Ecological studies on the community of drifting seaweeds in the south-eastern coastal waters of Izu Peninsula, central Japan. I: Seasonal changes of plants in species composition, appearance, number of species and size

2001 ◽  
Vol 49 (3) ◽  
pp. 215-229 ◽  
Author(s):  
Tetsu Hirata ◽  
Jiro Tanaka ◽  
Tetsuo Iwami ◽  
Takashi Ohmi ◽  
Akihiro Dazai ◽  
...  

2013 ◽  
Vol 1 (3) ◽  
pp. 125
Author(s):  
Valdino M E Rungkat ◽  
Jan FWS Tamanampo ◽  
Jhon L Tombokan

ABSTRACT This study was conducted to determine the species composition and commu-nity structure of Pomacentridae (relative density, diversity, dominance and even-ness of species). This research was conducted in waters of the Manado Bay, at Kelurahan Malalayang Dua shore, on August 14th, 2012. The studies was conduc-ted on 2 sites, one has 3 meters depth (01o27'40.5" NL 124o47'32.5" EL) and ano-ther at 10 meters depth (01o27'43.6" NL 124o47'27.8" EL). The results and analysis of data, the total number of species found at a depth of 2 points is 15 species, in which was found at a depth of 3 meters at a depth of 10 species and 15 species discovered 10 meters. The species most commonly found is Pomacentrus brachial and Dascyllus reticulatus. The highest relative density values at a depth of 3 meters is Dascyllus reticulatus (22%) and at depth10 meters is Pomacentrus brachialis (18%). Diversity index at 3 meters depth is 1.941 while at 10 meters is 2.326. The result showed that diversity of Pomacentridae is low at 3 meters depth and average at 10 meters depth which means moderate community hability. At both depths, there was no species dominance and the avenness was stable.   Keywords : Community Structure, Pomacentridae, Manado Gulf   ABSTRAK Penelitian ini dilakukan untuk mengetahui komposisi spesies dan struktur komunitas ikan Pomacentridae (kepadatan relatif, keanekaragaman, dominasi dan kemerataan spesies). Lokasi penelitian di Teluk Manado, tepatnya di perairan depan Kelurahan Malalayang Dua. Penelitian dilakukan pada 2 titik kedalaman yaitu kedalaman 3 meter (01o27’40.5” LU 124 o47’32.5” BT) dan kedalaman 10 meter pada koordinat (01o27’43.6” LU 124 o47’27.8” BT). Metode yang digunakan adalah metode sensus visual, dengan penentuan jalur mengunakan penanda me-teran sepanjang 50 meter yang diletakkan di daerah terumbu karang yang sejajar garis pantai. Hasil penelitian dan analisis data, jumlah total spesies yang ditemu-kan pada 2 titik kedalaman adalah 15 spesies, di mana pada kedalaman 3 meter ditemukan 10 spesies dan pada kedalaman 10 meter ditemukan 15 spesies. Spe-sies yang paling banyak ditemukan adalah Pomacentrus brachialis dan Dascyllus reticulatus. Nilai kepadatan relatif tertinggi pada kedalaman 3 meter ada-lah spe-sies Dascyllus reticulatus 22% dan pada kedalaman 10 meter adalah Pomacentrus brachialis 18%. Indeks keanekaragaman pada kedalaman 3 meter adalah 1,941 sedangkan pada kedalaman 10  meter  dengan  nilai 2,326. Hal  ini  menunjukkanbahwa keanekaragaman ikan Pomacentridae pada kedalaman 3 meter adalah rendah dan pada kedalaman 10 meter keanekaragamannya adalah sedang dengan kestabilan komunitas sedang. Pada ke dua kedalaman ini tidak ada spesies dominasi dan kemerataannya adalah stabil. Kata kunci : struktur komunitas, Pomacentridae, Teluk Manado 1Bagian dari skripsi 2Mahasiswa Program Studi Manajemen Sumberdaya Perairan FPIK-UNSRAT



2017 ◽  
Vol 64 (3) ◽  
Author(s):  
N. Sen Ozdemir ◽  
A. M. Feyzioglu ◽  
F. Caf ◽  
I. Yildiz

