scholarly journals Seasonal Changes in the Intertidal and Subtidal Algal Communities of Extremely and Moderately Polluted Coastal Regions of Sanya Bay (Hainan Island, China)

2019 ◽  
Vol 7 (4) ◽  
pp. 93
Author(s):  
Eduard A. Titlyanov ◽  
Tamara V. Titlyanova ◽  
Hui Huang ◽  
Anna V. Scriptsova ◽  
Huili Xu ◽  
...  
Keyword(s):  
Species Diversity ◽  
Seasonal Changes ◽  
Rainy Season ◽  
Hainan Island ◽  
Dry Season ◽  
Polluted Area ◽  
Algal Communities ◽  
Intertidal Zones ◽  
Polluted Sites ◽  
Sanya Bay

At the end of the rainy season in 2016 and at the end of the dry season in 2017, we conducted a floristic study of marine macrophytic algae in the intertidal and subtidal zones in moderately and heavily polluted areas at Luhuitou reef, Sanya Bay, Hainan Island, China. A total of 109 species of marine macrophytes were found during these samplings. At the end of the rainy season, 72 species of macrophytes (50% reds, 19% browns, and 31% greens) were found. At the end of the dry season, we found and identified 92 species of macrophytes (46% reds, 20% browns, and 34% greens). Seasonal changes in species diversity, species composition, and the structure of algal communities at differently polluted sites exhibited common features as well as specific characteristics. By the end of the dry season, the diversity of macroalgal species was increased, and the composition of dominant and accompanying species of macrophytes in polydominant communities was changed in moderately and heavily polluted areas. Seasonal changes in the marine flora of differently polluted areas were characterized by specific features as follows: Less changes in species diversity of heavily polluted area compared with moderately polluted area during the change from the rainy season to the dry season; significant increase in the biomass of green algae and their projective coverage in the middle and low intertidal zones of heavily polluted sites in the dry season; and the increase in the numbers of mono- and bidominant communities in the middle and low intertidal zones of heavily polluted sites by the end of the dry season.

Seasonal changes in the intertidal algal communities of Sanya Bay (Hainan Island, China)

2014 ◽  
Vol 94 (5) ◽  
pp. 879-893 ◽  
Author(s):  
Eduard A. Titlyanov ◽  
Tamara V. Titlyanova ◽  
Xiubao Li ◽  
Gayle I. Hansen ◽  
Hui Huang
Keyword(s):  
Red Algae ◽  
Intertidal Zone ◽  
Rainy Season ◽  
Dominant Species ◽  
Hainan Island ◽  
Dry Season ◽  
Splash Zone ◽  
Intertidal Zones ◽  
Species Numbers ◽  
Sanya Bay

A floristic study of marine macrophytic algae and Cyanobacteria in the splash and intertidal zones at Luhuitou reef, Sanya Bay, Hainan Island, China, was conducted during the rainy and dry seasons of 2008−2012 utilizing 148 of the most common species. Macrophytic algal diversity increased from the splash zone to the low intertidal zone, while cyanobacterial diversity decreased. In the upper and middle intertidal zones, the dominant species (primarily highly productive ephemerals) changed frequently throughout each year. In the low intertidal zone, the dominant species (mainly annual fleshy, foliose and coriaceous forms) also changed. In the dry season, species numbers were 33% higher than in the rainy season. During the rainy season, Cyanobacteria dominated the splash zone, while green and red algae dominated in increasing numbers from the upper to the low intertidal zones. During the dry season the splash zone was devoid of all macrophytic algae, and only one species of Cyanobacteria survived. In the upper intertidal, Cyanobacteria and red algae prevailed, while in the mid and low zones, red and green algae were the most diverse. In spite of heavy pollution in Sanya Bay, there was no evidence of dramatic changes in species numbers or composition, and the marine flora was similar to that of unpolluted regions in the Indo-Pacific.

