scholarly journals Major impacts of climate change on deep-sea benthic ecosystems

Elem Sci Anth ◽  
2017 ◽  
Vol 5 ◽  
Author(s):  
Andrew K. Sweetman ◽  
Andrew R. Thurber ◽  
Craig R. Smith ◽  
Lisa A. Levin ◽  
Camilo Mora ◽  
...  
Keyword(s):  
Water Column ◽  
Deep Sea ◽  
Oil And Gas ◽  
Environmental Parameters ◽  
Societal Implications ◽  
Environmental Properties ◽  
Water Formation ◽  
Ne Pacific ◽  
Benthic Ecosystems ◽  
Impacts Of Climate Change

The deep sea encompasses the largest ecosystems on Earth. Although poorly known, deep seafloor ecosystems provide services that are vitally important to the entire ocean and biosphere. Rising atmospheric greenhouse gases are bringing about significant changes in the environmental properties of the ocean realm in terms of water column oxygenation, temperature, pH and food supply, with concomitant impacts on deep-sea ecosystems. Projections suggest that abyssal (3000–6000 m) ocean temperatures could increase by 1°C over the next 84 years, while abyssal seafloor habitats under areas of deep-water formation may experience reductions in water column oxygen concentrations by as much as 0.03 mL L–1 by 2100. Bathyal depths (200–3000 m) worldwide will undergo the most significant reductions in pH in all oceans by the year 2100 (0.29 to 0.37 pH units). O2 concentrations will also decline in the bathyal NE Pacific and Southern Oceans, with losses up to 3.7% or more, especially at intermediate depths. Another important environmental parameter, the flux of particulate organic matter to the seafloor, is likely to decline significantly in most oceans, most notably in the abyssal and bathyal Indian Ocean where it is predicted to decrease by 40–55% by the end of the century. Unfortunately, how these major changes will affect deep-seafloor ecosystems is, in some cases, very poorly understood. In this paper, we provide a detailed overview of the impacts of these changing environmental parameters on deep-seafloor ecosystems that will most likely be seen by 2100 in continental margin, abyssal and polar settings. We also consider how these changes may combine with other anthropogenic stressors (e.g., fishing, mineral mining, oil and gas extraction) to further impact deep-seafloor ecosystems and discuss the possible societal implications.

scholarly journals Environmental properties of the southern Gulf of Aqaba, Red Sea, Egypt

2012 ◽  
Vol 13 (2) ◽  
pp. 179 ◽  
Author(s):  
M.M. DORGHAM ◽  
M.M. EL-SHERBINY ◽  
M.H. HANAFI
Keyword(s):  
Dissolved Oxygen ◽  
Water Column ◽  
Chlorophyll A ◽  
Red Sea ◽  
Environmental Parameters ◽  
Gulf Of Aqaba ◽  
High Concentration ◽  
Environmental Properties ◽  
Epipelagic Zone ◽  
Deep Layers

Environmental properties (temperature, dissolved oxygen, nutrients and chlorophyll a) of the epipelagic zone off SharmEl-Sheikh, Red Sea, Egypt were studied seasonally throughout a year from March 1995 to March 1996. Water samples werecollected from five water depths (0, 25, 50, 75 & 100 m). The studied parameters exhibited clear seasonal variability along the water column. The vertical distribution of water temperature showed thermal homogeneity during most seasons, and thermal stratification in summer. Dissolved oxygen attained slightly high concentrations (5.3-7.8 mg l-1) in the whole water column, with slight seasonal variation. The concentrations of nutrients reflected dominant oligotrophic conditions in the epipelagic zone and occasional mesotrophic status at some depths. Phosphate fluctuated between 0-0.7 μM, ammonium (0-2.27 μM), nitrite (0-0.72 μM), nitrate (0-1.49 μM) and silicate (0-6.48 M). Phytoplankton biomass was generally low in the epipelagic zone throughout the study, whereas chlorophyll a was less than 0.5 μg l-1, except relatively high concentration (0.7-1.12 μg l-1) in deep layers in spring. In comparison with previous studies on the Gulf of Aqaba all environmental parameters during present study showed pronouncedlydifferent values.

