scholarly journals The spatial distribution of shallow-water (<150 m) black corals (Cnidaria: Antipatharia) in the Hawaiian Archipelago

2015 ◽  
Vol 8 ◽  
Author(s):  
Daniel Wagner
Keyword(s):  
Spatial Distribution ◽  
Coral Species ◽  
Individual Species ◽  
Hawaiian Archipelago ◽  
Black Coral ◽  
Ecological Features ◽  
Black Corals ◽  
Single Category ◽  
The Mean ◽  
Hard Substrates

The Hawaiian Archipelago contains some of the best surveyed black coral populations on the globe; however, most previous surveys have grouped all black coral species into a single category. As a result, the unique ecological features of individual species have not been identified. This study mapped the spatial distribution of eight antipatharian species (Antipathes griggi,Antipathes grandis,Cirrhipathescf.anguina,Stichopathes echinulata,Stichopathes?sp.,Aphanipathes verticillata,Acanthopathes undulataandMyriopathescf.ulex) found in shallow-waters (&lt;150 m) along the Hawaiian Archipelago, and compared data on substrate type, depth and temperature among species. All black coral species were exclusively recorded on hard substrates and were generally widely distributed along the Hawaiian Islands. Additionally, antipatharian species were found at overlapping depths and temperatures, although there were significant differences in the mean depths and temperatures between most species. In cases where species did not have significant differences in mean depths, the overlapping species had different colony and polyp morphologies, which may serve to minimize competition by allowing species to grow most efficiently under particular current regimes. This study represents one of the first to map the spatial distribution of sympatric antipatharian species, and indicates that individual species exploit unique environments in terms of depth and temperature or have unique morphologies to avoid overlap.

scholarly journals Assessing population changes of historically overexploited black corals (Order: Antipatharia) in Cozumel, Mexico

2017 ◽  
Author(s):  
Erika Gress ◽  
Dominic A Andradi-Brown
Keyword(s):  
Coral Species ◽  
Ecological Role ◽  
Population Changes ◽  
Mesophotic Coral Ecosystems ◽  
Juvenile Mortality ◽  
Recruitment Failure ◽  
Black Coral ◽  
Black Corals ◽  
Cozumel Island ◽  
The Government

Black corals (Antipatharians) play a crucial structural and ecological role on many mesophotic coral ecosystems (MCEs; reefs 30-150 m depth). In Mexico, black corals are harvested for the jewellery industry, which has historically led to populations depletion. Harvesting began in the early 1960s, and was concentrated around Cozumel Island until 1995. Here we compare populations between 1998 and 2016 for the two black coral species targeted by the jewellery industry. We found that densities of Plumapathes pennacea in 2016 are substantially lower than in 1998. However, the 2016 P. pennacea population has shifted to be dominated by larger colonies, suggesting disproportionate juvenile mortality or recruitment failure. No change in population density or colony size of Antipathes caribbeana was detected between 1998 and 2016. We advocate for the adequate protection of black corals in Mexico, and for the government to ensure sustainability of the harvesting before issuing future permits.

scholarly journals Assessing population changes of historically overexploited black corals (Order: Antipatharia) in Cozumel, Mexico

2017 ◽  
Author(s):  
Erika Gress ◽  
Dominic A Andradi-Brown
Keyword(s):  
Coral Species ◽  
Ecological Role ◽  
Population Changes ◽  
Mesophotic Coral Ecosystems ◽  
Juvenile Mortality ◽  
Recruitment Failure ◽  
Black Coral ◽  
Black Corals ◽  
Cozumel Island ◽  
The Government

Black corals (Antipatharians) play a crucial structural and ecological role on many mesophotic coral ecosystems (MCEs; reefs 30-150 m depth). In Mexico, black corals are harvested for the jewellery industry, which has historically led to populations depletion. Harvesting began in the early 1960s, and was concentrated around Cozumel Island until 1995. Here we compare populations between 1998 and 2016 for the two black coral species targeted by the jewellery industry. We found that densities of Plumapathes pennacea in 2016 are substantially lower than in 1998. However, the 2016 P. pennacea population has shifted to be dominated by larger colonies, suggesting disproportionate juvenile mortality or recruitment failure. No change in population density or colony size of Antipathes caribbeana was detected between 1998 and 2016. We advocate for the adequate protection of black corals in Mexico, and for the government to ensure sustainability of the harvesting before issuing future permits.

scholarly journals Assessing population changes of historically overexploited black corals (Order: Antipatharia) in Cozumel, Mexico

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5129 ◽  
Author(s):  
Erika Gress ◽  
Dominic A. Andradi-Brown
Keyword(s):  
Coral Species ◽  
Scientific Evidence ◽  
Population Changes ◽  
Mesophotic Coral Ecosystems ◽  
Juvenile Mortality ◽  
Recruitment Failure ◽  
Black Coral ◽  
Black Corals ◽  
Cozumel Island ◽  
Mexican Caribbean