Seasonal changes in benthic algal communities of the upper subtidal zone in Sanya Bay (Hainan Island, China)

2013 ◽  
Vol 94 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Eduard A. Tytlyanov ◽  
Tamara V. Titlyanova ◽  
Hui Huang ◽  
Xiubao Li
Keyword(s):  
Seasonal Changes ◽  
Inorganic Nitrogen ◽  
Algal Species ◽  
Hainan Island ◽  
Subtidal Zone ◽  
Nitrogen And Phosphorus ◽  
Thalassia Hemprichii ◽  
Algal Communities ◽  
Green Algal ◽  
Sanya Bay

A floristic study of the marine plants and algae at Luhuitou reef, Sanya Bay, Hainan Island, China, was conducted during the rainy (October 2008 and November 2010) and dry seasons (April 2009 and February 2012). Specimens were collected in the upper subtidal zone (from 0.5 to 3 m depth at low tide). A total of 156 taxa were collected, including 143 macrophyte species (90%), 12 blue–green algal species (10%), and the seagrass, Thalassia hemprichii. The most diverse group was the Rhodophyta (79 taxa or 55%), followed by the Chlorophyta (38 taxa or 25%) and then the Phaeophyceae (26 taxa or 20%). In the upper subtidal zone, macroalgae formed two types of communities: polydominant communities of turf-forming algae and monodominant and bidominant communities of foliose or fleshy algae. Seasonal changes occurred in the dominant species, which appear to be caused by periodic annual events of thalli detachment and subsequent community succession. In spite of heavy pollution from dissolved inorganic nitrogen and phosphorus in Sanya Bay, the subtidal flora has not undergone any dramatic changes in species numbers or composition and is similar to that of unpolluted regions in the Indo-Pacific.

scholarly journals Interannual and Seasonal Changes in the Benthic Algae Flora of Coral Reef in Xiaodong Hai (Hainan Island, China)

2019 ◽  
Vol 7 (8) ◽  
pp. 243
Author(s):  
Eduard A. Titlyanov ◽  
Tamara V. Titlyanova ◽  
Anna V. Scriptsova ◽  
Yuxiao Ren ◽  
Xiubao Li ◽  
...  
Keyword(s):  
Species Diversity ◽  
Seasonal Changes ◽  
Dominant Species ◽  
Benthic Algae ◽  
Hainan Island ◽  
Algal Turf ◽  
Macroalgal Species ◽  
Antarctic Waters ◽  
Maximum Similarity ◽  
The Tropics

Intensive algal sampling conducted in 2016–2019 in the Xiaodong Hai locality (Hainan Island, South China Sea), yielded a total of 198 benthic macroalgal species and their taxonomic forms (54% reds, 20% browns and 26% greens) and 20 species of Cyanobacteria. The largest number of species belonged to the families Rhodomelaceae, Ceramiaceae and Corallinaceae (Rhodophyta); Sargassaceae and Dictyotaceae (Phaeophyceae); Cladophoraceae and Caulerpaceae (Chlorophyta). The majority (79%) of species inhabiting only the tropics or subtropics were previously recorded and 21% of the species were also inhabiting temperate latitudes. Cosmopolitan algae inhabiting from the tropics to Arctic or Antarctic waters amounted to 14%. The level of maximum similarity of macroalgal species diversity in different years was on average more than 70%, interannual species specificity was observed only in the group of dominating species in algal turf communities. The seasonal variability of floras was manifested in a significant decrease in species diversity from the dry season to the rainy and in the change of dominant species in algal turf communities.

scholarly journals KELIMPAHAN DAN KEANEKARAGAMAN SPESIES SERANGGA PREDATOR DAN PARASITOID Aphis gossypii DI SUMATERA SELATAN

2011 ◽  
Vol 11 (1) ◽  
pp. 57-68
Author(s):  
Riyanto Riyanto ◽  
Siti Herlinda ◽  
Chandra Irsan ◽  
Abu Umayah
Keyword(s):  
Species Diversity ◽  
Rainy Season ◽  
Aphis Gossypii ◽  
Dry Season ◽  
Predatory Insects

 This study was aimed to analysis abundance and species diversity of predatory insects and parasitoid of Aphis gossypii from lowland and highland areas of South Sumatra.    Survey of was conducted in 11 vegetable centers of  South Sumatra.  The results showed that 20 species of predatory insects and 3 species of parasitoids were found from the survey. The predatory insects consisted of 15 species of coccinellid beetles, two species of syrphids, and  one species of chamaemyiid, mantid and staphylinid.  Parasitoid found were 2 species of Aphidiidae (Diaretiella rapae and Aphidius sp.) and a species of Aphelinidae (Aphelinus sp.).  The highest abundance of the predator was found in Soak (42.61 larvae and adults) and the highest abundance of the parasitoid was found in Talang Buruk (25.99 adults).  The highest species diversity of the predator and the parasitoid were found in Soak (15 species and H’= 0.94) and in Talang Buruk (2 species and H’ = 0.27), respectively.  Abundance and species diversity of the predators and parasitoids were higher in the dry season than those in rainy season. Thus, the abundance and species diversity of the predators and parasiotids were higher in the lowland than highland areas in South Sumatra, while the seasons affected the abundance and species diversity of the predators and parasitoids.