scholarly journals Relationships between Environmental Factors and Pathogenic Vibrios in the Northern Gulf of Mexico

2010 ◽  
Vol 76 (21) ◽  
pp. 7076-7084 ◽  
Author(s):  
C. N. Johnson ◽  
A. R. Flowers ◽  
N. F. Noriea ◽  
A. M. Zimmerman ◽  
J. C. Bowers ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Water Column ◽  
Vibrio Vulnificus ◽  
Environmental Parameters ◽  
Sampling Period ◽  
Pathogenicity Factor ◽  
Hemolysin Gene ◽  
Thermostable Direct Hemolysin ◽  
Pathogenic Vibrios ◽  
Abundance And Distribution

ABSTRACT Although autochthonous vibrio densities are known to be influenced by water temperature and salinity, little is understood about other environmental factors associated with their abundance and distribution. Densities of culturable Vibrio vulnificus containing vvh (V. vulnificus hemolysin gene) and V. parahaemolyticus containing tlh (thermolabile hemolysin gene, ubiquitous in V. parahaemolyticus), tdh (thermostable direct hemolysin gene, V. parahaemolyticus pathogenicity factor), and trh (tdh-related hemolysin gene, V. parahaemolyticus pathogenicity factor) were measured in coastal waters of Mississippi and Alabama. Over a 19-month sampling period, vibrio densities in water, oysters, and sediment varied significantly with sea surface temperature (SST). On average, tdh-to-tlh ratios were significantly higher than trh-to-tlh ratios in water and oysters but not in sediment. Although tlh densities were lower than vvh densities in water and in oysters, the opposite was true in sediment. Regression analysis indicated that SST had a significant association with vvh and tlh densities in water and oysters, while salinity was significantly related to vibrio densities in the water column. Chlorophyll a levels in the water were correlated significantly with vvh in sediment and oysters and with pathogenic V. parahaemolyticus (tdh and trh) in the water column. Furthermore, turbidity was a significant predictor of V. parahaemolyticus density in all sample types (water, oyster, and sediment), and its role in predicting the risk of V. parahaemolyticus illness may be more important than previously realized. This study identified (i) culturable vibrios in winter sediment samples, (ii) niche-based differences in the abundance of vibrios, and (iii) predictive signatures resulting from correlations between environmental parameters and vibrio densities.

scholarly journals Sustained deposition of contaminants from the Deepwater Horizon spill

2016 ◽  
Vol 113 (24) ◽  
pp. E3332-E3340 ◽  
Author(s):  
Beizhan Yan ◽  
Uta Passow ◽  
Jeffrey P. Chanton ◽  
Eva-Maria Nöthig ◽  
Vernon Asper ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbon ◽  
Water Column ◽  
Deepwater Horizon ◽  
Diatom Bloom ◽  
Drilling Mud ◽  
Deep Sediment ◽  
Pelagic Food Webs ◽  
Polycyclic Aromatic ◽  
Large Diatom ◽  
Benthic Ecosystems

The 2010 Deepwater Horizon oil spill resulted in 1.6–2.6 × 1010 grams of petrocarbon accumulation on the seafloor. Data from a deep sediment trap, deployed 7.4 km SW of the well between August 2010 and October 2011, disclose that the sinking of spill-associated substances, mediated by marine particles, especially phytoplankton, continued at least 5 mo following the capping of the well. In August/September 2010, an exceptionally large diatom bloom sedimentation event coincided with elevated sinking rates of oil-derived hydrocarbons, black carbon, and two key components of drilling mud, barium and olefins. Barium remained in the water column for months and even entered pelagic food webs. Both saturated and polycyclic aromatic hydrocarbon source indicators corroborate a predominant contribution of crude oil to the sinking hydrocarbons. Cosedimentation with diatoms accumulated contaminants that were dispersed in the water column and transported them downward, where they were concentrated into the upper centimeters of the seafloor, potentially leading to sustained impact on benthic ecosystems.

