A simple, cost-effective, morphometric marker for characterising abalone populations at multiple spatial scales

The ability to identify and separately manage component populations is becoming increasingly important in guarding against overexploitation of many marine species. Blacklip abalone (Haliotis rubra) form isolated populations with variable life history characteristics as a result of the heterogenous areas they inhabit. Many of these populations are ‘stunted’, reaching a lower maximum size compared with those in adjacent areas. We obtained a range of morphological measurements from samples of ‘stunted’ and ‘non-stunted’ H. rubra collected from sites spread across broad (tens of kilometres) and fine (hundreds of metres) spatial scales in southern South Australia. The ratio between shell length and shell height showed clear and significant differences among samples from ‘stunted’ and ‘non-stunted’ sites. The morphometric collections from the sub-sites suggested that ‘stunted’ populations existed at smaller spatial scales (up to 400 m) compared with that for ‘non-stunted’ populations (at least 1000 m). The ‘morphometric marker’ developed in the present study has the potential to be used as a tool to identify individual populations rapidly and cost-effectively that can then be managed separately. Our approach is applicable to other species of abalone as well as other sedentary invertebrates with limited larval dispersal.

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Facilitating recruitment of Amphibolis as a novel approach to seagrass rehabilitation in hydrodynamically active waters

Marine and Freshwater Research ◽

10.1071/mf09314 ◽

2010 ◽

Vol 61 (10) ◽

pp. 1123 ◽

Cited By ~ 16

Author(s):

Rachel J. Wear ◽

Jason E. Tanner ◽

Sonja L. Hoare

Keyword(s):

Large Scale ◽

Spatial Scales ◽

South Australia ◽

Cost Effective ◽

Belowground Biomass ◽

Small Scale ◽

Past Century ◽

Wastewater Management ◽

Novel Approach ◽

High Wave Energy

Worldwide, 29% of seagrass habitats have been lost over the past century. Compared with large-scale losses, successful restoration programs are usually only small scale (a few hectares). One area of significant seagrass loss (>5200 ha) is Adelaide, South Australia. Improvements to wastewater management have raised the possibility of rehabilitation in this area. Traditional methods of seagrass restoration are expensive and have had limited success owing to high wave energy. We investigated a range of biodegradable substrates, mostly made of hessian (burlap), to enhance Amphibolis recruitment as an alternative. After 5 weeks, 16 514 seedlings, or 157 seedlings m–2, had recruited. Survival declined over the following 12 months to 31.4%, and down to 7.2% after 3 years, in part as a result of breakdown of the hessian, and the wave-exposed nature of the sites. During the initial 12 months, above- and belowground biomass increased 2.6- and 6.4-fold, respectively. The technique may represent a non-destructive, cost-effective (<AU$10 000 ha–1) method to restore Amphibolis over large spatial scales and in areas that are hydrodynamically too active for traditional techniques, thus helping ameliorate some of the large-scale losses of seagrasses that have occurred globally.

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Gigapixel behavioral and neural activity imaging with a novel multi-camera array microscope

10.1101/2021.10.05.461695 ◽

2021 ◽

Author(s):

Eric Thomson ◽

Mark Harfouche ◽

Pavan Konda ◽

Catherine W Seitz ◽

Kanghyun Kim ◽

...

Keyword(s):

Neural Activity ◽

Spatial Scales ◽

Cost Effective ◽

Model Organisms ◽

Multiple Spatial Scales ◽

Carpenter Ants ◽

Camera Array ◽

Wide Range ◽

Freely Moving ◽

Living Organisms

The dynamics of living organisms are organized across many spatial scales, yet existing, cost-effective imaging systems can measure only a subset of these scales at once. Here, we have created a scalable multi-camera array microscope (MCAM) that enables comprehensive high-resolution recording from multiple spatial scales simultaneously, ranging from cellular structures to large-group behavioral dynamics. By collecting data from up to 96 cameras, we computationally generate gigapixel-scale images and movies near cellular resolution and 5 um sensitivity over hundreds of square centimeters. This allows us to observe the behavior and fine anatomical features of numerous freely moving model organisms on multiple spatial scales, including larval zebrafish, fruit flies, nematodes, carpenter ants, and slime mold. The MCAM architecture allows stereoscopic tracking of the z-position of organisms using the overlapping field of view from adjacent cameras. Further, we demonstrate the ability to acquire dual color fluorescence video of multiple freely moving zebrafish, recording neural activity via ratiometric calcium imaging. Overall, the MCAM provides a powerful platform for investigating cellular and behavioral processes across a wide range of spatial scales, but without the bottlenecks imposed by single-camera image acquisition systems.