scholarly journals Effects of seasonal upwelling on hydrography and mesozooplankton communities in a Pacific tropical cove off Colombia

2019 ◽  
Vol 67 (4) ◽  
Author(s):  
Bellineth Valencia ◽  
Alan Giraldo ◽  
Marisol Rivera-Gómez ◽  
Vanessa Izquierdo ◽  
Andrés Cuellar-Chacón
Keyword(s):  
Water Column ◽  
Seasonal Changes ◽  
Rainy Season ◽  
Physiological Stress ◽  
Dry Season ◽  
Coastal Zones ◽  
Subsurface Waters ◽  
Northern Pacific ◽  
Field Campaigns

Introduction: The effects of seasonal upwelling on the conditions of the water column and mesozooplankton communities are poorly understood in the coastal zones of the Eastern Tropical Pacific (ETP), despite the important role of upwelling events in the modulation of productivity in these zones. Objective: To evaluate the influence of seasonal upwelling over the Panama Bight on the structure of the water column and mesozooplankton communities in a tropical cove of the ETP. Methods: Hydrographic data and mesozooplankton samples were collected during four field campaigns in Ensenada de Utría (December 2011, February 2012, October 2013, and February 2013), an estuary located in the Northern Pacific coast of Colombia. Non-parametric and multivariate analyses were used to evaluate seasonal differences in the environmental and biotic variables. Results: Surface waters were warm (> 25 °C) and presented low salinities (< 30) throughout the study period. In contrast, subsurface waters were colder (< 20 °C), saltier (> 33), and presented low dissolved oxygen concentrations (< 2.0 ml l-1) during the dry season (January - March), whereas the water column was homogeneous during the rainy season (April - December). Despite the seasonal changes in the environmental conditions, the expected enhancement in the productivity of the system during the dry season (i.e., higher biomass and abundance of the mesozooplankton) only occurred in February 2012. Contrary to expectations, ichthyoplankton abundance was higher during the rainy season, when the assemblage was dominated by the larvae of anchovy (Cetengraulis mysticetus) and an unidentified Gobiidae. Conclusions: The entrance of upwelled waters into Ensenada de Utría is an important factor modulating the seasonal changes observed in the water column. However, there is high interannual variability in the response of mesozooplankton communities to the upwelling events. Because upwelled waters are oxygen-depleted and more acidic, the entrance of upwelled waters into Ensenada de Utría could be causing physiological stress to the benthic and pelagic organisms inhabiting the deepest zones of the cove. This condition may worsen in the future given the predicted increase of deoxygenation and ocean acidification due to climate change.

scholarly journals Vertical distribution, nutrient concentration and seasonal changes of fine root mass in a semi-deciduous tropical dry forest and in two adjacent pastures in the Western Llanos of Venezuela

2020 ◽  
Vol 8 (2) ◽  
pp. 93-104
Author(s):  
Ana Francisca González-Pedraza ◽  
Nelda Dezzeo
Keyword(s):  
Vertical Distribution ◽  
Seasonal Changes ◽  
Rainy Season ◽  
Nutrient Concentration ◽  
Fine Root ◽  
Tropical Dry Forest ◽  
Dry Season ◽  
Dry Forest ◽  
Nutrient Concentrations ◽  
Root Mass

