scholarly journals Ecosystem-based fisheries management forestalls climate-driven collapse

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
K. K. Holsman ◽  
A. C. Haynie ◽  
A. B. Hollowed ◽  
J. C. P. Reum ◽  
K. Aydin ◽  
...  

Abstract Climate change is impacting fisheries worldwide with uncertain outcomes for food and nutritional security. Using management strategy evaluations for key US fisheries in the eastern Bering Sea we find that Ecosystem Based Fisheries Management (EBFM) measures forestall future declines under climate change over non-EBFM approaches. Yet, benefits are species-specific and decrease markedly after 2050. Under high-baseline carbon emission scenarios (RCP 8.5), end-of-century (2075–2100) pollock and Pacific cod fisheries collapse in >70% and >35% of all simulations, respectively. Our analysis suggests that 2.1–2.3 °C (modeled summer bottom temperature) is a tipping point of rapid decline in gadid biomass and catch. Multiyear stanzas above 2.1 °C become commonplace in projections from ~2030 onward, with higher agreement under RCP 8.5 than simulations with moderate carbon mitigation (i.e., RCP 4.5). We find that EBFM ameliorates climate change impacts on fisheries in the near-term, but long-term EBFM benefits are limited by the magnitude of anticipated change.

2021 ◽  
Vol 8 ◽  
Author(s):  
Yuru Li ◽  
Shuyang Ma ◽  
Caihong Fu ◽  
Yongjun Tian ◽  
Jianchao Li ◽  
...  

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.


2019 ◽  
Vol 11 (4) ◽  
pp. 1521-1538
Author(s):  
Muhammad Zia ur Rahman Hashmi ◽  
Amjad Masood ◽  
Haris Mushtaq ◽  
Syed Ahsan Ali Bukhari ◽  
Burhan Ahmad ◽  
...  

Abstract In transboundary river basins, climate change is being considered as a concern of higher degree than it is in other parts of the world. The Kabul River Basin, a sub-basin of the Indus River system shared by Pakistan and Afghanistan, is no exception. High level of sensitivity of its flow to temperature makes it imperative to analyse climate change impacts on the flow regime of this important river for efficient water resources management on both sides of the border. The snowmelt runoff model integrated with remote sensing snow cover product MODIS was selected to simulate daily discharges. Future projections were generated for two selected time slices, 2011–2030 (near future) and 2031–2050 (far future), based on output of an ensemble of four GCMs' RCP 4.5 and RCP 8.5 scenarios. Analysis shows a significant temperature increase under both scenarios in the near and far future at a high-altitude region of the basin which mostly receives snowfall that is also found increasing over time. Consequently, it causes a change in the flow regime and more frequent and heavier flooding events, thus calling for a joint strategy of the two riparian countries to mitigate the anticipated impacts in the basin for safety of people and overall prosperity.


2017 ◽  
Author(s):  
Josep M. Serra-Diaz ◽  
Charles Maxwell ◽  
Melissa S. Lucash ◽  
Robert M. Scheller ◽  
Danelle M. Laflower ◽  
...  

AbstractAs trees are long-lived organisms, the impacts of climate change on forest communities may not be apparent on the time scale of years to decades. While lagged responses to environmental change are common in forested systems, potential for abrupt transitions under climate change may occur in environments where alternative vegetation states are influenced by disturbances, such as fire. The Klamath mountains (northern California and southwest Oregon, USA) are currently dominated by carbon rich and hyper-diverse temperate conifer forests, but climate change could disrupt the mechanisms promoting forest stability– regeneration and fire tolerance— via shifts in the fire regime in conjunction with lower fitness of conifers under a hotter climate. Understanding how this landscape will respond to near-term climate change (before 2100) is critical for predicting potential climate change feedbacks and to developing sound forest conservation and management plans. Using a landscape simulation model, we estimate that 1/3 of the Klamath could transition from conifer forest to shrub/hardwood chaparral, triggered by an enhanced fire activity coupled with lower post-fire conifer establishment. Such shifts were more prevalent under higher climate change forcing (RCP 8.5) but were also simulated under the climate of 1950-2000, reflecting the joint influences of early warming trends and historical forest legacies. Our results demonstrate that there is a large potential for loss of conifer forest dominance—and associated carbon stocks and biodiversity- in the Klamath before the end of the century, and that some losses would likely occur even without the influence of climate change. Thus, in the Klamath and other forested landscapes subject to similar feedback dynamics, major ecosystem shifts should be expected when climate change disrupts key stabilizing feedbacks that maintain the dominance of long-lived, slowly regenerating trees.


