Variations in the fish catch composition in the Bay of St. Vincent, New Caledonia, as determined by experimental trawling

1990 ◽  
Vol 41 (1) ◽  
pp. 121 ◽  
Author(s):  
M Kulbicki ◽  
L Wantiez
Keyword(s):  
Trophic Structure ◽  
Environmental Changes ◽  
New Caledonia ◽  
Trophic Group ◽  
Trawl Survey ◽  
Population Fluctuations ◽  
Number Of Species ◽  
Fish Catch ◽  
Catch Composition ◽  
Induced Changes

An experimental trawl survey was conducted in the Bay of St Vincent between December 1984 and April 1986. In all, 85 hauls were performed during four cruises. The trawled fish represented 233 species and 59 families. Biomass and density estimates declined 13-fold between the first and last cruises. This decline is not due to the survey catch (less than 2% of the biomass of the bay), nor is it likely to be due to trawling-induced changes in habitat. Natural causes are the most likely reason for the decline. The r-type species (Leiognathidae, Lethrinus nematacanthus) had the largest population fluctuations, whilst longer living and later reproducing species (Saurida undosquamis, large Upeneus spp.) had the smallest. Trophic structure is studied using three expressions: number of species, biomass and density per trophic group. Number of species per trophic group was the most insensitive to changes in time and place, with density being the most sensitive. Study of the variations in trophic structure could help with the monitoring of major changes in fish populations caused by fishing or environmental changes.

Arthropods in the nests of lesser spotted eagle (Aquila pomarina)

Biologia ◽  
2009 ◽  
Vol 64 (5) ◽  
Author(s):  
Ján Krištofík ◽  
Peter Mašán ◽  
Zbyšek Šustek ◽  
Dušan Karaska
Keyword(s):  
Trophic Group ◽  
Trophic Groups ◽  
Significant Component ◽  
Free Living ◽  
Parasitic Species ◽  
Number Of Species ◽  
Aquila Pomarina ◽  
Investigation Period ◽  
First Time

AbstractIn 2001–2007, altogether 57 nests of lesser spotted eagle were collected in the Orava region in northwestern Slovakia and four groups of arthropods were extracted from them. Richest in number of species and individuals were mites (23 species, 17,500 ind.), followed by beetles (12 species, 725 ind.), whereas pseudoscorpions were represented only by Pselaphochernes scorpioides (39 ind.) and fleas by Ceratophyllus garei (3 ind.). Unlike nests of other birds, free-living mites predominated in the nests fauna (83% of individuals), followed by nidicolous species with more or less free relationship to the nests, while parasitic species represented only a negligible part of the fauna. For the first time we observed phoresy of Nenteria pandioni, a specific and abundant mite in the eagles’ nests, on the nidicolous staphylinid Haploglossa puncticollis. The beetle fauna in the nests was much poorer than in nests of other birds. The predatory H. puncticollis was dominant in the nests (83%) and occurred continuously during the whole investigation period. Other beetles, even the widely distributed nidicols such as the histerid Gnathoncus buyssoni, were found rarely in nests. Predators were also the only abundant trophic group of beetles in the nests, while other trophic groups of beetles abundantly co-occur in nests of majority of other birds. The occurrence of all beetles was very unevenly distributed during the investigation period, but was positively correlated with occurrence of mites. The relatively low number of species and individuals of mites and beetles in the lesser spotted eagle nests resulted from their position on tree tops, at a height of 20–30 m and their quick drying out by sun and wind. It was also indicated by an enormously low number of species and individuals of mycetophagous beetles, which represent a significant component of the fauna in nests of other birds.

scholarly journals A high-altitude peatland record of environmental changes in the NW Argentine Andes (24 ° S) over the last 2100 years

2016 ◽  
Vol 12 (5) ◽  
pp. 1165-1180 ◽  
Author(s):  
Karsten Schittek ◽  
Sebastian T. Kock ◽  
Andreas Lücke ◽  
Jonathan Hense ◽  
Christian Ohlendorf ◽  
...  
Keyword(s):  
High Altitude ◽  
Environmental Changes ◽  
Regional Scale ◽  
Central Andes ◽  
High Accumulation ◽  
Climate Conditions ◽  
Climate Anomalies ◽  
Dry Conditions ◽  
Induced Changes ◽  
The 19Th Century

