Species composition and habitat preferences of benthic ostracod and foraminifera in seagrass and non-seagrass systems within a tropical estuary

2020 ◽  
pp. 1-18
Author(s):  
Chandran Raynusha ◽  
Mohammad Rozaimi ◽  
Ramlan Omar ◽  
Noraswana Nor Faiz ◽  
Nur Munirah Hesan ◽  
...  
Keyword(s):  
Habitat Preferences ◽  
Environmental Parameters ◽  
Seagrass Habitat ◽  
Sediment Depth ◽  
Species Dominance ◽  
Seagrass Meadows ◽  
Foraminiferal Species ◽  
Baseline Information ◽  
Abundance And Distribution ◽  
Insight Into

Abstract Ostracods and foraminifera are excellent indicators of environmental change and can act as proxies for the presence of seagrass meadows. These proxies have been under-utilized in vulnerable coastal ecosystems in South-east Asia, and the fundamental habitat and environmental parameters required for such application in environmental monitoring have not yet been established. We investigated the habitat preferences of ostracods and foraminiferal species in seagrass and non-seagrass habitats within Sungai Pulai Estuary (Johor, Malaysia), a system currently undergoing major coastal changes. Samples consisted of surficial and downcore sediments collected from two seagrass meadows and a non-seagrass habitat. Multivariate analysis determined the variations in spatial and depth distribution of the meiofauna. Species dominance, abundance and distribution varied between sites, whereas diversity and community structure varied with sediment depth. We found fewer ostracod individuals (N = 1133) than foraminifera (N = 7242). Ostracods were more species-diverse (H′ = 3.34) in the non-vegetated area compared with seagrass areas (H′ = 2.74), whereas foraminifera species were most diverse (H′ = 3.60) in seagrass areas. Opportunistic species, such as Loxoconcha lilljeborgii, Asterorotalia pulchella, Murrayinella globosa, Ammonia tepida and Elphidium neosimplex dominated the meiofaunal assemblages. The presence of Nummulitidae and Paracyprididae in downcore samples provided information related to rare species and families. Salinity, organic matter and percentage of sand explained much of the meiofaunal distribution. Our findings provide new insight into the factors influencing the presence and distribution of ostracods and foraminifera in the estuary, comprising baseline information for understanding the vulnerability of such habitats to anthropogenic changes.

scholarly journals Community structure and condition of seagrass meadows in Ayau Islands, Raja Ampat Regency

2020 ◽  
Vol 45 (1) ◽  
pp. 13-24
Author(s):  
Andri Irawan ◽  
Muhammad Hafizt ◽  
Udhi Eko Hernawan
Keyword(s):  
Community Structure ◽  
Environmental Parameters ◽  
Water Clarity ◽  
Well Being ◽  
Common Species ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
Halophila Ovalis ◽  
Seagrass Cover ◽  
Baseline Information

Seagrass meadows are an important component of coastal ecosystems, providing many ecosystem services beneficial for human well-being. Basic information about seagrass meadows in Indonesia is relatively limited, particularly in the eastern part of Indonesia, such as the remote Ayau Islands in Raja Ampat. In this paper, we reported the community structure and condition of seagrass meadows in Ayau Islands surveyed during Nusa Manggala Expedition in November 2018. We conducted the seagrass survey using quadrat transect method at five locations, i.e. Reni, Rutum, Abidon, Kanober, and Dorehkar. In the survey, we assessed parameters of community structure, including habitat extent, species composition, seagrass cover, seagrass density, macroalgae and epiphyte cover. We also recorded environmental parameters, i.e. substrate types, water clarity, salinity, water temperature, and nutrient (phosphate and nitrate). Our study showed that seagrass meadows in Ayau Islands are multispecies meadows, composed of two to five species. In overall, five species recorded in Ayau Islands are Cymodocea rotundata, Enhalus acoroides, Halodule pinifolia, Halophila ovalis, and Thalassia hemprichii. The most common species is T. hemprichii as it can be found in all locations. Meadows in Reni, Rutum, and Dorehkar are in a healthy condition, while in Abidon and Kanober are in less healthy condition. This information is of significance as baseline information needed for seagrass conservation planning.

scholarly journals Relationships between Environmental Factors and Pathogenic Vibrios in the Northern Gulf of Mexico

2010 ◽  
Vol 76 (21) ◽  
pp. 7076-7084 ◽  
Author(s):  
C. N. Johnson ◽  
A. R. Flowers ◽  
N. F. Noriea ◽  
A. M. Zimmerman ◽  
J. C. Bowers ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Water Column ◽  
Vibrio Vulnificus ◽  
Environmental Parameters ◽  
Sampling Period ◽  
Pathogenicity Factor ◽  
Hemolysin Gene ◽  
Thermostable Direct Hemolysin ◽  
Pathogenic Vibrios ◽  
Abundance And Distribution