Black corals (Antipatharians) are crucial structural and ecological components of many mesophotic coral ecosystems (MCEs; reefs 30–150 m depth). In Mexico, black corals are harvested for the jewellery industry, which has historically led to population depletion. Harvesting began in the early 1960s and was concentrated around Cozumel Island until 1995. Since then, harvesting permits have been granted only for the mainland coast. Here we compare Cozumel populations between 1998 and 2016 for the two black coral species targeted by the jewellery industry. We found that densities of Plumapathes pennacea in 2016 were substantially lower than in 1998. However, the 2016 P. pennacea population has shifted to be dominated by larger colonies, suggesting disproportionate juvenile mortality or recruitment failure. Low numbers of Antipathes caribbeana were recorded, and no change in population density or colony size was detected between 1998 and 2016. Despite harvesting occurring for almost 70 years in the Mexican Caribbean, no information on reproduction, recruitment and other dynamics of the targeted species is available. We advocate for harvesting permits to be based on scientific evidence, and for implementation of future restrictions to prevent total depletion of black corals in the area.

scholarly journals Distribution of deep-water corals of the Flemish Cap, Flemish Pass, and the Grand Banks of Newfoundland (Northwest Atlantic Ocean): interaction with fishing activities

2010 ◽  
Vol 68 (2) ◽  
pp. 319-332 ◽  
Author(s):  
F. J. Murillo ◽  
P. Durán Muñoz ◽  
A. Altuna ◽  
A. Serrano
Keyword(s):  
Atlantic Ocean ◽  
Continental Slope ◽  
Deep Water ◽  
Coral Species ◽  
Habitat Mapping ◽  
Bottom Trawl ◽  
Soft Corals ◽  
Northwest Atlantic ◽  
Grand Banks ◽  
Black Corals

Abstract Murillo, F. J., Durán Muñoz, P., Altuna, A., and Serrano, A. 2011. Distribution of deep-water corals of the Flemish Cap, Flemish Pass, and the Grand Banks of Newfoundland (Northwest Atlantic Ocean): interaction with fishing activities. – ICES Journal of Marine Science, 68: 319–332. The distribution of deep-water corals of the Flemish Cap, Flemish Pass, and the Grand Banks of Newfoundland is described based on bycatch from Spanish/EU bottom trawl groundfish surveys between 40 and 1500 m depth. In all, 37 taxa of deep-water corals were identified in the study area: 21 alcyonaceans (including the gorgonians), 11 pennatulaceans, 2 solitary scleractinians, and 3 antipatharians. The greatest diversity of coral species was on the Flemish Cap. Corals were most abundant along the continental slope, between 600 and 1300 m depth. Soft corals (alcyonaceans), sea fans (gorgonians), and black corals (antipatharians) were most common on bedrock or gravel, whereas sea pens (pennatulaceans) and cup corals (solitary scleractinians) were found primarily on mud. The biomass of deep-water corals in the bycatches was highest in previously lightly trawled or untrawled areas, and generally low in the regularly fished grounds. The information derived from bottom-trawl bycatch records is not sufficient to map vulnerable marine ecosystems (VMEs) accurately, but pending more detailed habitat mapping, it provides a valuable indication of the presence/absence of VMEs that can be used to propose the candidate areas for bottom fishery closures or other conservation measures.

Phylogenetic relationships of Mediterranean black corals (Cnidaria : Anthozoa : Hexacorallia) and implications for classification within the order Antipatharia

2018 ◽  
Vol 32 (5) ◽  
pp. 1102 ◽  
Author(s):  
M. Bo ◽  
M. Barucca ◽  
M. A. Biscotti ◽  
M. R. Brugler ◽  
A. Canapa ◽  
...  
Keyword(s):  
Type Species ◽  
Sequence Data ◽  
Coral Fauna ◽  
Black Coral ◽  
Phylogenetic Studies ◽  
Black Corals ◽  
The Family ◽  
The Mediterranean ◽  
Its1 And Its2 Rdna ◽  
Its1 And Its2

The Mediterranean black coral fauna includes type species of four antipatharian genera belonging to four different families, therefore phylogenetic studies hold great potential for enhancing systematics within the order. The analysis of six Mediterranean antipatharian species by means of nuclear sequence data of internal transcribed spacer (ITS1 and ITS2) rDNA confirms the separation into different families, as was previously noted on a morphological basis, with a clear distinction of the family Leiopathidae, whose position is supported by a unique number of mesenteries and lack of spines on thicker ramifications. The position of a newly recorded black coral species for the Mediterranean basin belonging to the genus Phanopathes is discussed. Antipathes dichotoma, the type species of the genus Antipathes, on which the order Antipatharia was based, does not group with other members of the family Antipathidae. Supporting a recent finding based on mitochondrial markers, this suggests a critical need for revision of the families that will be impacted by reassignment of this nomenclaturally important taxon.

