Ecosystem-based Management Research Articles

Feeding ecology of Antarctic toothfish, Dissostichus mawsoni in the subarea 88.3 (Bellingshausen Sea and eastern Amundsen Sea) of the Southern Ocean

Understanding feeding ecology is essential for ecosystem-based management. As dietary data can show differences depending on the spatiotemporal and ontogenetic aspects of the sample, the results should be derived based on various size classes and samples over a wide spatiotemporal range. Morphological analysis of the stomach contents of Dissostichus mawsoni, a piscivore, collected at depths of 603–2,113 m in subarea 88.3 during the Antarctic summer fishing seasons from 2016 to 2020 was used to assess the dietary composition according to the research block, fishing season, depth, and size. Here, we used 1,639 D. mawsoni specimens with a total length range of 44.5–189.0 cm. The dietary composition of D. mawsoni did not show significant differences by fishing season but differed with research block, depth, and size. Macrouridae dominated research blocks 88.3_1 and 88.3_3; Nototheniidae dominated research blocks 88.3_2 and 88.3_6; and Channichthyidae dominated research blocks 88.3_4 and 88.3_5. The proportion of Nototheniidae decreased as depth increased, whereas the consumption of Channichthyidae increased gradually with depth in research blocks 88.3_3 and 88.3_4. The proportion of Channichthyidae decreased as body size increased, whereas the consumption of Macrouridae increased gradually with body size in both blocks 88.3_3 and 88.3_4. During the study period, the dietary composition of D. mawsoni in both blocks 88.3_3 and 88.3_4 did not show significant temporal differences, suggesting that these data could be used as a baseline for identifying future environmental changes in the region. This study provides information on the relationships between various species and benthic fish fauna, which are essential for ecosystem-based management.

New tools and recommendations for a better management of harmful algal blooms under the European Marine Strategy Framework Directive

Marine harmful algal blooms (HABs), caused by various aquatic microalgae, pose significant risks to ecosystems, some socio-economic activities and human health. Traditionally managed as a public health issue through reactive control measures such as beach closures, seafood trade bans or closure of mollusc production areas, the multifaceted linkages of HABs with environmental and socio-economic factors require more comprehensive ecosystem-based management approach tools to support policies. This study promotes a coordinated understanding and implementation of HAB assessment and management under the Marine Strategy Framework Directive (MSFD), targeting the achievement of Good Environmental Status (GES) in European marine waters. We introduce two novel tools: GES4HABs (GES for HABs) decision tree, and MAMBO (environMental mAtrix for the Management of BlOoms), a decision support matrix. These tools aim to streamline HABs reporting and prioritize resource allocation and management interventions. The GES4HABs decision tree defines a sequence of decision steps to identify HAB management strategies according to their state (evaluated against predefined baselines) and causes (anthropic or natural). MAMBO is proposed to address different HABs and their interaction with human and environmental pressures. The matrix utilizes two axes: natural trophic status and level of human influence, capturing major aspects such as nutrient supply. While acknowledging the limitations of this simplified framework, MAMBO categorizes marine regions into quadrants of varying management viability. Regions with high human influence and eutrophic conditions are identified as most suitable for effective management intervention, whereas regions with minimal or mixed human influence are deemed less amenable to active management. In addition, we explore and describe various indicators, monitoring methods and initiatives that may be relevant to support assessments of HAB status and associated pressures and impacts in the MSFD reporting. Finally, we provide some recommendations to promote the consideration of HABs in ecosystem-based management strategies, intensify efforts for harmonizing and defining best practices of analysis, monitoring and assessment methodologies, and foster international and cross-sectoral coordination to optimize resources, efforts and roles.

