scholarly journals Phlorotannin and Pigment Content of Native Canopy-Forming Sargassaceae Species Living in Intertidal Rockpools in Brittany (France): Any Relationship with Their Vertical Distribution and Phenology?

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 504
Author(s):  
Camille Jégou ◽  
Solène Connan ◽  
Isabelle Bihannic ◽  
Stéphane Cérantola ◽  
Fabienne Guérard ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Species Distribution ◽  
Xanthophyll Cycle ◽  
Intertidal Zone ◽  
Structural Complexity ◽  
Adaptive Process ◽  
Pigment Contents ◽  
Ecological Feature ◽  
High Production ◽  
Over Time

Five native Sargassaceae species from Brittany (France) living in rockpools were surveyed over time to investigate photoprotective strategies according to their tidal position. We gave evidences for the existence of a species distribution between pools along the shore, with the most dense and smallest individuals in the highest pools. Pigment contents were higher in lower pools, suggesting a photo-adaptive process by which the decreasing light irradiance toward the low shore was compensated by a high production of pigments to ensure efficient photosynthesis. Conversely, no xanthophyll cycle-related photoprotective mechanism was highlighted because high levels of zeaxanthin rarely occurred in the upper shore. Phlorotannins were not involved in photoprotection either; only some lower-shore species exhibited a seasonal trend in phlorotannin levels. The structural complexity of phlorotannins appears more to be a taxonomic than an ecological feature: Ericaria produced simple phloroglucinol while Cystoseira and Gongolaria species exhibited polymers. Consequently, tide pools could be considered as light-protected areas on the intertidal zone, in comparison with the exposed emerged substrata where photoprotective mechanisms are essential.

Whale geography

2017 ◽  
Vol 41 (5) ◽  
pp. 676-685 ◽  
Author(s):  
Rianna Burnham
Keyword(s):  
Population Dynamics ◽  
Species Distribution ◽  
Spatial Extent ◽  
Niche Space ◽  
Ambient Environment ◽  
Species Survival ◽  
Over Time ◽  
Species Ecology

Typically, organism-based biogeographic studies consider distribution and abundance over time on various scales. However, to be comprehensive, factors of environment and habitat, energetics, morphology, and population dynamics should also be included. In addition, these studies should consider not only the spatial extent that an individual or species occupies or can roam within, but also the space over which an animal can extract and interpret information, a less well-defined element of niche space which largely shapes its movements or distribution. Understanding the processes that inform patterns of species distribution, both intrinsic and external to the animal, is key to understanding a species’ ecology. Here, we consider the biogeography of whales, given these ideas, with a particular focus on the acoustical components of their biology and landscape. Cetaceans use of sound to communicate, navigate and forage, and so interpret the soundscape, is a central consideration. It has important implications in a changing ambient environment and will increasingly influence species’ survival.

Quantitative analyses of decapod crustaceans at a rocky intertidal shore in the Gulf of Oman, Iran: diversity, zonation and monsoonal fluctuations

2018 ◽  
Vol 99 (2) ◽  
pp. 445-459
Author(s):  
Saeed Ebrahimnezhad ◽  
Reza Naderloo
Keyword(s):  
Vertical Distribution ◽  
Intertidal Zone ◽  
New Records ◽  
Decapod Crustaceans ◽  
Intertidal Zones ◽  
Gulf Of Oman ◽  
South West ◽  
South West Monsoon ◽  
Significant Difference ◽  
High Intertidal Zone

This paper provides data on diversity, zonation and seasonal fluctuations of decapod crustaceans at the northern Gulf of Oman coast, based on quantitative and qualitative samplings. A total of 75 species belonging to four infraorders, 27 families and 48 genera were identified. These species include 20 new records for the entire Gulf of Oman and 13 new records for its Iranian coast. The mid-intertidal zone showed a higher mean diversity and abundance than high- and low-intertidal zones. The mean diversity and abundance in the high-intertidal zone showed significant differences with the mid- and low-intertidal zones. The indices of species richness (Margalef), diversity (Shannon) and evenness (Pielou) showed significant differences among the intertidal zones. Most of the identified species (>60%) that had high values in their frequency of occurrence and relative abundance showed an overlapping vertical distribution, and were present in all three or just in two of the three defined zones. Other species were found only in one of the three zones (non-overlapping vertical distribution). The decapod community in the mid-intertidal zone showed a higher dissimilarity with the high-intertidal zone than with the low-intertidal. Both abundance and diversity were found to be lowest and highest during south-west and north-east monsoons, respectively. During south-west monsoon, the abundance of decapods declined dramatically, but species diversity and ecological indices did not show any statistically significant difference among the sampling periods.

scholarly journals The vertical distribution of phytal ostracods in the intertidal zone at Gore Point, Bristol Channel, U.K.

