scholarly journals Seagrass, bioindicator, light, water quality, Zostera marina, Zostera noltii, Halodule wrightii, monitoring, Chlorophyll fluorescence, stable isotope, nutrients.

2020 ◽  
Author(s):  
◽  
Chiara M. Bertelli
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Marine Environment ◽  
Environmental Conditions ◽  
Zostera Marina ◽  
Environmental Drivers ◽  
Zostera Noltii ◽  
Halodule Wrightii ◽  
Storm Events ◽  
Seagrass Meadows

This thesis aims to investigate the effect of environmental drivers on seagrasses by studying shoot-scale and meadow-scale responses, focussing on Zostera marina, Zostera noltii and Halodule wrightii. Seagrasses are plants that have evolved from being terrestrial to living in an entirely marine environment which means they have become highly adapted. The conditions that effect seagrass growth can also be described as drivers as they have the ability to modify seagrass meadows in a variety of ways. These drivers can either be natural environmental factors or anthropogenic processes directly or indirectly affecting the marine environment in which seagrasses are found. These responses environmental conditions allow seagrasses to be used as indicators of the health of our coastal waters with poor water quality causing substantial impacts on seagrasses. Better knowledge of seagrass responses to local environmental conditions will help the identification of stressors which can then be managed. It will also help to comprehend the degree of risk to be expected from the threat of climate change including increased storm events, rises in sea level and sea temperature, and ocean acidification. Mitigating existing or potential impacts that lead to a reduction in water quality will improve the overall health and resilience of the seagrass to future threats from climate change.

scholarly journals Contrasting effects of climate change on seasonal survival of a hibernating mammal

2020 ◽  
Vol 117 (30) ◽  
pp. 18119-18126 ◽  
Author(s):  
Line S. Cordes ◽  
Daniel T. Blumstein ◽  
Kenneth B. Armitage ◽  
Paul J. CaraDonna ◽  
Dylan Z. Childs ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Dynamics ◽  
Life History ◽  
Environmental Conditions ◽  
Temporal Trends ◽  
Life History Strategies ◽  
Environmental Drivers ◽  
Age Classes ◽  
History Of ◽  
Colorado Rocky Mountains

Seasonal environmental conditions shape the behavior and life history of virtually all organisms. Climate change is modifying these seasonal environmental conditions, which threatens to disrupt population dynamics. It is conceivable that climatic changes may be beneficial in one season but result in detrimental conditions in another because life-history strategies vary between these time periods. We analyzed the temporal trends in seasonal survival of yellow-bellied marmots (Marmota flaviventer) and explored the environmental drivers using a 40-y dataset from the Colorado Rocky Mountains (USA). Trends in survival revealed divergent seasonal patterns, which were similar across age-classes. Marmot survival declined during winter but generally increased during summer. Interestingly, different environmental factors appeared to drive survival trends across age-classes. Winter survival was largely driven by conditions during the preceding summer and the effect of continued climate change was likely to be mainly negative, whereas the likely outcome of continued climate change on summer survival was generally positive. This study illustrates that seasonal demographic responses need disentangling to accurately forecast the impacts of climate change on animal population dynamics.

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 Establishing Climate Change Resilience in the Great Lakes in Response to Flooding

2020 ◽  
Vol 17 (01) ◽  
Author(s):  
Gwendolyn E Gallagher ◽  
Ryan K Duncombe ◽  
Timothy M Steeves
Keyword(s):  
Climate Change ◽  
United States ◽  
Water Quality ◽  
Great Lakes ◽  
Environmental Protection Agency ◽  
High Water ◽  
The United States ◽  
Water Levels ◽  
Storm Events ◽  
Freshwater Resource

Over the past decade, both the average rainfall and the frequency of high precipitation storm events in the Great Lakes Basin have been steadily increasing as a consequence of climate change. In this same period, cities and communities along the coasts are experiencing record high water levels and severe flooding events (ECC Canada et al. 2018). When cities are unprepared for these floods, the safety of communities and the water quality of the Great Lakes are jeopardized. For example, coastal flooding increases runoff pollution and contaminates the freshwater resource that 40 million people rely on for drinking water (Lyandres and Welch 2012, Roth 2016). Since the Great Lakes are shared between two nations, the United States and Canada, the region is protected by several international treaties and national compacts, including the Great Lakes Water Quality Agreement (GLWQA) and the Great Lakes Restoration Initiative (GLRI). In order to increase climate change resiliency against flooding in the region, we recommend the United States Environmental Protection Agency (EPA) work with Environment and Climate Change Canada to relocate the GLRI under the GLWQA in order to guarantee consistent funding and protection efforts. We additionally recommend expansion of both agreements in their scope and long-term commitments to engender cooperative efforts to protect the Great Lakes against climate change.

