Seasonal distribution of coastal mesozooplankton community in relation to the environmental factors in İskenderun Bay (north-east Levantine, Mediterranean Sea)

2012 ◽  
Vol 93 (5) ◽  
pp. 1163-1174 ◽  
Author(s):  
Tuba Terbiyik Kurt ◽  
Sevim Polat
Keyword(s):  
Environmental Factors ◽  
Seawater Temperature ◽  
Mesh Size ◽  
Distribution Patterns ◽  
Seasonal Distribution ◽  
Mesozooplankton Community ◽  
North East ◽  
Iskenderun Bay ◽  
Two Peaks ◽  
Main Factor

Mesozooplankton was studied during 2008 in coastal waters of the İskenderun Bay in order to determine seasonal changes in abundance, biomass, community structure and their relationship with environmental factors. Samples were collected seasonally at five stations using WP-2 net of 200 µ mesh size by vertical hauls. A total of 23 planktonic groups including 30 copepod species, 4 cladocerans and 4 chaetognaths were identified. Copepods were the most important group during the whole period of survey. Penilia avirostris was found to be dominant in spring, while Paracalanus parvus in summer and winter, and Acrocalanus gibber in autumn. Mesozooplankton abundance varied from 438 ind m−3 (autumn) to 7163 ind m−3 (spring), while biomass varied between 2.2 mg m−3 (summer) and 52.9 mg m−3 (autumn). Differences in abundance and biomass between seasons were statistically significant (P < 0.01). Clear seasonal distribution patterns were observed in the area. Two peaks in abundance were defined: a major peak in spring and a second minor one in autumn. It seems that the trophic element was the main factor affecting the density distribution of zooplankton populations, whereas species distributions were more affected by hydrographical parameters, namely: seawater temperature and salinity.

scholarly journals Mesozooplankton community development at elevated CO<sub>2</sub> concentrations: results from a mesocosm experiment in an Arctic fjord

2013 ◽  
Vol 10 (3) ◽  
pp. 1391-1406 ◽  
Author(s):  
B. Niehoff ◽  
T. Schmithüsen ◽  
N. Knüppel ◽  
M. Daase ◽  
J. Czerny ◽  
...  
Keyword(s):  
Fossil Fuels ◽  
Cold Water ◽  
World Ocean ◽  
Mesh Size ◽  
Co2 Concentration ◽  
Taxonomic Composition ◽  
Marine Biota ◽  
Mesozooplankton Community ◽  
Oithona Similis ◽  
Arctic Fjord

Abstract. The increasing CO2 concentration in the atmosphere caused by burning fossil fuels leads to increasing pCO2 and decreasing pH in the world ocean. These changes may have severe consequences for marine biota, especially in cold-water ecosystems due to higher solubility of CO2. However, studies on the response of mesozooplankton communities to elevated CO2 are still lacking. In order to test whether abundance and taxonomic composition change with pCO2, we have sampled nine mesocosms, which were deployed in Kongsfjorden, an Arctic fjord at Svalbard, and were adjusted to eight CO2 concentrations, initially ranging from 185 μatm to 1420 μatm. Vertical net hauls were taken weekly over about one month with an Apstein net (55 μm mesh size) in all mesocosms and the surrounding fjord. In addition, sediment trap samples, taken every second day in the mesocosms, were analysed to account for losses due to vertical migration and mortality. The taxonomic analysis revealed that meroplanktonic larvae (Cirripedia, Polychaeta, Bivalvia, Gastropoda, and Decapoda) dominated in the mesocosms while copepods (Calanus spp., Oithona similis, Acartia longiremis and Microsetella norvegica) were found in lower abundances. In the fjord copepods prevailed for most of our study. With time, abundance and taxonomic composition developed similarly in all mesocosms and the pCO2 had no significant effect on the overall community structure. Also, we did not find significant relationships between the pCO2 level and the abundance of single taxa. Changes in heterogeneous communities are, however, difficult to detect, and the exposure to elevated pCO2 was relatively short. We therefore suggest that future mesocosm experiments should be run for longer periods.