Author(s):  
Taylor Livingston ◽  
Edward McBean ◽  
Mason Marchildon ◽  
Bahram Gharabaghi

Water management activities are currently predicated on the assumption of a stationary climate, despite the reality of climate change. Hydrologic impacts of climate change for three sub-watersheds north of Toronto for 2041-70 were investigated using the Precipitation-Runoff Modeling System to model six GCM projections from each of RCP 2.6, RCP 4.5, and RCP 8.5. Annual groundwater recharge, evapotranspiration, and the 7Q20 low streamflow statistic were projected to change from 1976-2005 conditions by -2.2% to +20.5%, +0.9% to +14.4%, and -25.5% to +9.8%, respectively. Seasonal shifts included an earlier date of peak streamflow for the majority of simulations and a +14.0% to +103.9% increase in winter recharge. A steady-state MODFLOW model was employed as a preliminary assessment into the effects of climate change on Source Water Protection outputs. The results of this research further the understanding of climate change impacts on human and ecological systems in southern Ontario.


2020 ◽  
Vol 7 ◽  
Author(s):  
Hannah E. Fogarty ◽  
Christopher Cvitanovic ◽  
Alistair J. Hobday ◽  
Gretta T. Pecl

For Australian fisheries to remain productive and sustainable (environmentally and commercially), there is a need to incorporate climate change considerations into management and planning, and to implement planned climate adaptation options. Here, we determine the extent to which Australian state fisheries management documents consider issues relating to climate change, as well as how frequently climate change is considered a research funding priority within fisheries research in Australia. We conduct a content analysis of fisheries management documents investigating categories and themes relating to Australian state fisheries, climate, and environmental change. We also reviewed recent Research Priorities from the major fisheries research funding body for reference to climate change related themes, and the number of subsequently funded projects which considered climate change or related topics. Results show that commercial state fisheries management documents consider climate only to a limited degree in comparison to other topics, with less than one-quarter of all fisheries management documents having content relating to climate. However, we find that the south-east and south-west regions of the Australian coastline have the highest incorporation of “climate” and “environmental protection considerations” in their fisheries management documents, and that fisheries are more likely to have more “climate-related mentions” within their related management documents, if they (i) primarily target species with higher economic commercial catch values, (ii) commercial catch weights, or (iii) a greater number of commercial fish stocks existing. Only a small number of recently funded fisheries research projects considered climate change, representing only a small proportion of fisheries research investment. Given the extensive climate-driven impacts recently documented among key Australian fisheries species and associated ecosystems, we conclude that there is a clear need for fisheries management in Australia to consider longer-term climate adaptation strategies for Australian commercial state fisheries to remain sustainable into the future. We suggest that without additional climate-related fisheries research and funding, many Australian agencies and fisheries may not be prepared for the impacts and subsequent adaptation efforts required for sustainable fisheries under climate change.


Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1335
Author(s):  
Paola Faggian

To support the development of national adaptation policies and measures addressing climate change impacts over Italy, this work aims to analyze projected changes in mean temperatures and precipitations, and extreme events such as droughts and floods, highlighting some local trends in the different Italian regions that have been little considered to date. The investigations are made on the basis of a set of high-resolution Euro-CORDEX models (horizontal resolution 0.11°, about 12 km) to infer quantitative assessments about the danger of climate changes under three different Representative Concentration Pathways (RCPs): business as usual scenario, i.e., without a reduction in green-house gas emissions (RCP 8.5), medium stabilization scenario (RCP 4.5) and mitigation scenario (RCP 2.6). After filtering the models with limited performances in reconstructing the current climate, the multi-model climate change scenarios were characterized by comparing the ensemble mean values computed for the base-line period (1971–2000) with those elaborated for the short- (2021–2050), medium- (2041–2070) and long-term (2071–2100). Two WMO ETCCDI indices were considered to investigate climate extremes: Consecutive Dry Days and extreme precipitations. Despite some uncertainties (related to discrepancies among the models), drought conditions and extreme precipitations will likely exacerbate in the coming decades without mitigation (RCP 8.5). Such conditions will be less critical if partial mitigation actions will be undertaken (RCP 4.5) and are expected to be significantly reduced with decarbonization policies (RCP 2.6).


2021 ◽  
Author(s):  
Toju Esther Babalola ◽  
Philip Gbenro Oguntunde ◽  
Ayodele Ebenezer Ajayi ◽  
Francis Omowonuola Akinluyi

