scholarly journals Epiphytic bryozoan community of Posidonia oceanica (L.) Delile leaves in two different meadows at disturbed and control locations

2014 ◽  
Vol 15 (2) ◽  
pp. 390 ◽  
Author(s):  
F. KOCAK ◽  
S. AYDIN-ONEN
Keyword(s):  
Environmental Changes ◽  
Aegean Sea ◽  
Fish Farming ◽  
Posidonia Oceanica ◽  
Back Side ◽  
Bryozoan Species ◽  
Key Species ◽  
Different Depths ◽  
And Control ◽  
The Impact

The impact of fish farming activities on Posidonia oceanica meadows in the Aegean Sea have been detected by using bryozoan epiphytes as indicators of disturbance. Samples were collected by SCUBA diving in September 2004 for comparing assemblages between disturbed (I1:0-5 m; I2:5-10 m and I3:10-15 m) and control meadows (C1:0-5 m; C2:5-10 m and C3:10-15 m) located at different depths. Regarding to mean percentage cover of bryozoans, significant differences were found between stations, leaf sides, depths and their interactions (p<0.05). Bryozoan species were colonized densely on back side of the adult leaves. Bantariella verticillata, Alcyonidium sp., Aetea truncata, Chorizopora brongniartii, Fenestrulina joannae were frequently observed species on P. oceanica leaves. B. verticillata showed statistically significant side and station differences while other species showed only significant side differences. Moreover, the mean coverage of Aetea truncata showed neither station nor side variations. B. verticillata could be evaluated as an appropriate key species for environmental changes. In the impacted meadow, higher mean coverage values of the species were particularly determined on front side of the leaves. These results suggest that characteristics of localities, leaf sides and leaf parts can be responsible factors on coverage value of epiphytic bryozoan species.

scholarly journals The intensity of slope and fluvial processes after a catastrophic windthrow event in small catchments in the Tatra Mountains

2021 ◽  
Vol 18 (6) ◽  
pp. 1405-1423
Author(s):  
Dariusz Strzyżowski ◽  
Elżbieta Gorczyca ◽  
Kazimierz Krzemień ◽  
Mirosław Żelazny
Keyword(s):  
Environmental Changes ◽  
Bedload Transport ◽  
Strong Wind ◽  
Tatra Mountains ◽  
Salvage Logging ◽  
Fluvial Processes ◽  
Wind Events ◽  
And Control ◽  
The Tatra Mountains ◽  
The Impact

AbstractStrong wind events frequently result in creating large areas of windthrow, which causes abrupt environmental changes. Bare soil surfaces within pits and root plates potentially expose soil to erosion. Absence of forest may alter the dynamics of water circulation. In this study we attempt to answer the question of whether extensive windthrows influence the magnitude of geomorphic processes in 6 small second- to third-order catchments with area ranging from 0.09 km2 to 0.8 km2. Three of the catchments were significantly affected by a windthrow which occurred in December 2013 in the Polish part of the Tatra Mountains, and the other three catchments were mostly forested and served as control catchments. We mapped the pits created by the windthrow and the linear scars created by salvage logging operations in search of any signs of erosion within them. We also mapped all post-windthrow landslides created in the windthrow-affected catchments. The impact of the windthrow on the fluvial system was investigated by measuring a set of channel characteristics and determining bedload transport intensity using painted tracers in all the windthrow-affected and control catchments. Both pits and linear scars created by harvesting tend to become overgrown by vegetation in the first several years after the windthrow. The only signs of erosion were observed in 10% of the pits located on convergent slopes. During the period from the windthrow event in 2013 until 2019, 5 very small (total area <100 m2) shallow landslides were created. The mean distance of bedload transport was similar (t-test, p=0.05) in most of the windthrow-affected and control catchments. The mapping of channels revealed many cases of root plates fallen into a channel and pits created near a channel. A significant amount of woody debris delivered into the channels influenced the activity of fluvial processes by creating alternating zones of erosion and accumulation.

scholarly journals Posidonia oceanica molecular adaptation to the light environment

2015 ◽  
Author(s):  
Gabriele Procaccini ◽  
Emanuela Dattolo ◽  
Chiara Lauritano ◽  
Miriam Ruocco ◽  
Lazaro Marin-Guirao
Keyword(s):  
Environmental Changes ◽  
Light Availability ◽  
Posidonia Oceanica ◽  
Light Sensitivity ◽  
Light Environment ◽  
Molecular Adaptation ◽  
Important Species ◽  
Light Regimes ◽  
Seagrass Meadows ◽  
The Impact