scholarly journals Distribution Patterns of Odonate Assemblages in Relation to Environmental Variables in Streams of South Korea

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 152 ◽  
Author(s):  
Da-Yeong Lee ◽  
Dae-Seong Lee ◽  
Mi-Jung Bae ◽  
Soon-Jin Hwang ◽  
Seong-Yu Noh ◽  
...  
Keyword(s):  
Land Use ◽  
Ecosystem Services ◽  
Environmental Factors ◽  
South Korea ◽  
Habitat Heterogeneity ◽  
Environmental Variables ◽  
Environmental Changes ◽  
Distribution Patterns ◽  
Self Organizing Map ◽  
Factors Affecting

Odonata species are sensitive to environmental changes, particularly those caused by humans, and provide valuable ecosystem services as intermediate predators in food webs. We aimed: (i) to investigate the distribution patterns of Odonata in streams on a nationwide scale across South Korea; (ii) to evaluate the relationships between the distribution patterns of odonates and their environmental conditions; and (iii) to identify indicator species and the most significant environmental factors affecting their distributions. Samples were collected from 965 sampling sites in streams across South Korea. We also measured 34 environmental variables grouped into six categories: geography, meteorology, land use, substrate composition, hydrology, and physicochemistry. A total of 83 taxa belonging to 10 families of Odonata were recorded in the dataset. Among them, eight species displayed high abundances and incidences. Self-organizing map (SOM) classified sampling sites into seven clusters (A–G) which could be divided into two distinct groups (A–C and D–G) according to the similarities of their odonate assemblages. Clusters A–C were characterized by members of the suborder Anisoptera, whereas clusters D–G were characterized by the suborder Zygoptera. Non-metric multidimensional scaling (NMDS) identified forest (%), altitude, and cobble (%) in substrata as the most influential environmental factors determining odonate assemblage compositions. Our results emphasize the importance of habitat heterogeneity by demonstrating its effect on odonate assemblages.

scholarly journals Mesozooplankton community development at elevated CO<sub>2</sub> concentrations: results from a mesocosm experiment in an Arctic fjord

2012 ◽  
Vol 9 (8) ◽  
pp. 11479-11515 ◽  
Author(s):  
B. Niehoff ◽  
N. Knüppel ◽  
M. Daase ◽  
J. Czerny ◽  
T. Boxhammer
Keyword(s):  
Fossil Fuels ◽  
Cold Water ◽  
Mesh Size ◽  
Experimental Period ◽  
Sediment Traps ◽  
Taxonomic Composition ◽  
Marine Biota ◽  
Mesozooplankton Community ◽  
Co2 Concentrations ◽  
Arctic Fjord

Abstract. The increasing CO2 concentration in the atmosphere caused by burning fossil fuels leads to increasing pCO2 and decreasing pH in the world oceans. These changes may have severe consequences for marine biota, especially in cold-water ecosystems due to higher solubility of CO2. However, studies on the response of mesozooplankton communities to elevated pCO2 are yet lacking. In order to test whether abundance and taxonomic composition change with pCO2, we have sampled nine mesocosms, which were deployed in Kongsfjorden, an Arctic fjord at Svalbard, and were adjusted to eight CO2 concentrations, initially ranging from 185 μatm to 1420 μatm. Samples were taken weekly over a six-week period with an Apstein net (55 μm mesh size) in all mesocosms and the surrounding fjord. In addition, sediment trap samples, taken every second day in the mesocosms, were analyzed to account for losses due to vertical migration and mortality. The taxonomic analysis revealed that meroplanktonic larvae (cirripeds, polychaetes, bivalves, gastropod, and decapods) dominated in the mesocosms while copepods (Calanus spp., Oithona similis, Acartia longiremis and Microsetella norvegica) were found in lower abundances. In the fjord copepods prevailed for most of our study. With time, abundance and taxonomic composition developed similarly in all mesocosms; the pCO2 had no significant effect on the overall community structure. However, single taxa responded to elevated CO2 concentrations. The ratio of cirripedia nauplii to cypris larvae, the next developmental stage, in the sediment traps averaged over the entire experiment increased with pCO2 and this suggests that increased pCO2 may have delayed their development. Also, the number of bivalves, averaged over the experimental period, decreased significantly with increasing pCO2. The nature of the CO2 effect, either direct or indirect, remains open and needs to be addressed in future.

