scholarly journals Predicted regime shift in the seagrass ecosystem of the Gulf of Arguin driven by climate change

2021 ◽  
pp. e01890
Author(s):  
Rosa M. Chefaoui ◽  
Carlos M. Duarte ◽  
Ana I. Tavares ◽  
Duarte G. Frade ◽  
M.A. Sidi Cheikh ◽  
...  
Keyword(s):  
Climate Change ◽  
Regime Shift ◽  
Seagrass Ecosystem

scholarly journals A global algorithm for identifying changing streamflow regimes: application to Canadian natural streams (1966–2010)

2021 ◽  
Vol 25 (9) ◽  
pp. 5193-5217
Author(s):  
Masoud Zaerpour ◽  
Shadi Hatami ◽  
Javad Sadri ◽  
Ali Nazemi
Keyword(s):  
Climate Change ◽  
Regime Shift ◽  
Temporal Variations ◽  
Natural Streams ◽  
Regime Types ◽  
Finite Set ◽  
Streamflow Regime ◽  
Available Information ◽  
Global Algorithm ◽  
Impacts Of Climate Change

Abstract. Climate change affects natural streamflow regimes globally. To assess alterations in streamflow regimes, typically temporal variations in one or a few streamflow characteristics are taken into account. This approach, however, cannot see simultaneous changes in multiple streamflow characteristics, does not utilize all the available information contained in a streamflow hydrograph, and cannot describe how and to what extent streamflow regimes evolve from one to another. To address these gaps, we conceptualize streamflow regimes as intersecting spectrums that are formed by multiple streamflow characteristics. Accordingly, the changes in a streamflow regime should be diagnosed through gradual, yet continuous changes in an ensemble of streamflow characteristics. To incorporate these key considerations, we propose a generic algorithm to first classify streams into a finite set of intersecting fuzzy clusters. Accordingly, by analyzing how the degrees of membership to each cluster change in a given stream, we quantify shifts from one regime to another. We apply this approach to the data, obtained from 105 natural Canadian streams, during the period of 1966 to 2010. We show that natural streamflow in Canada can be categorized into six regime types, with clear hydrological and geographical distinctions. Analyses of trends in membership values show that alterations in natural streamflow regimes vary among different regions. Having said that, we show that in more than 80 % of considered streams, there is a dominant regime shift that can be attributed to simultaneous changes in streamflow characteristics, some of which have remained previously unknown. Our study not only introduces a new globally relevant algorithm for identifying changing streamflow regimes but also provides a fresh look at streamflow alterations in Canada, highlighting complex and multifaceted impacts of climate change on streamflow regimes in cold regions.

Seagrass Ecosystem and Climate Change: An Indian Perspective

2015 ◽  
Vol 1 (1,2) ◽  
pp. 67-74 ◽  
Author(s):  
Gurmeet Singh ◽  
Dipnarayan Ganguly ◽  
A. Paneer Selvam ◽  
Kakolee Kakolee ◽  
R. Purvaja ◽  
...  
Keyword(s):  
Climate Change ◽  
Seagrass Ecosystem ◽  
Indian Perspective

scholarly journals Climate change, regime shift and stock management

2002 ◽  
Vol 68 (sup1) ◽  
pp. 148-153 ◽  
Author(s):  
TSUYOSHI KAWASAKI
Keyword(s):  
Climate Change ◽  
Regime Shift ◽  
Stock Management

scholarly journals Ocean warming and acidification modify top-down and bottom-up control in a tropical seagrass ecosystem

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vina Listiawati ◽  
Haruko Kurihara
Keyword(s):  
Climate Change ◽  
High Temperature ◽  
Sea Urchin ◽  
Ocean Warming ◽  
Ecosystem Functions ◽  
Future Climate Change ◽  
Top Down ◽  
Thalassia Hemprichii ◽  
Bottom Up ◽  
Seagrass Ecosystem

AbstractSeagrass ecosystem is one of the most productive ecosystems in coastal waters providing numerous ecological functions and supporting a large biodiversity. However, various anthropogenic stressors including climate change are impacting these vulnerable habitats. Here, we investigated the independent and combined effects of ocean warming and ocean acidification on plant–herbivore interactions in a tropical seagrass community. Direct and indirect effects of high temperature and high pCO2 on the physiology of the tropical seagrass Thalassia hemprichii and sea urchin Tripneustes gratilla were evaluated. Productivity of seagrass was found to increase under high pCO2, while sea urchin physiology including feeding rate decreased particularly under high temperature. The present study indicated that future climate change will affect the bottom-up and top-down balance, which potentially can modify the ecosystem functions and services of tropical seagrass ecosystems.