ABSTRACT Although autochthonous vibrio densities are known to be influenced by water temperature and salinity, little is understood about other environmental factors associated with their abundance and distribution. Densities of culturable Vibrio vulnificus containing vvh (V. vulnificus hemolysin gene) and V. parahaemolyticus containing tlh (thermolabile hemolysin gene, ubiquitous in V. parahaemolyticus), tdh (thermostable direct hemolysin gene, V. parahaemolyticus pathogenicity factor), and trh (tdh-related hemolysin gene, V. parahaemolyticus pathogenicity factor) were measured in coastal waters of Mississippi and Alabama. Over a 19-month sampling period, vibrio densities in water, oysters, and sediment varied significantly with sea surface temperature (SST). On average, tdh-to-tlh ratios were significantly higher than trh-to-tlh ratios in water and oysters but not in sediment. Although tlh densities were lower than vvh densities in water and in oysters, the opposite was true in sediment. Regression analysis indicated that SST had a significant association with vvh and tlh densities in water and oysters, while salinity was significantly related to vibrio densities in the water column. Chlorophyll a levels in the water were correlated significantly with vvh in sediment and oysters and with pathogenic V. parahaemolyticus (tdh and trh) in the water column. Furthermore, turbidity was a significant predictor of V. parahaemolyticus density in all sample types (water, oyster, and sediment), and its role in predicting the risk of V. parahaemolyticus illness may be more important than previously realized. This study identified (i) culturable vibrios in winter sediment samples, (ii) niche-based differences in the abundance of vibrios, and (iii) predictive signatures resulting from correlations between environmental parameters and vibrio densities.

scholarly journals Exquisitely Preserved Fossil Snakes of Messel: Insight into the Evolution, Biogeography, Habitat Preferences and Sensory Ecology of Early Boas

Diversity ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 100 ◽  
Author(s):  
Agustín Scanferla ◽  
Krister T. Smith
Keyword(s):  
Body Size ◽  
New World ◽  
Middle Eocene ◽  
Habitat Preferences ◽  
Sensory Ecology ◽  
Morphological Diversity ◽  
Predator Prey ◽  
Upper Jaw ◽  
Spectrum Evaluation ◽  
Insight Into

Our knowledge of early evolution of snakes is improving, but all that we can infer about the evolution of modern clades of snakes such as boas (Booidea) is still based on isolated bones. Here, we resolve the phylogenetic relationships of Eoconstrictor fischeri comb. nov. and other booids from the early-middle Eocene of Messel (Germany), the best-known fossil snake assemblage yet discovered. Our combined analyses demonstrate an affinity of Eoconstrictor with Neotropical boas, thus entailing a South America-to-Europe dispersal event. Other booid species from Messel are related to different New World clades, reinforcing the cosmopolitan nature of the Messel booid fauna. Our analyses indicate that Eoconstrictor was a terrestrial, medium- to large-bodied snake that bore labial pit organs in the upper jaw, the earliest evidence that the visual system in snakes incorporated the infrared spectrum. Evaluation of the known palaeobiology of Eoconstrictor provides no evidence that pit organs played a role in the predator–prey relations of this stem boid. At the same time, the morphological diversity of Messel booids reflects the occupation of several terrestrial macrohabitats, and even in the earliest booid community the relation between pit organs and body size is similar to that seen in booids today.

scholarly journals Habitat value of a developing estuarine brackish marsh for fish and macrocrustaceans

2003 ◽  
Vol 60 (2) ◽  
pp. 278-289 ◽  
Author(s):  
H Hampel ◽  
A Cattrijsse ◽  
M Vincx
Keyword(s):  
Carcinus Maenas ◽  
Environmental Parameters ◽  
Shore Crab ◽  
Total Biomass ◽  
Density Peak ◽  
Frequency Distributions ◽  
Species Dominance ◽  
Large Numbers ◽  
Mesopodopsis Slabberi ◽  
Mysid Shrimp