Seagrass meadows are among the most productive ecosystems, with Posidonia oceanica being the most important species along the Mediterranean coastline. This species forms extensive mono-specific meadows that are extremely sensitive to medium-high levels of disturbance and are being threatened by fast environmental changes caused by global warming and increasing human activities. The impact can either reflect in higher turbidity along the water column and in increased UV radiation, making the light availability one of the most important factors affecting P. oceanica distribution. Plants developed mechanisms of adaptations at multiple levels to track and cope with fluctuations and changes in the light environment. At molecular level, the modulation of gene expression in response to environmental changes allows plants to optimize the utilization of light energy for growth and to prevent damages due to its excess. To detect the relevant molecular adaptation strategies evolved by P. oceanica and to assess the plasticity showed in the acclimation under different light regimes, we are employing studies both in natural and controlled conditions. Here, we describe the differences in photo acclimation of plants living along the bathymetric cline observed in field and in a common garden experiment in mesocosms, after the exposition to contrasting light regimes. Using a transcriptional approach (both RT -qPCR and RNA-seq) coupled with a physiological one, we are also testing potential divergences existing among populations and individuals related to light sensitivity. These data should supply new insights for the management of seagrasses ecosystems, for the development of most successful transplantation strategies and ultimately for conservation of biodiversity of these precious ecosystems.

scholarly journals Preliminary data on the impact of fish farming facilities on Posidonia oceanica meadows in the Mediterranean

1999 ◽  
Vol 22 (1) ◽  
pp. 95-107 ◽  
Author(s):  
Gérard Pergent ◽  
Stéphane Mendez ◽  
Christine Pergent-Martini ◽  
Vanina Pasqualini
Keyword(s):  
Preliminary Data ◽  
Fish Farming ◽  
Posidonia Oceanica ◽  
The Mediterranean ◽  
The Impact

scholarly journals A quantitative eDNA-based method to monitor spawning activity of two emblematic fish species in lake Geneva

2021 ◽  
Vol 4 ◽  
Author(s):  
Marine Vautier ◽  
Cécile Chardon ◽  
Chloé Goulon ◽  
Jean Guillard ◽  
Isabelle Domaizon
Keyword(s):  
Fish Species ◽  
Environmental Changes ◽  
Coregonus Lavaretus ◽  
Lake Geneva ◽  
Spawning Activity ◽  
Anthropogenic Pressures ◽  
European Perch ◽  
Non Invasive ◽  
Key Species ◽  
The Impact

Anthropogenic pressures and more recently climatic change have increased the interest to study the impact of environmental changes on the key stages of fish life cycle. In lake Geneva, a deep peri-alpine lake, climate change and phosphorous level are known to have consequences on salmonid and percid populations, including key species for recreational and commercial fisheries, whose stocks are subject to significant fluctuations. To follow these stock variations, the spawning activity of European perch (Perca fluviatilis) and whitefish (Coregonus lavaretus) is monitored in this lake since several years using traditional methods, unfortunately mostly destructive or damaging (e.g. gillnetting and collection of fertilized eggs). DNA isolated from the environment (eDNA) has been widely developed for the detection of specific species or whole biological communities, and this non-invasive method offers an alternative to conventional surveying tools. Until recently, the methods used for eDNA analysis (e.g. qPCR, metabarcoding) could be limited by their sensitivity, quantification limit or price, but the emergence of new methods, such as the droplet digital PCR (ddPCR), offers the possibility to quantify an absolute eDNA signal in a very sensitive way and at a lower cost. Here, we show for the first time the applicability of an eDNA method to monitor the spawning activity of two fish species in a lake by using ddPCR. During two spawning seasons for whitefish and one spawning season for European perch, water samples were collected every week from the subsurface, simultaneously to traditional monitoring sampling, and filtered through sterile cartridges. The eDNA was then extracted and analyzed using ddPCR, targeting the mitochondrial DNA of the two fish species. The results demonstrate the efficiency of eDNA coupled with ddPCR to identify the timing and duration of the spawning periods, as well as the peak of the spawning activity for whitefish and European perch in Lake Geneva. This study shows that we have reached an operational level to use this non-invasive eDNA monitoring of the spawning activity of these fish species in lakes.

scholarly journals The impact of stock collapse on small-scale fishers’ behavior: evidence from Japan

2018 ◽  
Vol 75 (12) ◽  
pp. 2241-2254 ◽  
Author(s):  
Shoichi Kiyama ◽  
Satoshi Yamazaki
Keyword(s):  
Environmental Changes ◽  
Alternative Form ◽  
Small Scale ◽  
Key Species ◽  
Development Policies ◽  
Management And Development ◽  
Declining Species ◽  
Using Data ◽  
Substantial Decline ◽  
The Impact

