scholarly journals Appraising the Status of Fish Community Structure in the Yellow Sea Based on an Indicator-Testing Framework

2021 ◽  
Vol 8 ◽  
Author(s):  
Yuru Li ◽  
Shuyang Ma ◽  
Caihong Fu ◽  
Yongjun Tian ◽  
Jianchao Li ◽  
...  
Keyword(s):  
Climate Change ◽  
Fisheries Management ◽  
Fish Community ◽  
Large Scale ◽  
The Yellow Sea ◽  
Total Catch ◽  
Fish Community Structure ◽  
Testing Framework ◽  
The Status ◽  
Ecosystem Based Fisheries Management

Fish community structure (FCS) of the Yellow Sea (YS) is affected by multiple pressures. Quantifying the responses of indicators of FCS (IFCSs) to pressures is a key aspect of ecosystem-based fisheries management. Quantitative methodology has hitherto been rarely applied to evaluate the performance of ecological indicators in response to physical and anthropogenic pressures and management actions. In this study, we adopted a quantitative and flexible framework to quantify the performance of IFCSs in the YS as well as to identify a suite of operational IFCSs to evaluate the status of the FCS via two state-space approaches. A total of 22 IFCSs were tested for their responses to three types of pressures including anthropogenic activities (fishing), large-scale climate change, and regional environmental variables. Our results indicate that the majority of IFCSs have good performance in terms of sensitivity in their responses to pressures, but weak performance in terms of robustness. The IFCSs tend to respond stronger to fishing than to large-scale climatic indices and regional environmental indices both in terms of sensitivity and robustness. A final indicator suite of five best-performing IFCSs was identified. The five IFCSs include total catch (ToC), mean trophic level (MTL), the ratio of catch of large predatory groups to total catch (LPC/ToC), mean temperature of catch (MTC) [or alternatively catch of small pelagic groups (SPC)], and functional evenness based on thermal groups (T-J′FD), all of which show regime shift patterns consistent with climate change. Compared to a reference period (1960–1964), the status of the current FCS has been obviously changed, and the long-term trajectories of the final indicator suite is consistent with that of fishing pressure. This study demonstrates the applicability of the indicator-testing framework in appraising the status of FCS, and facilitates moving towards ecosystem-based fisheries management in the YS.

Dissolved oxygen and temperature best predict deep-sea fish community structure in the Gulf of California with climate change implications

2020 ◽  
Vol 637 ◽  
pp. 159-180
Author(s):  
ND Gallo ◽  
M Beckwith ◽  
CL Wei ◽  
LA Levin ◽  
L Kuhnz ◽  
...  
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Community Composition ◽  
Environmental Conditions ◽  
Deep Sea ◽  
Gulf Of California ◽  
Fish Community ◽  
Demersal Fish ◽  
Fish Community Structure ◽  
Explained Variance

Natural gradient systems can be used to examine the vulnerability of deep-sea communities to climate change. The Gulf of California presents an ideal system for examining relationships between faunal patterns and environmental conditions of deep-sea communities because deep-sea conditions change from warm and oxygen-rich in the north to cold and severely hypoxic in the south. The Monterey Bay Aquarium Research Institute (MBARI) remotely operated vehicle (ROV) ‘Doc Ricketts’ was used to conduct seafloor video transects at depths of ~200-1400 m in the northern, central, and southern Gulf. The community composition, density, and diversity of demersal fish assemblages were compared to environmental conditions. We tested the hypothesis that climate-relevant variables (temperature, oxygen, and primary production) have more explanatory power than static variables (latitude, depth, and benthic substrate) in explaining variation in fish community structure. Temperature best explained variance in density, while oxygen best explained variance in diversity and community composition. Both density and diversity declined with decreasing oxygen, but diversity declined at a higher oxygen threshold (~7 µmol kg-1). Remarkably, high-density fish communities were observed living under suboxic conditions (<5 µmol kg-1). Using an Earth systems global climate model forced under an RCP8.5 scenario, we found that by 2081-2100, the entire Gulf of California seafloor is expected to experience a mean temperature increase of 1.08 ± 1.07°C and modest deoxygenation. The projected changes in temperature and oxygen are expected to be accompanied by reduced diversity and related changes in deep-sea demersal fish communities.

scholarly journals Assessing the Vulnerability of Marine Fisheries in China: Towards an Inter-Provincial Perspective

