Ocean Warming and Acidification Modify Top-Down and Bottom-Up Control in A Tropical Seagrass Ecosystem

2020 ◽  
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 ◽  
Seagrass Meadows ◽  
Seagrass Community

Abstract Seagrass ecosystems are classified as one of the most productive ecosystems in coastal waters providing numerous of ecological functions, 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 synergistically increase under the combination of high temperature and 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 botom-up and top-down balance leading to a shift to a seagrass-dominated ecosystem, which potentially decrease biodiversity as well as ecosystem functions and services of tropical seagrass meadows.

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.

scholarly journals Temperature, but not pH, compromises sea urchin fertilization and early development under near-future climate change scenarios

2009 ◽  
Vol 276 (1663) ◽  
pp. 1883-1888 ◽  
Author(s):  
Maria Byrne ◽  
Melanie Ho ◽  
Paulina Selvakumaraswamy ◽  
Hong D. Nguyen ◽  
Symon A. Dworjanyn ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Urchin ◽  
Ocean Warming ◽  
Future Climate ◽  
Interactive Effects ◽  
Future Climate Change ◽  
Marine Biota ◽  
Climate Change Scenarios ◽  
Eastern Australia ◽  
Near Future

Global warming is causing ocean warming and acidification. The distribution of Heliocidaris erythrogramma coincides with the eastern Australia climate change hot spot, where disproportionate warming makes marine biota particularly vulnerable to climate change. In keeping with near-future climate change scenarios, we determined the interactive effects of warming and acidification on fertilization and development of this echinoid. Experimental treatments (20–26°C, pH 7.6–8.2) were tested in all combinations for the ‘business-as-usual’ scenario, with 20°C/pH 8.2 being ambient. Percentage of fertilization was high (>89%) across all treatments. There was no difference in percentage of normal development in any pH treatment. In elevated temperature conditions, +4°C reduced cleavage by 40 per cent and +6°C by a further 20 per cent. Normal gastrulation fell below 4 per cent at +6°C. At 26°C, development was impaired. As the first study of interactive effects of temperature and pH on sea urchin development, we confirm the thermotolerance and pH resilience of fertilization and embryogenesis within predicted climate change scenarios, with negative effects at upper limits of ocean warming. Our findings place single stressor studies in context and emphasize the need for experiments that address ocean warming and acidification concurrently. Although ocean acidification research has focused on impaired calcification, embryos may not reach the skeletogenic stage in a warm ocean.

scholarly journals Sea-louse abundance on salmon farms in relation to parasite-control policy and climate change

2020 ◽  
Author(s):  
Sean C Godwin ◽  
Martin Krkosek ◽  
John D Reynolds ◽  
Andrew W Bateman
Keyword(s):  
Climate Change ◽  
High Temperature ◽  
Current System ◽  
Control Policy ◽  
Sea Lice ◽  
Future Climate Change ◽  
Parasite Control ◽  
Management Scenarios ◽  
Farmed Fish ◽  
Wild Salmon

Abstract The ectoparasitic copepods, sea lice (Lepeophtheirus salmonis and Caligus spp.), are major pests to salmon aquaculture and can also affect the health and survival of wild salmon. Policies exist to protect wild salmon by delousing farmed fish when louse abundance exceeds a threshold, but their effectiveness under future climate change is uncertain. We fitted a Bayesian model for sea-louse population dynamics and management to timeseries data of sea lice on farmed salmon in Pacific Canada and analysed the model under scenarios of warmer climates. We found that in high-temperature years, current parasite control policy becomes ineffective as sea-louse abundance is expected to increase. We simulated two alternative management scenarios and observed that both would decrease average louse counts on farms in high-temperature years relative to the current system but relied on more delousing treatments than are currently performed. We also found evidence that non-salmonids can play a role in louse transmission to farms, as increased farm colonization of Caligus clemensi occurs in April, coincident with wild herring (Clupea pallasii) spawner abundance. Our results highlight the need for careful management of sea lice on salmon farms in warmer years and the importance of policies designed to account for future environmental change.

scholarly journals Assessment of local genetic structure and connectivity of the common eelgrass Zostera marina for seagrass restoration in northern Europe

2021 ◽  
Vol 664 ◽  
pp. 103-116
Author(s):  
L Martínez-García ◽  
B Hansson ◽  
J Hollander
Keyword(s):  
Climate Change ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Genetic Differentiation ◽  
Baltic Sea ◽  
Zostera Marina ◽  
Anthropogenic Impacts ◽  
Ecosystem Functions ◽  
Long Distance ◽  
Seagrass Meadows