scholarly journals How Does Ocean Acidification Affect the Early Life History of Zostera marina? A Series of Experiments Find Parental Carryover Can Benefit Viability or Germination

2021 ◽  
Vol 8 ◽  
Author(s):  
Alyson Lowell ◽  
Eduardo Infantes ◽  
Laura West ◽  
Lauren Puishys ◽  
Claudia E. L. Hill ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Zostera Marina ◽  
Seed Quality ◽  
Global Climate ◽  
Seed Viability ◽  
Early Life History ◽  
Western Coast ◽  
Seagrass Meadows ◽  
Germination Success ◽  
Development Outcomes

Elevated partial pressure of carbon dioxide (pCO2) as a concomitant of global climate change may facilitate the establishment of future seagrass meadows and subsequently its benefit could be incorporated into techniques to increase restoration success. In five manipulative experiments, we determined how increased CO2 affects the maturation of flowers, and the development of seeds and seedlings for the foundation species Zostera marina. Experiments tested the development from both seeds collected from non-treated flowering shoots (direct) and seeds harvested from flowering shoots after CO2 exposure (parental carryover). Flowering shoots were collected along the western coast of Sweden near the island of Skafto. The seeds produced were used in experiments conducted at Kristineberg, Sweden and Dauphin Island, AL, United States. Experiments varied in temperature (16, 18°C) and salinity (19, 33 ppt), as well as duration and magnitude of elevated CO2 exposure. Environmental conditions among experiments, such as temperature (16, 18°C) and salinity (19, 33 ppt), as well as duration and magnitude of pCO2 exposure differed. Flowering maturation, spathe number, seed production, and indicators of seed quality did not appear to be affected by 39–69 days of exposure to CO2 conditions outside of natural variability (pCO2 = 1547.2 ± 267.60 μatm; pHT = 7.53 ± 0.07). Yet, seeds produced from these flowers showed twofold greater germination success. In another experiment, flowering shoots were exposed to an extreme CO2 condition (pCO2 = 5950.7 ± 1,849.82 μatm; pHT = 6.96 ± 0.15). In this case, flowers generated seeds that demonstrated a fivefold increase in an indicator for seed viability (sinking velocity). In the latter experiment, however, germination appeared unaffected. Direct CO2 effects on germination and seedling production were not observed. Our results provide evidence of a parental CO2 effect that can benefit germination or seed viability, but early benefits may not lead to bed establishment if other environmental conditions are not well suited for seedling development. Outcomes have implications for restoration; CO2 can be supplied to flowering shoot holding tanks to bolster success when the purpose is to redistribute seeds to locations where beds are extant and water quality is adequate.

Growth and reproductive responses of the seagrass Zostera marina to sediment nutrient enrichment

2021 ◽  
Author(s):  
Le-Zheng Qin ◽  
Zhaxi Suonan ◽  
Seung Hyeon Kim ◽  
Kun-Seop Lee
Keyword(s):  
Climate Change ◽  
Sexual Reproduction ◽  
Nutrient Enrichment ◽  
Zostera Marina ◽  
Vegetative Growth ◽  
Anthropogenic Activity ◽  
P Availability ◽  
Shoot Height ◽  
Seagrass Meadows ◽  
N Enrichment

Abstract Nutrient loading into coastal sediments is increasing due to anthropogenic activity and climate change. We examined the effects of sediment nutrient enrichment on the growth and reproduction of Zostera marina by adding nitrogen (N) and phosphorus (P) fertilizers into sediments. Areal productivity and shoot density increased by ca. 60% in N and N + P enrichment plots and by ca. 20% in the P enrichment plots. Biomass and shoot height were also higher in the N and N + P enrichment plots than in the P enrichment and control plots. These results suggest that sediment N availability was more important than P availability in stimulating the vegetative growth of Z. marina . The density and morphology of reproductive shoots and seed production increased in only the N enrichment plots. The sediment N enrichment stimulated both the vegetative growth and sexual reproduction, improving the meadow resilience through both sexual and asexual mechanisms. The P enrichment slightly increased only the vegetative growth and might have limited influence on seagrass reproduction. According to these results, the alteration of the sediment nutrient regimes might shift the balance between the vegetative growth and sexual reproduction of Z. marina. These findings may have important implications for the management of seagrass meadows under fluctuations in sediment nutrients caused by anthropogenic activity and climate change.