1982 ◽  
Vol 1 (1) ◽  
pp. 71-84 ◽  
Author(s):  
David J. Horne
Keyword(s):  
New Species ◽  
Vertical Distribution ◽  
Age Structure ◽  
Intertidal Zone ◽  
Life Cycles ◽  
Individual Species ◽  
Tidal Level ◽  
Percentage Composition ◽  
Annual Water ◽  
The Vertical Distribution

Abstract. The first detailed investigation of the vertical distribution of ostracods inhabiting intertidal algae is presented herein. A study was made of the ostracod faunas obtained from samples of Corallina collected at various levels along transects of the intertidal zone at Gore Point in the Bristol Channel. A total of 28 species were recorded, including four new species presently left in open nomenclature. Both the composition of the ostracod fauna and the population age structure of individual species were found to vary considerably according to tidal level. The development of instars apparently proceeds at a faster rate at higher tidal levels, probably due to higher mean annual water temperatures. Among the factors which may determine the percentage composition of the ostracod fauna at a given level are temperature, pH, and the life-cycles and migratory habits of individual species.

Annual and spatial variation of intertidal benthic community zonation in a breakwater off the Rio de Janeiro coast, south-eastern Brazil

2009 ◽  
Vol 89 (2) ◽  
pp. 225-234 ◽  
Author(s):  
Bruno Pereira Masi ◽  
Isabela Maria Macedo ◽  
Ilana Rosental Zalmon
Keyword(s):  
Vertical Distribution ◽  
Air Temperature ◽  
Benthic Community ◽  
Intertidal Zone ◽  
Rio De Janeiro ◽  
Exposure Condition ◽  
Benthic Assemblages ◽  
Air Exposure ◽  
The Vertical Distribution ◽  
Community Zonation

The present study aims to evaluate the vertical distribution of intertidal benthic organisms in different periods of the year, relating them to tide, air temperature, height and wave periodicity in breakwaters off the northern Rio de Janeiro State, and to compare the zonation at two sites (Pier and Barra) with distinct hydrodynamics, due to different wave swell. Quadrats of 400 cm2 were sampled by a photoquadrat method. The upper limit of the marine organisms was higher at the Barra site (intertidal zone of 3.8 m) than at the Pier site (intertidal zone of 2.2 m). The littoral fringe assemblage did not show significant differences between sites, but a larger range of this fringe and the upper eulittoral band at Barra was quite evident. This site was mostly characterized by species of more exposed areas such as Chaetomorpha sp. and Perna perna in the upper and lower eulittoral bands, and by C. teedii and Ulva fasciata in the sublittoral fringe. A seasonal difference was identified in the air exposure degree at the Pier site, which was higher in October 2005 and February 2006. The air temperature and wave height and periodicity differed significantly among the four studied periods. The typical seasonal species were F. clenchi (July 2005 and October 2005), Gigartina domingensis (July 2005), Grateloupia sp. (October 2005) and Porphyra acanthophora (October 2005 and February 2006). The intermediate benthic band of the intertidal zone occupied a narrow zone, changing its spatial location according to the season of the year. The hypothesis of annual variation of the benthic community zonation according to the seasonal variability of tides, air temperatures and wave's height and periodicity was accepted for the intermediate band of the intertidal zone, due to the taxonomic differences and the abundance of dominant species in the four seasons. The difference in the vertical distribution of the intertidal benthic assemblages of both breakwaters highlights a distinct wave exposure condition, and reflects the breakwaters' orientation and the wave swell at each site.

scholarly journals Characteristics of exhaled particle production in healthy volunteers: possible implications for infectious disease transmission

F1000Research ◽  
2013 ◽  
Vol 2 ◽  
pp. 14 ◽  
Author(s):  
Fatima Wurie ◽  
Olivier Le Polain de Waroux ◽  
Matthew Brande ◽  
Wesley DeHaan ◽  
Katherine Holdgate ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Respiratory Infection ◽  
Disease Transmission ◽  
Particle Production ◽  
Great Majority ◽  
Transmission Risk ◽  
Linear Regression Models ◽  
Tidal Breathing ◽  
High Production ◽  
Over Time

