment, many natural sites were converted to coniferous plantations in southern China. Retention of the canopy during stand conversion may be desirable to promote ecological function and meet conservation objectives. We tested the impact of planting density, foliar nitrogen and soil chemical properties on the canopy development of Chinese fir (Cunninghamia lanceolata) mid-age monoculture stands. Low density (1450 trees hm−2 with planting spacing of 2.36 × 2.36 m), intermediate-density (2460 trees hm−2 with planting spacing of 1.83 × 1.83 m) and high density (3950 trees hm−2 with planting spacing of 1.44 × 1.44 m) stands were selected in Xinkou forest plantations in Sanming City, China. Canopy characteristics such as leaf area index (LAI), mean tilt angle of the leaf (MTA) and average canopy openness index (DIFN) were measured. Measurements were taken using LAI-2200 PCA. The results illustrated that stand density was the primal factor responsible in canopy structuring while soil chemical properties seem to play a secondary role for canopy dynamics. LAI increased from 3.974 m2 m-2 to 5.072 m2 m-2 and MTA increases from 34.8° to 48.7° as the stand density increased while the DIFN decreased from 0.1542 to 0.0902 with the increasing stand density but it was no significantly different in intermediate and high-density stands. Additionally, LAI and MTA were positively correlated to foliar nitrogen while the DIFN was negatively correlated. In general, soil available nitrogen, available phosphorus and soil pH were not significant to canopy parameters. The results presented provide guiding principles about the canopy dynamics distribution in varying stand densities from LICOR measurements in mid-age Chinese fir monoculture. Furthermore, this provides a base to study canopy dynamics at mature stage forests because of more senescence activities.

Mitigating negative livelihood impacts of no-take MPAs on small-scale fishers

Marine Protected Areas (MPAs) have the potential to support small-scale fishers in managing their resources. However, a general failure to consider the varying levels of vulnerability of fishers has resulted in MPAs that, often unintentionally, adversely impact small-scale fishers. Furthermore, when fishers lack the capacity to adapt to MPA-related changes, MPAs may fail to meet conservation objectives because fishers do not comply with MPA regulations. In this study, we developed a systematic method to identify individuals who are most vulnerable to being negatively impacted by no-take MPAs through an index that represents individual-level vulnerability. We designed a method for identifying these individuals based on four socioeconomic factors pertaining to vulnerability to MPA changes: livelihood diversity, education, age and wealth, then applied this method in two socially and economically heterogeneous communities in Myanmar's Myeik Archipelago. We used empirical data collected from 80 small-scale fishers in this area to represent each factor, then generated a local-level ‘Livelihood Impact Potential Index’ (LIPI) that reflects the degree to which a no-take MPA would impact an individual fisher's ability to support his or her livelihood. When attributed to each fisher's most frequented fishing ground, the LIPI can identify locations where no-take MPAs would be most detrimental to small-scale fishers' livelihoods based on their levels of vulnerability. The LIPI can thus be used alongside ecological and commercial fishing data to support planners in designing local-scale MPAs that maximise positive impact on biodiversity and minimise adverse impacts on the most vulnerable fishers in a community.

Land Trusts as Conservation Boundary Organizations in Rapidly Exurbanizing Landscapes: A Case Study from Southern Appalachia

Exurban development is occurring in many formerly rural areas nationwide, often outpacing the ability of institutions to update land use regulations. These pressures can negatively impact local ecosystems and natural resources, including reduced biodiversity and degraded water quality. Local nongovernmental organizations play an important role in promoting conservation in exurban landscapes, where there is relatively little regulatory and institutional infrastructure. Here, we draw on boundary organization theory to discuss how land trusts can function as boundary organizations, by using boundary objects and working as a bridge between community members, scientists, and governments to navigate complex conservation challenges. Mainspring Conservation Trust in southern Appalachia serves as a case study to explore methods for engaging and connecting diverse stakeholders. We show that land trusts can provide a flexible and necessary alternative to regulations for meeting conservation objectives by working at the boundary between science and local action.

Propuesta de un Parque Ecológico para el fomento del Turismo

La finalidad de la presente investigación fue, elaborar una propuesta para la creación de un Parque Ecológico adscrito al Consejo Provincial de Orellana para favorecer al turismo, La investigación lleva procesos que permiten gestionar los espacios naturales a través de planes que contienen medidas para la administración del espacio protegido, áreas de recreación y manejo. La finalidad de estas actuaciones es cumplir con los objetivos de conservación, expresado en la norma legal que recoge la declaración del espacio protegido. Para la aplicación del proyecto, cuenta con las políticas ambientales, contables, financieras que lleven a fomentar el turismo y mejorar la calidad de vida de la población a través de ella.