Seagrass meadows are one of the most important habitats in coastal regions since they constitute a multifunctional ecosystem providing high productivity and biodiversity. They play a key role in carbon sequestration capacity, mitigation against coastal erosion and as nursery grounds for many marine fish and invertebrates. However, despite these ecosystem functions and services, seagrass meadows are a threatened ecosystem worldwide. In the Baltic Sea, seagrass meadows have declined rapidly, mainly because of eutrophication, anthropogenic activities and climate change. This decline has the potential to erode the genetic variation and genetic structure of the species. In this study, we assessed how genetic variation and genetic differentiation vary among Zostera marina meadows and with a number of environmental characteristics in the county of Scania in southern Sweden. A total of 205 individuals sampled at 12 locations were analysed with 10 polymorphic microsatellite loci. Results showed that in spite of anthropogenic impacts and climate change pressures, locations of Z. marina possessed high genetic variation and weak genetic differentiation, with 3 major genetic clusters. Long-distance dispersal and/or stepping-stone dispersal was found among locations, with higher migration rates within the west coast. Organic matter, salinity and maximum depth appeared to be factors most strongly associated with the genetic structure and morphological variation of Z. marina. These findings contribute significantly in the identification of potential donor sites and the viability of impacted areas to recover from natural recruitment, for the development of effective transplantation measures of Z. marina in the southern Baltic Sea and temperate regions elsewhere.

scholarly journals Ocean warming and acidification have complex interactive effects on the dynamics of a marine fungal disease

2014 ◽  
Vol 281 (1778) ◽  
pp. 20133069 ◽  
Author(s):  
Gareth J. Williams ◽  
Nichole N. Price ◽  
Blake Ushijima ◽  
Greta S. Aeby ◽  
Sean Callahan ◽  
...  
Keyword(s):  
Climate Change ◽  
Coral Reef ◽  
Coral Reefs ◽  
Fungal Disease ◽  
Ocean Warming ◽  
Interactive Effects ◽  
Coralline Algae ◽  
Future Climate Change ◽  
Disease Dynamics ◽  
Crustose Coralline Algae

Diseases threaten the structure and function of marine ecosystems and are contributing to the global decline of coral reefs. We currently lack an understanding of how climate change stressors, such as ocean acidification (OA) and warming, may simultaneously affect coral reef disease dynamics, particularly diseases threatening key reef-building organisms, for example crustose coralline algae (CCA). Here, we use coralline fungal disease (CFD), a previously described CCA disease from the Pacific, to examine these simultaneous effects using both field observations and experimental manipulations. We identify the associated fungus as belonging to the subphylum Ustilaginomycetes and show linear lesion expansion rates on individual hosts can reach 6.5 mm per day. Further, we demonstrate for the first time, to our knowledge, that ocean-warming events could increase the frequency of CFD outbreaks on coral reefs, but that OA-induced lowering of pH may ameliorate outbreaks by slowing lesion expansion rates on individual hosts. Lowered pH may still reduce overall host survivorship, however, by reducing calcification and facilitating fungal bio-erosion. Such complex, interactive effects between simultaneous extrinsic environmental stressors on disease dynamics are important to consider if we are to accurately predict the response of coral reef communities to future climate change.

scholarly journals Ecological connectivity of seagrasses with mangroves increases the carbon storage of tropical seagrass meadows of an island ecosystem

2021 ◽  
Author(s):  
Amrit Kumar Mishra ◽  
Deepak Apte ◽  
Syed Hilal Farooq
Keyword(s):  
Climate Change ◽  
Carbon Storage ◽  
Climate Change Mitigation ◽  
Total Carbon ◽  
Total Biomass ◽  
Thalassia Hemprichii ◽  
Sediment Grain Size ◽  
Seagrass Meadows ◽  
Mitigation And Adaptation ◽  
Change Mitigation