A new Meso-Scale coarse-filter indicator for the Canadian boreal forest

Forest management planning and management agencies in Canada have been moving towards an ecosystem-based management (EBM) approach that honours whole ecosystem dynamics over all time and space scales. As part of this evolution, provincial, national, and international agencies have added coarse filter indicators to represent pre-industrial, or ‘natural’ range of variation (NRV) ecosystem conditions as ecologically defendable baselines. The intent was to balance the more traditional species specific (i.e., fine filter) approach to sustainability with a more holistic (i.e., coarse scale) model of ecosystem dynamics. The development and acceptance of coarse filter indicators has been neither linear nor straightforward. One of the more important assumptions inherent in an NRV strategy is that it captures relevant, meaningful patterns at the most appropriate scales in a practical way. To test this assumption, I used a spatially explicit simulation model to compare landscapes created under pre-industrial conditions with those created using four different thresholds of disturbance size commonly used today in boreal Canada. The results suggest that even a 10,000 ha upper size limit create significantly higher levels of homogeneity and fragmentation at intermediate spatial scales relative to pre-industrial landscape patterns. Towards developing a new, more robust coarse filter indicator, the net area burned at four grid sizes over 10 and 20 years was calculated for natural wildfire data from northern Saskatchewan. The results suggest that wildfire tends to cluster at all scales due largely to the influence of large infrequent wildfires. In contrast, data from two forest management areas in Alberta summarized at the same scales confirm that harvesting activity tends to spread out evenly across the landscape. Based on these findings, the NRV data was then refined to capture; 1) the percentage of grid cells where high disturbance levels occur (WHEREs – or WHERE you are) and the proportion where no disturbance occurs (WYNs – or Where You are Not). The WHERE-WYN indicator is unique in that it specifically integrates time as a dimension of landscape dynamics. It is also easily understood and calculated, corresponds directly to management activities, has NRV equivalents, and applicable to most of boreal Canada. Augmenting the current suite of coarse filter indicator with the WHERE-WYN combination addresses a critical gap in our NRV toolkit and will ultimately help create more sustainable landscapes.

Multilevel meta-analysis of stated preference values of marine ecosystem services in China

On the basis of a review of studies on the stated preference valuation of China’s marine ecosystem services conducted between 1996 and 2021, this paper presents a meta-analysis of the estimates of marine ecosystem service benefits by using a multilevel modeling approach. The results indicate that a range of factors influence the estimated economic values of China’s marine ecosystem services, including ecosystem area, ecosystem type, respondent identity, regional gross domestic product (GDP) per capita, ecosystem services being valued, valuation method, and hypothetical scenario being employed. Additionally, the meta-regression results indicate that the willingness to pay for marine ecosystem services in China depends largely on people’s perception of the importance of an ecosystem service. Such a perception is influenced by national policies, educational attainment, and the degree to which the service is linked to people’s lives. This situation is evidenced by the high willingness of people to pay for coastal wetlands and recreational services. People were also found to be most willing to pay for conservation scenarios and least willing to pay for environmental compensation scenarios. These findings contribute to the research on the valuation of marine ecosystem services in China and to the incorporation of research results into ecosystem-based management decisions by clarifying the effects of different factors on valuation estimates.

Community Science in Support of Ecosystem-Based Management: A Case Study from the Damariscotta River Estuary, Maine, USA

Community Science in Support of Ecosystem-Based Management: A Case Study from the Damariscotta River Estuary, Maine, USA

Recreational beneficiaries and their landscape dependencies across national estuary program sites: Tillamook Bay (OR) and Tampa Bay (FL), USA

ABSTRACT This study aims to characterize the value associated with nature-based recreational opportunities and identify estuarine attributes most valued by users. With the National Ecosystem Service Classification System as a framework, we assessed the relationship between recreational beneficiary subclasses and ecological end-products available to beneficiaries in Tillamook Bay, OR, and Tampa Bay, FL estuaries. We used the InVEST recreation model to assess the spatial distribution and intensity of recreation in both estuaries, then inform site selection in subsequent analyses. We evaluated photo content and collected observational data at sites with the highest utilization. Surveys of location attributes helped determine the availability of ecosystem service ecological end-products. Ordination techniques were employed to evaluate similarities in natural and human-made attributes across stations and establish groups of stations that could offer comparable recreational experiences. Recreational ‘experiencers and viewers’ were the dominant beneficiary group, as they took the most photos and were most often encountered during passive onsite observations. Composite features (e.g. viewscapes) were the predominant ecological end-products. Counter to hypothesized outcomes, there was no detectable difference in the number of recreational beneficiaries predicted between estuaries after accounting for site-scale variability. Locations with multiple natural and human-made attributes, including access points, had more recreational users. Onsite observations also revealed a potential need for more safe and equitable access options in high-use locations. Findings highlight the importance of recreational ‘experiencers and viewers’ valuing habitat mosaics, even across vastly different geographical settings. This exploration of how humans derive well-being from coastal landscapes is crucial to ecosystem-based management.

