156 research outputs found
Antarctic marine biodiversity challenged by global change: the CAML/SCAR-MarBIN benchmark
There is now undisputed evidence that
climate change and modifications of
the Earth system occurs, at faster rates
in the polar regions. Among the many
consequences we will be facing, the loss of
biodiversity is probably of highest concern.
CAML and SCAR-MarBIN are striving to
provide the baseline information needed
to assess the potential impact of climate
change on Antarctic marine biodiversity.
Through strong science plans, efficient
data management and an unprecedented
collaborative research effort within the IPY
framework, CAML and SCAR-MarBIN intend
to provide to scientists, environmental
managers and decision-makers a sound
benchmark against which future changes
can reliably be assessed. This paper gives a
brief description of the project’s synergies
Sexual and individual foraging segregation in Gentoo penguins Pygoscelis papua from the Southern Ocean during an abnormal winter
Knowledge about sexual segregation and gender-specific, or indeed individual specialization, in marine organisms has improved considerably in the past decade. In this context, we tested the “Intersexual Competition Hypothesis” for penguins by investigating the feeding ecology of Gentoo penguins during their austral winter non-breeding season. We considered this during unusual environmental conditions (i.e. the year 2009 had observations of high sea surface and air temperatures) in comparison with the long term average at Bird Island, South Georgia. Through conventional (i.e. stomach contents) and stable isotopic values from red blood cells, plasma and feathers of both male and female Gentoo penguins, we showed that there were significant differences between sexes, with males feeding mainly on fish (54% by mass) followed by crustaceans (38%) whereas females fed mainly on crustaceans (89% by mass) followed by fish (4%). Themisto gaudichaudii was the most important crustacean prey for males (64% by mass; 82% by number; 53% by frequency of occurrence) and females (63% by mass; 77% by number; 89% by frequency of occurrence), contrasting with all previous studies that found Antarctic krill Euphausia superba were generally the main prey. Stable isotopic data showed that, in terms of habitat use (based on δ 13C), there were significant differences in short-term carbon signatures between males and females (based on plasma and red blood cells), suggesting that both sexes explored different habitats, with females exploring more offshore pelagic waters and males feeding more in coastal benthic waters. Based on δ 15N, males fed on significantly higher trophic level than females (based on plasma and red blood cells), in agreement with our diet results., Thus, Gentoo penguins behave in a similar manner to other non-breeding penguins species (e.g. king, macaroni and rockhopper penguins), albeit at a smaller spatial scale (as they do not disperse as these other penguins do), in that they have a wider habitat and trophic niche during the Antarctic Winter (in comparison to Summer). We also detected individual specialization in feeding/trophic levels for each gender, with certain males feeding mainly on fish and certain females mainly on crustaceans, which may be driven the prevailing environmental conditions that lead individuals to search for alternative prey, and cause sexual diet segregation. Our results provide further information to help improve understanding about sexual segregation and individual specialization of marine organisms, while contributing valuable information on the winter diet for Antarctic monitoring programs and for modelling Antarctic marine food webs
Analisis Rasio Likuiditas, Aktivitas, dan Profitabilitas terhadap Return Saham Perusahaan Wholesale yang Terdaftar di Bursa Efek Indonesia
Globalisasi mengakibatkan perkembangan Perusahaan di dunia sangat pesat, sehingga menimbulkan persaingan antar Perusahaan sejenis yang sangat ketat. Perusahaan dihadapkan dengan adanya masalah produktivitas yang tinggi, sehingga dapat memenuhi permintaan konsumennya, selain masalah produktivitas yang tinggi tentunya Perusahaan juga harus memperhatikan tingkat atau harga saham yang ada pada Perusahaan, dengan begitu tujuan Perusahaan bisa tercapai. Penelitian ini bertujuan untuk mengetahui pengaruh rasio likuiditas (current ratio), rasio aktivitas (assets turn over), dan rasio profitabilitas (return on equity) terhadap return saham pada Perusahaan Wholesale (Durable & Non Durable Goods). Metode yang digunakan adalah asosiatif.Populasi penelitian berjumlah 32 Perusahaan dengan teknik pengambilan sampel purposive sampling dan dari 32 Perusahaan diambil 10 Perusahaan yang memenuhi kriteria.Hasil penelitian menunjukanreturn on equity berpengaruh positif dan signifikan terhadap return saham, sementara current ratio dan assets turnover berpengaruh negatif terhadap return saham.sebaiknya manajemen Perusahaan memperhatikan aspek likuiditas dan perputaran aset sehingga peningkatan kinerja dari kedua variabel tersebut akan meningkatkan return saham Perusahaan. Kata kunci:current rasio, assets turn over, return on equity
The World Amphipoda Database: history and progress
We provide an overview of the World Amphipoda Database (WAD), a global species database that is part of the World Register of Marine Species (WoRMS). Launched in 2013, the database contains entries for over 10,500 accepted species names. Edited currently by 31 amphipod taxonomists, following WoRMS priorities, the WAD has at least one editor per major group. All accepted species are checked by the editors, as is the authorship available for all of the names. The higher classification is documented for every species and a type species is recorded for every genus name. This constitutes five of the 13 priorities for completion, set by WoRMS. In 2015, five LifeWatch grants were allocated for WAD activities. These included a general training workshop in 2016, together with data input for the superfamily Lysianassoidea and for a number of non-marine groups. Philanthropy grants in 2019 and 2021 covered more important gaps across the whole group. Further work remains to complete the linking of unaccepted names, original descriptions, and environmental information. Once these tasks are completed, the database will be considered complete for 8 of the 13 priorities, and efforts will continue to input new taxa annually and focus on the remaining priorities, particularly the input of type localities. We give an overview of the current status of the order Amphipoda, providing counts of the number of genera and species within each family belonging to the six suborders currently recognized
Amphipodes lysianasso\uefdes n\ue9crophages des \ueeles Kerguelen (Crustacea) : 1. Orchomenella guillei n. sp
Volume: 7Start Page: 205End Page: 21
- …