scholarly journals Differences in composition of territories in relation to behaviour, stage, and depth of the three-spot damselfish, Stegastes planifrons, in Caribbean coral reefs

SURG Journal ◽  
2013 ◽  
Vol 6 (1) ◽  
pp. 52-57
Author(s):  
Maria J. Arroyo Gerez
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Large Scale ◽  
Life Stage ◽  
Small Scale ◽  
Fish Behaviour ◽  
Short Term ◽  
Algal Diversity ◽  
Stegastes Planifrons

Coral reef diversity is correlated with the depth at which the reefs are found, the energy available for biological processes, and the species’ roles and presence throughout the food chain. Can a specific species activity alter the whole ecosystem? Can a small-scale, short-term activity such as fish behaviour have a long-term effect on a larger scale, that of the reef? Can the life stage of a species mediate substrate competition? The three-spot damselfish (Stegastes planifrons) is hypothesized to regulate competition between substrate coverage by actively farming – protecting from herbivores and weeding – in order to regulate the algal species composition and percent coverage of the reef. This behaviour is observed in both juvenile and adult fish. Deeper patches are predicted to have less coral diversity and higher algal diversity; juvenile fish are predicted to have less diversity in their patches than adults. Coral and algal diversity are hypothesized to be negatively correlated. In this study, behaviour of the S. planifrons was classified into one of four categories (active patrolling, passing patrolling, farming, and hiding) and palatable algae surface area coverage was digitized from photographs; life stage was either juvenile or adult. Coral and algal genus diversity were measured along a depth gradient of 0-16 m where the diversity of the reef was thought to be the highest. A three-way ANCOVA was performed to test whether fish behaviour (a small-scale, short-term process), depth, or fish development stage (juvenile or adult) had a significant effect on coral or algal diversity (a large-scale, long-term process). Results showed a significant effect of fish behaviour category on algal genera diversity, and a significant effect of depth on both algal and coral genera diversity. Farming yielded significantly more algal coverage than hiding. This study shows that small-scale, short-term behaviours by S. planifrons can have an effect on algal genera diversity on coral reefs in Utila, Honduras. Keywords: Stegastes planifrons (three-spotted damselfish); behaviours (short-term, small-scale); stage of development (juvenile, adult); depth; coral reef and algal diversity (long-term, large-scale); damselfish territories

scholarly journals Population signatures of large-scale, long-term disjunction and small-scale, short-term habitat fragmentation in an Afromontane forest bird

Heredity ◽  
2014 ◽  
Vol 113 (3) ◽  
pp. 205-214 ◽  
Author(s):  
J C Habel ◽  
R K Mulwa ◽  
F Gassert ◽  
D Rödder ◽  
W Ulrich ◽  
...  
Keyword(s):  
Habitat Fragmentation ◽  
Large Scale ◽  
Small Scale ◽  
Short Term ◽  
Forest Bird ◽  
Afromontane Forest

From Small Scale, Short Term to Large Scale, Long Term: Integrating ‘Sustainability’ into Engineering Education

1996 ◽  
Vol 21 (4) ◽  
pp. 353-386 ◽  
Author(s):  
S. M LEMKOWITZ ◽  
B. H BIBO ◽  
G. H LAMERIS ◽  
J. A. B. A. F. BONNET
Keyword(s):  
Engineering Education ◽  
Large Scale ◽  
Small Scale ◽  
Short Term

scholarly journals Reproductive performance and natural antagonists of univoltine population of Ips typographus (Coleoptera, Curculionidae, Scolytinae) at epidemic level: a study from Šumava Mountains, Central Europe

Beskydy ◽  
2012 ◽  
Vol 5 (2) ◽  
pp. 153-162 ◽  
Author(s):  
K. Lukášová ◽  
J. Holuša ◽  
Š. Grucmanová
Keyword(s):  
Bark Beetle ◽  
Large Scale ◽  
Developmental Stages ◽  
Female Offspring ◽  
Small Scale ◽  
Short Term ◽  
Spruce Bark Beetle ◽  
Outbreak Area ◽  
Spruce Bark

Population ofI. typographuswas studied in one locality with small-scale and short-term outbreak distant from large-scale and long-term outbreak area by several hundred meters. In total, ten spruce trees infested by the spruce bark beetle were examined. Always four stripes of bark (sample area) with the length equal to half the circumference of the trunk and the width of approximately 0.5 m were analyzed. The local spruce bark beetle population was characterized by high population density (1.5±1.2 entry holes per dm2), low number of eggs per female, and short maternal galleries. Relatively low reproductive success (0.8 female offspring per one mother beetle, percentage of surviving individuals varies between 1and 18 % was documented. The parasitism rate of living developmental stages of spruce bark beetle by larval parasitoids averaged 14 %. The level of infestation by pathogens and endoparasitoids in maternal beetles from their galleries was low. Highly likely, it is a result of short-term outbreak during which response of parasitoids was delayed in time.

scholarly journals How many fish could be vocal? An estimation from a coral reef (Moorea Island)