Understanding behavioral responses of resource users to environmental changes and incentives created by management systems is imperative to implement effective resource management and development policies. A small-scale mixed fishery in the Maizuru Bay, Japan, provides a natural experiment to evaluate changes in small-scale fishers’ harvesting and targeting behavior over the years that one of the key species in the fishery experienced a collapse of the stock. Using data on individual fishers across the pre- and postcollapse periods, we find that inefficient fishers were forced to shut down or stay idle along with the collapse of the stock, and this behavior led to an increase in the overall efficiency in the production of clams (Venerupis philippinarum). The depletion of the stock, however, imposed a natural constraint on the operation, resulting in a substantial decline in the maximum production achievable by the remaining fishers. We further show that the collapse of the stock not only affected the harvesting behavior against the declining species but also led to the expansion of the fishing capacity and effort to catch other species and the development of aquaculture as an alternative form of fish production in the region.

scholarly journals Posidonia oceanica molecular adaptation to the light environment

2015 ◽  
Author(s):  
Gabriele Procaccini ◽  
Emanuela Dattolo ◽  
Chiara Lauritano ◽  
Miriam Ruocco ◽  
Lazaro Marin-Guirao
Keyword(s):  
Environmental Changes ◽  
Light Availability ◽  
Posidonia Oceanica ◽  
Light Sensitivity ◽  
Light Environment ◽  
Molecular Adaptation ◽  
Important Species ◽  
Light Regimes ◽  
Seagrass Meadows ◽  
The Impact

Seagrass meadows are among the most productive ecosystems, with Posidonia oceanica being the most important species along the Mediterranean coastline. This species forms extensive mono-specific meadows that are extremely sensitive to medium-high levels of disturbance and are being threatened by fast environmental changes caused by global warming and increasing human activities. The impact can either reflect in higher turbidity along the water column and in increased UV radiation, making the light availability one of the most important factors affecting P. oceanica distribution. Plants developed mechanisms of adaptations at multiple levels to track and cope with fluctuations and changes in the light environment. At molecular level, the modulation of gene expression in response to environmental changes allows plants to optimize the utilization of light energy for growth and to prevent damages due to its excess. To detect the relevant molecular adaptation strategies evolved by P. oceanica and to assess the plasticity showed in the acclimation under different light regimes, we are employing studies both in natural and controlled conditions. Here, we describe the differences in photo acclimation of plants living along the bathymetric cline observed in field and in a common garden experiment in mesocosms, after the exposition to contrasting light regimes. Using a transcriptional approach (both RT -qPCR and RNA-seq) coupled with a physiological one, we are also testing potential divergences existing among populations and individuals related to light sensitivity. These data should supply new insights for the management of seagrasses ecosystems, for the development of most successful transplantation strategies and ultimately for conservation of biodiversity of these precious ecosystems.

scholarly journals The latrine effect: impact of howler monkeys on the distribution of small seeds in a tropical rain-forest soil

2009 ◽  
Vol 25 (3) ◽  
pp. 239-248 ◽  
Author(s):  
Sandrine Pouvelle ◽  
Sylvie Jouard ◽  
François Feer ◽  
Thomas Tully ◽  
Jean-François Ponge
Keyword(s):  
French Guiana ◽  
Soil Seed Bank ◽  
Seed Viability ◽  
Howler Monkey ◽  
Alouatta Seniculus ◽  
Different Depths ◽  
Growth Habits ◽  
And Control ◽  
The Impact ◽  
Red Howler

Abstract:We studied the impact of dung deposition by the red howler monkey (Alouatta seniculus), and subsequent burial by dung beetles and other biotic and abiotic processes, on the distribution of small seeds in the soil seed bank (Nouragues Reserve, French Guiana). Seeds were collected from 54 soil samples taken under three sleeping sites and adjoining control sites, at three positions according to a fixed grid and at three different depths (0–2, 2–4 and 4–6 cm). Despite large differences between the three sites, defecation areas (latrines) were found to contain more seeds and higher seed diversity than control areas. Seed density decreased with depth in the top 6 cm in two sites but not in the third. Shannon diversity decreased with depth in both defecation and control areas. Differences in the distribution of seeds of different species were found according to size and growth habits (pioneer vs non-pioneer species). The viability of seeds, ascertained from toughness and integrity of the seed coat, varied according to depth, site and defecation. Seed viability was on average higher in defecation areas compared with control areas.

Suppressed, but Not Forgotten

2011 ◽  
Vol 70 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Beat Meier ◽  
Anja König ◽  
Samuel Parak ◽  
Katharina Henke
Keyword(s):  
Memory Trace ◽  
Thought Suppression ◽  
Test Phase ◽  
Indirect Test ◽  
Final Test ◽  
Test Experiment ◽  
And Control ◽  
Cue Words ◽  
The Impact

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.

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