Abstract. High-altitude cushion peatlands are versatile archives for high-resolution palaeoenvironmental studies, due to their high accumulation rates, range of proxies, and sensitivity to climatic and/or human-induced changes. Especially within the Central Andes, the knowledge about climate conditions during the Holocene is limited. In this study, we present the environmental and climatic history for the last 2100 years of Cerro Tuzgle peatland (CTP), located in the dry Puna of NW Argentina, based on a multi-proxy approach. X-ray fluorescence (XRF), stable isotope and element content analyses (δ13C, δ15N, TN and TOC) were conducted to analyse the inorganic geochemistry throughout the sequence, revealing changes in the peatlands' past redox conditions. Pollen assemblages give an insight into substantial environmental changes on a regional scale. The palaeoclimate varied significantly during the last 2100 years. The results reflect prominent late Holocene climate anomalies and provide evidence that in situ moisture changes were coupled to the migration of the Intertropical Convergence Zone (ITCZ). A period of sustained dry conditions prevailed from around 150 BC to around AD 150. A more humid phase dominated between AD 200 and AD 550. Afterwards, the climate was characterised by changes between drier and wetter conditions, with droughts at around AD 650–800 and AD  1000–1100. Volcanic forcing at the beginning of the 19th century (1815 Tambora eruption) seems to have had an impact on climatic settings in the Central Andes. In the past, the peatland recovered from climatic perturbations. Today, CTP is heavily degraded by human interventions, and the peat deposit is becoming increasingly susceptible to erosion and incision.

scholarly journals FACTORS INFLUENCING THE PERFORMANCE OF TRAWL OPERATION IN THE WATERS AREA OF TARAKAN

2018 ◽  
Vol 23 (2) ◽  
pp. 79
Author(s):  
Asep Priatna ◽  
Suprapto Suprapto
Keyword(s):  
Principal Component ◽  
Bottom Trawl ◽  
Fish Density ◽  
Trawl Survey ◽  
Door Opening ◽  
Test Of Significance ◽  
Towing Speed ◽  
Bottom Depth ◽  
Catch Composition

Any fish on swept area of bottom trawl could not be caught due to some technical factors during towing. However, it could be estimated by integrated of bottom trawl and acoustic survey. This paper describes the determination of some factors that affect the performance of trawl net during the bottom trawl survey in the waters of Tarakan. Surveys were carried out in May, August, and November 2012. A total of 57 stations of simultaneously acoustic-trawl were completed. Data collected from each station include catch composition, and variables of trawling operation (i.e. bottom depth, warp length, trawl door opening, towing speed, towing duration, and acoustic fish density). Principal component analysis was applied to identify variables might impact of trawling performance (i.e. fish density at the waters area, towing speed, towing duration, warp length, horizontal opening of trawl door, density of non-demersal at cod end, and bottom depth). Both towing speed and towing duration were not major component for trawl operation. According to test of significance for four variables (i.e. bottom depth, warp length, horizontal opening, biota non-demersal at cod end) which affected to fish density at waters area, that both of variable (i.e. warp length and bottom depth) were significant as the principal components for the performance of bottom trawl. 

scholarly journals The Effect of Bait on The Catch Composition of Square Folding Trap in Rawa Pening Semarang Regency

2020 ◽  
Vol 6 (2) ◽  
pp. 30-37
Author(s):  
Eko Setyo Budi
Keyword(s):  
Catch Rate ◽  
Real Difference ◽  
Anova Test ◽  
Trash Fish ◽  
Fish Catch ◽  
Catch Composition ◽  
One Way Anova

This study aims to determine the effect of the type of bait on the composition of the catch fish, catch rate, and trap rate using square folding traps. The study was conducted at three fishing locations in October 2019-January 2020 using the experimental fishing method. The operation of square folding traps was done by a total of 60 units. The types of bait used are golden snails, shrimp paste, and trash fish. Fish catches were recorded in number, type, length, and weight, and analyzed using one-way anova test and kruskal wallis test. The composition of the square folding traps catches consists of six species. Marble goby (Oxyeleotris marmorata) is the most dominant catch (60%). The highest catch rate was obtained from box folding traps which were given golden snail bait at 173.50 g/trip, then trash fish bait at 76.88 g/trip and shrimp paste feed at 59.22 g/trip. The highest trap rate is golden snail bait of 12.33%. The bait treatment gives a real difference to the amount and weight of the catch, the golden snail bait gives the highest total number and weight of the catch compared to other baits.

scholarly journals KOMPOSISI DAN FLUKTUASI HASIL TANGKAPAN TUGUK DI SUNGAI LEMPUING, SUMATERA SELATAN

2017 ◽  
Vol 15 (2) ◽  
pp. 105
Author(s):  
Dharmadi Dharmadi ◽  
Endi Setiadi Kartamihardja ◽  
Agus Djoko Utomo ◽  
Dian Oktaviani
Keyword(s):  
Fish Species ◽  
Descriptive Analysis ◽  
Dry Season ◽  
Survey Method ◽  
Wet Season ◽  
River Waters ◽  
Transition Season ◽  
Fish Catch ◽  
Catch Composition ◽  
Mystus Nemurus