Ecosystem-based Management through the lenses of International Seabed Authority stakeholders: current status, implications, and opportunities for the deep-sea mining regime in the Area

The ocean is threatened by human activities, which undermine the health of its ecosystems. To overcome this scenario, there is a converging understanding that a more encompassing approach, such as Ecosystem-based Management (EBM), is essential to manage human activities. EBM implementation in scenarios of limited knowledge and potentially irreversible impacts, such as deep-sea mining (DSM), is thus highly appropriate, although the translation of this approach into practice is not intuitive and rather challenging. The International Seabed Authority (ISA), the organization with the mandate to award exploration and exploitation contracts for minerals on the international seabed, has recognized the need to incorporate EBM in its instruments but has not specified how to implement it. Through an online survey and in-depth interviews, ISA stakeholders have been inquired about their perception of the understanding, current status, implications, and opportunities of EBM for the deep-sea mining regime. The findings reveal that stakeholders perceive EBM as more related to ecological and impact aspects and less with participation, socio-ecological systems interlinks, and other forms of knowledge that are not scientific. Few respondents recognize EBM within the ISA, reporting its reflection in management instruments such as Regional Environmental Management Plans and Environmental Impact Assessments. No common definition exists, regarded as an obstacle to decision-making and EBM operationalization. According to them, opportunities to improve EBM implementation include collaboration with organizations already familiar with EBM, capacity development activities, workshops, and dedicated side events focusing on the issue. Finally, most of them recognize that a lack of consensus regarding EBM can impact decision-making and EBM operationalization, thus compromising ISA’s mandate. In this context, the clarification on what EBM entails for the seabed mining regime should be a matter of major interest to the ISA and all its stakeholders, as the mineral resources found in the seabed beyond the limits of national jurisdictions (the Area) are the common heritage of humankind, and therefore, its maintenance and benefits must be ensured to future generations.

SCAIRM: A spatial cumulative assessment of impact risk for management

This study introduces SCAIRM, a Spatially explicit Cumulative Impact Assessment method specifically developed for application to guide Ecosystem-Based Management. The method incorporates relevant human activities, their pressures and their impacts on ecosystem components. Cumulative assessment methods usually apply categorical semi-quantitative scores based on expert judgement in order to be comprehensive, or alternatively, only cover a small subset of interactions using more sophisticated quantitative information. The SCAIRM approach aims to capture 'the best of both worlds': it builds on categorical risk-based approaches, but modified such that their outcome, i.e. Impact Risk from cumulative pressures, is conceptually identical to the outcome from the quantitative approaches. This allows harmonization of qualitative and quantitative approaches into a single method, that has the advantage that it is comprehensive and can be used in data-poor situations while allowing the use of available quantitative information in more data-rich situations. It results in an improved capacity to inform policy or provide operational-centric guidance required for the essentially sectoral management. The method was applied to the North Sea ecosystem as an illustrative example of the typical output of most Cumulative Impact Assessments: indicating the ecosystem components mostly under threat, and the main activities and their pressures responsible for it. To that end, SCAIRM provides an assessment outcome expressed in ecologically meaningful terms, i.e. potential change in state compared to an undisturbed situation, implying all receptors except the pelagic water column to be potentially “endangered” (more than 50% decrease) and requiring conservation efforts. A decision tree was developed to guide management towards an increased effectiveness showing that much of the Impact Risk (41%) is caused by few well-known stressors (7%) that are difficult to mitigate but a remaining 29% of the Impact Risk from many often lesser-known stressors (59%) where management is likely to perform better.