Abstract Marsh creation receives worldwide attention in mitigating loss of coastal wetlands and in management retreat of estuaries. In the Westerschelde, the former Selena Polder, south from the marsh of Saeftinghe, developed into the Sieperda marsh after several dyke breaches. Soon after the tides regained access to the polder, a tidal creek was formed. After 10 years, a developing marsh system was found adjacent to a mature marsh system. This situation offered the opportunity to compare the utilization by nekton species of a natural mature marsh with a recently created developing marsh under similar circumstances. Between April and October 1999, both the mature Saeftinghe marsh and the developing Sieperda marsh were sampled every 6 weeks on 2 consecutive days. Each sampling occasion covered the whole tidal cycle. The most important environmental parameters (water height, temperature, salinity, turbidity and dissolved oxygen) were similar in both marsh creeks. A distinct difference in nekton community structure between the two marshes was observed. The total biomass and densities of nekton species were higher in Saeftinghe. In Saeftinghe, a density peak occurred in July and was mainly due to large numbers of the mysid, Neomysis integer. In Sieperda, maximum abundance of the mysid, Mesopodopsis slabberi, caused the peak density in September. This difference in species dominance was observed in all samples. Biomass peaked in July in the mature marsh and in October in the developing marsh. Mysid shrimp (N. integer) and fish (mainly Pomatoschistus microps) were the main contributors to the biomass Saeftinghe. Herring, sprat (Clupeidae) and shore crab (Carcinus maenas) were more important in Sieperda. For P. microps, distinct differences in length–frequency distributions were noted between the marshes. While creek morphology influences the abundance and species composition of visiting nekton, the age of a marsh and its maturity are believed to be the prime factors in determining the habitat function of creek systems of developing and mature marshes.

Historical dynamics of the demersal fish community in the East and South China Seas

2020 ◽  
Vol 71 (9) ◽  
pp. 1073 ◽  
Author(s):  
Jin Gao ◽  
James T. Thorson ◽  
Cody Szuwalski ◽  
Hui-Yu Wang
Keyword(s):  
South China ◽  
Collaborative Work ◽  
Habitat Preferences ◽  
Fishing Effort ◽  
Otter Trawl ◽  
Historical Records ◽  
China Seas ◽  
Important Species ◽  
Catch Rates ◽  
Abundance And Distribution

Taiwan has a long history of fishery operations and contributes significantly to the global fishery harvest. The East and South China seas are important fishing grounds for which publicly available data are very limited. More efforts are needed to digitise and analyse historical catch rate data to illuminate species and community changes in this region. In this study we digitised historical records of catch and effort from government fishery reports for nine commercial species caught by otter trawl, and reported quarterly from 1970 to 2001, from the East and South China seas. We analysed the four seasons and present abundance indices, distributions and among-species correlations for nine commercially important species from 1970 to 1988 (a period with high fishing effort) using a multispecies spatiotemporal model that estimates both covariation in multispecies catch rates, attributed to spatial habitat preferences and environmental responses, and indices representing trends in abundance and distribution. We found substantial spatial, temporal and spatiotemporal variation in the distribution of fishes and season-specific patterns. We recommend collaborative work from various adjacent countries to digitise historical records of fishing catch rates, because more records would potentially address scientific disagreements regarding trends in the abundance and distribution of commercial fishes in this region through comparative studies.

Effects of Lyngbya majuscula (Cyanophycea) blooms on sediment nutrients and meiofaunal assemblages in seagrass beds in Moreton Bay, Australia

2006 ◽  
Vol 57 (2) ◽  
pp. 155 ◽  
Author(s):  
Rosa García ◽  
Ron W. Johnstone
Keyword(s):  
Depth Distribution ◽  
East Coast ◽  
Oxygen Depletion ◽  
Seagrass Beds ◽  
Biogeochemical Processes ◽  
Sediment Depth ◽  
Lyngbya Majuscula ◽  
Moreton Bay ◽  
Bloom Period ◽  
Abundance And Distribution

Blooms of Lyngbya majuscula have been increasingly recorded in the waters of Moreton Bay, on the south-east coast of Queensland, Australia. The influences of these blooms on sediment infauna and the implications for sediment biogeochemical processes was studied. Sediment samples were taken from Moreton Bay banks during and after the bloom season. The deposition of L. majuscula seems to be responsible for the higher total Kjedahl nitrogen (TKN) concentrations measured during the bloom period. Total organic carbon (TOC) concentrations did not change. Lyngbya majuscula blooms had a marked influence on the meiobenthos. Nematodes, copepods and polychaetes were the most abundant groups of meiofauna, and the bloom produced a decrease in the abundance and a change in the sediment depth distribution of these organisms. The distribution of nematodes, copepods and polychaetes in sediment became shallower. Further, the bloom did not affect the abundance and distribution of polychaetes as strongly as it did copepods and nematodes. The changes observed in the distribution of meiofauna in the sediment during the bloom period indicate that L. majuscula produces oxygen depletion in sediments, and that different fauna seem to be affected to different degrees.

Ecology of the rufous hare-wallaby, Lagorchestes hirsutus Gould (Marsupialia : Macropodidae) in the Tanami Desert, Northern Territory.I Patterns of habitat use.