2018 ◽  
Vol 10 (11) ◽  
pp. 4302 ◽  
Author(s):  
Qi Chen ◽  
Weiteng Shen ◽  
Bing Yu
Keyword(s):  
Climate Change ◽  
Adaptive Capacity ◽  
Fisheries Management ◽  
Vocational Training ◽  
Large Scale ◽  
Environmental Changes ◽  
Marine Pollution ◽  
Marine Fisheries ◽  
Intergovernmental Panel ◽  
Adaptation Measures

China’s marine fisheries are undergoing large-scale environmental changes associated with climate change, marine pollution, and overfishing. The assessment of marine fisheries vulnerability has become extremely necessary for fisheries management and sustainable development. However, studies on China’s marine fisheries vulnerability remains sparse. This study aimed to provide an analysis of the inter-provincial level vulnerability of China’s marine fisheries under multiple disturbances. The vulnerability measure was composed of exposure, sensitivity, and adaptive capacity indicators specific to marine fisheries based on the Intergovernmental Panel on Climate Change (IPCC) definitions. Results showed that Liaoning, Hebei, Fujian, and Hainan provinces appeared to be the most vulnerable; Shanghai appeared to be less vulnerable among China’s 11 coastal provinces; and the key sources of vulnerability differed considerably among coastal regions. The high vulnerability regions could be divided into two different patterns according to the combination of exposure, sensitivity, and adaptive capacity, but they all had one thing in common: relatively low adaptive capacity. While some existing coercive measures to reduce dependence on fisheries were found to be helpful in China, the reality showed that appropriate adaptation measures such as improving fishermen’s education level and increasing vocational training may be helpful in enhancing the existing policy effectiveness.

scholarly journals Atlantic puffin diet reflects haddock and redfish abundance in the Gulf of Maine

2020 ◽  
Vol 656 ◽  
pp. 75-87
Author(s):  
KM Depot ◽  
LC Scopel ◽  
SW Kress ◽  
P Shannon ◽  
AW Diamond ◽  
...  
Keyword(s):  
Fisheries Management ◽  
Large Scale ◽  
Gulf Of Maine ◽  
Strong Predictor ◽  
Principal Component ◽  
Melanogrammus Aeglefinus ◽  
Generalist Predator ◽  
Successful Implementation ◽  
Ecosystem Based Fisheries Management ◽  
Atlantic Puffin

Ecosystem-based fisheries management, which considers the interactions between fisheries, target species, and the physical and biological components of ecosystems, is necessary to ensure that directed fisheries avoid adverse impacts to ecosystems over the long term. The successful implementation of ecosystem-based fisheries management requires an understanding of predator-prey relationships and ways to operationalize such relationships to inform fisheries management. Here, we investigated if the diet of a generalist predator, Atlantic puffin Fratercula arctica, can be used as an indicator of the abundance of 2 commercially exploited prey species (haddock Melanogrammus aeglefinus and Acadian redfish Sebastes fasciatus) in the Gulf of Maine. Because haddock and redfish eaten by puffins are juveniles (age 0), there is potential to use their proportions and lengths in puffin diet to better understand the processes influencing haddock and redfish recruitment. By using principal component analysis to develop measures of diet across multiple puffin colonies, we show both spatial variation and large-scale patterns in the proportions and lengths of haddock and redfish in puffin diet. Spawning stock biomass was a strong predictor of haddock proportion in puffin diet and a moderate predictor of redfish proportion; however, proportions in puffin diet did not predict age-1 recruitment, suggesting that variation in recruitment is caused by processes that occur after the puffin breeding season and which affect the survival of older juveniles. Haddock length on one colony was a moderate predictor of age-1 recruitment. We conclude that puffin diet can be used as an indicator of haddock and redfish abundance.

Benthic Habitats and the Effects of Fishing

2005 ◽  
Keyword(s):  
Fisheries Management ◽  
Large Scale ◽  
Scale Effects ◽  
Ecosystem Processes ◽  
Fishing Effort ◽  
Habitat Types ◽  
Benthic Habitats ◽  
Management Actions ◽  
Ecosystem Effects ◽  
Ecosystem Based Fisheries Management