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Inhibition of coral settlement at multiple spatial scales by a pervasive algal competitor

Marine Ecology Progress Series ◽

10.3354/meps12879 ◽

2019 ◽

Vol 612 ◽

pp. 29-42 ◽

Cited By ~ 4

Author(s):

NR Evensen ◽

C Doropoulos ◽

KM Morrow ◽

CA Motti ◽

PJ Mumby

Keyword(s):

Spatial Scales ◽

Coral Settlement ◽

Multiple Spatial Scales

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Worldview-2 and Landsat 8 Satellite Data for Seaweed Mapping along Karachi Coast

Pakistan Journal of Engineering Technology & Science ◽

10.22555/pjets.v5i2.920 ◽

2016 ◽

Vol 5 (2) ◽

Cited By ~ 1

Author(s):

Muhammad Danish Siddiqui ◽

Arjumand Z Zaidi

Keyword(s):

Satellite Data ◽

Spatial Scales ◽

Economic Value ◽

Vegetation Indices ◽

Cost Effective ◽

Geographical Information ◽

Landsat 8 ◽

Coverage Area ◽

Breeding Sites ◽

Marine Plant

Seaweed is a marine plant or algae which has economic value in many parts of the world. The purpose of this study is to evaluate different satellite sensors such as high-resolution WorldView-2 (WV2) satellite data and Landsat 8 30-meter resolution satellite data for mapping seaweed resources along the coastal waters of Karachi. The continuous monitoring and mapping of this precious marine plant and their breeding sites may not be very efficient and cost effective using traditional survey techniques. Remote Sensing (RS) and Geographical Information System (GIS) can provide economical and more efficient solutions for mapping and monitoring coastal resources quantitatively as well as qualitatively at both temporal and spatial scales. Normalized Difference Vegetation Indices (NDVI) along with the image enhancement techniques were used to delineate seaweed patches in the study area. The coverage area of seaweed estimated with WV-2 and Landsat 8 are presented as GIS maps. A more precise area estimation wasachieved with WV-2 data that shows 15.5Ha (0.155 Km2)of seaweed cover along Karachi coast that is more representative of the field observed data. A much larger area wasestimated with Landsat 8 image (71.28Ha or 0.7128 Km2) that was mainly due to the mixing of seaweed pixels with water pixels. The WV-2 data, due to its better spatial resolution than Landsat 8, have proven to be more useful than Landsat 8 in mapping seaweed patches

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Highly restricted dispersal in habitat-forming seaweed may impede natural recovery of disturbed populations

Scientific Reports ◽

10.1038/s41598-021-96027-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Florentine Riquet ◽

Christiane-Arnilda De Kuyper ◽

Cécile Fauvelot ◽

Laura Airoldi ◽

Serge Planes ◽

...

Keyword(s):

Genetic Structure ◽

Spatial Scales ◽

Mediterranean Ecosystems ◽

Dispersal Distance ◽

Genetic Connectivity ◽

Restricted Gene Flow ◽

Isolated Populations ◽

Natural Recovery ◽

Limited Dispersal ◽

Ecological Importance

AbstractCystoseira sensu lato (Class Phaeophyceae, Order Fucales, Family Sargassaceae) forests play a central role in marine Mediterranean ecosystems. Over the last decades, Cystoseira s.l. suffered from a severe loss as a result of multiple anthropogenic stressors. In particular, Gongolaria barbata has faced multiple human-induced threats, and, despite its ecological importance in structuring rocky communities and hosting a large number of species, the natural recovery of G. barbata depleted populations is uncertain. Here, we used nine microsatellite loci specifically developed for G. barbata to assess the genetic diversity of this species and its genetic connectivity among fifteen sites located in the Ionian, the Adriatic and the Black Seas. In line with strong and significant heterozygosity deficiencies across loci, likely explained by Wahlund effect, high genetic structure was observed among the three seas (ENA corrected FST = 0.355, IC = [0.283, 0.440]), with an estimated dispersal distance per generation smaller than 600 m, both in the Adriatic and Black Sea. This strong genetic structure likely results from restricted gene flow driven by geographic distances and limited dispersal abilities, along with genetic drift within isolated populations. The presence of genetically disconnected populations at small spatial scales (< 10 km) has important implications for the identification of relevant conservation and management measures for G. barbata: each population should be considered as separated evolutionary units with dedicated conservation efforts.