Ecological and Socio-Economic Effects of Highly Protected Marine Areas (HPMAs) in Temperate Waters

This study provides a synthesis of current scientific evidence on the ecological and socio-economic effects of highly protected marine areas (HPMAs), primarily in temperate waters. The aim was to establish if HPMAs can provide benefits beyond those afforded by other types of marine protected area (MPA). We identify critical interactions within and between ecological and socio-economic effects to help marine planners and managers to make informed decisions about the trade-offs of alternate management actions or measures for MPAs. Well-designed and enforced MPAs with high levels of protection (HPMAs) often provide conservation benefits within their boundaries beyond those afforded by other types of MPA. Much remains to be learned about the socio-economic effects of HPMAs. Empirical evidence to date suggests that potential benefits cannot all be maximised simultaneously because potentially conflicting trade-offs exist not only between but also within ecological and socio-economic effects. Marine planners and managers must be able to evaluate the impact and distribution of trade-offs for differing management regimes to make informed decisions about levels of protection required in MPAs to ensure sustainable use of marine resources and meet conservation objectives. One of the main challenges remains providing evidence of the societal benefits from restricting use in these areas.

Assessing the importance of protected areas in human-dominated lowland for brown bear (Ursus arctos) winter denning

Protected areas are often designed with conservation focus on rare species. However, provision of essential areas for other species is crucial for maintenance of overall biodiversity. The brown bear (Ursus arctos), throughout most of its present distribution area, helps to maintain diverse ecosystems through trophic effects. As with other hibernating mammals, undisturbed wintering areas are a highly important resource for bears. In lowland areas containing intensively managed forests, undisturbed winter dens might largely be confined to protected areas. Here, we assess the importance of protected areas for bear winter denning in a forested landscape. We employed maximum entropy modelling and data of 80 bear winter den locations in a 39,000 km2 area of mainland Estonia to evaluate areas suitable for winter denning. We compared the amount of highly suitable wintering areas (suitability index > 0.6) in 22 protected areas with two ring buffers around these areas to assess the relative importance of adjoining areas for bear wintering. The proportion of highly suitable wintering area was significantly lower in protected areas than in nearby ring buffers. Therefore, our results demonstrate that protected areas do not provide much conservation support for denning brown bears, and we recommend focussing attention on managed forests to meet conservation objectives. The results reveal the importance of larger forest areas for brown bear wintering in lowland to avoid constant disturbance.

Developing a marine protected area network with multiple objectives in China

AbstractSystematic conservation planning (SCP) is an efficient tool to design marine protected area (MPA) networks. Although China has decades of experience in developing MPAs, its current MPA designs are limited to small spatial scales and are infrequently supported by a systematic planning approach.As one of few studies to incorporate biological and socio‐economic information in marine conservation prioritization in China, this study, targeting Haizhou Bay in China, provides a range of MPA network alternatives and evaluates the current design for four scenarios with different objectives. This corresponds to the major challenges for China's MPAs: conserve biodiversity; protect ecologically and economically important species; minimize socio‐economic costs; and reduce enforcement costs. Furthermore, this study considers the compatibility of aquaculture practices, economically critical to China's coastal regions, in MPA designs and implementations.This study determines that current MPA designs are inadequate to meet conservation objectives. For instance, existing MPAs cover less than 10% of the ranges of target species for conservation. There are substantial conservation gaps offshore.By constructing and analysing planning scenarios, this study demonstrates the trade‐offs in objectives as well as the importance of implementing SCP in China's MPA network design. Lessons learned from this study are also applicable to multi‐objective conservation prioritization in other countries.

Commonalities in stream connectivity restoration alternatives: an attempt to simplify barrier removal optimization

AbstractMovement within stream corridors is a basic life history requirement of many aquatic organisms. Barrier removal in streams has become a common practice in the United States aimed to restore organism dispersal and meet conservation objectives; however, there are social and economic costs to the removal of barriers. Accordingly, tools to prioritize barrier removal, particularly optimization techniques, can be used to evaluate cost‐benefit trade‐offs. Many of these techniques, however, require programming experience and are not available to natural resource managers. Furthermore, conservation objectives vary considerably depending on the life histories of organisms under consideration, and these opposing objectives, in conjunction with variant socioeconomic costs, will influence optimization solutions, specifically which barriers to remove. To promote the use of optimization tools, straightforward and open‐access platforms are needed to support use by managers, while also providing general approaches for holistic basin‐scale connectivity restoration. Herein, we use two case studies, White Oak Creek (small watershed) and the Roanoke River Basin (large basin), to explore the divergent outcomes stemming from different conservation objectives and socioeconomic costs used to prioritize barrier removal. We conducted optimization modeling using a widely accessible platform along with an open‐access solver plug‐in to support a wide variety of conservation objectives. We used simple approaches to find commonalities in barriers identified for removal among divergent conservation objectives and provide alternative (i.e., hybrid removal‐passage) strategies for approaching habitat restoration for diverse aquatic communities while increasing social benefits (i.e., hydropower energy). As expected, different conservation objectives aimed to support varied species life histories (e.g., diadromy, large‐river vs. small‐river potamodromy) have very different effects on optimization solutions. In both case studies, however, commonalities in solutions were identified through clustering groups of barriers into general connectivity restoration strategies. Furthermore, strategy types for a given barrier could be predicted with ≥72% accuracy using only four metrics. This suggests that optimization results can be simplified into general standards to support adoption of sustainable basin connectivity criteria strategies. Our framework provides a flexible and open‐access approach to conduct relatively complex optimization modeling for stream barrier prioritization, while examining potential for agreement among divergence conservation objectives.