scholarly journals Global biogeography of living brachiopods: Bioregionalization patterns and possible controls

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259004
Author(s):  
Facheng Ye ◽  
G. R. Shi ◽  
Maria Aleksandra Bitner
Keyword(s):  
Large Scale ◽  
Coastal Upwelling ◽  
Seawater Temperature ◽  
Regional Scale ◽  
Distribution Patterns ◽  
Global Scale ◽  
Biodiversity Hotspots ◽  
Network Analyses ◽  
Ocean Gyres ◽  
Ecological Variable

The global distribution patterns of 14918 geo-referenced occurrences from 394 living brachiopod species were mapped in 5° grid cells, which enabled the visualization and delineation of distinct bioregions and biodiversity hotspots. Further investigation using cluster and network analyses allowed us to propose the first systematically and quantitatively recognized global bioregionalization framework for living brachiopods, consisting of five bioregions and thirteen bioprovinces. No single environmental or ecological variable is accountable for the newly proposed global bioregionalization patterns of living brachiopods. Instead, the combined effects of large-scale ocean gyres, climatic zonation as well as some geohistorical factors (e.g., formation of land bridges and geological recent closure of ancient seaways) are considered as the main drivers at the global scale. At the regional scale, however, the faunal composition, diversity and biogeographical differentiation appear to be mainly controlled by seawater temperature variation, regional ocean currents and coastal upwelling systems.

Takhtajan's floristic regions and foliicolous lichen biogeography: a compatibility analysis

2003 ◽  
Vol 35 (1) ◽  
pp. 33-53 ◽  
Author(s):  
Robert Lücking
Keyword(s):  
Large Scale ◽  
New Caledonia ◽  
Vascular Plant ◽  
Distribution Patterns ◽  
Plant Distribution ◽  
Sufficient Information ◽  
East African ◽  
Foliicolous Lichens ◽  
North East ◽  
Compatibility Analysis

AbstractTakhtajan's floristic regions of the world, based on vascular plant distribution, were used for a comparative analysis of foliicolous lichen biogeography. Of the 35 regions distinguished by that author, 23 feature foliicolous lichens. The South-East African, Fijian, Polynesian and Hawaiian regions lack sufficient information and were excluded from further analysis. Using multi-dimensional scaling and cluster and cladistic analyses, the remaining 19 regions were grouped into six lichenogeographical regions: (1) Neotropics, (2) African Paleotropics (including Madagascar, Réunion and Seychelles), (3) Eastern Paleotropics (including North-East Australia and New Caledonia), (4) Valdivian region (temperate rainforest in southern South America), (5) Tethyan region (subtropical areas of Macaronesia, Mediterranean, and Western Irano-Turanian) and (6) Neozealandic-Tasmanian region (temperate rainforests of New Zealand and Tasmania). Affinities between these six large scale regions, with 57–77% shared species, are still stronger than those between the 35 smaller scale regions denned by Takhtajan [(20−)40–60(−75)% shared species]. Based on presence/absence within each of the six regions, 22 potential distribution patterns were defined for foliicolous lichens. Many species are widely distributed; 21% are cosmopolitan or pantropical, while 19% are disjunct on at least two continents, and only 60% are restricted to one of the three major tropical areas (nearly 100% in vascular plants). Most of the latter are found in the Neotropics, while the African Paleotropics are poor in endemics. Most genera deviate significantly from overall distribution patterns; for example, Strigula and Calopadia have higher proportions of widely distributed species, while Porina displays a concentration of Eastern Paleotropical endemics. Species diversity and composition of the six regions indicate that the three extra-tropical foliicolous lichen biotas (Valdivian, Tethyan, Neozealandic-Tasmanian) are the result of partly separate evolutionary histories. On the other hand, there is a strong affinity between the Neotropics and the African Paleotropics, suggesting a shared Western Gondwanan element in the foliicolous lichen biotas of these two regions.

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