Abstract Ecologically connected ecosystems are considered more resilient to climate change mitigation by storing increased amounts of carbon than individual ecosystems. This study quantified the carbon storage capacity of seagrass (Thalassia hemprichii) meadows that are adjacent to mangroves (MG; Rhizophora apiculate) and without mangroves (WMG) at three locations in tropical Andaman and Nicobar Islands (ANI) of India. The sediment organic matter (OM) carbon (Corg) content was 2-fold higher at the MG sites than WMG sites of all three locations within the top 10 cm. The Corg in the total biomass was higher at MG sites than the biomass at WMG sites. The sediment grain size positively influenced the sediment OM and Corg content. The canopy height of T. hemprichii showed a better relationship with sediment OM and Corg at MG sites. In contrast, the shoot density of T. hemprichii showed a better relationship with sediment OM and Corg at WMG sites. The total carbon in 144 ha of T. hemprichii meadows of all three MG sites was 11031± 5223 Mg C, whereas the carbon in 148 ha of WMG sites was 4921±3725 Mg C. These T. hemprichii meadows of ANI store around 40487±19171 ton of CO2 in the MG sites and 18036 ±13672 ton of CO2 at WMG sites. The social cost of these carbon stored in these T. hemprichii meadows is around US$ 34.82 and 1.5 million at the MG and WMG sites, respectively. This study points out the efficiency of seagrass ecosystems of ANI as carbon sinks and the potential of these connected seascapes in increasing the efficiency of seagrass carbon storage. Therefore, this connectivity approach should be further explored to include these connected ecosystems of India as a nature-based solution for climate change mitigation and adaptation plans.

scholarly journals Seasonal and annual calcification rates of the Hawaiian reef coral, Montipora capitata, under present and future climate change scenarios

2016 ◽  
Vol 74 (4) ◽  
pp. 1083-1091 ◽  
Author(s):  
Keisha D. Bahr ◽  
Paul L. Jokiel ◽  
Ku‘ulei S. Rodgers
Keyword(s):  
High Temperature ◽  
Elevated Temperatures ◽  
Polynomial Regression ◽  
High Irradiance ◽  
Ocean Warming ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Montipora Capitata ◽  
The Impact

The response of corals to future conditions of global warming and ocean acidification (OA) is a topic of considerable interest. However, little information is available on the seasonal interaction between temperature, pCO2, and irradiance under ecologically relevant experimental conditions. Controlled experiments were performed in continuous-flow mesocosms under full solar radiation to describe the direct and interactive effects of temperature, irradiance, and pCO2 on growth of a Hawaiian reef building coral (Montipora capitata) over an annual cycle. Corals were subjected to 12 experimental treatments consisting of two pCO2 levels (present-day levels, 2× present), two temperature regimes (ambient, heated +2°C), and three conditions of irradiance (ambient, 50 and 90% reduction). A multiple polynomial regression model with full factorial fixed factors (temperature, pCO2, irradiance) was developed. Temperature and irradiance were the primary factors driving net calcification (Gnet) rates of M. capitata, with pCO2 playing a lesser role. Gnet showed a curvilinear response to irradiance and temperature, which defines thresholds at the end members. Also, high irradiance regimes under elevated temperatures showed a negative synergistic effect on Gnet. Therefore, decreasing irradiance penetration resulting from greater depth and/or higher turbidity will lower the impact of ocean warming on M. capitata. Results suggest that under future climate conditions, the interaction of environmental parameters may shift seasonal patterns in Gnet and timing of growth optima for M. capitata. Ocean warming in shallow water environments with high irradiance poses a more immediate threat to coral growth than acidification for this dominant coral species. In the future, increased temperature and the interaction between high irradiance and high temperature will be the main factors controlling Gnet with OA playing a less important role. This observation is congruent with other reports that high temperature combined with high irradiance is the main cause of high coral mortality during mass bleaching events.

What we can learn from the parallels between the COVID-19 and the future climate change crises

2020 ◽  
Author(s):  
Rubén D. Manzanedo ◽  
Peter Manning
Keyword(s):  
Climate Change ◽  
Global Economy ◽  
Global Climate ◽  
Future Climate Change ◽  
Substantial Portion ◽  
Preventative Measures ◽  
The Future ◽  
Behavioral Norm ◽  
Climate Crisis ◽  
Global Population

The ongoing COVID-19 outbreak pandemic is now a global crisis. It has caused 1.6+ million confirmed cases and 100 000+ deaths at the time of writing and triggered unprecedented preventative measures that have put a substantial portion of the global population under confinement, imposed isolation, and established ‘social distancing’ as a new global behavioral norm. The COVID-19 crisis has affected all aspects of everyday life and work, while also threatening the health of the global economy. This crisis offers also an unprecedented view of what the global climate crisis may look like. In fact, some of the parallels between the COVID-19 crisis and what we expect from the looming global climate emergency are remarkable. Reflecting upon the most challenging aspects of today’s crisis and how they compare with those expected from the climate change emergency may help us better prepare for the future.

Responses of Irish Vegetation to Future Climate Change

2006 ◽  
Vol 106 (3) ◽  
pp. 323-334 ◽  
Author(s):  
Michael B. Jones ◽  
Alison Donnelly ◽  
Fabrizio Albanito
Keyword(s):  
Climate Change ◽  
Future Climate ◽  
Future Climate Change
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