scholarly journals Ocean acidification impacts spine integrity but not regenerative capacity of spines and tube feet in adult sea urchins

2017 ◽  
Vol 4 (5) ◽  
pp. 170140 ◽  
Author(s):  
Chloe E. Emerson ◽  
Helena C. Reinardy ◽  
Nicholas R. Bates ◽  
Andrea G. Bodnar
Keyword(s):  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Structural Integrity ◽  
Sea Urchins ◽  
Lytechinus Variegatus ◽  
Negative Consequences ◽  
Compensatory Mechanisms ◽  
Seawater Chemistry ◽  
Righting Response ◽  
Tube Feet

Increasing atmospheric carbon dioxide (CO 2 ) has resulted in a change in seawater chemistry and lowering of pH, referred to as ocean acidification. Understanding how different organisms and processes respond to ocean acidification is vital to predict how marine ecosystems will be altered under future scenarios of continued environmental change. Regenerative processes involving biomineralization in marine calcifiers such as sea urchins are predicted to be especially vulnerable. In this study, the effect of ocean acidification on regeneration of external appendages (spines and tube feet) was investigated in the sea urchin Lytechinus variegatus exposed to ambient (546 µatm), intermediate (1027 µatm) and high (1841 µatm) partial pressure of CO 2 ( p CO 2 ) for eight weeks. The rate of regeneration was maintained in spines and tube feet throughout two periods of amputation and regrowth under conditions of elevated p CO 2 . Increased expression of several biomineralization-related genes indicated molecular compensatory mechanisms; however, the structural integrity of both regenerating and homeostatic spines was compromised in high p CO 2 conditions. Indicators of physiological fitness (righting response, growth rate, coelomocyte concentration and composition) were not affected by increasing p CO 2 , but compromised spine integrity is likely to have negative consequences for defence capabilities and therefore survival of these ecologically and economically important organisms.

scholarly journals The influence of food supply on the response of Olympia oyster larvae to ocean acidification

2013 ◽  
Vol 10 (3) ◽  
pp. 5781-5802 ◽  
Author(s):  
A. Hettinger ◽  
E. Sanford ◽  
T. M. Hill ◽  
J. D. Hosfelt ◽  
A. D. Russell ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ocean Acidification ◽  
Food Availability ◽  
Food Supply ◽  
Atmospheric Carbon Dioxide ◽  
Shell Growth ◽  
Dry Weight ◽  
Food Level ◽  
Negative Consequences ◽  
Olympia Oyster

Abstract. Increases in atmospheric carbon dioxide drive accompanying changes in the marine carbonate system as carbon dioxide (CO2) enters seawater and alters its pH (termed "ocean acidification"). However, such changes do not occur in isolation, and other environmental factors have the potential to modulate the consequences of altered ocean chemistry. Given that physiological mechanisms used by organisms to confront acidification can be energetically costly, we explored the potential for food supply to influence the response of Olympia oyster (Ostrea lurida) larvae to ocean acidification. In laboratory experiments, we reared oyster larvae under a factorial combination of pCO2 and food level. High food availability offset the negative consequences of elevated pCO2 on larval shell growth and total dry weight. Low food availability, in contrast, exacerbated these impacts. In both cases, effects of food and pCO2 interacted additively rather than synergistically, indicating that they operated independently. Despite the potential for abundant resources to counteract the consequences of ocean acidification, impacts were never completely negated, suggesting that even under conditions of enhanced primary production and elevated food availability, impacts of ocean acidification may still accrue in some consumers.