With the objective to contribute to a better understanding of ecological consequences of deforestation on the below-ground system in the Western Llanos of Venezuela, we evaluated the vertical distribution, nutrient concentration and seasonal changes of total fine root mass (FRM) (<2 mm diameter) in a semi-deciduous tropical dry forest and in 2 adjacent pastures of Cynodon nlemfuensis: a young pasture (YP, 5 years old) and an old pasture (OP, 18 years old) in the Obispo municipality, Barinas State. This evaluation included measurements at the end of the rainy season, during the dry season and during the subsequent early rainy season in 2005/2006. Highest FRM was recorded during the dry season, which probably indicates a plant water-stress response mechanism. The highest proportion (63‒88%) of FRM was concentrated in the 10–20 cm soil layer at all studied sites, probably due to a higher nutrient and moisture content at that depth. Non-significant differences (P>0.05) were observed in the total concentrations of organic carbon, nitrogen, phosphorus, calcium and magnesium in the FRM in soils supporting forest, OP and YP at the evaluated depths. Non-significant changes in the total FRM and nutrient concentrations were observed between the sampling periods and the 3 study sites. YP soils showed a slight increase in FRM that could be associated with the root growth of secondary vegetation, which is considered a weed and is periodically removed. Our results suggest that the land use change from tropical forest to pastures has not significantly affected the mass of fine roots and their carbon and nutrient concentrations. Further studies are needed to determine if these findings apply to other ecosystems.

scholarly journals Struktur Komunitas Fitoplankton sebagai Dasar Pengelolaan Kualitas Perairan Pantai Mangrove di Tapak Tugurejo Semarang

2017 ◽  
Vol 18 (2) ◽  
pp. 157
Author(s):  
Nurul Lathifah ◽  
Jafron Wasiq Hidayat ◽  
Fuad Muhammad
Keyword(s):  
Community Structure ◽  
Species Diversity ◽  
Coastal Waters ◽  
Rainy Season ◽  
Diversity Index ◽  
Common Species ◽  
Dry Season ◽  
Species Diversity Index ◽  
Rain Season

Phytoplankton has of important role in water as of base of the food chain this is also can service a bioindicator the pollution of waters. This study aims to assess the phytoplankton community structure in Tapak Semarang, assessing the level of fertility of inshore mangrove community, and to assess the water quality of inshore. Samples were take in is in the mangrove region of Tapak Semarang. This study was conducted in May 2016 (rain season) and in September 2016 (dry season). Selection of the stations were based on different environmental conditions in the research include the pond and public waters in the waters of coastal mangrove the soles of Semarang. Analysis of index diversity, index evennes and index saprobik. The results showed that the spesies of phytoplankton obtained during the study on mangrove coastal waters Tapak Tugurejo Semarang were 13 species (rainy season) and 25 species (dry season). The most common species of phytoplankton found in all stations wereCerataulina bergonii, Nitzhcia sp, Rhizosolenia spp, Synedra ulna, Netrium digitus, Gloeotrichia echinulata, and Oscillatoria Formosa. Index of species diversity (H’) that exist in mangrove coastal waters Tapak Tugurejo Semarang were in the range of 0.73 to 1.95 low to moderate with low to moderate quality of stabilities during the rainy season. Mean while in the dry season of high species diversity index in the range of 2.24 to 2.82 which indicated stability of the ecosystem was low to moderate. The value of evennes index (e) ranged from 0.66 to 0.97 during the rainy season, and 0.90 to 0.94 in the dry seasons these indices illustrated that each station has a moderate to high similaritas. In term of saprobitas level it was at Oligosaprobik state to β-Meso/Oligosaprobik describe very mild to light polluted. The quality of mangrove coastal waters based DO, temperature, salinity and pH are still good for fish farming. Keywords: community structure, phytoplankton, Tapak, Tugurejo, Semarang..

Prevalence and seasonal changes in the gastro-intestinal helminths of Nigerian goats

1996 ◽  
Vol 70 (4) ◽  
pp. 329-333 ◽  
Author(s):  
C.O. Nwosu ◽  
A.F. Ogunrinade ◽  
B.O. Fagbemi
Keyword(s):  
Seasonal Changes ◽  
Rainy Season ◽  
Dry Season ◽  
Intestinal Helminth ◽  
Helminth Parasites ◽  
Cysticercus Tenuicollis ◽  
Large Numbers ◽  
Oesophagostomum Columbianum ◽  
Faecal Samples ◽  
First Time