Tujuan penelitian ini adalah untuk mengetahui komposisi dan fluktuasi hasil tangkapan tuguk pada periode berbeda yang dioperasikan di Sungai Lempuing, Sumatera Selatan. Kegiatan penelitian dilaksanakan dengan metode survei pada periode musim peralihan penghujan sampai dengan kemarau (bulan April), musim kemarau (bulan Juni) dan musim penghujan (bulan Desember) tahun 2007. Komposisi jenis ikan dan hasil tangkapan diperoleh berdasarkan pada data pengambilan contoh pada saat ke lapangan dan data harian hasil tangkapan tuguk yang dicatat oleh 3 orang enumerator. Data dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa hasil tangkapan tuguk berbeda menurut periode waktu. Hasil tangkapan terdiri atas 11 jenis ikan untuk musim peralihan dan kemarau masing-masing berkisar 400-450 kg per unit per hari (rata-rata 411,2+14,1 kg per unit per hari) dan 250-300 kg per unit per hari (rata-rata 263,3+13,4 kg per unit per hari) dan 13 jenis ikan pada musim penghujan (bulan Desember) berkisar 700-750 kg per unit per hari (rata-rata 724,8+17,7 kg per unit per hari). Hasil tangkapan didominansi oleh jenis ikan lele (Clarias melanoderma) dan baung (Mystus nemurus). Selama penelitian, kandungan oksigen terlarut di perairan relatif rendah, berkisar 2-4 mg per l, namun dapat ditolelir oleh kelompok jenis ikan rawa (black fish). This research proposed to observed a catch composition and fluctuation of filtering device in different periods operated in the Lempuing River, South Sumatera. The research was conducted using survey method at a respective month of April (transition season), June (dry season) and December 07 (wet season). Fish composition and catch of tuguk were noted during survey and based on recording 3 enumerators. Descriptive analysis was used in this study. The results show that the catch of filtering device differed on diferent season periodes. A number of 11 fish species was caught at a respective season of transition season (April) of 400-450 kg per unit per day (average=411.2+14,1 kg per unit per day), dry season (June) of 250 300 kg per unit per day (average = 263,3+13,4 kg per unit per day), whilst at rainy season (December), fish catch composed of 13 fish species, ranging 700-750 kg per unit per day or (average = 724.8+17.7 kg per unit per day). Clarias melanoderma and Mystus nemurus were dominantly caught in the Lempuing River waters. During observation, dissolved oxygen content was relatively low (2-4 mg per l), that but could be tolerated by black fish.

Integrative taxonomic revision of the New Caledonian endemic genus Taophila Heller (Coleoptera: Chrysomelidae, Eumolpinae)

2021 ◽  
pp. 1-74
Author(s):  
Leonardo Platania ◽  
Jesús Gómez-Zurita
Keyword(s):  
New Caledonia ◽  
Taxonomic Revision ◽  
Actual Number ◽  
Mtdna Sequences ◽  
Endemic Genus ◽  
Number Of Species ◽  
Morphological Differences ◽  
Mtdna Introgression ◽  
Eleven Species ◽  
Mtdna Genealogy

Abstract There are 96 endemic species of Eumolpinae (Coleoptera: Chrysomelidae) described from New Caledonia, but some estimates propose that the actual number could be at least twice this figure. Not surprisingly, when a particular species assemblage has been revised, the number of species in that group increases significantly. Here, we revise the New Caledonian endemic genus Taophila Heller, 1916, the best studied in this fauna and currently known to include eleven species, one in the subgenus Jolivetiana Gómez-Zurita & Cardoso, 2014, and ten in the nominal subgenus. The analysis of morphological differences in a large sample of Taophila and the validation of the resulting species hypotheses in an integrative fashion based on a phylogenetic analysis of partial mtDNA sequences (cox1 and rrnS) resulted in the addition of eleven more taxa. Taxonomic splits mainly reinterpreted the previous observation of mtDNA paraphyly affecting T. subsericea Heller, 1916, shown to represent a complex of species mostly distinguishable by diagnostic differences among females. The new species described are: T. bituberculata n. sp., T. carinata n. sp., T. dapportoi n. sp., T. davincii n. sp., T. draco n. sp., T. goa n. sp., T. hackae n. sp., T. samuelsoni n. sp., T. sideralis n. sp., T. taaluny n. sp. and T. wanati n. sp. These additions and the synonymy T. subsericea Heller = Stethotes mandjeliae Jolivet, Verma & Mille, 2010 n. syn., bring to 21 the total number of species in Taophila. Moreover, we also found the first evidence of mtDNA introgression between species of New Caledonian Eumolpinae, resulting from putative recent hybridization of T. subsericea and T. dapportoi where these species coexist. We describe a model incorporating the mtDNA genealogy of T. subsericea about the conditions that may have favored the secondary geographic encounter required for the hybridization of these species.

