Distribution and abundance of dugongs in Moreton Bay, Queensland, Australia

2003 ◽  
Vol 30 (4) ◽  
pp. 397 ◽  
Author(s):  
Janet M. Lanyon
Keyword(s):  
Hot Spots ◽  
Population Estimates ◽  
Correction Factors ◽  
Water Turbidity ◽  
Mean Intensity ◽  
Moreton Bay ◽  
Perception Bias ◽  
Species Specific ◽  
High Degree ◽  
Specific Correction

Dugong abundances in Moreton Bay (south-east Queensland) were estimated during six bi-monthly aerial surveys throughout 1995. Sampling intensity ranged between 20 and 80% for different sampling zones within the Bay, with a mean intensity of 40.5%. Population estimates for dugongs were corrected for perception bias (the proportion of animals visible in the transect that were missed by observers), and standardised for availability bias (the proportion of animals that were invisible due to water turbidity) with survey and species-specific correction factors. Population estimates for dugongs in Moreton Bay ranged from 503 ± 64 (s.e.) in July to 1019 ± 166 in January. The highest uncorrected count was 857 dugongs in December. This is greater than previous population estimates, suggesting that either previous surveys have underestimated abundance and/or that this population may have increased through recruitment, immigration, or a combination of both. The high degree of variation in population estimates between surveys may be due to temporal differences in distribution and herding behaviour. In winter, dugongs were found in smaller herds and were dispersed over a wider area than in summer. The Eastern Banks region of the bay supported 80–98% of the dugong population at any one time. Within this region, there were several dugong 'hot spots' that were visited repeatedly by large herds. These 'hot spots' contained seagrass communities that were dominated by species that dugongs prefer to eat. The waters of Rous Channel, South Passage and nearby oceanic waters are also frequently inhabited by dugongs in the winter months. Dugongs in other parts of Moreton Bay were at much lower densities than on the Eastern Banks.

The distribution and abundance of the dugong in Shark Bay, Western Australia

1994 ◽  
Vol 21 (2) ◽  
pp. 149 ◽  
Author(s):  
H Marsh ◽  
RIT Prince ◽  
WK Saafeld ◽  
R Shepherd
Keyword(s):  
Western Australia ◽  
Large Scale ◽  
Correction Factors ◽  
Water Turbidity ◽  
Shark Bay ◽  
Northern Half ◽  
Perception Bias ◽  
Calving Rate ◽  
Specific Correction ◽  
Eastern Half

In July 1989, dugongs were counted from the air at an overall sampling intensity of 7.9% over 14 239 km2 in Shark Bay, Western Australia. Counts were corrected for perception bias (the proportion of dugongs visible in the transect that are missed by observers), and standardised for availability bias (the proportion of animals invisible because of water turbidity) with survey-specific correction factors. The resultant minimum population estimate was 10146 � 1665 (s.e.) dugongs at an overall density of 0.71 � 0.12 (s.e.) dugongs km-2, the highest density ever recorded on a large-scale dugong survey. The proportion of calves (19%) was higher than for most other dugong surveys conducted in Shark Bay and elsewhere, suggesting an exceptionally high calving rate in 1988. Dugong density was highest (>5 km-2) in relatively deep water (12-16 m) in the eastern half of Shark Bay opposite the tip of Peron Peninsula and in the western Bay opposite the northern half of Dirk Hartog Island. Fewer than 4% of dugongs sighted in Shark Bay during the survey were in waters colder than 18�C. Results of aerial surveys over 906 km2 in the Faure Sill region of the eastern Bay in November 1990 and January 1991 suggest that between a third and a half of the dugongs in Shark Bay are located in this region during the summer. In contrast, only one dugong was sighted there during the winter survey. The survey confirms that Shark Bay is an internationally significant dugong habitat.

Distribution and Abundance of Dugongs in the Northern Great Barrier-Reef Marine Park

1989 ◽  
Vol 16 (4) ◽  
pp. 429 ◽  
Author(s):  
H Marsh ◽  
WK Saalfeld
Keyword(s):  
Great Barrier Reef ◽  
Population Estimate ◽  
Seagrass Beds ◽  
Barrier Reef ◽  
Correction Factors ◽  
Water Turbidity ◽  
Density Estimates ◽  
Marine Park ◽  
Perception Bias ◽  
Specific Correction