Expanding the scope and roles of social sciences and humanities to support integrated ecosystem assessments and ecosystem-based management

Abstract Understanding social-ecological systems (SESs) is an important part of ecosystem-based management (EBM). One of the main decision support frameworks to develop scientific advice for EBM is integrated ecosystem assessments (IEAs). Human dimensions in SESs are primarily captured through indicators derived from three social sciences: economics, anthropology, and sociology. The breadth of social sciences and humanities (SSH) research is much greater than those three fields, but they are generally underused in natural science-based decision support processes such as IEAs. Greater contributions of SSHs can enhance IEAs through various direct (e.g. to develop indicators) and indirect ways (e.g. to establish and maintain ethical practices). We examine a wider range of SSH disciplines and conclude that scientific advice processes that inform EBM can benefit from broader integration of SSH theories and methods through themes of contextualizing, facilitating, communicating, evaluating, and anticipating. We see this an opportunity to both widen the vocabulary used to describe social scientists and those who work in humanities in IEAs, and apply the underlying worldviews used to conduct SSH research to fundamentally enhance the IEA process and to further progress in EBM.

Ecosystem-based fishery management that accounts for trade-offs between fishing and enhancement stocking: A case study of Juehua Island in the Bohai Sea

The implementation of marine ecosystem management requires modeling that accounts for the trade-off between exploitation in fisheries and protection activities (e.g., enhancement and release, artificial reefs). Researchers are increasingly interested in the trends of fishery resources under these joint driving forces due to the negative impacts of resource exploitation and the positive impacts of marine protection. Using the sea around Juehua Island in China’s Bohai Sea as a case study, we developed a marine ecosystem model based on the Ecopath with Ecosim software to analyze the trends in fishery resources driven both by fishing and stock enhancement. When the fishing effort exceeded 42 % of the 2019 value, the biomass of top predator Platycephalus indicus decreased by 50 %, indicating a regime shift. When the fishing effort increased to 340 % of the 2019 level, the ecosystem shifts to an alternative stable state occurs, indicating destabilization of the marine ecosystem. The impact of fishing effort on the marine ecosystem was not well compensated by release of a single target species. We also designed an orthogonal experiment with three factors (the key species Fenneropenaeus chinensis, Paralichthys olivaceus, and Charybdis japonica) and four restocking release levels to determine both the optimal release rate for each species individually and the optimal combination of different species. If the 2019 fishing effort is maintained, the release of 125 × 106 juvenile F. chinensis, 400 × 103 juvenile P. olivaceus, and 15 × 106 juvenile C. japonica would be an optimal solution to improve the marine biomass, trophic level, and biodiversity. Our results provide insights into ecosystem-based management strategies for implementing a policy to limit fishing in the study area and for scientifically determining the restocking release rates.

Simulating impacts of fishing toothfish on the pelagic community in the Cooperation Sea, Southern Ocean

There is increasing attention to the use of Antarctic toothfish (Dissostichus mawsoni) and Patagonian toothfish (Dissostichus eleginoides). Understanding the responses of toothfish and other species to fishing activities favors the sustainable use of natural resources. We developed an end-to-end model OSMOSE-CooperationSea to simulate the food web dynamics in the Cooperation Sea and evaluate the impact of toothfish fishery. Fishes and cephalopods played important roles in the energy pathways from krill species and other zooplankton species to toothfish and Weddell seal (Leptonychotes weddellii) whose trophic levels were higher than 5.0. Adélie penguin (Pygoscelis adéliae), Crabeater seal (Lobodon carcinophaga), and Baleen whales were strongly krill-reliant. The spawning stock of toothfish decreased more quickly than the recruitments with increasing fishing pressure. Fishing impacts on the recruitments of toothfish were hysteretic due to the fishing selectivity. The model considered an ontogenetic diet shift of toothfish that mesopelagic fish was influential to toothfish juveniles. The overexploitation of toothfish stock might result in a trophic cascade that mesopelagic fish biomass increased and krill biomass declined. Adélie penguin, Crabeater seal, and Baleen whales preyed on more small fishes in response to the decline of krill biomass. Considering the impacts of changes in Antarctic krill availability, the biomass of Adélie penguin, Crabeater seal, and Baleen whales declined with a heavy toothfish fishery. The study highlights the importance of precautionary and ecosystem-based management to toothfish fishery.