scholarly journals Finding the pattern: online extraction of spatial structure during virtual navigation

2019 ◽  
Author(s):  
Kathryn Nicole Graves ◽  
James Antony ◽  
Nicholas Turk-Browne
Keyword(s):  
Spatial Distribution ◽  
Animal Behavior ◽  
Virtual Water ◽  
Single Session ◽  
Statistical Knowledge ◽  
Navigation Patterns ◽  
The Mean ◽  
Online Extraction ◽  
Human Participants ◽  
The Individual

While navigating the world, we pick up on patterns of where things tend to appear. According to theories of memory and studies of animal behavior, knowledge of these patterns emerges gradually over days or weeks, via consolidation of individual navigation episodes. Here we discover that navigation patterns can also be extracted online, prior to the opportunity for offline consolidation, as a result of rapid statistical learning. Human participants navigated a virtual water maze in which platform locations were drawn from a spatial distribution. Within a single session, participants increasingly navigated through the mean of the distribution. This behavior was better simulated by random walks from a model with only an explicit representation of the current mean, compared to a model with only memory for the individual platform locations. These results suggest that participants rapidly summarized the underlying spatial distribution and used this statistical knowledge to guide future navigation.

Chemical Concentration and Spatial Uniformity of a Premixing In-Line Injection System Attached to a Variable-Rate Orchard Sprayer

2021 ◽  
Vol 64 (6) ◽  
pp. 1977-1987
Author(s):  
Zhihong Zhang ◽  
Heping Zhu ◽  
Zhiming Wei ◽  
Ramon Salcedo
Keyword(s):  
Spatial Distribution ◽  
Duty Cycle ◽  
Spray Deposition ◽  
Injection System ◽  
List Type ◽  
Variable Rate ◽  
Chemical Concentration ◽  
Fluorescent Tracer ◽  
Distribution Uniformity ◽  
The Mean

HighlightsA newly developed premixing in-line injection system attached to a variable-rate orchard sprayer was evaluated.Tests were conducted to verify the in-line injection system performance using a vertical spray patternator.Concentration accuracy and spatial distribution uniformity were determined with a fluorescent tracer.Uniform spray mixtures were obtained for different spray viscosities and duty cycle combinations.Abstract. Pesticide spray application efficiency is highly dependent on the chemical concentration accuracy and spatial distribution uniformity. In this study, the performance of a newly developed premixing in-line injection system was evaluated when it was attached to a laser-guided, pulse width modulated (PWM), variable-rate orchard sprayer. The chemical concentration accuracy was determined with respect to spray deposition with a fluorescent tracer, and the spatial distribution uniformity was determined with spray deposits at different heights on a vertical spray patternator. Outdoor tests were conducted with 27 combinations of target chemical concentration (1.0%, 1.5%, and 2.0%), viscosity of the simulated pesticide (1.0, 12.0, and 24.0 mPa·s), and various spray outputs manipulated with PWM duty cycles. For each injection loop, the amounts of the chemical concentrate and water discharged into the mixing line were measured separately in response to preset target concentrations. The results showed that the measured concentrations were consistent across the patternator heights, spray viscosities, and duty cycle combinations. For all treatments, the mean absolute percentage error (MAPE) of the measured concentration was 6.96%, indicating that the concentration accuracy of the system was acceptable. The mean coefficient of variation was 3.35%, indicating that the spatial distribution uniformity of the system was in the desirable range. In addition, there was little variation in chemical concentration for spray mixtures collected at different heights on the patternator. Thus, the premixing in-line injection system could adequately dispense chemical concentrate and water to produce accurate concentrations and uniform spray mixtures for variable-rate nozzles to discharge to targets. Keywords: Environment protection, Precision pesticide application, Laser-guided sprayer, Tank mixture disposal, Specialty crop.

scholarly journals Occurrence and Spatial Distribution of Dibothriocephalus Latus (Cestoda: Diphyllobothriidea) in Lake Iseo (Northern Italy): An Update

2020 ◽  
Vol 17 (14) ◽  
pp. 5070
Author(s):  
Vasco Menconi ◽  
Paolo Pastorino ◽  
Ivana Momo ◽  
Davide Mugetti ◽  
Maria Cristina Bona ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Perca Fluviatilis ◽  
Northern Italy ◽  
Commercial Fishing ◽  
European Perch ◽  
Chi Square ◽  
Mean Intensity ◽  
Southern Area ◽  
Total Prevalence ◽  
The Mean