In 1984 and 1985, dugongs were censused from the air at an overall sampling intensity of 9% over a total area of 31 288 km2 within the northern sections of the Great Barrier Reef Marine Park. Sightings were corrected for perception bias (the proportion of animals visible in the transect which are missed by observers), and availability bias (the proportion of animals that are invisible due to water turbidity) with survey-specific correction factors. There were no significant differences between population and density estimates obtained from repeat surveys of the same areas. The resultant population estimate (�s.e.) was 8110 � 1073 dugongs at an overall density (� s.e.) of 0.26�0.03 km-2, a precision of 13%. Dugongs occurred up to 58 km offshore and in water up to 37 m deep. The highest density of animals was seen on coastal seagrass beds at depths of <5 m. Maps of density and distribution are given. The design and timing of future surveys is also discussed.

scholarly journals Microscale Heterogeneous Distribution and Speciation of Phosphorus in Soils Amended with Mineral Fertilizer and Cattle Manure Compost

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 121
Author(s):  
Noriko Yamaguchi ◽  
Toshiaki Ohkura ◽  
Atsuko Hikono ◽  
Yohey Hashimoto ◽  
Aomi Suda ◽  
...  
Keyword(s):  
Hot Spots ◽  
Mineral Fertilizer ◽  
Chemical Extraction ◽  
Heterogeneous Distribution ◽  
Edge Structure ◽  
Soil P ◽  
Macro Scale ◽  
Cattle Manure Compost ◽  
High Degree

Global concerns for the sustainability of agriculture have emphasized the need to reduce the use of mineral fertilizer. Although phosphorus (P) is accumulated in farmland soils due to the long-term application of fertilizer, most soil P is not readily available to plants. The chemical speciation of P in soils, which comprise heterogeneous microenvironments, cannot be evaluated with a high degree of specificity using only macroscopic analyses. In this study, we investigated the distribution and speciation of P accumulated in soils by using both macro- and microscopic techniques including chemical extraction, solution and solid-state 31P NMR, bulk- and micro- P K-edge X-ray absorption near edge structure (XANES), and electron probe microanalysis (EPMA). Soil samples were collected from a field in which cabbage was cultivated under three amendment treatments: i) mineral fertilizer (NPK), ii) mineral fertilizer and compost (NPK + compost), and iii) mineral fertilizer plus compost but without nitrogen fertilizer (PK + compost). Macro-scale analyses suggested that accumulated P was predominantly inorganic P and associated with Al-bearing minerals. The repeated application of compost to the soils increased the proportion of P associated with Ca which accounted for 17% in the NPK + compost plot and 40% in the PK + compost plot. At the microscale, hot spots of P were heterogeneously distributed, and P was associated with Fe and Ca in hot spots of the NPK + compost (pH 6) and PK + compost (pH 7) treated samples, respectively. Our results indicate that application of compost contributed to creating diverse microenvironments hosting P in these soils.

Aerial Surveys of Sea Turtles in the Northern Great Barrier-Reef Marine Park

1989 ◽  
Vol 16 (3) ◽  
pp. 239 ◽  
Author(s):  
H Marsh ◽  
WK Saalfeld
Keyword(s):  
Great Barrier Reef ◽  
Sea Turtles ◽  
Analysis Of Covariance ◽  
Seagrass Beds ◽  
Barrier Reef ◽  
Sea State ◽  
Water Turbidity ◽  
Density Estimates ◽  
Marine Park ◽  
Specific Correction

In 1984 and 1985, during surveys designed primarily to census dugongs, six species of sea turtles were counted from the air at an overall sampling intensity of 9% over a total area of 31 288 km2 within the northern sections of the Great Barrier Reef Marine Park. The sea turtles were not identified to species. We attempted to correct sightings for perception bias (the proportion of animals visible in the transect which are missed by observers), and to standardise for availability bias (the.proportion of animals that are invisible due to water turbidity) with survey-specific correction factors. The resultant minimum population estimate in November 1985 was (mean � s.e.) 32 187 � 2532 sea turtles at an overall density of 1.03 � 0.08 km-2, a precision of 8%. We consider this to be a gross underestimate of numbers present. Significant differences between population and density estimates obtained from repeat surveys of the same areas were accounted for by differences in Beaufort sea state and cloud cover. The analysis of covariance data suggested that we had not been successful in standardising all biases. Turtles were widely distributed throughout the Great Barrier Reef lagoon from inshore seagrass beds to mid- and outer-shelf reefs. Highest densities were observed on inshore seagrass beds and on mid-shelf reefs, particularly between Murdoch Island and Cape Melville, and in Princess Charlotte Bay. Maps of density and distribution are given. We discuss the value and limitations of this survey regime for censusing sea turtles.

scholarly journals A species-specific nucleosomal signature defines a periodic distribution of amino acids in proteins