2021 ◽  
Vol 151 ◽  
Author(s):  
Eric Parmentier ◽  
Frédéric Bertucci ◽  
Marta Bolgan ◽  
David Lecchini
Keyword(s):  
Coral Reef ◽  
High Resolution ◽  
Coral Reefs ◽  
Large Scale ◽  
Fish Populations ◽  
Successful Management ◽  
Acoustic Behaviour ◽  
Management Plans ◽  
Moorea Island

A recurrent question arising in fish bioacoustics research concerns the number of vocal fish species that may exist. Although it is not possible to provide a precise globally valid number, an estimation based on recordings already collected at coral reefs (Moorea) and on morphological approaches indicates that approximately half of the fish families of this particular environment has at least one known sound-producing species. In light of this, acoustic behaviour should be fully considered in biology, ecology and management plans as it may provide information on a consistent portion of fish biodiversity. Fish bioacoustics has switched from anecdotal reports to long-term, large-scale monitoring studies, capable of providing high resolution information on fish populations’ composition and dynamics. This information is vital for successful management plans in our quickly changing seas.

scholarly journals Law and the Exclusionary Essence of Large-Scale Investments in Sub-Saharan Africa Land

2014 ◽  
Vol 6 (2-3) ◽  
pp. 315-335 ◽  
Author(s):  
Tomaso Ferrando
Keyword(s):  
Rural Areas ◽  
Large Scale ◽  
Sub Saharan Africa ◽  
Small Scale ◽  
Land Grabbing ◽  
Short Term ◽  
Global Land ◽  
Sub Saharan ◽  
Small Scale Farmers

Abstract ‘Global land grabbing’ represents one of the hottest topics of debate within the areas of developmental and agricultural studies. However, this article claims that a narrow focus on the illegality and consequences of the ‘grabbing’, rather than on large scale investments in land (LaSIL) as a form of economic development which is inherently exclusionary, can be detrimental to the future of small-scale farmers. A short-term perspective overlooks the indirect consequences of industrialization, and legitimizes long-term exclusions and marginalization. Through past and present evidence, this paper demonstrates that LaSIL as competing projects will inevitably produce the abandonment of rural areas, the proletarianization of peasants, and the increase in social inequality, against any possibility for coexistence and harmonious cooperation.

scholarly journals Suggestion of Measurement Management Criteria for Soil Slope Failure Based on Displacement

2021 ◽  
Vol 21 (1) ◽  
pp. 251-260
Author(s):  
Sun-Gyu Choi ◽  
Jae-Wook Suk ◽  
Hyang-Seon Jeong
Keyword(s):  
Literature Review ◽  
Field Data ◽  
Large Scale ◽  
Slope Failure ◽  
Small Scale ◽  
Soil Slope ◽  
Short Term ◽  
Literature Reviews ◽  
Under Construction

This paper describes the Measurement Management Criteria (MMC) of a soil slope failure based on displacement using literature reviews, small-scale experiments, large-scale experiments, and field data. Two types of measurement management criteria were developed, i.e., short-term criteria for slopes under construction or requiring urgent measurements, and long-term criteria for slopes under continuous management. First, the measurement criteria for the short term were determined based on small- and-large scale experiments, and were determined to be “1 mm/min for the watch level,” “4 mm/min for the caution level,” and “21 mm/min for the alert level.” Next, the criteria for the long term were determined through a literature review and field data, and were “2 mm/day for the watch level,” “8 mm/day for the caution level,” and “56 mm/day for the alert level”.

scholarly journals Stokes drift through corals

2021 ◽  
Author(s):  
Joseph J. Webber ◽  
Herbert E. Huppert
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Porous Layer ◽  
Large Scale ◽  
Fluid Layer ◽  
Ocean Waves ◽  
Stokes Drift ◽  
Inviscid Fluid ◽  
Porous Bed ◽  
Vertical Drift

AbstractMotivated by shallow ocean waves propagating over coral reefs, we investigate the drift velocities due to surface wave motion in an effectively inviscid fluid that overlies a saturated porous bed of finite depth. Previous work in this area either neglects the large-scale flow between layers (Phillips in Flow and reactions in permeable rocks, Cambridge University Press, Cambridge, 1991) or only considers the drift above the porous layer (Monismith in Ann Rev Fluid Mech 39:37–55, 2007). Overcoming these limitations, we propose a model where flow is described by a velocity potential above the porous layer and by Darcy’s law in the porous bed, with derived matching conditions at the interface between the two layers. Both a horizontal and a novel vertical drift effect arise from the damping of the porous bed, which requires the use of a complex wavenumber k. This is in contrast to the purely horizontal second-order drift first derived by Stokes (Trans Camb Philos Soc 8:441–455, 1847) when working with solely a pure fluid layer. Our work provides a physical model for coral reefs in shallow seas, where fluid drift both above and within the reef is vitally important for maintaining a healthy reef ecosystem (Koehl et al. In: Proceedings of the 8th International Coral Reef Symposium, vol 2, pp 1087–1092, 1997; Monismith in Ann Rev Fluid Mech 39:37–55, 2007). We compare our model with field measurements by Koehl and Hadfield (J Mar Syst 49:75–88, 2004) and also explain the vertical drift effects as documented by Koehl et al. (Mar Ecol Prog Ser 335:1–18, 2007), who measured the exchange between a coral reef layer and the (relatively shallow) sea above.