Effects of Climate Change and Fisheries on the Marine Ecosystem of the Baltic Sea

2019 ◽  
Author(s):  
Christian Möllmann
Keyword(s):  
Climate Change ◽  
Baltic Sea ◽  
Regime Shift ◽  
Sea Water ◽  
Marine Ecosystem ◽  
Trophic Levels ◽  
Ecosystem Structure ◽  
The Baltic Sea ◽  
Recruitment Failure ◽  
The Baltic

Climate change and fisheries have significantly changed the Baltic Sea ecosystem, with the demise of Eastern Baltic cod (Gadus morhua callarias) being the signature development. Cod in the Central Baltic Sea collapsed in the late 1980s as a result of low reproductive success and overfishing. Low recruitment and hence small year-classes were not able to compensate for fishing pressures far above sustainable levels. Recruitment failure can be mainly related to the absence of North Sea water inflows to the Central Baltic deep basins. These major Baltic inflows (MBIs) occurred regularly until the 1980s, when their frequency decreased to a decadal pattern, a development attributed to changes in atmospheric circulation patterns. MBIs are needed for ventilation of otherwise stagnating Baltic deep waters, and their absence caused reduced oxygen and salinity levels in cod-spawning habitats, limiting egg and larval survival. Climate change, on the other hand, has promoted a warmer environment richer in zooplanktonic food for larval Baltic sprat (Sprattus sprattus). Resulting large year-classes and low predation by the collapsed cod stock caused an outburst of the sprat stock that cascaded down to the zoo- and phytoplankton trophic levels. Furthermore, a large sprat population controlled cod recruitment and hence hindered a recovery of the stock by predation on cod eggs, limiting cod larval food supply. The change in ecosystem structure and function caused by the collapse of the cod stock was a major part and driver of an ecosystem regime shift in the Central Baltic Sea during the period 1988 to 1993. This reorganization of ecosystem structure involved all trophic levels from piscivorous and planktivorous fish to zoo- and phytoplankton. The observed large-scale ecosystem changes displayed the characteristics of a discontinuous regime shift, initiated by climate-induced changes in the abiotic environment and stabilized by feedback loops in the food web. Discontinuous changes such as regime shifts are characteristically difficult to reverse, and the Baltic ecosystem recently rather shows signs of increasing ecological novelty for which the failed recovery of the cod stock despite a reduction in fishing pressure is a clear symptom. Unusually widespread deficient oxygen conditions in major cod-spawning areas have altered the overall productivity of the population by negatively affecting growth and recruitment. Eutrophication as a consequence of intensive agriculture is the main driver for anoxia in the Baltic Sea amplified by the effects on continuing climate change and stabilized by self-enforcing feedbacks. Developing ecological novelty in the Baltic Sea hence requires true cross-sectoral ecosystem-based management approaches that truly integrate eutrophication combatment, species conservation, and living resources management.

scholarly journals Regime shifts in the Anthropocene: drivers, risks, and resilience

2015 ◽  
Author(s):  
Juan Carlos Carlos Rocha ◽  
Garry D Peterson ◽  
Reinette Oonsie Biggs
Keyword(s):  
Climate Change ◽  
Global Change ◽  
Food Production ◽  
Regime Shift ◽  
Regime Shifts ◽  
Central Question ◽  
Global Risk ◽  
Rapid Reduction ◽  
Change Policy ◽  
Global Drivers