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Assessment of clogging in constructed wetlands by saturated hydraulic conductivity measurements

Water Science & Technology ◽

10.2166/wst.2019.045 ◽

2019 ◽

Vol 79 (2) ◽

pp. 314-322 ◽

Cited By ~ 6

Author(s):

F. Licciardello ◽

R. Aiello ◽

V. Alagna ◽

M. Iovino ◽

D. Ventura ◽

...

Keyword(s):

Sensitivity Analysis ◽

Hydraulic Conductivity ◽

Constructed Wetlands ◽

Spatial Scales ◽

Pilot Scale ◽

Laboratory Scale ◽

Test Method ◽

Conductivity Measurements ◽

Multiple Spatial Scales ◽

Ks Values

Abstract This study aims at defining a methodology to evaluate Ks reductions of gravel material constituting constructed wetland (CW) bed matrices. Several schemes and equations for the Lefranc's test were compared by using different gravel sizes and at multiple spatial scales. The falling-head test method was implemented by using two steel permeameters: one impervious (IMP) and one pervious (P) on one side. At laboratory scale, mean K values for a small size gravel (8–15 × 10−2 m) measured by the IMP and the P permeameters were equal to 19,466 m/d and 30,662 m/d, respectively. Mean Ks values for a big size gravel (10–25 × 10−2 m) measured by the IMP and the P permeameters were equal to 12,135 m/d and 20,866 m/d, respectively. Comparison of Ks values obtained by the two permeameters at laboratory scale as well as a sensitivity analysis and a calibration, lead to the modification of the standpipe equation, to evaluate also the temporal variation of the horizontal Ks. In particular, both permeameters allow the evaluation of the Ks decreasing after 4 years-operation and 1–1.5 years' operation of the plants at full scale (filled with the small size gravel) and at pilot scale (filled with the big size gravel), respectively.

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FORMULATION OF THE HEAT CONDUCTION EQUATION FOR HETEROGENEOUS MEDIA WITH MULTIPLE SPATIAL SCALES USING REITERATED HOMOGENIZATION

Revista de Engenharia Térmica ◽

10.5380/reterm.v15i1.62165 ◽

2016 ◽

Vol 15 (1) ◽

pp. 96

Author(s):

E. Iglesias-Rodríguez ◽

M. E. Cruz ◽

J. Bravo-Castillero ◽

R. Guinovart-Díaz ◽

R. Rodríguez-Ramos ◽

...

Keyword(s):

Heat Conduction ◽

Small Parameter ◽

Heat Conduction Equation ◽

Heterogeneous Media ◽

Spatial Scales ◽

Conduction Equation ◽

Small Scale ◽

Multiple Spatial Scales ◽

Effective Coefficients ◽

Reiterated Homogenization

Heterogeneous media with multiple spatial scales are finding increased importance in engineering. An example might be a large scale, otherwise homogeneous medium filled with dispersed small-scale particles that form aggregate structures at an intermediate scale. The objective in this paper is to formulate the strong-form Fourier heat conduction equation for such media using the method of reiterated homogenization. The phases are assumed to have a perfect thermal contact at the interface. The ratio of two successive length scales of the medium is a constant small parameter ε. The method is an up-scaling procedure that writes the temperature field as an asymptotic multiple-scale expansion in powers of the small parameter ε . The technique leads to two pairs of local and homogenized equations, linked by effective coefficients. In this manner the medium behavior at the smallest scales is seen to affect the macroscale behavior, which is the main interest in engineering. To facilitate the physical understanding of the formulation, an analytical solution is obtained for the heat conduction equation in a functionally graded material (FGM). The approach presented here may serve as a basis for future efforts to numerically compute effective properties of heterogeneous media with multiple spatial scales.

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