Ocean acidification affects parameters of immune response and extracellular pH in tropical sea urchins Lytechinus variegatus and Echinometra luccunter

2016 ◽  
Vol 180 ◽  
pp. 84-94 ◽  
Author(s):  
Débora Alvares Leite Figueiredo ◽  
Paola Cristina Branco ◽  
Douglas Amaral dos Santos ◽  
Andrews Krupinski Emerenciano ◽  
Renata Stecca Iunes ◽  
...  
Keyword(s):  
Immune Response ◽  
Ocean Acidification ◽  
Sea Urchins ◽  
Extracellular Ph ◽  
Lytechinus Variegatus ◽  
Tropical Sea

scholarly journals The Covering Reaction of Sea-Urchins

1956 ◽  
Vol 33 (3) ◽  
pp. 508-523
Author(s):  
NORMAN MILLOTT
Keyword(s):  
Light Intensity ◽  
Light Source ◽  
Sea Urchins ◽  
Bright Light ◽  
Lytechinus Variegatus ◽  
Strong Light ◽  
Dim Light ◽  
Tube Feet

1. Lytechinus variegatus (Lamarck) covers the parts of its skin that are exposed to light with fragments taken from its surroundings. 2. The covering is taken up by the tube feet, assisted by the spines, and held in place by the tube feet acting in relays. It may be orientated with respect to the light source. There are indications of adaptability of behaviour where the covering pieces offer resistance to being lifted. 3. Covering is related to light and to diurnal light changes, being assumed in strong light and rejected, after a varying interval of time, in darkness. Both continuous bright light and decreases in light intensity evoke covering. The tube feet react to the same stimuli and the speed of their extension is roughly proportional to the change of intensity. 4. The tendency to cover is increased after a sojourn in darkness and is greater in pale individuals than in dark ones. 5. Urchins can be photosensitized by injection of dyes so that they cover in dim light. 6. The prehension and holding of covering does not involve the oral and aboral nerve rings. 7. The relation of covering to light and environment favours the idea that it acts as a screen against strong light.

scholarly journals Ecological effects of ocean acidification and habitat complexity on reef-associated macroinvertebrate communities

2014 ◽  
Vol 281 (1775) ◽  
pp. 20132479 ◽  
Author(s):  
K. E. Fabricius ◽  
G. De'ath ◽  
S. Noonan ◽  
S. Uthicke
Keyword(s):  
Ocean Acidification ◽  
Habitat Complexity ◽  
Atmospheric Carbon Dioxide ◽  
Coral Cover ◽  
Ecological Effects ◽  
Macroinvertebrate Communities ◽  
Dead Coral ◽  
Marine Communities

The ecological effects of ocean acidification (OA) from rising atmospheric carbon dioxide (CO 2 ) on benthic marine communities are largely unknown. We investigated in situ the consequences of long-term exposure to high CO 2 on coral-reef-associated macroinvertebrate communities around three shallow volcanic CO 2 seeps in Papua New Guinea. The densities of many groups and the number of taxa (classes and phyla) of macroinvertebrates were significantly reduced at elevated CO 2 (425–1100 µatm) compared with control sites. However, sensitivities of some groups, including decapod crustaceans, ascidians and several echinoderms, contrasted with predictions of their physiological CO 2 tolerances derived from laboratory experiments. High CO 2 reduced the availability of structurally complex corals that are essential refugia for many reef-associated macroinvertebrates. This loss of habitat complexity was also associated with losses in many macroinvertebrate groups, especially predation-prone mobile taxa, including crustaceans and crinoids. The transition from living to dead coral as substratum and habitat further altered macroinvertebrate communities, with far more taxa losing than gaining in numbers. Our study shows that indirect ecological effects of OA (reduced habitat complexity) will complement its direct physiological effects and together with the loss of coral cover through climate change will severely affect macroinvertebrate communities in coral reefs.

scholarly journals Does ocean acidification induce an upward flux of marine aggregates?

