Factorial Analysis in the Ecology of Rocky Subtidal Areas Near Brest (West Brittany, France)

Author(s):  
A. Castric ◽  
C. Chasse

In order to investigate the characteristic species and the relative importance of selected environmental conditions of rocky bottom communities in coastal waters and to estimate their richness, 27 sites in the Brest area were surveyed by diving. The abundances of underwater species, from a check-list of 115, were plotted as number of individuals or colonies in m2 or in percentage cover of the rock, against the environmental conditions (depth, bedrock slope, substrate type and sediment nature of the nearest soft bottom). Raw data were converted to biovolume expressed as mm3 m–2 and expressed as log 10 (x + 1).Various correspondence analyses were applied to these data: the first included bedrock slope (lit/dark surfaces) and takes into account the four biological formations according to the depth. It shows zonation with depth and decreasing light as factor 1, hydrodynamic conditions (waves or current) as factor 2, mixing of estuarine and oceanic waters as factor 3 and turbidity as factor 4. Four species assemblages emerge from these four axes, for which the main species contributing to the four axes may be considered as characteristic species. These correspond well to four broad communities described in British waters: very exposed to wave-action, semi-exposed to wave-action, exposed to strong tidal current, very sheltered sites. The second analysis, in which lit and dark surfaces are distinguished, but some very close sites are fused together, shows in detail the photophilous or sciaphilous nature of the species. Values of hydrodynamic conditions and percentage of surface light plotted on the 'stations-points' of the graphs allow drawing of a factorial network which may be used as hydrodynamic and illumination scales.

2018 ◽  
Author(s):  
Richard Robert Suminski Jr ◽  
Gregory Dominick ◽  
Philip Sapanaro

BACKGROUND A considerable proportion of outdoor physical activity is done on sidewalk/streets. For example, we found that ~70% of adults who walked during the previous week used the sidewalks/streets around their homes. Interventions conducted at geographical levels (e.g., community) and studies examining relationships between environmental conditions (e.g., traffic) and walking/biking, necessitate a reliable measure of physical activities performed on sidewalks/streets. The Block Walk Method (BWM) is one of the more common approaches available for this purpose. Although it utilizes reliable observation techniques and displays criterion validity, it remains relatively unchanged since its introduction in 2006. It is a non-technical, labor-intensive, first generation method. Advancing the BWM would contribute significantly to our understanding of physical activity behavior. OBJECTIVE Therefore, the objective of the proposed study is to develop and test a new BWM that utilizes a wearable video device (WVD) and computer video analysis to assess physical activities performed on sidewalks/streets. The following aims will be completed to accomplish this objective. Aim 1: Improve the BWM by incorporating a WVD into the methodology. The WVD is a pair of eyeglasses with a high definition video camera embedded into the frames. We expect the WVD to be a viable option for improving the acquisition and accuracy of data collected using the BWM. Aim 2: Advance the WVD-enhanced BWM by applying machine learning and recognition software to automatically extract information on physical activities occurring on the sidewalks/streets from the videos. METHODS Trained observers (one wearing and one not wearing the WVD) will walk together at a set pace along predetermined, 1000 ft. sidewalk/street observation routes representing low, medium, and high walkable areas. During the walks, the non-WVD observer will use the traditional BWM to record the number of individuals standing/sitting, walking, biking, and running along the routes. The WVD observer will only record a video while walking. Later, two investigators will view the videos to determine the numbers of individuals performing physical activities along the routes. For aim 2, the video data will be analyzed automatically using multiple deep convolutional neural networks (CNNs) to determine the number of humans along an observation route as well as the type of physical activities being performed. Bland Altman methods and intraclass correlation coefficients will be used to assess agreement. Potential sources of error such as occlusions (e.g., trees) will be assessed using moderator analyses. RESULTS Outcomes from this study are pending; however, preliminary studies supporting the research protocol indicate that the BWM is reliable and the number of individuals were seen walking along routes are correlated with several environmental characteristics (e.g., traffic, sidewalk defects). Further, we have used CNNs to detect cars, bikes, and pedestrians as well as individuals using park facilities. CONCLUSIONS We expect the new approach will enhance measurement accuracy while reducing the burden of data collection. In the future, the capabilities of the WVD-CNNs system will be expanded to allow for the determination of other characteristics captured by the videos such as caloric expenditure and environmental conditions.