Many ecosystems can experience regime shifts: surprising, large and persistent changes in the function and structure of ecosystems. Assessing whether continued global change will lead to further regime shifts, or has the potential to trigger cascading regime shifts has been a central question in global change policy. Addressing this issue has, however, been hampered by the focus of regime shift research on specific cases and types of regime shifts. To systematically assess the global risk of regime shifts we conducted a comparative analysis of 25 generic types of regime shifts across marine, terrestrial and polar systems; identifying their drivers, and impacts on ecosystem services. Our results show that the drivers of regime shifts are diverse and co-occur strongly, which suggests that continued global change can be expected to synchronously increase the risk of multiple regime shifts. Furthermore, many regime shift drivers are related to climate change and food production, whose links to the continued expansion of human activities makes them difficult to limit. Because many regime shifts can amplify the drivers of other regime shifts, continued global change can also be expected to increase the risk of cascading regime shifts. Nevertheless, the variety of scales at which regime shift drivers operate provides opportunities for reducing the risk of many types of regime shifts by addressing local or regional drivers, even in the absence of rapid reduction of global drivers.

scholarly journals Recent Trends in Oceanic Conditions in the Western Part of East/Japan Sea: An Analysis of Climate Regime Shift That Occurred after the Late 1990s

2021 ◽  
Vol 9 (11) ◽  
pp. 1225
Author(s):  
Hae-Kun Jung ◽  
S. M. Mustafizur Rahman ◽  
Hee-Chan Choi ◽  
Joo-Myun Park ◽  
Chung-Il Lee
Keyword(s):  
Climate Change ◽  
Regime Shift ◽  
Japan Sea ◽  
Climate Factors ◽  
Atmospheric Conditions ◽  
Climate Regime ◽  
Climate Regime Shift ◽  
Recent Climate ◽  
Latitudinal Shift ◽  
The Kuroshio

The western part of East/Japan Sea (WES) is an important area for understanding climate change processes and interactions between atmospheric and oceanic conditions. We analyzed the trends in recent oceanic conditions in the WES after the recent climate regime shift (CRS) that occurred in the late 1990s in the North Pacific. We explored the most important climate factors that affect oceanic conditions and determined their responses to changes in climate change. In the CRS that occurred in the late 1980s, changes in oceanic conditions in the WES were influenced by intensity changes in climate factors, and, in the late 1990s, it was by spatial changes in climate factors. The latitudinal shift of the Aleutian low (AL) pressure influences recent changes in oceanic and atmospheric conditions in the WES. The intensity of the Kuroshio Current and the sea level pressure in the Kuroshio extension region associated with the latitudinal shift of the AL pressure affects the volume of transport of the warm and saline water mass that flows into the WES and its atmospheric conditions. In addition, the fluctuations in the oceanic conditions of the WES affect various regions and depth layers differently, and these variations are evident even within the WES.

scholarly journals Predicting ecological regime shift under climate change: New modelling techniques and potential of molecular-based approaches

2013 ◽  
Vol 59 (3) ◽  
pp. 403-417 ◽  
Author(s):  
Richard Stafford ◽  
V. Anne Smith ◽  
Dirk Husmeier ◽  
Thomas Grima ◽  
Barbara-ann Guinn
Keyword(s):  
Climate Change ◽  
Bayesian Network ◽  
Species Interactions ◽  
Rocky Shore ◽  
Regime Shift ◽  
Predictive Modelling ◽  
Kelp Forests ◽  
Stable Regime ◽  
Ecological Regime ◽  
Stable Community

Abstract Ecological regime shift is the rapid transition from one stable community structure to another, often ecologically inferior, stable community. Such regime shifts are especially common in shallow marine communities, such as the transition of kelp forests to algal turfs that harbour far lower biodiversity. Stable regimes in communities are a result of balanced interactions between species, and predicting new regimes therefore requires an evaluation of new species interactions, as well as the resilience of the ‘stable’ position. While computational optimisation techniques can predict new potential regimes, predicting the most likely community state of the various options produced is currently educated guess work. In this study we integrate a stable regime optimisation approach with a Bayesian network used to infer prior knowledge of the likely stress of climate change (or, in practice, any other disturbance) on each component species of a representative rocky shore community model. Combining the results, by calculating the product of the match between resilient computational predictions and the posterior probabilities of the Bayesian network, gives a refined set of model predictors, and demonstrates the use of the process in determining community changes, as might occur through processes such as climate change. To inform Bayesian priors, we conduct a review of molecular approaches applied to the analysis of the transcriptome of rocky shore organisms, and show how such an approach could be linked to meas-ureable stress variables in the field. Hence species-specific microarrays could be designed as biomarkers of in situ stress, and used to inform predictive modelling approaches such as those described here.

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