2008 ◽  
Vol 5 (4) ◽  
pp. 1023-1031 ◽  
Author(s):  
X. Mari
Keyword(s):  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
New Caledonia ◽  
Seawater Acidification ◽  
Seawater Ph ◽  
Biogenic Carbon ◽  
Marine Aggregates ◽  
Atmospheric Carbon ◽  
Carbon Dioxide Co2 ◽  
Sedimentation Processes

Abstract. The absorption of anthropogenic atmospheric carbon dioxide (CO2) by the ocean provokes its acidification. This acidification may alter several oceanic processes, including the export of biogenic carbon from the upper layer of the ocean, hence providing a feedback on rising atmospheric carbon concentrations. The effect of seawater acidification on transparent exopolymeric particles (TEP) driven aggregation and sedimentation processes were investigated by studying the interactions between latex beads and TEP precursors collected in the lagoon of New Caledonia. A suspension of TEP and beads was prepared and the formation of mixed aggregates was monitored as a function of pH under increasing turbulence intensities. The pH was controlled by addition of sulfuric acid. Aggregation and sedimentation processes driven by TEP were drastically reduced when the pH of seawater decreases within the expected limits imposed by increased anthropogenic CO2 emissions. In addition to the diminution of TEP sticking properties, the diminution of seawater pH led to a significant increase of the TEP pool, most likely due to swollen structures. A diminution of seawater pH by 0.2 units or more led to a stop or a reversal of the downward flux of particles. If applicable to oceanic conditions, the sedimentation of marine aggregates may slow down or even stop as the pH decreases, and the vertical flux of organic carbon may reverse. This would enhance both rising atmospheric carbon and ocean acidification.

scholarly journals Effect of elevated CO<sub>2</sub> on the dynamics of particle attached and free living bacterioplankton communities in an Arctic fjord

2012 ◽  
Vol 9 (8) ◽  
pp. 10725-10755 ◽  
Author(s):  
M. Sperling ◽  
J. Piontek ◽  
G. Gerdts ◽  
A. Wichels ◽  
H. Schunck ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Intergenic Spacer ◽  
Extracellular Enzyme ◽  
The Arctic ◽  
Organic Substrates ◽  
Viral Lysis ◽  
Free Living ◽  
High Co2 ◽  
Carbon Dioxide Co2

Abstract. The increase in atmospheric carbon dioxide (CO2) results in acidification of the oceans, expected to lead to the fastest drop in ocean pH in the last 300 million years, if anthropogenic emissions are continued at present rate. Due to higher solubility of gases in cold waters and increased exposure to the atmosphere by decreasing ice cover, the Arctic Ocean will be among the areas most strongly affected by ocean acidification. Yet, the response of the plankton community of high latitudes to ocean acidification has not been studied so far. This work is part of the Arctic campaign of the European Project on Ocean Acidification (EPOCA) in 2010, employing 9 in situ mesocosms of about 45 000 l each to simulate ocean acidification in Kongsfjorden, Svalbard (78°56.2' N 11°53.6' E). In the present study, we investigated effects of elevated CO2 on the composition and richness of particle attached (PA; >3 μm) and free living (FL; <3 μm >0.2 μm) bacterial communities by Automated Ribosomal Intergenic Spacer Analysis (ARISA) in 6 of the mesocosms and the surrounding fjord, ranging from 185 to 1050 initial μatm pCO2. ARISA was able to resolve about 20–30 bacterial band-classes per sample and allowed for a detailed investigation of the explicit richness. Both, the PA and the FL bacterioplankton community exhibited a strong temporal development, which was driven mainly by temperature and phytoplankton development. In response to the breakdown of a picophytoplankton bloom (phase 3 of the experiment), number of ARISA-band classes in the PA-community were reduced at low and medium CO2 (∼180–600 μatm) by about 25%, while it was more or less stable at high CO2 (∼ 650–800 μatm). We hypothesise that enhanced viral lysis and enhanced availability of organic substrates at high CO2 resulted in a more diverse PA-bacterial community in the post-bloom phase. Despite lower cell numbers and extracellular enzyme activities in the post-bloom phase, bacterial protein production was enhanced in high CO2-treatments, suggesting a positive effect of community richness on this function and on carbon cycling by bacteria.