<strong><em>Abstract. </em></strong>We review the impacts of towed gears on benthic habitats and communities and predict the consequences of these impacts for ecosystem processes. Our emphasis is on the additive and synergistic large-scale effects of fishing, and we assess how changes in the distribution of fishing activity following management action are likely to affect production, turnover time, and nutrient fluxes in ecosystems. Analyses of the large-scale effects of fishing disturbance show that the initial effects of fishing on a habitat have greater ecosystem consequences than repeated fishing in fished areas. As a result, patchy fishing effort distributions have lower total impacts on the ecosystem than random or uniform effort distributions. In most fisheries, the distribution of annual fishing effort within habitats is more patchy than random, and patterns of effort are maintained from year to year. Our analyses suggest that many vulnerable species and habitats have only persisted in heavily fished ecosystems because effort is patchy. Ecosystem-based fisheries management involves taking account of the ecosystem effects of fishing when setting management objectives. One step that can be taken toward ecosystem-based fisheries management is to make an a priori assessment of the ecosystem effects of proposed management actions such as catch controls, effort controls, and technical measures. We suggest a process for predicting the ecosystem consequences of management action. This requires information on habitat distributions, models to predict changes in the spatial distribution of fleets following management action, and models of the impacts of trawling disturbance on ecosystem processes. For each proposed management action, the change in disturbance affecting different habitat types would be predicted and used to forecast the consequences for the ecosystem. These simulations would be used to produce a decision table, quantifying the consequences of alternative management actions. Actions that minimize the ecosystem effects of fishing could then be identified. In data-poor situations, we suggest that management strategies that maintain or maximize the patchiness of effort within habitat types are more consistent with the precautionary approach than those that lead to more uniform fishing effort distributions.

Response of a floodplain fish community to river-floodplain connectivity: natural versus managed reconnection

2014 ◽  
Vol 71 (2) ◽  
pp. 236-245 ◽  
Author(s):  
R.J. Stoffels ◽  
K.R. Clarke ◽  
R.A. Rehwinkel ◽  
B.J. McCarthy
Keyword(s):  
Native Species ◽  
Fish Community ◽  
Large Scale ◽  
Environmental Flows ◽  
Regulated River ◽  
Pest Species ◽  
Fish Community Structure ◽  
River Floodplain ◽  
Natural Connection ◽  
Flood Pulses

To restore lateral connectivity in highly regulated river-floodplain systems, it has become necessary to implement localized, “managed” connection flows, made possible using floodplain irrigation infrastructure. These managed flows contrast with “natural”, large-scale, overbank flood pulses. We compared the effects of a managed and a natural connection event on (i) the composition of the large-bodied fish community and (ii) the structure of an endangered catfish population of a large floodplain lake. The change in community composition following the managed connection was not greater than that exhibited between seasons or years during disconnection. By contrast, the change in fish community structure following the natural connection was much larger than that attributed to background, within- and between-year variability during disconnection. Catfish population structure only changed significantly following the natural flood. While the natural flood increased various population rates of native fishes, it also increased those of non-native carp, a pest species. To have a positive influence on native biodiversity, environmental flows may need to be delivered to floodplains in a way that simulates the properties of natural flood pulses. A challenge, however, will be managing river-floodplain connectivity to benefit native more than non-native species.

scholarly journals Risk-based evaluation of the vulnerability of the Skagerrak–Kattegat marine fish community to Swedish fisheries

2020 ◽  
Author(s):  
Sara Hornborg ◽  
Alistair J Hobday ◽  
Louisa Borthwick ◽  
Daniel Valentinsson
Keyword(s):  
Fisheries Management ◽  
Marine Fish ◽  
Fish Community ◽  
Cost Effective ◽  
Risk Levels ◽  
Potential Risks ◽  
Single Score ◽  
Data Deficient ◽  
Ecosystem Based Fisheries Management ◽  
Species Productivity

Abstract Progress towards ecosystem-based fisheries management calls for useful tools to prioritize actions. To select suitable methods for local circumstances, evaluating approaches used in other jurisdictions can be a cost-effective first step. We tested Productivity Susceptibility Analysis (PSA) to assess the potential vulnerability of the marine fish community in the Skagerrak–Kattegat (Eastern North Sea) to possible interactions with all Swedish fisheries operating in the area. This analysis combines attributes for a species productivity with attributes related to the susceptibility to capture to quantify a single score for vulnerability: high, medium, or low risk. Results indicate that demersal trawl and gillnet fisheries were associated with the highest risk levels if interaction occurs, i.e. having the highest prevalence of species with potentially high vulnerability to the fisheries. Mixed results were seen when comparing the assessment results with available data. The main benefit of utilizing PSA in the area is the comprehensiveness of the assessment, including data-deficient fisheries and species. Drawbacks include potential overestimation of actual risks. Overall, together with available data, PSA in the studied area provides a comprehensive map of potential risks for further actions and may progress a science-based, precautionary management of the area.