Ecological Offsetting in China’s Coastal Wetlands: Existing Challenges and Strategies for Future Improvement

Land-use changes in coastal wetlands have led to a worldwide degradation of marine coastal ecosystems and a loss of the ecological services they provide. Ecological offsetting is a popular strategy and an effective mitigation measure for ecosystems that have been degraded, damaged, or destroyed and is critical for habitats where natural recovery is hindered. However, the current understanding of the theory and practice of ecological offsetting for coastal wetlands is extremely limited in many developing countries. We conducted a review of ecological offsetting for coastal wetlands projects and studies in China in 1979–2017 to explore the application and limitations of ecological offsetting theory. It was found that China’s coastal ecological offsetting regime has recently entered a rapidly developing stage, with an increasing number of different types of offsetting projects conducted, but theoretical research lags behind practical applications. Considerable governmental, social, technological and ethical challenges remain to resolve. Coastal ecological offsetting schemes have been inconsistent in meeting conservation objectives or preventing net losses because of the challenges of ensuring they are fully consistent in practice (mainly in-kind offsets) and theory (mainly out-of-kind offsets). Ecological offsetting projects were primarily implemented by government, developers, and non-profit organizations. The available funding of coastal ecological offsetting projects is insufficient, which makes ecological offsetting a risky operation. Therefore, we propose strategies for improvement that integrate the consideration of theoretical and practical challenges in the offsetting process, while providing a scientific basis and directional guidance for the future practice of biodiversity conservation and environmental management.

Management effectiveness of large pelagic fisheries in the high seas

AbstractLarge pelagic fishes are assessed and managed by tuna Regional Fisheries Management Organizations (tRFMOs). These organizations have been criticized for not meeting conservation objectives, which may relate to aspects of governance and management. No previous studies have systematically evaluated why management performance differs among tRFMOs and among stocks within each tRFMO. In this study, we collected data on the nature of research, management, enforcement and socioeconomics of management systems in the five principal tRFMOs of the world's oceans. We quantified influences of economic and fishery‐related factors on these management characteristics and examined how these factors vary among tRFMOs. We found that tRFMOs with a greater number of member countries, a greater economic dependency on tuna resources, a lower mean per capita gross domestic product, a greater number of fishing vessels and smaller vessels were associated with less intensive research, management and enforcement in these tuna fisheries. We also quantified the influence of specific management attributes and of biological, economic and fishery‐related factors on the trends and current status of large pelagic fish stocks in these regions. The most important factors correlated with trends and current stock status were external to the management systems, and included stock size, age at maturity, ex‐vessel price and economic dependency of countries on tuna fisheries. To improve the overall status of large pelagic fish stocks in the global high seas, more intensive data collection, research and management are needed in certain areas, especially in the Indian Ocean, and for certain stocks, especially non‐target species.

Opportunism on the High Seas: Foraging Ecology of Olive Ridley Turtles in the Eastern Pacific Ocean

Stable isotopic compositions in animal tissues have been widely used to gain insight into trophic dynamics, especially of mobile aquatic predators whose behavior and dietary preferences are difficult to directly measure. Olive ridley sea turtles (Lepidochelys olivacea) range across >3 million km2 of the tropical and subtropical eastern Pacific Ocean and their trophic ecology in open ocean areas has not yet been adequately described. Individuals feed within biogeographic regions where varying nutrient cycling regimes result in phytoplankton with distinct δ13C and δ15N values that are assimilated by the turtles. We sampled 346 turtles at-sea between 2003 and 2009 and used bulk tissue (n = 346) and amino acid compound specific isotope analysis (AA-CSIA, n = 31) to empirically support the conventional understanding that olive ridleys are omnivores. Bulk δ15N values did not significantly vary with carapace length, a proxy for age, or with putative sex of adults. We therefore hypothesize that trophic position (TP) does not vary across age or sex. In line with other isotopic studies of this biogeographic scale in the same region, we observed a trend of bulk tissue 15N enrichment with increasing latitude. Using AA-CSIA to account for δ15N baseline shifts among food webs (space), we estimated the TP of adult foragers using two methods. We found that across their eastern Pacific range, olive ridley δ13C and δ15N niche area varied, but median TP of adults remained constant (~3.1). Using the simpler, two-amino acid TP estimation method, we detected a small but notable elevation of TP for olive ridleys on the Costa Rica Dome. This study underscores the value of large-scale in-water olive ridley sea turtle research across oceanic foraging habitats to confirm or challenge anecdotal understanding of trophic roles, susceptibility to environmental change, and critical habitats. Further, it improves our understanding of why this species is now abundant in the eastern Pacific Ocean. A prey generalist with plenty of suitable foraging habitat can recover from the brink of extinction despite the presence of major threats. However, such foraging characteristics may require dynamic open ocean management approaches to meet conservation objectives if threats persist and/or increase.