Heavy browsing pressure by moose (Alces alces) can interfere with the objectives of ecosystem-based forest management

Forest management can enhance the ecosystem services forests provide, but it can also alter the capacity of forests to provide those services in the future. Ecosystem-based management has been widely implemented to mitigate the deterioration of forest ecosystems by reducing dissimilarities between managed and natural forests. Ecosystem-based management objectives generally aim to maintain community composition, stand structure, ecosystem functions and services. Heavy browsing pressure by ungulates at densities unrepresentative of past abundance could interfere with these objectives by chronically and selectively browsing tree regeneration following logging.Using a browsing exclusion experiment, we investigated how the effects of different moose browsing pressures on tree regeneration could interfere with ecosystem management objectives in boreal forests of Quebec, Canada. Management objectives in this region include, among others, reaching targeted coniferous trees densities for commercial harvest, favouring the conservation of birches (Betula spp.) to maintain soil quality and conserving fruit-bearing trees due to their ecological significance for biodiversity. We used path analyses to differentiate direct and indirect effects of moose on seedling density and mixed models to investigate how browsing affected sapling recruitment and whether resulting densities are compatible with ecosystem management objectives.By directly reducing the overall sapling density, moose browsing indirectly increased seedlings densities of all deciduous species. This indirect effect increased with browsing pressure and favoured raspberry cover, which was positively or negatively linked to seedling density, depending on tree species. Moderate and heavier browsing pressures reduced coniferous sapling density below the ecosystem management target. Moose suppressed birch saplings so that the minimal target of 50 birches ha−1 was not met under heavier browsing pressure. Sapling density of fruit-bearing trees was low under all browsing pressures when compared to exclosures.Policy implicationsHeavy moose browsing is preventing the achievement of ecosystem management objectives in our study area. Positive indirect effects on seedling densities suggest that reducing moose density could allow released seedlings to replenish the sapling layer, but we discuss why this would not guarantee reaching ecosystem management objectives. To help forest managers evaluate and respond to challenges posed by high ungulate densities, we suggest incorporating browsing inventories in national forest surveys to monitor this chronic disturbance and modulate decisions for forest ecosystem management.

European Approaches Support an Essential Definition of Ecosystem-Based Management and Demonstrate Its Implementation for the Oceans

Unclear, contested definitions and high complexity have been used to explain why ecosystem-based management (EBM) has been hard to implement. This still seems to be a problem, judging from the unspecific references to it in recent international instruments and other approaches being preferred. This article argues that an essential definition of EBM that captures its indispensable roles can clarify its meaning. Beyond that, a wide diversity can be found due to adaptations to different ecological, social, and political contexts. In short, EBM entails managing human activities for sustainable use, so the cumulative impacts of uses are kept below critical thresholds for the ecosystem to be managed. The specific integrative role of EBM is integration across ecosystem components, governance arrangements, and broad strands of knowledge in support of management. This understanding should not be controversial and is supported by approaches to implementing EBM in Norway and the EU. Their approaches to EBM for the oceans share key characteristics: They operate on similar spatial scales; use strategic planning; define cyclic, adaptive processes with similar content; and apply management by objectives. With the proclaimed nature crisis, renewed attention to the definition and implementation of EBM is needed.

Assessment of Ecosystem-Based Disaster Risk Reduction Strategies in Coastal Environments of Taiwan

Taiwan’s rapid economic and industrial growth has put enormous pressure on its natural environment. This is especially visible in the coastal zone, where risks such as sea-level rise, coastal erosion, land subsidence, and flooding threaten the already vulnerable ecosystems. Ecosystem-based disaster risk reduction (Eco-DRR) is a management strategy that uses ecosystems to reduce disaster risks. While this type of strategy is promoted in the ‘Taiwan Coastal Zone Management Act’ (TCZMA), there is still a lack of data on the implementation of Eco-DRR methods in Taiwan. This study examines papers on policy analyses of the TCZMA, and five main barriers for implementation of Eco-DRR in Taiwan are identified. Subsequently, in order to assess Eco-DRR strategies in the coastal zone of Taiwan, case studies and evaluation data on ecosystem-based management strategies were assembled and evaluated. The results of this study show that initial strategies to plant mangroves for reduction of wave energy have not always been successful; in certain areas they were removed again due to invasiveness in endemic wetland ecosystems. Moreover, artificially building sand dunes can have negative side effects, like oversteepening of the dune profile or deteriorating the natural dune dynamics. To address and tackle aforementioned challenges, a novel framework is introduced for improved uptake of Eco-DRR in Taiwan and beyond, and suggestions for future strategies are proposed.