Stochastic analysis of time-series related to ocean acidification

2021 ◽  
Author(s):  
Georgios Vagenas ◽  
Theano Iliopoulou ◽  
Panayiotis Dimitriadis ◽  
Demetris Koutsoyiannis
Keyword(s):  
Carbon Dioxide ◽  
Time Series ◽  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Anthropogenic Activities ◽  
Time Lag ◽  
Carbon Dioxide Concentration ◽  
Carbon Dioxide Partial Pressure ◽  
Chemical Transformations ◽  
Mauna Loa

&lt;p&gt;Since the pre-industrial era at the end of the 18&lt;sup&gt;th&lt;/sup&gt; century, the atmospheric carbon dioxide concentration (CO&lt;sub&gt;2&lt;/sub&gt;) has increased by 47.46% from the level of 280 ppmv (parts per million volume) to 412.89 ppmv (Mauna Loa &amp;#8211; NOAA Station, November 2020). These increased concentrations caused by natural &amp; anthropogenic activities, interact with the aquatic environment which acts as a safety valve. Nevertheless, the absorbed CO&lt;sub&gt;2 &lt;/sub&gt;amounts undergo chemical transformations, resulting in increasing ionized concentrations that can significantly reduce the water&amp;#8217;s pH, a process described as ocean acidification. Here, we use the HOT (Hawaii-Ocean-Time series) to perform time series analysis for temperature, carbon dioxide partial pressure and pH. More specifically, we analyze their temporal changes in month and annual time lag. Then, we proceed in comparisons with relevant studies on atmospheric data to evaluate the produced results. Finally, we make an effort to disentangle the results with simplified assumptions connected with the observed impact of ocean acidification on the aquatic ecosystems.&lt;/p&gt;

Certain Aspects of State Service Reform

2020 ◽  
Vol 27 (1) ◽  
pp. 14-25
Author(s):  
Serhii Gusarov
Keyword(s):  
Trade Unions ◽  
System Analysis ◽  
Civil Service ◽  
Civil Servants ◽  
Negative Consequences ◽  
Compensatory Mechanisms ◽  
National Legislation ◽  
Law System ◽  
Labor Legislation ◽  
The Government

The study of the issues of civil service reform in Ukraine in the current conditions of development of Ukrainian society and the state is an extremely relevant subject and requires appropriate research. The author aims to analyse the most resonant reform measures in the civil service, which were recently initiated by the government and received mixed reviews, in particular, the announced redundancy in the staff of civil servants and the introduction of a contract form of civil service, as well as to offer scientifically sound proposals for improvement of appropriate measures. In the work with the use of general scientific and special methods of scientific knowledge (dialectical, Aristotelian, comparative law, system analysis) the legal bases and scientific sources on redundancy of staff and contractual form of employment are considered; the provisions of the national labor legislation were compared with the provisions of the national legislation on the civil service, which provide for the rules of staffing cuts among civil servants, including guarantees of their rights upon dismissal on appropriate grounds; the provisions of the national legislation concerning the rules of application of contracts upon appointing civil servants are investigated. The conclusion is made: 1) on the need for appropriate revision of the Law of Ukraine "On Civil Service"; 2) on the expediency of creating new productive jobs in various sectors of the national economy, where redundant civil servants will be sent after retraining; 3) that any reforms of society and public administration must be carried out subsequent to an in-depth study of public opinion, analysis of possible negative consequences, development and implementation of compensatory mechanisms. It is emphasized that it is mandatory to involve scientists, experts-practitioners, employers, and representatives of public, in particular trade unions, in the process of developing reforms in civil service.

Ocean acidification weakens the structural integrity of coralline algae

2012 ◽  
Vol 18 (9) ◽  
pp. 2804-2812 ◽  
Author(s):  
Federica Ragazzola ◽  
Laura C. Foster ◽  
Armin Form ◽  
Philip S.L. Anderson ◽  
Thor H. Hansteen ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Structural Integrity ◽  
Coralline Algae
Sign in / Sign up

Export Citation Format

Share Document