AbstractA total of 120 gastro-intestinal tracts and 960 faecal samples were examined to assess the prevalence and seasonal changes in the gastro-intestinal helminth parasites of Red Sokoto (maradi) goats slaughtered at Ibadan between May 1991 and April 1992. Egg types of strongyles, Strongyloides, Trichuris, Skrjabinema, Dicrocoelium and Moniezia were encountered in 93%, 83%, 44%, 0.9%, 2.3% and 31% of the faecal samples respectively. However, only strongyle, Strongyloides and Trichuris eggs occurred in large numbers and were more common during the rainy season than in the dry season. The parasites recorded and their prevalences were Haemonchus contortus (90.0%), H. ovis (5.0%), Strongyloides papillosus (80.8%), Trichostrongylus colubriformis (78.3%), T. axei (69.2%), Trichuris ovis (72.5%), T. globulosa (38.3%), Oesophagostomum columbianum (67.5%), Cooperia curticei (58.3%) Gaigeria pachyscelis (40.8%), Skrjabinema ovis (5.0%), Nematodirus battus (5.8%), Moniezia expansa (29.2%), M. benedeni (10.0%), Paramphistomum spp. (5.0%) and Cysticercus tenuicollis (33.3%). Haemonchus ovis is reported for the first time in Nigeria. Mixed infections were most prevalent. Young goats were more commonly infected and had higher worm counts than adult goats. Only Haemonchus, Trichostrongylus, Strongyloides and Cooperia spp. occurred in large numbers. Irrespective of the age of the goats, higher worm counts were generally encountered during the rainy season than in the dry season. The results are discussed in relation to the control of helminthiasis in grazing animals in Nigeria.

scholarly journals Effects of forest conversion and seasonal changes on the assembly of bacterial and fungal communities in tropical forests

2021 ◽  
Author(s):  
G Lan ◽  
Bangqian Chen ◽  
Zhixiang Wu ◽  
Chuan Yang ◽  
Xicai Zhang
Keyword(s):  
Community Assembly ◽  
Bacterial Communities ◽  
Seasonal Changes ◽  
Rainy Season ◽  
Tropical Rainforest ◽  
Dry Season ◽  
Fungal Communities ◽  
Forest Conversion ◽  
Rubber Plantation ◽  
Soil Microbial

To date, few studies have assessed the impact of forest conversion or seasonal changes on soil microbial community assembly. To fill this research gap, 16S rRNA and ITS gene sequences were used to evaluate the effects of forest conversion and seasonal changes on the assembly of bacterial and fungal communities using 260 soil samples collected from tropical rainforest and rubber plantation sites across Hainan Island, South China. A majority (~60%) of observed OTUs conformed with neutral model expectations, indicating that neutral processes were important for the assembly of soil microbial communities. For bacterial communities, the NST (normalized stochasticity ratio) was higher in the tropical rainforest (0.746 in the dry season, 0.684 in the rainy season) versus rubber plantation sites (0.647, 0.584), regardless of season. Thus, forest conversion decreased the importance of stochasticity for soil bacterial community assembly. For fungal communities, rubber plantation communities showed greater stochasticity (NST = 0.578) than rainforest communities (NST = 0.388) in the dry season, but the reverse was true in the rainy season (NST = 0.852 for rubber plantations; NST = 0.978 for rainforest). Both the NST results and structural equation modeling showed that bacterial communities were more stochastic in the dry season, while fungal communities were more stochastic in the rainy season; the effects of seasonal changes on assembly therefore differed between bacterial and fungal communities. More importantly, forest conversion did not have a direct impact on the assembly of bacterial or fungal communities, but exerted indirect effects via soil pH and soil AK.

scholarly journals Composition and seasonal variation of the ichthyofauna from upper Rio Paraguaçu (Chapada Diamantina, Bahia, Brazil)

2007 ◽  
Vol 50 (4) ◽  
pp. 663-672 ◽  
Author(s):  
Alexandre Clistenes de Alcântara Santos ◽  
Érica Pellegrini Caramaschi
Keyword(s):  
Seasonal Variation ◽  
Seasonal Changes ◽  
Rainy Season ◽  
Multivariate Analyses ◽  
Dry Season ◽  
The Other ◽  
Chapada Diamantina ◽  
Number Of Species ◽  
Abiotic Variables

The aim of this work was to characterize the composition of the ichthyofauna of the upper course of the Rio Paraguaçu. Two excursions were carried out, one in the dry season, and the other in the rainy season, with 36 localities sampled. A total of 63 species were collected. Multivariate analyses indicated that abiotic variables such as the channel order and altitude were the main influences on the number of species present. The number of species in each excursion was equivalent in the two seasons, suggesting that seasonal changes have little influence on the ichthyofauna of this area.

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