Seasonal changes in abundance, lipid and fatty acid composition of Calanus euxinus Hulsemann, 1991 were analysed monthly during the period from March 2012 to February 2013. The highest abundance of C. euxinus was recorded in February (847 ind. m-3) during the sampling period. Female and male C. euxinus peaked in February (587 ind. m3, 169 ind. m-3, respectively). However, copepodites peaked in November (107 ind. m-3). Average total lipid content was determined as percentage (%) and per individual (mg ind-1). It was proportionally highest in February (7.03%) and lowest in September (3.02%). However, average lipid content per individual was highest in February (0.11 mg ind-1) and lowest in September and November (0.04 mg ind-1). Major fatty acids in C. euxinus were identified as 16:0, 16:1 n-7, EPA and DHA. ΣSFA, ΣMUFA, ΣPUFA and ΣHUFA were observed to be correlated with temperature. ΣSFA and ΣMUFA increasedwith the rise in temperature (r2=0.74, r2=0.73, p<0.05, respectively) whereas ΣPUFA and ΣHUFA increased as temperature decreased (r2=-0.73, r2=-0.80, respectively, p<0.05). Additionally, while ΣPUFA and ΣHUFA increased (r2=0.61, r2=-0.68, respectively, p<0.05), ΣMUFA decreased (r2=-0.68, p<0.05) as chlorophyll-a increased. It was observed that the degree of unsaturation increased as temperature decreased. Results of the study revealed that C. euxinus has rich lipid content as well as fatty acid composition and it plays an important role in the South-eastern Black Sea ecosystem functionalities especially having key role in energy fluxes to higher trophic levels.





2007 ◽  
Vol 73 (3) ◽  
pp. 593-608 ◽  
Author(s):  
Noriyuki TAKAI ◽  
Noriyuki HIROSE ◽  
Takuya OSAWA ◽  
Kazuyuki HAGIWARA ◽  
Takahito KOJIMA ◽  
...  


Sociobiology ◽  
2020 ◽  
Vol 67 (3) ◽  
pp. 376
Author(s):  
Kelley Rita Przybyszewski ◽  
Ricardo José Silva ◽  
Ricardo Eduardo Vicente ◽  
João Victor Garcia Freitas ◽  
Mônica Josene Barbosa Pereira ◽  
...  

Ants  and  dung  beetles  are  widely  used  in  monitoring  biodiversity  and  are  considered  excellent  environmental  indicators.  Although  the pitfall trap is the most commonly used method to sample dung beetles and ants in ecological studies, beetles are usually sampled using dung‐baited pitfall traps while ants are sampled using un‐baited pitfalls. In the protocol for collecting the beetles it is necessary to have attractive baits in pitfalls. In order to minimize collection effort and costs and to facilitate logistics, it is necessary to determine if there is an effect of the baits on the biodiversity of ants collected in the same traps. Therefore, the objective of this work was to find out whether baited pitfalls could replace conventional pitfalls for the capture of ants. In a total of 42 areas of native habitat, three baited pitfall traps and three without bait were installed, all in the same transect, equidistant ten meters and in activity for 48 hours. In total, 150 species were collected, of which 131 were recorded in non‐baited pitfalls and 107 in baited pitfalls. Traps without bait contributed to 28% of the total number of species captured in this study, whereas pitfalls with bait contributed only to 12% of the total species caught. However, 60% of the total species were captured regardless of the method. In addition to the loss of species among the types of traps, the effect of the method modifies the species composition. We concluded that depending on the type of study, a small decrease in the number of species and change in the composition can influence the results. Thus, we recommend that baited pitfalls should not replace conventional pitfalls.Palavras-chave: Método de coleta; Protocolo de coleta; Desenho da amostra; Esforço de amostragem.



2018 ◽  
Vol 18 (2) ◽  
pp. 166-177
Author(s):  
Le Thi Thu Thao ◽  
Vo Van Quang ◽  
Nguyen Phi Uy Vu