Analysis of Global and National Scenario of Tuber Crops Production: Trends and Prospects

2020 ◽  
pp. 500-510
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Climatic Conditions ◽  
Sweet Potatoes ◽  
Nutritional Security ◽  
Rate Analysis ◽  
Self Reliance ◽  
The Status ◽  
Food And Nutritional Security ◽  
Tuber Crops

This paper attempts to explore the status of tuber crops cultivation with regard to area, production and productivity across countries and exports of cassava and sweet potatoes from India. The result indicated that among various tuber crops, potatoes were vastly cultivated and consumed by Europe and Asia. At the same time, cassava and sweet potatoes were generally grown and consumed by Africa and Asia. In India, cassava and sweet potatoes are the most important tuber crops due to their large scale and varied uses. The growth rate analysis showed that the area under cassava (-1.38 percent) and sweet potatoes (-0.70 percent) as a whole showed a declining trend in India due to various agro-climatic conditions and socioeconomic constraints. In the context of climate change and considering the importance of root and tuber crops for food and nutritional security, it would be a smart move to bring more area under tuber crops cultivation to achieve 'self-reliance' and ' Make in India Mission'.

Multispecies and Watershed Approaches to Freshwater Fish Conservation

2019 ◽  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Fisheries Management ◽  
Species Distribution ◽  
Large Scale ◽  
Species Distribution Models ◽  
Distribution Models ◽  
Climate Conditions ◽  
Resource Sustainability ◽  
Riparian Protection

<em>Abstract</em>.—Increasingly, fisheries managers must make important decisions in complex environments where rapidly changing landscape and climate conditions interact with historical impacts to influence resource sustainability. Successful fisheries management in this setting will require that we adapt traditional management approaches to incorporate information on these complex interacting factors—a process referred to as resilient fisheries management. Large-scale species distribution data and predictive models have the potential to enhance the management of freshwater fishes through improved understanding of how past, present, and future natural and anthropogenic factors combine to determine species vulnerability and resiliency. Here we describe a resilient fisheries management framework that provides guidance on how and when these models can be incorporated into traditional approaches to meet specific goals and objectives for resource sustainability. In addition to elucidating complex drivers of distributional patterns and change, species distribution models can inform the prioritization, application, and implementation of management activities such as restoration (e.g., instream habitat and riparian), protection (e.g., areas where additional land use would result in a change in species distribution), and regulations (e.g., harvest restriction) in a way that informs resiliency to land use and climate change. Although considerable progress has been made with respect to applying species distribution models to the management of Brook Trout <em>Salvelinus fontinalis </em>and other aquatic species, there are several areas where a more unified research and management effort could increase the ability of distribution models to inform resilient management. Future efforts should aim to improve (1) data availability, consistency (sampling methodology), and quality (accounting for detection); (2) partnerships among researchers, agencies, and managers; and (3) model accessibility and understanding of limitations and potential benefits to managers (e.g., incorporation into publicly available decision support systems). The information and recommendations provided herein can be used to promote and advance the use of models in resilient fisheries management in the face of continued large-scale land use and climate change.

scholarly journals The impact of climate change on the fish community structure of the eastern continental shelf of the Bay of Biscay

2005 ◽  
Vol 62 (7) ◽  
pp. 1436-1443 ◽  
Author(s):  
Jean-Charles Poulard ◽  
Fabian Blanchard
Keyword(s):  
Continental Shelf ◽  
Fish Species ◽  
Fish Community ◽  
Large Scale ◽  
Temporal Trends ◽  
Distribution Range ◽  
Bay Of Biscay ◽  
Fish Community Structure ◽  
Abundance Indices ◽  
The Impact

Abstract Many fish species are at the southern or northern limit of their distribution range in the Bay of Biscay, where large-scale hydroclimatic changes have occurred in recent decades. We attempt here to identify the impact of these changes on the fish community of the eastern continental shelf of the Bay of Biscay. Data collected during 14 autumn groundfish surveys in 1973 and from 1987 to 2002 are used. The study area is between latitudes 48°30′N and 43°30′N while the depth ranges from 15 to 200 m. Annual abundance indices (number of individuals per km2) of 56 fish taxa present on average in at least 5% of the tows are computed. Multivariate analysis is used to detect temporal trends in these species' abundance indices. Assuming that increased water temperature may favour subtropical species and hinder temperate ones, knowledge about the latitudinal distribution range is used to interpret time trends. Results show an increasing abundance trend with time for fish species having a wide distribution range in latitude (mainly subtropical ones), whereas the abundance of temperate and the least widely distributed species decreased steadily.

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