2021 ◽  
Vol 17 (2) ◽  
pp. 77-89
Author(s):  
Jessico H Sermatang ◽  
Charlotha I Tupan ◽  
Laura Siahainenia

Seagrass as a flowering plant can live from muddy substrates to coral fractures. Differences in the characteristics of substrate type, nutrient content and aquatic environmental conditions can affect morphometric seagrass. The purpose of the study was to analyze environmental conditions and nutrient content as well as the morphometric characteristics of T. hemprichii seagrass based on differences in substrate type. This study was conducted in the waters of Tanjung Tiram Coastal, Poka from February-April 2021. Seagrass sampling was using the purposive sampling method. Data analysis was conducted using ANOVA with SPSS. The results of environmental parameters analysis showed that the water conditions of Tanjung Tiram, Poka are still at the tolerance limit intended for seagrass life. The substrate consists of sand substrate, gravel mixed sand substrate and mud substrate. The results of ANOVA showed that there was a significant difference in the content of sedimentary nutrients, especially phosphates in each substrate type and there was a significant difference in morphometric seagrass based on differences in substrate type and nutrient content.   ABSTRAK Lamun sebagai tumbuhan berbunga dapat hidup mulai dari substrat berlumpur sampai dengan patahan karang. Perbedaan karakteristik jenis substrat, kandungan nutrien dan kondisi lingkungan perairan dapat mempengaruhi morfometrik lamun. Tujuan dari penelitian ini adalah menganalisis kondisi lingkungan dan kandungan nutrien serta karakteristik morfometrik lamun T. hemprichii berdasarkan perbedaan tipe substrat. Penelitian ini dilaksanakan di Perairan Pantai Tanjung Tiram, Poka pada Bulan Februari-April 2021. Pengambilan sampel lamun menggunakan metode purposive sampling. Analisis data menggunakan ANOVA dengan SPSS. Hasil analisis parameter lingkungan, menunjukan bahwa kondisi perairan Tanjung Tiram, Poka masih berada pada batas toleransi yang diperuntukan untuk kehidupan lamun. Substrat terdiri dari substrat pasir, pasir campur kerikil dan lumpur. Hasil anova menunjukan bahwa terdapat perbedaan kandungan nutrien sedimen khususnya fosfat secara signifikan pada masing masing tipe substrat dan terdapat perbedaan morfometrik lamun secara signifikan berdasarkan perbedaan tipe substrat dan kandungan nutrien. Kata Kunci: morfometrik, nutrien, substrat, Tanjung Tiram, Thalassia hemprichii


2015 ◽  
Author(s):  
Stefano Acunto ◽  
Luigi Piazzi ◽  
Francesco L. Cinelli ◽  
Anna Maria De Biasi ◽  
Lorenzo Pacciardi ◽  
...  

Transplantation of seagrasses is considered a useful method to favour the recovery of degraded meadows. Hence, many projects have been carried out worldwide and a manifold of techniques have been applied. However, the choice of transplantation procedures remains a main problem to be assessed. In order to optimize efforts and to minimize risks of plants loss, the applied methodologies should take into account typology of hosting substratum, hydrodynamic conditions, depth and seagrass species. Due to their fundamental ecological role in the Mediterranean coastal system, many restoration projects aiming to preserve Posidonia oceanica meadows took place in the last decades. Several transplantation techniques have produced different results. In fact the same transplanting methodology may originate diverse results under different environmental conditions. Recently, naturalistic engineering techniques developed on land, have been used for transplantations of P. oceanica. Pilot projects concerning small surfaces were carried out between 2006 and 2010. More recently, a large-scale program (0.1 km2) was realized in 2012 at Civitavecchia (Roma, Thyrrenian Sea). The applied technique consists basically of mattresses filled with sand coupled with a net covering able to hold steady in situ the plant rhizomes. These structures have been variously modified in time to be adapted to the different type of substratum and various hydrodynamic conditions of the transplanting sites. Following the results of these transplantation experiences, we analyzed pros and cons of the techniques in order to improve the methodology. Firstly, these techniques may be considered suitable to large-scale projects allowing to minimize transplantation times. Secondly, the rhizomes may be successfully fixed to the structures; the majority of the transplanted shoots was not damaged showing a very good vegetative vitality with the production of new rhizomes, leaves and roots few months after transplanting. Finally, this procedure is flexible, as the basic technique can be modified and tailored to the various environmental conditions of the different receiving site. However, the results obtained in different areas are highly heterogeneous suggesting that a careful selection of the hosting site is a focal point. To this aim, a pilot study before the beginning of large-scale project seems mandatory, providing a fundamental support to guarantee successful results.