1993 ◽  
Vol 20 (4) ◽  
pp. 457 ◽  
Author(s):  
G Lundie-Jenkins
Keyword(s):  
Habitat Use ◽  
Environmental Parameters ◽  
Home Ranges ◽  
Faecal Pellets ◽  
Habitat Features ◽  
Food Diversity ◽  
Local Contraction ◽  
Feeding Area ◽  
Controlled Burns ◽  
Insight Into

A 2-year study was conducted to investigate two aspects of the local distribution of the rufous harewallaby, Lagorchestes hirsutus, in a region of the Tanami Desert. These were: (a) patterns of habitat use in response to changing environmental conditions and (b) environmental parameters influencing 'local' choice of habitat. Counts of faecal pellets and tracks were used to obtain indices of hare-wallaby activity within occupied sites and to gain an insight into the movements by individuals. Local choice of habitat was analysed by assessment of numerous habitat features at occupied and unoccupied sites in the region. Previous surveys over the greater part of the study area provide evidence of a significant local decline and local contraction of range by L. hirsutus during recent times. Hare-wallabies showed seasonal trends in the relative use of different vegetation systems in response to the relative availability of food items within each habitat. The home ranges of hare-wallabies consisted of two distinct areas of activity: a large sparsely used area within the dense Triodia pungens vegetation and a small concentrated feeding area within the neighbouring caliche system. Hare-wallabies were dependent upon a specialised form of spinifex habitat. Patchiness, hummock size, food diversity and the degree of floral senescence affected suitability for hare-wallabies. Within the Tanami Desert site, suitable combinations of these characters were associated with tight mosaics of different regenerative stages after fire. Fire is therefore clearly implicated as an important force in creating a greater diversity of feeding and sheltering habitats for the hare-wallabies in the otherwise uniform spinifex sandplains. There is an obvious role for the application of controlled burns as a means of managing habitats to favour L. hirsutus in the Tanami Desert.

scholarly journals Bicoid gradient formation mechanism and dynamics revealed by protein lifetime analysis

2018 ◽  
Author(s):  
Lucia Durrieu ◽  
Daniel Kirrmaier ◽  
Tatjana Schneidt ◽  
Ilia Kats ◽  
Sarada Raghavan ◽  
...  
Keyword(s):  
Developmental Biology ◽  
Quantitative Analysis ◽  
Formation Mechanism ◽  
Novel Approach ◽  
Gradient Formation ◽  
Lifetime Analysis ◽  
Abundance And Distribution ◽  
Insight Into ◽  
Anterior Posterior ◽  
Rule Out

AbstractEmbryogenesis relies on instructions provided by spatially organized signaling molecules known as morphogens. Understanding the principles behind morphogen distribution and how cells interpret locally this information remains a major challenge in developmental biology. Here we introduce morphogen-age measurements as a novel approach to retrieve key parameters in morphogen dynamics. Using a tandem fluorescent timer (tFT) as a protein-age sensor we find a gradient of increasing age of Bicoid (Bcd) along the anterior-posterior (AP) axis in the early Drosophila embryo. Quantitative analysis retrieves parameter that are most consistent with the synthesis-diffusion-degradation (SDD) model underlying Bcd-gradient formation, and rule out some other hypotheses for gradient formation. Moreover, we show that the timer can detect transitions in the dynamics associated with syncytial cellularization. Our results provide new insight into Bcd gradient formation, and demonstrate how morphogen age-information can complement knowledge about movement, abundance and distribution, which should be widely applicable for other systems.

scholarly journals Community Structure of Gastropods in Seagrass Meadows at Coastal Area of Nusi and Gersen, Nabire Regency

2020 ◽  
pp. 89
Author(s):  
Marce Souisa ◽  
Simon P. Leatemia ◽  
Selfanie Talakua
Keyword(s):  
Coastal Waters ◽  
Diversity Index ◽  
Similarity Index ◽  
Seagrass Habitat ◽  
Dominance Index ◽  
Seagrass Meadows ◽  
Physical Chemical ◽  
Seagrass Ecosystem ◽  
Measurement Results ◽  
Chemical Factors

Gastropods plays an important role in the food chain on seagrass ecosystem and its existence are depend on the physical-chemical factors in the seagrass ecosystem. This study aims to determine the density and diversity of gastropods associated in seagrass habitat in Nusi and Gersen coastal waters. The measurement results of some physical-chemical waters variables, are still quite good for the life of gastropods. Species composition of gastropod in Nusi at higher than at the Gersen, but instead of individual density in Gersen more higher than Nusi. Diversity index of gastropods at Nusi station is higher (3,757) than Gersen (3.053), on the contrary the eveness and dominance index are higher at Gersen station than Nusi station. Community similarity index by species is low between the two stations, which indicates that the species of gastropods at both stations is quite different. The influence of human activity and higher utilizatin of gastropods in Nusi has lowered the density of gastropods in seagrass habitat, so it needs awareness efforts on the importance of gastropods and the seagrass habitat for coastal ecosystem.

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