Open Biology ◽  
2015 ◽  
Vol 5 (4) ◽  
pp. 140218 ◽  
Author(s):  
Luis Quintales ◽  
Ignacio Soriano ◽  
Enrique Vázquez ◽  
Mónica Segurado ◽  
Francisco Antequera
Keyword(s):  
Amino Acids ◽  
Protein Composition ◽  
Open Reading Frames ◽  
Yeast Genome ◽  
Relative Distribution ◽  
Periodic Distribution ◽  
Wide Range ◽  
Average Distribution ◽  
Species Specific ◽  
High Degree

Nucleosomes are the basic structural units of chromatin. Most of the yeast genome is organized in a pattern of positioned nucleosomes that is stably maintained under a wide range of physiological conditions. In this work, we have searched for sequence determinants associated with positioned nucleosomes in four species of fission and budding yeasts. We show that mononucleosomal DNA follows a highly structured base composition pattern, which differs among species despite the high degree of histone conservation. These nucleosomal signatures are present in transcribed and non-transcribed regions across the genome. In the case of open reading frames, they correctly predict the relative distribution of codons on mononucleosomal DNA, and they also determine a periodicity in the average distribution of amino acids along the proteins. These results establish a direct and species-specific connection between the position of each codon around the histone octamer and protein composition.

scholarly journals The Role of Plasticity and Adaptation in the Incipient Speciation of a Fire Salamander Population

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 875
Author(s):  
Joana Sabino-Pinto ◽  
Daniel J. Goedbloed ◽  
Eugenia Sanchez ◽  
Till Czypionka ◽  
Arne W. Nolte ◽  
...  
Keyword(s):  
Gene Expression ◽  
Phenotypic Plasticity ◽  
Local Adaptation ◽  
Habitat Preferences ◽  
Genetic Change ◽  
Incipient Speciation ◽  
Expression Of Genes ◽  
Species Specific ◽  
Reciprocal Transfer ◽  
High Degree

Phenotypic plasticity and local adaptation via genetic change are two major mechanisms of response to dynamic environmental conditions. These mechanisms are not mutually exclusive, since genetic change can establish similar phenotypes to plasticity. This connection between both mechanisms raises the question of how much of the variation observed between species or populations is plastic and how much of it is genetic. In this study, we used a structured population of fire salamanders (Salamandra salamandra), in which two subpopulations differ in terms of physiology, genetics, mate-, and habitat preferences. Our goal was to identify candidate genes for differential habitat adaptation in this system, and to explore the degree of plasticity compared to local adaptation. We therefore performed a reciprocal transfer experiment of stream- and pond-originated salamander larvae and analyzed changes in morphology and transcriptomic profile (using species-specific microarrays). We observed that stream- and pond-originated individuals diverge in morphology and gene expression. For instance, pond-originated larvae have larger gills, likely to cope with oxygen-poor ponds. When transferred to streams, pond-originated larvae showed a high degree of plasticity, resembling the morphology and gene expression of stream-originated larvae (reversion); however the same was not found for stream-originated larvae when transferred to ponds, where the expression of genes related to reduction-oxidation processes was increased, possibly to cope with environmental stress. The lack of symmetrical responses between transplanted animals highlights the fact that the adaptations are not fully plastic and that some level of local adaptation has already occurred in this population. This study illuminates the process by which phenotypic plasticity allows local adaptation to new environments and its potential role in the pathway of incipient speciation.

scholarly journals Variation in selection constraints on teleost TLRs with emphasis on their repertoire in the Walking catfish, Clarias batrachus

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Manisha Priyam ◽  
Sanjay K. Gupta ◽  
Biplab Sarkar ◽  
T. R. Sharma ◽  
A. Pattanayak
Keyword(s):  
Phylogenetic Analysis ◽  
Positive Selection ◽  
Strong Evidence ◽  
Selection Pressure ◽  
Arms Race ◽  
Clarias Batrachus ◽  
Toll Like Receptors ◽  
Specific Variation ◽  
Species Specific ◽  
High Degree

AbstractThe high degree of conservation of toll-like receptors (TLRs), and yet their subtle variations for better adaptation of species in the host–pathogen arms race make them worthy candidates for understanding evolution. We have attempted to track the trend of TLR evolution in the most diverse vertebrate group—teleosts, where Clarias batrachus was given emphasis, considering its traits for terrestrial adaptation. Eleven C. batrachus TLRs (TLR1, 2, 3, 5, 7, 8 9, 13, 22, 25, 26) were identified in this study which clustered in proximity to its Siluriformes relative orthologues in the phylogenetic analysis of 228 TLRs from 25 teleosts. Ten TLRs (TLR1, 2, 3, 5, 7, 8 9, 13, 21, 22) with at least 15 member orthologues for each alignment were processed for selection pressure and coevolutionary analysis. TLR1, 7, 8 and 9 were found to be under positive selection in the alignment-wide test. TLR1 also showed maximum episodic diversification in its clades while the teleost group Eupercaria showed the maximum divergence in their TLR repertoire. Episodic diversification was evident in C. batrachus TLR1 and 7 alignments. These results present a strong evidence of a divergent TLR repertoire in teleosts which may be contributing towards species-specific variation in TLR functions.