Zootaxa ◽  
2021 ◽  
Vol 4915 (4) ◽  
pp. 506-528
Author(s):  
L. DOCIO ◽  
M. PAROLIN ◽  
U. PINHEIRO

This paper provides a comprehensive review of the environments where freshwater sponges occur and evaluates the use of sponge spicules as a proxy in paleoenvironmental studies in the Neotropical region. The paper aims to: I) review the information about the ecology of inland sponges to facilitate the use of spicules as a paleoenvironmental tool; and II) identify possible incongruities in the use of this information in paleoenvironmental reconstructions that have been conducted in Neotropical regions. The study compiled data on 77 sponge species, specialist or generalist that occur under certain environmental conditions, such as: substrate type for growth, hydrodynamic types, as well as salinity and acidity concentrations. In addition, it provides a comparison of the paleoenvironmental conditions applied to reconstruction studies that have been carried out within this biogeographic region, highlighting incongruities regarding the current ecology of the sponges. 


2014 ◽  
Vol 638-640 ◽  
pp. 1261-1265 ◽  
Author(s):  
Yun Peng Zhang ◽  
Ming Liang Zhang ◽  
Zi Ning Hao ◽  
Yuan Yuan Xu ◽  
Yang Qiao

This paper presents a spectral wave action model to simulate random wave deformation and transformation. The wave model is based on the wave action balance equation and can simulate wave fields by accounting for wave breaking, shoaling, refraction, diffraction and wind effect in coastal waters. It is a finite-difference, phase averaged model for the steady-state wave spectral transformation. The wave model is applied to verify different experimental cases and real life case of considering the several factor effects. The calculated results agree with the experimental and field data. The results show that the wave model presented herein should be useful in simulating the wave transformation processes in complicated coastal waters.


2019 ◽  
Vol 71 (4) ◽  
pp. 629-637
Author(s):  
Nemanja Rajcevic ◽  
Biljana Nikolic ◽  
Petar Marin

Many studies show the influence of the environment on terpene composition, but not many of them deal with the terpene composition variability in correlation with environmental factors in Pinus. We chose two endemic species ? P. heldreichii Christ. (Bosnian pine) and P. peuce Griseb. (Macedonian pine) ? two relict and (sub)endemic species of the Balkan peninsula. They mainly form pure stands but can appear in mixed populations, most commonly with each other. These species belong to different subgenera and thus differ greatly, especially in needle anatomy. ?-pinene, limonene and germacrene D predominated in Bosnian pine leaf oleoresins, while Macedonian pine oleoresin contained high amounts of ?-pinene. Furthermore, there were three chemotypes present in Bosnian, and only one in Macedonian pine. Oleoresins of Bosnian pine did not show correlation with climate, however, its composition changed in response to geological substrate type. Macedonian pine oleoresin showed a high correlation with the climate but changed only a little in response to geological substrate type. The oleoresin profiles showed strong species-dependent composition and variability. However, since each species expressed different responses to tested environmental conditions, it is important to take into consideration these variables when analyzing natural populations of the species.


2019 ◽  
Author(s):  
Rafał M. Olszyński ◽  
Ewelina Szczepocka ◽  
Joanna Żelazna-Wieczorek

Background. The ecological state of surface waters is typically assessed by a multi-aspect approach based on a determination of its chemical and physical parameters, by hydromorphology and the use of indicator organisms such as benthic diatoms. By assigning ecological indicator values, it is possible to create diatom indices which serve as the basic tool in assessing the ecological status of surface waters. These ecological indicator values are set according to classification systems, such as the Van Dam et al. 1994 system, which classifies species of diatoms according to seven different ecological factors. However, recent studies on the autecology of diatoms have shown the need to verify and establish new ecological indicator values. To this end, aquatic ecosystems are good environments to observe the range of tolerance of benthic diatoms to environmental conditions due to their unique physical and chemical parameters. The aim of the present study was to propose the establishment of new, or altered, ecological indicator values, according to Van Dam et al. classification, of species of diatoms characteristic of three post-mining aquatic ecosystems. Methods. In total, 36 species were identified that were characteristic of three waterbodies: a salt aquatic complex (water outflow, a drainage ditch and a pond), a mined iron ore reservoir and a mined lignite reservoir. Their ecological indicator values were calculated using OMNIDIA software, and the environmental conditions prevailing in the studied ecosystems were determined. Of the 36 characteristic species, 16 lacking at least one assigned ecological indicator value were analysed further. The analysis identified three groups of selected characteristic species which showed a correlation, or lack of such, to the tested physical and chemical parameters. Results. Based on this multistage study of the autecology of characteristic diatoms, comprising an analysis of environmental conditions, literature analysis and reference ecological indicator values of other species, it is proposed that 32 ecological indicator values be established or adjusted for 16 species, and that Planothidium frequentissimum be excluded from water quality assessments.


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