The size and concentration of exhaled particles may influence respiratory infection transmission risk. We assessed variation in exhaled particle production between individuals, factors associated with high production and stability over time.We measured exhaled particle production during tidal breathing in a sample of 79 healthy volunteers, using optical particle counter technology. Repeat measurements (several months after baseline) were obtained for 37 of the 79 participants.   Multilevel linear regression models of log transformed particle production measures were used to assess risk factors for high production.  Stability between measurements over time was assessed using Lin’s correlation coefficients.Ninety-nine percent of expired particles were <1μm in diameter. Considerable variation in exhaled particle production was observed between individuals and within individuals over time. Distribution of particle production was right skewed.  Approximately 90% of individuals produce <150 particles per litre in normal breathing.  A few individuals had measurements of over 1000 particles per litre (maximum 1456). Particle production increased with age (p<0.001) and was associated with high tree pollen counts. Particle production levels did not remain stable over time [rho 0.14 (95%CI -0.10, 0.38, p=0.238)].Sub-micron particles conducive to airborne rather than droplet transmission form the great majority of exhaled particles in tidal breathing. There is a high level of variability between subjects but measurements are not stable over time. Production increases with age and may be influenced by airway inflammation caused by environmental irritants. Further research is needed to determine whether the observed variations in exhaled particle production affect transmission of respiratory infection.

Species composition and vertical distribution of chitons (Mollusca: Polyplacophora) in a rocky intertidal zone of the Pacific coast of Costa Rica

2008 ◽  
Vol 88 (4) ◽  
pp. 807-816 ◽  
Author(s):  
K.M. Jörger ◽  
R. Meyer ◽  
I.S. Wehrtmann
Keyword(s):  
Costa Rica ◽  
Species Composition ◽  
Vertical Distribution ◽  
Intertidal Zone ◽  
Rocky Intertidal ◽  
Salinity Range ◽  
Tide Pool ◽  
Exposed Rock ◽  
The Pacific ◽  
Peak Abundance

The present study describes the species composition and vertical distribution of chitons in tide pools and on exposed rock areas of the intertidal zone of Samara, Guanacaste, Pacific Costa Rica. Nine different species of chitons were recorded, and their densities and sizes were determined using quadrate sampling. Physical (period of emersion, temperature and salinity range) and biotic (presence and diversity of food resources) factors were examined to assess their influence on distribution and abundance of each species. Ischnochiton dispar was the predominant species with densities of up to 200 ind m−2, representing 85.4% of all sampled individuals (N = 4193). The size of I. dispar was positively correlated with the size of the inhabited boulders. Two species (I. dispar and Stenoplax limaciformis) showed segregation in size: I. dispar being negatively and S. limaciformis positively correlated to the distance from the shore. Two of the nine species (Chiton stokesii and Acanthochitona hirundiniformis) occurred mainly on rocky areas outside the tide pools with variable amounts of exposure to air during each tidal cycle. In both species the tide pool specimens were significantly smaller than those collected in the rocky areas. Distribution of all other species was restricted to the tide pools and species had their peak abundance in the zones with more moderate conditions and a higher diversity of algae, resulting in the highest chiton diversity in these areas.

Molecular Changes in Dissolved Organic Matter After Soil Rewetting

2021 ◽  
Author(s):  
Alice Orme ◽  
Simon Benk ◽  
Markus Lange ◽  
Christian Zerfaß ◽  
Georg Pohnert ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Mass Spectrometry Analysis ◽  
Microbial Decomposition ◽  
Molecular Changes ◽  
Spectrometry Analysis ◽  
Subsurface Waters ◽  
High Production ◽  
High Concentrations ◽  
Over Time