Dibothriocephalus latus (Linnaeus, 1758) (Cestoda: Diphyllobothriidea; syn. Diphyllobothrium latum), is a fish-borne zoonotic parasite responsible for diphyllobothriasis in humans. Although D. latus has long been studied, many aspects of its epidemiology and distribution remain unknown. The aim of this study was to investigate the prevalence, mean intensity of infestation, and mean abundance of plerocercoid larvae of D. latus in European perch (Perca fluviatilis) and its spatial distribution in three commercial fishing areas in Lake Iseo (Northern Italy). A total of 598 specimens of P. fluviatilis were caught in 2019. The total prevalence of D. latus was 6.5%. However, there were significant differences between areas (10.2% North; 7.3% Center; 1.5% South) (Chi-square test, p = 0.0018). The mean intensity of infestation ranged from 1 larva in southern area to 1.2 larvae in both the central and northern (Pisogne) areas. In addition, the mean abundance ranged from 0.02 in the southern area to 0.26 in the northern area (Pisogne). The total number of larvae (anterior dorsal—AD = 21; anterior ventral—AV = 1; posterior dorsal—PD = 15; posterior ventral—PV = 5) differed significantly between the four anatomical quadrants (Kruskal–Wallis test; p = 0.0001). The prevalence of D. latus plerocercoid larvae in European perch from Lake Iseo has long been investigated, but without an appropriate sampling design. With the present study, a broader analysis in spatial distribution has been added to the existing literature, revealing new information about D. latus distribution and occurrence in Lake Iseo, with new data that will be useful for health authorities and future studies.

Rabbit warren distribution in relation to pasture communities in Mediterranean habitats: consequences for management of rabbit populations

2005 ◽  
Vol 32 (8) ◽  
pp. 723 ◽  
Author(s):  
G. Gea-Izquierdo ◽  
J. Muñoz-Igualada ◽  
A. San Miguel-Ayanz
Keyword(s):  
Spatial Distribution ◽  
Selection Index ◽  
Wild Rabbit ◽  
Grassland Community ◽  
Mediterranean Habitats ◽  
The Mean ◽  
Grassland Communities ◽  
Shallow Soils ◽  
Deep Soils ◽  
The Relationship

Iberian wild rabbit numbers have decreased in the last decades. The management implemented to recover rabbit populations includes several techniques, one of the most common being the construction of artificial rabbit warrens. To optimally distribute the artificial warrens in the field it is essential to understand natural warren microhabitat. Few studies have investigated the relationship between rabbits and grassland communities. In this work we study the spatial distribution and characteristics of rabbit warrens as well as their relation to grasslands in Mediterranean woodlands of central Spain. During the summer of 2001, three 12.5-ha study plots, including the most representative grassland communities of the area, were selected. All rabbit warrens were surveyed and the active and total entrances, shrub cover, grassland community and warren cover type were characterised. A grassland community selection index was calculated and the warren spatial distribution analysed. Ploughed lands and shallow soils were unsuitable for warren establishment. The mean number of burrow entrances per warren was 5.8 (4.4 active), and warren clustering occurred only in ploughed plots. However, pasture communities composed of annual and perennial species growing on unploughed deep sandy soils were preferentially selected. Most warrens (81.4%) were dug under some kind of protection such as shrub roots and rocks. According to our results, when designing rabbit restocking programs that include the provision of artificial warrens, unploughed deep soils with plenty of shrubs and rocks should be preferentially selected to locate the artificial warrens, which should be spaced so there are ~10 warrens per hectare and ~5–6 burrow entrances per warren.

scholarly journals On the influence of the spatial distribution of fine content in the hydraulic conductivity of sand-clay mixtures

2018 ◽  
Vol 22 (4) ◽  
pp. 239-249 ◽  
Author(s):  
William Mario Fuentes ◽  
Carolina Hurtado ◽  
Carlos Lascarro
Keyword(s):  
Spatial Distribution ◽  
Hydraulic Conductivity ◽  
Numerical Model ◽  
Soil Sample ◽  
Gaussian Distribution ◽  
Geotechnical Engineering ◽  
Empirical Relation ◽  
Fine Content ◽  
The Mean

Sand-clay mixtures are one of the most usual types of soils in geotechnical engineering. These soils present a hydraulic conductivity which highly depends on the fine content. In this work, it will be shown, that not only the mean fine content of a soil sample affects its hydraulic conductivity, but also its spatial distribution within the sample. For this purpose, a set of hydraulic conductivity tests with sand-clay mixtures have been conducted to propose an empirical relation of the hydraulic conductivity depending on the fine content. Then, a numerical model of a large scaled hydraulic conductivity test is constructed. In this model, the heterogeneity of the fine content is simulated following a Gaussian distribution. The equivalent hydraulic conductivity resulting of the whole model is then computed and the influence of the spatial distribution of the fine content is evaluated. The results indicate that the hydraulic conductivity is not only related to the mean fine content, but also on its heterogeneity.

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