scholarly journals Adaptations by Zostera marina Dominated Seagrass Meadows in Response to Water Quality and Climate Forcing

Diversity ◽  
2018 ◽  
Vol 10 (4) ◽  
pp. 125 ◽  
Author(s):  
Erin Shields ◽  
Kenneth Moore ◽  
David Parrish
Keyword(s):  
Water Quality ◽  
Chesapeake Bay ◽  
Zostera Marina ◽  
Human Disturbance ◽  
Climatic Factors ◽  
Water Clarity ◽  
Growth Patterns ◽  
Climate Forcing ◽  
Seagrass Meadows ◽  
Response To Water

Global assessments of seagrass declines have documented accelerating rates of loss due to anthropogenic sediment and nutrient loadings, resulting in poor water quality. More recently, global temperature increases have emerged as additional major stressors. Seagrass changes in the Chesapeake Bay, USA provide important examples of not only the effects of human disturbance and climate forcing on seagrass loss, but also meadow recovery and resiliency. In the York River sub-tributary of the Chesapeake Bay, the meadows have been monitored intensively using annual aerial imagery, monthly transect surveys, and continuous water quality measurements. Here, Zostera marina has been demonstrating a shift in its historical growth patterns, with its biomass peaking earlier in the growing season and summer declines beginning earlier. We found an increasing trend in the length of the most stressful high temperature summer period, increasing by 22 days since 1950. Over the past 20 years, Z. marina’s abundance has exhibited periods of decline followed by recovery, with recovery years associated with greater spring water clarity and less time spent at water temperatures > 28 °C. Although human disturbance and climatic factors have been altering these seagrass meadows, resilience has been evident by an increase in reproductive output and regrowth from Z. marina seedlings following declines, as well as expansions of Ruppia maritima into areas previously dominated by Z. marina.

scholarly journals Climate-driven changes in functional biogeography of Arctic marine fish communities

2017 ◽  
Vol 114 (46) ◽  
pp. 12202-12207 ◽  
Author(s):  
André Frainer ◽  
Raul Primicerio ◽  
Susanne Kortsch ◽  
Magnus Aune ◽  
Andrey V. Dolgov ◽  
...  
Keyword(s):  
Climate Change ◽  
Functional Traits ◽  
Marine Environment ◽  
Ecosystem Functioning ◽  
Barents Sea ◽  
Spatial Scales ◽  
Fish Communities ◽  
The Arctic ◽  
Environmental Drivers ◽  
The Impact

Climate change triggers poleward shifts in species distribution leading to changes in biogeography. In the marine environment, fish respond quickly to warming, causing community-wide reorganizations, which result in profound changes in ecosystem functioning. Functional biogeography provides a framework to address how ecosystem functioning may be affected by climate change over large spatial scales. However, there are few studies on functional biogeography in the marine environment, and none in the Arctic, where climate-driven changes are most rapid and extensive. We investigated the impact of climate warming on the functional biogeography of the Barents Sea, which is characterized by a sharp zoogeographic divide separating boreal from Arctic species. Our unique dataset covered 52 fish species, 15 functional traits, and 3,660 stations sampled during the recent warming period. We found that the functional traits characterizing Arctic fish communities, mainly composed of small-sized bottom-dwelling benthivores, are being rapidly replaced by traits of incoming boreal species, particularly the larger, longer lived, and more piscivorous species. The changes in functional traits detected in the Arctic can be predicted based on the characteristics of species expected to undergo quick poleward shifts in response to warming. These are the large, generalist, motile species, such as cod and haddock. We show how functional biogeography can provide important insights into the relationship between species composition, diversity, ecosystem functioning, and environmental drivers. This represents invaluable knowledge in a period when communities and ecosystems experience rapid climate-driven changes across biogeographical regions.

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.

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