scholarly journals Beaver dam capacity of Canada’s boreal plain in response to environmental change

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nichole-Lynn Stoll ◽  
Cherie J. Westbrook
Keyword(s):  
Environmental Conditions ◽  
Environmental Changes ◽  
Water Cycle ◽  
Stream Networks ◽  
Stream Network ◽  
Beaver Dam ◽  
Riding Mountain National Park ◽  
Induced Changes ◽  
Response To Environmental Change ◽  
Beaver Dams

Abstract Environmental changes are altering the water cycle of Canada’s boreal plain. Beaver dams are well known for increasing water storage and slowing flow through stream networks. For these reasons beavers are increasingly being included in climate change adaptation strategies. But, little work focuses on how environmental changes will affect dam building capacity along stream networks. Here we estimate the capacity of the stream network in Riding Mountain National Park, Manitoba, Canada to support beaver dams under changing environmental conditions using a modelling approach. We show that at capacity, the park’s stream network can support 24,690 beaver dams and hold between 8.2 and 12.8 million m3 of water in beaver ponds. Between 1991 and 2016 the park’s vegetation composition shifted to less preferred beaver forage, which led to a 13% decrease in maximum dam capacity. We also found that dam capacity is sensitive to the size of regularly-occurring floods—doubling the 2-year flood reduces the park’s dam capacity by 21%. The results show that the potential for beaver to offset some expected climatic-induced changes to the boreal water cycle is more complex than previously thought, as there is a feedback wherein dam capacity can be reduced by changing environmental conditions.

scholarly journals A new Troglosiro species (Opiliones, Cyphophthalmi, Troglosironidae) from New Caledonia

Zootaxa ◽  
2005 ◽  
Vol 1053 (1) ◽  
pp. 47 ◽  
Author(s):  
PRASHANT SHARMA ◽  
GONZALO GIRIBET
Keyword(s):  
New Species ◽  
Sea Level ◽  
New Caledonia ◽  
Type Locality ◽  
Anterior Portion ◽  
Endemic Genus ◽  
The Real ◽  
Number Of Species ◽  
A New Species

A new species of Cyphophthalmi belonging to the New Caledonian endemic genus Troglosiro Juberthie, 1979 is described and illustrated using SEM, including the first description of a troglosironid ovipositor. T. longifossa sp. nov., known only from its type locality in Port Boisé, and found at low elevation near sea level, constitutes the seventh species of Troglosiro to be described to date. The new species has a unique disposition of the four ventral opisthosomal gland pores in the anterior portion of a long depression of the sternal segments 3 to 7. Information on other specimens recently collected in New Caledonia indicates that the number of described species in the island is a gross underestimate of the real diversity of New Caledonian Cyphophthalmi, both in number of species and morphology.

Alien and native fish in gill nets at Rhodes, eastern Mediterranean (2014–2015)

2017 ◽  
Vol 97 (3) ◽  
pp. 635-642 ◽  
Author(s):  
Maria Corsini-Foka ◽  
Stefanos Mastis ◽  
Gerasimos Kondylatos ◽  
Ioannis E. Batjakas
Keyword(s):  
Native Species ◽  
Fish Assemblages ◽  
Eastern Mediterranean ◽  
Aegean Sea ◽  
Total Biomass ◽  
Coastal Fish ◽  
Gill Net ◽  
Fish Catch ◽  
Siganus Rivulatus ◽  
Catch Composition

Fish catch composition in 21 gill net samplings performed between 2014 and 2015 at Rhodes Island (Aegean Sea, Greece) was analysed, with the aim to contribute in filling scattered information on coastal fish assemblages in a Mediterranean region heavily impacted by biological invasions. A total biomass of 183 kg was collected comprising 1070 fish individuals, distributed along 43 native and six Lessepsian migrant species. The alien Siganus luridus prevailed in terms of frequency of occurrence, followed by the native Sparisoma cretense, which exhibited the higher abundance and biomass, followed by S. luridus, Scorpaena scrofa and Siganus rivulatus. Ratios between alien and native species as well as between their abundance and biomass are discussed.

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