Preliminary estimates of stocks of the king prawn, Penaeus plebejus, in south-east Queensland

1974 ◽  
Vol 25 (1) ◽  
pp. 35 ◽  
Author(s):  
C Lucas
Keyword(s):  
Population Estimates ◽  
Population Parameters ◽  
Offshore Area ◽  
Moreton Bay

Population estimates of the king prawn, Penaeus plebejus, in Moreton Bay and adjacent offshore areas are made from a study of commercial catches and by tag-recapture experiments. Juvenile prawns which are abundant in Moreton Bay during the summer months rapidly migrate to adjacent offshore areas and form the basis of an offshore fishery. Population parameters for Moreton Bay are F1 = 0.04, E1 = 0.17 and M1 ≤ 0.22 week-1. For the adjacent offshore area the parameters are F2 = 0.02, M2 = 0.05 week-1. These estimates indicate that of the order of 17% of the available stock is caught in Moreton Bay and that of the order of 26% of the available stock is caught in the offshore area off Mooloolaba. From a yield equation the response in catch to variations in fishing intensity is estimated.

An empirical derivation of the X-ray optic transmission profile used in calibrating the Planetary Instrument for X-ray Lithochemistry (PIXL) for Mars 2020

2018 ◽  
Vol 33 (2) ◽  
pp. 162-165 ◽  
Author(s):  
C. M. Heirwegh ◽  
W. T. Elam ◽  
D. T. Flannery ◽  
A. C. Allwood
Keyword(s):  
Energy Region ◽  
High Energy ◽  
Conventional Approach ◽  
Smoothing Algorithm ◽  
Correction Factors ◽  
High Energy Region ◽  
X Ray ◽  
Straightforward Method ◽  
Specific Correction ◽  
Energy Portion

Calibration of the prototype Planetary Instrument for X-ray Lithochemistry (PIXL) selected for Mars 2020 has commenced with an empirical derivation of the X-ray optic transmission profile. Through a straightforward method of dividing a measured “blank” spectrum over one calculated assuming no optic influence, a rudimentary profile was formed. A simple boxcar-smoothing algorithm was implemented to approximate the complete profile that was incorporated into PIQUANT. Use of this form of smoothing differs from the more conventional approach of using a parameter-based function to complete the profile. Comparison of element-specific correction factors, taken from a measurement of NIST SRM 610, was used to assess the accuracy of the new profile. Improvement in the low- to mid-energy portion of the data was apparent though the high-energy region diverged from unity, and thus, requires further refinement.

The occurrence ofCaryophyllaeus laticepsin the naseChondrostoma nasusfrom Austrian rivers: possible anthropogenic factors

2008 ◽  
Vol 82 (1) ◽  
pp. 53-58 ◽  
Author(s):  
F. Jirsa ◽  
R. Konecny ◽  
C. Frank
Keyword(s):  
Ecological Integrity ◽  
First Record ◽  
Fish Population ◽  
Anthropogenic Factors ◽  
Mean Intensity ◽  
Chondrostoma Nasus ◽  
The Mean ◽  
Low Prevalence ◽  
Anthropogenic Alterations ◽  
High Degree

AbstractBetween April 2003 and November 2006 a total of 198 naseChondrostoma nasus(L.) were examined for parasites from seven river sites in Austria. The selected sites showed different levels of anthropogenic alterations in river morphology ranging from pristine areas, with minor anthropogenic alterations, to strongly physically altered rivers. A variety of parasites were recovered from the skin, gills, swimbladder and eyes, withCaryophyllaeus laticeps(Pallas) being identified as the only cestode species occurring in the intestine. This is the first record of this species in nase in Austria.Caryophyllaeus laticepswas confined to the first 20% of the intestine, even in heavily infected hosts. The occurrence ofC. laticepswithin the fish population seems to be correlated with the degree of anthropogenic changes of the nase's habitat. In rivers with a high degree of ecological integrity or in rivers that are only partially dammed,C. laticepsis either absent inC. nasusor occurs with low prevalence (5.6–20%) and low mean intensity values (1.0–4.0). Where anthropogenic factors have changed the entire river into a reservoir, and fish cannot escape, the prevalence of infection withC. laticepsincreases from 46.2 to 78.2% and the mean intensity from 8.8 to 17.2.

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