scholarly journals Two Stage Continuous Gesture Recognition Based on Deep Learning

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 534
Author(s):  
Huogen Wang
Keyword(s):  
Gesture Recognition ◽  
Large Scale ◽  
Short Term Memory ◽  
Short Term ◽  
Hand Motion ◽  
Spatiotemporal Features ◽  
Spatiotemporal Information ◽  
Video Frames ◽  
Depth Sequences

The paper proposes an effective continuous gesture recognition method, which includes two modules: segmentation and recognition. In the segmentation module, the video frames are divided into gesture frames and transitional frames by using the information of hand motion and appearance, and continuous gesture sequences are segmented into isolated sequences. In the recognition module, our method exploits the spatiotemporal information embedded in RGB and depth sequences. For the RGB modality, our method adopts Convolutional Long Short-Term Memory Networks to learn long-term spatiotemporal features from short-term spatiotemporal features obtained from a 3D convolutional neural network. For the depth modality, our method converts a sequence into Dynamic Images and Motion Dynamic Images through weighted rank pooling and feed them into Convolutional Neural Networks, respectively. Our method has been evaluated on both ChaLearn LAP Large-scale Continuous Gesture Dataset and Montalbano Gesture Dataset and achieved state-of-the-art performance.

Species Responses to Grazing and Environmental-Factors in an Arid Halophytic Shrubland Community

1987 ◽  
Vol 35 (2) ◽  
pp. 135 ◽  
Author(s):  
RB Hacker
Keyword(s):  
Environmental Factors ◽  
Soil Salinity ◽  
Large Scale ◽  
Chemical Properties ◽  
Grazing Pressure ◽  
Aerial Photographs ◽  
Small Scale ◽  
Factors Affecting ◽  
Species Responses

Species responses to grazing and environmental factors were studied in an arid halophytic shrubland community in Western Australia. The grazing responses of major shrub species were defined by using reciprocal averaging ordination of botanical data, interpreted in conjunction with a similar ordination of soil chemical properties and measures of soil erosion derived from large-scale aerial photographs. An apparent small-scale interaction between grazing and soil salinity was also defined. Long-term grazing pressure is apparently reduced on localised areas of high salinity. Environmental factors affecting species distribution are complex and appear to include soil salinity, soil cationic balance, geomorphological variation and the influence of cryptogamic crusts on seedling establishment.

scholarly journals Measuring Sound at a Cold-Water Coral Reef to Assess the Impact of COVID-19 on Noise Pollution

2021 ◽  
Vol 8 ◽  
Author(s):  
Laurence H. De Clippele ◽  
Denise Risch
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Sea Level ◽  
Cold Water ◽  
Noise Pollution ◽  
Ecosystem Functions ◽  
Noise Levels ◽  
Level Height ◽  
Water Coral

This study compares the noise levels at the cold-water coral Tisler reef, before and after the closure of the border between Norway and Sweden, which occurred as a direct result of the COVID-19 pandemic. The Tisler reef is a marine protected area located under a ferry “highway” that connects Norway and Sweden. Cold-water coral reefs are recognised as being important hotspots of both biodiversity and biomass, they function as breeding and nursing grounds for commercially important fish and are essential in providing ecosystem functions. Whilst studies have shown that fishery, ocean warming, and acidification threaten them, the effects of noise pollution on cold-water coral reefs remains unstudied. To study the severity of noise pollution at the Tisler reef, a long-term acoustic recorder was deployed from 29 January 2020 until 26 May 2020. From 15 March COVID-19 lockdown measures stopped passenger vessel traffic between Norway and Sweden. This study found that the overall noise levels were significantly lower after border closure, due to reduced ferry traffic, wind speeds, and sea level height. When comparing the median hourly noise levels of before vs. after border closure, this study measured a significant reduction in the 63–125 Hz 1/3 octave band noise levels of 8.94 ± 0.88 (MAD) dB during the day (07:00:00–19:59:59) and 1.94 ± 0.11 (MAD) dB during the night (20:00:00–06:59:59). Since there was no ferry traffic during the night, the drop in noise levels at night was likely driven by seasonal changes, i.e., the reduction in wind speed and sea level height when transitioning from winter to spring. Taking into account this seasonal effect, it can be deduced that the COVID-19 border closure reduced the noise levels in the 63–125 Hz 1/3 octave bands at the Tisler reef by 7.0 ± 0.99 (MAD) dB during the day. While the contribution of, and changes in biological, weather-related and geophysical sound sources remain to be assessed in more detail, understanding the extent of anthropogenic noise pollution at the Tisler cold-water coral reef is critical to guide effective management to ensure the long-term health and conservation of its ecosystem functions.

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