Trophic interactions and the diet composition of sympatric finfish predators in the tropical demersal ecosystem in the Bay of Bengal.

The dietary composition, foraging strategies, and interspecific trophic interactions were identified for four major demersal carnivorous finfishes, namely, croaker Otolithes ruber, hairtail Trichiurus lepturus, threadfin bream Nemipterus japonicus, and lizardfish Saurida undosquamis, along the north-western part of Bay of Bengal from 2014 to 2016. Two species, Trichiurus lepturus and Saurida undosquamis, were identified as finfish feeders due to the high number of teleost (clupeids and engraulids) prey. One species, Nemipterus japonicus, had a significantly different diet of metapenaeids and charybdids, and was identified as a shellfish feeder. The final species, Otolithes ruber, preyed equally on crustaceans and teleosts, and was identified as a shellfish-finfish feeder. The feeding activity of all four species was lower during peak spawning periods and tended to increase with maturity. Feeding preferences varied with seasons. The trophic level ranged from 3.49 to 4.01, classifying the four species as medium-carnivores or meso-predators. Niche breadth ranged from 0.170 to 0.421, with seasonal and ontogenetic variations. Individual or subgroup specialization was observed on dominant prey, but intraspecific diet variations indicated all four species to be opportunistic predators. There was substantial prey overlap for Saurida undosquamis with Otolithes ruber and Trichiurus lepturus, which increased ontogenetically and coincided with their peak spawning. Sharing of abundant prey resources together with temporal and ontogenetic resource partitioning at intra- and interspecific levels possibly lowered dietary competition, thereby facilitating the coexistence of these demersal predators. This study provides new information on feeding interactions from a tropical demersal ecosystem that can be applied for the ecosystem-based management of trawl fisheries.

Coastal Groundwater-Dependent Ecosystems are Falling Through Policy Gaps.

Coastal groundwater-dependent ecosystems (GDEs), such as wetlands, estuaries and nearshore marine habitats,are biodiversity hotspots that provide valuable ecosystem services to society. However, coastal groundwater and associated ecosystems are under threat from groundwater exploitation and depletion, as well as climate change impacts from sea-level rise and extreme flood and drought events. Despite many well-intentioned policies focused on sustainable groundwater use and species protection, coastal GDEs are falling through gaps generated by siloed policies and as a result, are declining in extent and ecological function. This study summarized then examined policies related to the management of coastal groundwater and connected ecosystems in two key case study areas: Queensland (Australia) and California (USA). Despite both areas being regarded as having progressive groundwater policy, our analysis revealed three universal policy gaps, including (1) a lack of recognition of the underlying groundwater system, (2) fragmented policies and complex governance structures that limit coordination, and (3) inadequate guidance for coastal GDE management. Overall, our analysis revealed that coastal GDE conservation relied heavily on inclusion within protected areas or was motivated by species recovery, meaning supporting groundwater systems remained underprotected and outside the remit of conservation efforts. To close these gaps, we consider the adoption of ecosystem-based management principles to foster integrated governance between disparate agencies and consider management tools that bridge traditional conservation realms. Our findings advocate for comprehensive policy frameworks that holistically address the complexities of coastal GDEs across the land-sea continuum to foster their long-term sustainability and conservation.

Can we use recovery timescales to define Good Environmental Status?

Ecosystem-based management is mandated by international legislation, including the Marine Strategy Framework Directive (MSFD) in the EU. This introduces a requirement for marine environments to achieve “Good Environmental Status” or GES, implying that the ecosystem is in a healthy and biodiverse state which does not limit the management options of future generations. Indicators of GES typically refer to the current or past state; however, an alternative approach that defines GES in terms of being able to recover to the appropriate reference unperturbed state within 30 years if human activities cease has been suggested. In this study we evaluate this “longest recovery timescales” (LRT) approach using the StrathE2E2 “big picture” model, an end-to-end ecosystem model designed to evaluate both top-down and bottom-up effects at an ecosystem level. We ask whether the approach is enough to prevent severe depletion as well as ensuring recovery at some future time. We also ask whether implementation is practical given uncertainties in defining appropriate baselines for recovery, defining what recovery looks like relative to this baseline, and taking account of natural variability. We find that the main issues with implementation of LRT are a) defining the appropriate baseline for recovery in a changing environment, and b) ensuring that there is stakeholder acceptance of any recommended actions in the event that they differ substantially from current policy. Subject to these two issues, we conclude that the LRT method is a valuable addition to management in support of achieving GES alongside existing methods that focus on current or near-future states.