Study on the Characteristics of Well Completion Technology in Deepwater Oil and Gas Field Development

2021 ◽  
Vol 3 (8) ◽  
pp. 70-72
Author(s):  
Jianbo Hu ◽  
◽  
Yifeng Di ◽  
Qisheng Tang ◽  
Ren Wen ◽  
...  
Keyword(s):  
Deep Water ◽  
Deep Sea ◽  
Oil And Gas ◽  
Gas Field ◽  
Marine Research ◽  
Field Development ◽  
Research Technology ◽  
Well Completion ◽  
Development Capacity ◽  
Exploration And Development

In recent years, China has made certain achievements in shallow sea petroleum geological exploration and development, but the exploration of deep water areas is still in the initial stage, and the water depth in the South China Sea is generally 500 to 2000 meters, which is a deep water operation area. Although China has made some progress in the field of deep-water development of petroleum technology research, but compared with the international advanced countries in marine science and technology, there is a large gap, in the international competition is at a disadvantage, marine research technology and equipment is relatively backward, deep-sea resources exploration and development capacity is insufficient, high-end technology to foreign dependence. In order to better develop China's deep-sea oil and gas resources, it is necessary to strengthen the development of drilling and completion technology in the oil industry drilling engineering. This paper briefly describes the research overview, technical difficulties, design principles and main contents of the completion technology in deepwater drilling and completion engineering. It is expected to have some significance for the development of deepwater oil and gas fields in China.

scholarly journals Rhodoliths in Brazil: Current knowledge and potential impacts of climate change

2016 ◽  
Vol 64 (spe2) ◽  
pp. 117-136 ◽  
Author(s):  
Paulo Antunes Horta ◽  
Pablo Riul ◽  
Gilberto M. Amado Filho ◽  
Carlos Frederico D. Gurgel ◽  
Flávio Berchez ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Change ◽  
Ocean Acidification ◽  
Heat Waves ◽  
Current Knowledge ◽  
Coastal Pollution ◽  
Brazil Current ◽  
Run Off ◽  
Benthic Ecosystems ◽  
Impacts Of Climate Change

Abstract Rhodolith beds are important marine benthic ecosystems, representing oases of high biodiversity among sedimentary seabed environments. They are found frequently and abundantly, acting as major carbonate 'factories' and playing a key role in the biogeochemical cycling of carbonates in the South Atlantic. Rhodoliths are under threat due to global change (mainly related to ocean acidification and global warming) and local stressors, such as fishing and coastal run-off. Here, we review different aspects of the biology of these organisms, highlighting the predicted effects of global change, considering the additional impact of local stressors. Ocean acidification (OA) represents a particular threat that can reduce calcification or even promote the decalcification of these bioengineers, thus increasing the eco-physiological imbalance between calcareous and fleshy algae. OA should be considered, but this together with extreme events such as heat waves and storms, as main stressors of these ecosystems at the present time, will worsen in the future, especially if possible interactions with local stressors like coastal pollution are taken into consideration. Thus, in Brazil there is a serious need for starting monitoring programs and promote innovative experimental infrastructure in order to improve our knowledge of these rich environments, optimize management efforts and enhance the needed conservation initiatives.

scholarly journals Updated definitions on piezophily as suggested by hydrostatic pressure dependence on temperature

2020 ◽  
Author(s):  
Alberto Scoma
Keyword(s):  
Hydrostatic Pressure ◽  
Deep Sea ◽  
Ambient Pressure ◽  
Environmental Parameters ◽  
Microbial Life ◽  
Deep Waters ◽  
Microbial Response ◽  
Definition Of ◽  
Substrate Ph ◽  
Cell Functionality