The changing climate is a concern to sustainable water resources. This study examined climate change impacts on river discharge seasonality in two West African river basins; the Niger river basin and the Hadejia-Jama’are Komadugu-Yobe Basin (HJKYB). The basins have their gauges located within Nigeria and cover the major climatic settings. Here, we set up and validated the hyper resolution global hydrological model PCR-GLOBWB for these rivers. Time series plots as well five performance evaluation metrics such as Kling–Gupta efficiency (KGE),); the ratio of RMSE-observations standard deviation (RSR); per cent bias (PBIAS); the Nash–Sutcliffe Efficiency criteria (NSE); and, the coefficient of determination (r2), were employed to verify the PCR-GLOBWB simulation capability. The validation results showed from satisfactory to very good on individual rivers as specified by PBIAS (−25 to 0.8), NSE (from 0.6 to 0.8), RSR (from 0.62 to 0.4), r2 (from 0.62 to 0.88), and KGE (from 0.69 to 0.88) respectively. The impact assessment was performed by driving the model with climate projections from five global climate models for the representative concentration pathways (RCPs) 4.5 and 8.5. We examined the median and range of expected changes in seasonal discharge in the far future (2070–2099). Our results show that the impacts of climate change cause a reduction in discharge volume at the beginning of the high flow period and an increase in discharge towards the ending of the high flow period relative to the historical period across the selected rivers. In the Niger river basin, at the Lokoja gauge, projected decreases added up to 512 m3/s under RCP 4.5 (June to July) and 3652 m3/s under RCP 8.5 (June to August). The three chosen gauges at the HJKYB also showed similar impacts. At the Gashua gauge, discharge volume increased by 371 m3/s (RCP8.5) and 191 m3/s (RCP4.5) from August to November. At the Bunga gauge, a reduction/increase of -91 m3/s/+84 m3/s (RCP 8.5) and -40 m3/s/+31 m3/s/(RCP 4.5) from June to July/August to October was simulated. While at the Wudil gauge, a reduction/increase in discharge volumes of −39/+133 m3/s (RCP8.5) and −40/133 m3/s (RCP 4.5) from June to August/September to December is projected. This decrease is explained by a delayed start of the rainy season. In all four rivers, projected river discharge seasonality is amplified under the high-end emission scenario (RCP8.5). This finding supports the potential advantages of reduced greenhouse gas emissions for the seasonal river discharge regime. Our study is anticipated to provide useful information to policymakers and river basin development authorities, leading to improved water management schemes within the context of changing climate and increasing need for agricultural expansion.


2020 ◽  
Vol 648 ◽  
pp. 1-17
Author(s):  
A Bryndum-Buchholz ◽  
DG Boyce ◽  
DP Tittensor ◽  
V Christensen ◽  
D Bianchi ◽  
...  

Climate-induced changes in the world’s oceans will have implications for fisheries productivity and management. Using a model ensemble from the Fisheries and Marine Ecosystem Model Intercomparison Project (Fish-MIP), we analyzed future trajectories of climate-change impacts on marine animal biomass and associated environmental drivers across the North Atlantic Ocean and within the Northwest Atlantic Fisheries Organization (NAFO) convention area and evaluated potential consequences for fisheries productivity and management. Our ensemble results showed that the magnitude of projected biomass changes increased over time and from a low (RCP2.6) to high (RCP8.5) emissions scenario. Within individual NAFO divisions, however, projected biomass changes differed in the magnitude and sometimes direction of change between near (the 2030s) and far future (the 2090s) and contrasting emissions scenarios. By the 2090s, most NAFO divisions with historically (1990-1999) high fisheries landings were projected to experience biomass decreases of 5-40%, while Arctic and subarctic divisions with lower historical landings were projected to experience biomass increases between 20 and 70% under RCP8.5. Future trajectories of sea surface temperature and primary production corroborated that the far-future, high-emissions scenario poses the greatest risk to marine ecosystems and the greatest challenges to fisheries management. Our study summarizes future trends of marine animal biomass and underlying uncertainties related to model projections under contrasting climate-change scenarios. Understanding such climate-change impacts on marine ecosystems is imperative for ensuring that marine fisheries remain productive and sustainable in a changing ocean.


2021 ◽  
Vol 8 ◽  
Author(s):  
Kelly Ortega-Cisneros ◽  
Kevern L. Cochrane ◽  
Nina Rivers ◽  
Warwick H. H. Sauer

The marine fisheries sector is one of the most important income sectors in South Africa and plays an important role in food security for small-scale and subsistence fishers. Climate-driven impacts have resulted in distribution shifts and declines in abundance of important fisheries targets, with negative consequences to the users dependent on these resources. The sustainability of the sector depends on its readiness to adapt to climate change. The inclusion of climate change impacts and adaptation in fisheries management documents in South Africa is essential to ensure adequate climate adaptation responses are implemented at the short- and long-term. This study aims to 1) determine if the relevant fisheries national management documents address climate change and adaptation, 2) determine if the relevant national climate change documents address climate change and adaptation in the fisheries sector and 3) evaluate the extent to which fisheries management documents address climate change and adaptation. A content analysis of fisheries management and climate change documents was carried out to determine if they incorporated information on climate change impacts and adaptation and marine fisheries respectively. Fisheries management documents were then screened against nine pre-determined criteria (or themes) based on climate change adaptation to determine the level of inclusion of best practice for climate change adaptation. Results indicate that climate change impacts and adaptation are rarely incorporated in the main fisheries management documents, except for the Climate Change Adaptation and Mitigation Plan for the agriculture, fisheries and forestry sectors. However, this document is still waiting to be adopted. The only direct reference identified in all the fisheries documents that supports climate change adaptation was ‘conservation and sustainable management of biodiversity’. With regards to indirect references to climate change adaptation, ‘equity,’ ‘participatory management,’ and ‘capacity building’ were most frequently incorporated in fisheries management documents. There is a need to explicitly incorporate information on climate change impacts and adaptation in South African fisheries management documents and increase the human and financial capacity at national institutions to ensure that the fisheries sector can adequately adapt to climate change.


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