Structural Characterization of Island Rainforests and Secondary Groves in Southern Nigeria

This study characterized the structural attributes of island rainforests and secondary groves within Orogun region in southern Nigeria. The quasi-experimental design was used, and the vegetation structural characteristics were determined in both secondary groves (experimental sites) and island rainforests (control sites). The randomized systematic sampling was employed in dividing the study area into 6 zones which were selected upon the presence of mature rainforest islands and secondary groves respectively. Six plots were sampled in each ecosystem. Tree heights, tree girths, and plot sizes were the data collected. Both secondary groves and island rainforest plots were measured to first determine uniformity in the area covered by the trees, after which, size of 200 ft X 100 ft was chosen as the uniform area of plot from which data were gathered. Tree girths at breast height were determined using measuring tape; while tree heights were determined by the use of Abney level and measuring tape. The 15.0 version of the Statistical Package for the Social Sciences (SPSS) was used in the statistical tests of the stated hypotheses. Statistical results showed that t-value = 7.05, P(0.001) > 0.05 for tree heights; and t-value = 3.122, P(0.026) > 0.05 for the tree girths. The mean differences in the structural characteristics between the secondary and mature island rainforest were significant at 0.05 alpha level. This implies that trees within island rainforests are significantly taller and bigger. The higher structural attributes of the island rainforest revealed that over time, conservation of rainforest trees could positively impact on its structural attributes. Therefore, ecosystem-based management approach was recommended for the management and conservation of the rainforest trees and covers

Ecological distribution patterns in Chinese seas and adjacent waters: Marine ecological zones

To provide a natural foundation and regionalization framework for ecological monitoring, assessment, and mapping to support ecosystem-based management practices of natural resources, three levels of ecological zones were classified in Chinese seas and adjacent waters using top-down and step wise nesting. At the largest spatial scale, the Chinese seas and adjacent waters were classified into three first-level ecological zones according to latitudinal zones and geographic profiles. To incorporate the dimensionalities and mobility of the seas, 22 second-level ecological zones were classified according to changes in water depth and the distribution of large water masses, and 53 third-level ecological zones were further delineated according to the type of geomorphology and the distribution of water masses and currents. This study identifies dominant factors at different spatiotemporal scales and defines the physical geographical patterns and ecological characteristics in Chinese seas and adjacent waters in a readily understood manner and fills the gap in research on ecological zoning in China.

Delineating the fish-based ecosystem services of a small tropical Indian estuary: Identification, evaluation and management

In this study, we evaluate the fish-based ecosystem services (ES) of Chettuva, a small tropical estuary (CE) on the south-west coast of India. Besides the direct benefits (provisioning and cultural), the primary regulatory and supporting services provided by fish in estuaries were also documented using secondary data and focused group discussions (FGD). The major obstacles impeding the fisheries-based ES were also identified, and priority-based management options were proposed. The annual economic value of the major fish-based ES of the estuary was estimated to be ₹814.55 million (₹36.96 million for provisioning, ₹569.52 million for supporting, ₹177.6 million for regulating and ₹30.47 million for cultural and information services including recreation, tourism, scientific and information services, respectively). The estuarine fishery in CE is still traditional, employing non-motorized boats and supporting the livelihood of about 300 active fishers. Our findings revealed that stakeholders rated higher values on provisioning, supporting, and cultural services while providing little significance on the regulating services. The current findings indicated that, as the primary means of livelihood, fisheries not only provide a pragmatic overview of the economic value of estuarine systems but also signifies the use of fisheries-based ES as a valuable tool in developing an ecosystem-based management plan. Based on the findings, it would be reasonable to highlight the need for ES-based approach for resource conservation in fisheries management of the small tropical estuaries.