Three surveys were carried out in May, August and December 2014 at 7 sampling location to determine species composition of fish fauna in the coastal waters of Quang Ngai province (the Central Vietnam). A total number of 178 species of fishes were identified belonging to 125 genera, 68 families and 13 orders. Analysis of community structure of fish fauna showed that Perciformes order was the most popular, making up 71.9%; Tetraodontiformes (8.4%); Pleuronectiformes (5.6%). Serranidae family was the most abundant with 14 species, making up 7.9% of the total number of species; Carangidae: 12 species (6.7%); Lutjanidae, Gobiidae had the same number of species with 9 species (5.1%); Scombridae: 7 species (3.9%); Soleidae: 6 species (3.4%); Haemulidae, Mullidae, Tetraodontidae: 5 species (2.8%);... Cluster analysing based on the Bray-Curtis similarity index of nine fish faunas (Thai Binh, Son Tra, Thu Bon, Quang Nam, Nha Phu-Binh Cang, Ben Tre and Tra Vinh) showed that fish composition of the coastal estuaries of Tra Vinh and Ben Tre had the highest similarity (80%), subsequently fish fauna of Quang Ngai had similarity with that of Nha Phu-Binh Cang (39%), Quang Ngai and Quang Nam (42%), Quang Nam and Nha Phu-Binh Cang (41%), Quang Nam and Son Tra (38%), Thai Binh and Ben Tre (37%), Quang Ngai and Son Tra (36%). The result was also classified into two distinct groups of 7 fish faunas: Group 1-Tra Vinh, Ben Tre and Thai Binh; group 2-Quang Ngai, Quang Nam, Nha Phu-Binh Cang and Son Tra. The species richness (Margalef’s index) of Quang Ngai (34.2) was less abundant than other areas, the highest species richness belonged to Tra Vinh (38.2), Thai Binh (38.0), Quang Nam (37.8), Nha Phu-Binh Cang (35.1), Son Tra (30.9), Ben Tre (29.4). The diversity of species composition according to the level taxa in each region showed the characteristic of each fish fauna.



PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5562
Author(s):  
Lidia Dzierzbicka-Glowacka ◽  
Anna Lemieszek ◽  
Marcin Kalarus ◽  
Evelina Griniene

Background Copepods are major secondary producers in the World Ocean. They represent an important link between phytoplankton, microzooplankton and higher trophic levels such as fish. They are an important source of food for many fish species but also a significant producer of detritus. In the terms of the role they play in the marine food web, it is important to know how environmental variability affects the population of copepods. Methods The study of the zooplankton community in the south-eastern Baltic Sea conducted during a 24-month survey (from January 2010 to November 2011) resulted in the identification of 24 invertebrate species (10 copepods, seven cladocerans, four rotifers, one ctenophore, one larvacean, and one amphipod). Data were collected at two stations located in the open sea waters of the Gulf of Gdansk: the Gdansk Deep (P1) (54°50′N, 19°19′E) and in the western, inner part of the Gulf of Gdansk (P2) (54°32′N, 18°48.2′E). The vertical hauls were carried out with the use of two kinds of plankton nets with a mesh size of 100 µm: a Copenhagen net (in 2010), and a WP-2 net (in 2011). Results The paper describes the seasonal changes in the abundance and biomass of copepods, taking into account the main Baltic calanoid copepod taxa (Acartia spp., Temora longicornis and Pseudocalanus sp.). They have usually represented the main component of zooplankton. The average number of copepods at the P1 Station during the study period of 2010 was 3,913 ind m−3(SD 2,572) and their number ranged from 1,184 ind m−3 (in winter) to 6,293 ind m−3(in spring). One year later, the average count of copepods was higher, at 11,723 ind m−3(SD 6,980), and it ranged from 2,351 ind m−3(in winter) to 18,307 ind m−3(in summer). Their average count at P2 Station in 2010 was 29,141 ind m−3, ranging from 3,330 ind m−3(in March) to 67,789 ind m−3(in May). The average count of copepods in 2011 was much lower at 17,883 ind m−3, and it ranged from 1,360 ind m−3 (in April) to 39,559 ind m−3 (in May). Discussion The environmental conditions of the pelagic habitat change in terms of both depth and distance from the shore. Although the qualitative (taxonomic) structure of zooplankton is almost identical to that of the coastal waters, the quantitative structure (abundance and biomass) changes quite significantly. The maximum values of zooplankton abundance and biomass were observed in the summer season, both in the Gdansk Deep and in the inner part of the Gulf of Gdansk. Copepods dominated in the composition of zooplankton for almost the entire time of the research duration. Quantitative composition of copepods at the P1 Station differed from the one at P2 Station due to the high abundance of Pseudocalanus sp. which prefers colder, more saline waters.



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