AbstractMicrobial preference for elevated hydrostatic pressure (HP) is a recognized key feature of environmental and industrial processes. HP effects on macromolecules and, consequently, cell functionality has been accurately described in the last decades. While there is little debate about the importance of HP in shaping microbial life, a systematic definition of microbial preference for increased HP is missing. The lack of a consensus about ‘true’ piezophiles, and ‘low’ or ‘high’ HP levels, has deleterious repercussions on microbiology and biotechnology. As certain levels are considered ‘low’ they are not applied to assess microbial activity. Most microorganisms collected in deep waters or sediments have not been tested (nor isolated) using the corresponding HP at which they were captured. Microbial response to HP is notoriously dependent on other environmental parameters, most notably temperature, but also on availability of nutrients, growth substrate, pH and salinity. This implies that countless isolates retrieved from ambient pressure conditions may very well require increased HP to grow optimally, as already demonstrated in both Archaea and Bacteria.In the present study, I collected the data from described piezophilic isolates and used the fundamental correlation existing between HP and temperature, as first suggested in seminal works by Yayanos, to update the definition of piezophiles. Thanks to the numerous new piezophilic isolates available since such seminal studies, the present analysis brings forward updated definitions which concern 1) the actual beginning of the piezosphere, the area in the deep sea where piezophiles thrive; 2) the HP thresholds which should be considered low, medium and high HP, and their implications for experimental design in Microbiology; and 3) the nature of obligate piezophiles and their location in the deep sea.

Simple harpacticoid composition observed at deep hydrothermal vent sites on sea knoll calderas in the North-west Pacific

2022 ◽  
pp. 1-10
Author(s):  
Futa Nakasugi ◽  
Motohiro Shimanaga ◽  
Hidetaka Nomaki ◽  
Hiromi Kayama Watanabe ◽  
Tomo Kitahashi ◽  
...  
Keyword(s):  
Deep Sea ◽  
Hydrothermal Vent ◽  
Hydrothermal Vents ◽  
Environmental Parameters ◽  
Sea Floor ◽  
North West ◽  
Isotopic Signatures ◽  
Carbon Isotopic ◽  
The North ◽  
Spatial Differences

Abstract Dirivultid copepods (Siphonostomatoida), one of the most successful meiobenthic organisms found at deep-sea hydrothermal vents, have been the focus of most previous ecological studies among meiofauna in these habitats. The ecology of Harpacticoida, a major benthic copepod group in typical deep-sea floor, however, is not well understood in terms of variations in community structure and controlling factors at venting sites. The spatial heterogeneities in benthic harpacticoid composition and their association with environmental parameters were investigated at hydrothermal vent chimney structures in the calderas of three neighbouring sea knolls (Bayonnaise Knoll, Myojin Knoll and Myojin-sho Caldera) in the western North Pacific. While a previous study had reported the distribution of dirivultids was strongly associated with spatial differences in stable carbon isotopic signatures (δ13C) of organic matter in the detritus on active chimneys in the field, multivariate analyses detected no significant corelation between the parameter and harpacticoid composition in this study. Instead, high associations of the harpacticoid composition with differences in water depth and total organic carbon (TOC) concentration were detected. Ectinosomatidae dominated at vent sites with lower TOC values in the shallowest Bayonnaise Knoll, while they were less prevalent at deeper vent fields in the other knolls, where Miraciidae was the most abundant family. This study indicated the availability of vent chemoautotrophic carbon is not a primary factor controlling the composition of harpacticoids even in the habitats on the hydrothermal vents, but instead by the food amount, regardless of its resources (including marine snow from the sea surface), in the study area.

scholarly journals Influence of Water Masses on the Biodiversity and Biogeography of Deep-Sea Benthic Ecosystems in the North Atlantic

2020 ◽  
Vol 7 ◽  
Author(s):  
Patricia Puerta ◽  
Clare Johnson ◽  
Marina Carreiro-Silva ◽  
Lea-Anne Henry ◽  
Ellen Kenchington ◽  
...  
Keyword(s):  
North Atlantic ◽  
Deep Sea ◽  
Water Masses ◽  
The North ◽  
Influence Of Water ◽  
The North Atlantic ◽  
Benthic Ecosystems
Sign in / Sign up

Export Citation Format

Share Document