&lt;p&gt;The intensity and occurrence of droughts is projected to increase due to climate change. Dried soils release high concentrations of dissolved organic matter (DOM) into subsurface waters when they are rewet, the so-called rewetting peak. To more accurately predict the role of rewetting of soils after drought on the carbon cycle in a changing climate, it is important to understand the processes behind this DOM release.&lt;/p&gt;&lt;p&gt;The DOM rewetting peak origin is disputed between soil organic matter (SOM) from breakdown of soil particles; accumulated root exudates; and microbial release due to a change in osmotic potential through osmolytes or cell bursting. To better understand the origin of the rewetting DOM peak, we took a rewetting series of soil water samples from different vegetation types between December 2018 and April 2019 for targeted and untargeted metabolomics. Initial results using untargeted ultrahigh-resolution mass spectrometry analysis revealed a clear temporal trend, indicating that vegetation-independent molecular changes occur following rewetting. An increase in O/C and a decrease in H/C over time was observed which is attributed to microbial decomposition, supported by a decrease in m/z over time. We also observed an increase in the content of lipidic compounds (R &gt; 0.6) following rewetting. This indicates that cells do not burst upon rewetting and, over time, microbial activity increases, suggesting that the DOM rewetting peak is caused by a lack of decomposition, rather than a high production, of organic matter.&lt;/p&gt;

scholarly journals The staying power of adhesion-associated antioxidant activity in Mytilus californianus

2015 ◽  
Vol 12 (111) ◽  
pp. 20150614 ◽  
Author(s):  
Dusty R. Miller ◽  
Jamie E. Spahn ◽  
J. Herbert Waite
Keyword(s):  
Antioxidant Activity ◽  
Intertidal Zone ◽  
Protein Concentration ◽  
Mytilus Californianus ◽  
Structure And Properties ◽  
Interfacial Chemistry ◽  
Extractable Protein ◽  
Adhesive Proteins ◽  
Mussel Byssus ◽  
Over Time

The California mussel, Mytilus californianus , adheres in the highly oxidizing intertidal zone with a fibrous holdfast called the byssus using 3, 4-dihydroxyphenyl- l -alanine (DOPA)-containing adhesive proteins. DOPA is susceptible to oxidation in seawater and, upon oxidation, loses adhesion. Successful mussel adhesion thus depends critically on controlling oxidation and reduction. To explore how mussels regulate redox during their functional adhesive lifetime, we tracked extractable protein concentration, DOPA content and antioxidant activity in byssal plaques over time. In seawater, DOPA content and antioxidant activity in the byssus persisted much longer than expected—50% of extractable DOPA and 30% of extractable antioxidant activity remained after 20 days. Antioxidant activity was located at the plaque–substrate interface, demonstrating that antioxidant activity keeps DOPA reduced for durable and dynamic adhesion. We also correlated antioxidant activity to cysteine and DOPA side chains of mussel foot proteins (mfps), suggesting that mussels use both cysteine and DOPA redox reservoirs for controlling interfacial chemistry. These data are discussed in the context of the biomaterial structure and properties of the marine mussel byssus.

Long-term patterns in the decay, collapse, and abundance of trees with hollows in the mountain ash (Eucalyptus regnans) forests of Victoria, southeastern Australia

2010 ◽  
Vol 40 (1) ◽  
pp. 48-54 ◽  
Author(s):  
David B. Lindenmayer ◽  
Jeff T. Wood
Keyword(s):  
Population Dynamics ◽  
Structural Complexity ◽  
Time Dependent ◽  
Old Growth ◽  
Eucalyptus Regnans ◽  
Southeastern Australia ◽  
Large Trees ◽  
Mountain Ash ◽  
Over Time

Large trees with hollows are an important component of stand structural complexity worldwide. Understanding their population dynamics is needed to manage cavity-dependent biota. We quantified long-term rates of collapse of 302 measured trees with hollows in 1939-aged regrowth mountain ash ( Eucalyptus regnans F. Muell.) forest in southeastern Australia. We identified time-dependent dynamics in which the collapse rates of trees slowed from ∼4% annually between 1983 and 1993 to ∼2.2% between 1993 and 2007. Transitions of trees between different decay states (forms) also slowed over time. Nevertheless, during the 24-year period of our study, over half of our marked and measured trees had fallen, but there was no recruitment of new trees with hollows. Under current projections, few trees with hollows will occur on our field sites by ∼2050, although more had been forecast in earlier investigations. Such a paucity of trees with hollows in extensive areas of regrowth mountain ash forests will lead to a shortage of nesting and sheltering sites for cavity-dependent biota. We suggest a short–medium (10- to 100-year) focus on the conservation of old growth and multi-aged stands will be needed to maintain populations of those species strongly associated with trees with hollows in mountain ash forests.

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