Modeling of the Migration of the European Glass Eel

2005 ◽  
Vol 1048 (1) ◽  
pp. 85-91
Author(s):  
ALEKSANDAR HEGEDIŠ ◽  
ALEKSANDAR KALAUZI ◽  
BRANISLAV MIĆKOVIĆ ◽  
MIROSLAV NIKČEVIĆ ◽  
RADOSLAV K. ANDJUS
Keyword(s):  
Glass Eel

Challenges to quantifying glass eel abundance from large and dynamic estuaries

2017 ◽  
Vol 75 (2) ◽  
pp. 727-737 ◽  
Author(s):  
Sarah Walmsley ◽  
Julie Bremner ◽  
Alan Walker ◽  
Jon Barry ◽  
David Maxwell
Keyword(s):  
Large Scale ◽  
Anguilla Anguilla ◽  
Commercial Fishing ◽  
European Eel ◽  
Estuarine System ◽  
Glass Eel ◽  
The North ◽  
Adequate Sampling ◽  
South Shore ◽  
Glass Eels

Abstract European eel Anguilla anguilla recruitment into the rivers of the northeastern Atlantic has declined substantially since the 1980s. Monitoring of recruiting juveniles, or glass eels, is usually undertaken in small estuaries and rivers. Sampling of large-scale estuaries is rare, due to the size of the sampling area and the resources needed to provide adequate sampling levels. Here we describe surveys for glass eels in the UK’s largest estuarine system, the Severn Estuary/Bristol Channel. We sampled across a 20 km-wide stretch of the estuary in 2012 and 2013, using a small-meshed net deployed from a commercial fishing trawler, and the surveys yielded over 2500 glass eels. Eels were more abundant in the surface layer (0–1.4 m depth) than at depth (down to 8.4 m depth), were more abundant close to the south shore than along the north shore or middle of the estuary, and were more abundant in lower salinity water. Numbers were higher in the second year than in the first and eels were more abundant in February than April. The difficulties and logistics of sampling in such a large estuary are discussed, along with the level of resources required to provide robust estimates of glass eel abundance.

scholarly journals What are the best upland river characteristics for glass eel restocking practice?

2021 ◽  
pp. 147042
Author(s):  
Billy Nzau Matondo ◽  
Jean-Philippe Benitez ◽  
Arnaud Dierckx ◽  
Séverine Renardy ◽  
Xavier Rollin ◽  
...  
Keyword(s):  
Glass Eel

scholarly journals When will the eel recover? A full life-cycle model

2007 ◽  
Vol 64 (7) ◽  
pp. 1491-1498 ◽  
Author(s):  
Mårten Åström ◽  
Willem Dekker
Keyword(s):  
Life Cycle ◽  
Distribution Area ◽  
European Eel ◽  
Life Cycle Model ◽  
Cycle Model ◽  
Glass Eel ◽  
Full Life Cycle ◽  
Long Run ◽  
Spawning Stock ◽  
Full Life

Abstract Åström M., and Dekker W. 2007. When will the eel recover? A full life-cycle model. – ICES Journal of Marine Science, 64: 000–000: –. The European eel population has declined over the past decades in most of its distribution area, and the stock is outside safe biological limits. The EU has taken up the challenge to design a management system that ensures the escapement of 40% of spawning-stock biomass, relative to unexploited, unpolluted circumstances in unobstructed rivers. This ultimately aims to restore the spawning stock to a level at which glass eel production is not impaired, i.e. to restore to full historical glass eel recruitment. To explore the trajectory from the current depleted state to full recruitment recovery, we developed a simple model of stock dynamics, based on a simplified stock–recruitment relationship and the conventional dynamic pool assumptions. Recruitment trajectories under different future fishery regimes are explored, for the medium (one generation time) and long time-span (until full recruitment recovery). Reducing fisheries to zero, recovery is expected within ∼80 years, whereas under an ultimately sustainable fishing regime of just 10% of the current rate of fishing mortality, recovery may take more than 200 years. Moreover, management regimes, apparently leading to slight recovery of the stock in the coming 5–15 years, might still be unsustainable in the long run.

scholarly journals Size and Ambundance of glass eel Anguilla spp in mouth of Poigar River

2019 ◽  
Vol 7 (1) ◽  
pp. 212
Author(s):  
Kristanto R. Lumi ◽  
Victor N. R. Watung ◽  
Nego E. Bataragoa
Keyword(s):  
River Flow ◽  
Average Length ◽  
Sampling Site ◽  
River Estuary ◽  
Average Density ◽  
Fishing Gear ◽  
Sampling Area ◽  
Glass Eel ◽  
Phase Sampling ◽  
New Moon

The  aims of this study are determine the composition of the length and abundance of glass eel Anguilla spp that migrates at the mouth of the Poigar River. Sampling is done every month for four months in the new moon phase. Sampling site on one side of the Poigar River estuary, by making a 10 meter track in the direction of the river flow. The fishing gear used is a triangle-shaped handy scoop net with a length of 100 cm and a width of 75 cm. The catch of Glass eel eel for four months (from April to July 2018) as many as 3,551 individuals. Average length (± SD) in April was 44.4 ± 1.4 cm, May 48.7 ± 1.6 cm, June 51.1 ± 2.0 cm and July 51.1 ± 2.4 cm. The highest number of catches in May was 1,841 individuals, followed by June 785, July 860 individuals and April as many as 55 individuals. The average density of eels in April, Mai, June and July 2018 migrating in the sampling area of 10 x 0.7 meters is 1,160 individuals.Keywords: glass eel, size, abundance, Poigar River.ABSTRAKPenelitian ini bertujuan untuk mengetahui komposisi ukuran panjang dan kelimpahan  ‘‘glass eel’’ sidat Anguilla spp yang bermigrasi di muara Sungai Poigar.  Pengambilan sampel dilakukan setiap bulan selama empat bulan pada  fase  bulan baru. Tempat sampling  pada  satu sisi muara Sungai Poigar, dengan membuat lintasan sepanjang 10 meter searah aliran sungai. Alat tangkap yang digunakan adalah seser (handy scoop net) berbentuk segitiga dengan panjang 100 cm dan lebar 75 cm. Hasil tangkapan Glass eel sidat selama empat bulan (dari bulan April sampai Juli 2018) sebanyak 3.551 individu.  Rata-rata  panjang (± SD) pada bulan April 44,4±1,4 cm, Mei 48,7±1,6 cm, Juni 51,1±2,0 cm dan Juli 51,1±2,4 cm.  Jumlah tangkapan terbanyak pada bulan Mei 1.841 individu, diikuti bulan Juni 785, bulan Juli 860 individu dan bulan April sebanyak 55 individu.  Rata-rata kepadatan sidat pada bulan April, Mai, Juni dan Juli 2018 yang bermigrasi dalam wilayah sampling 10 x 0,7 meter adalah 1.160 individu.Kata kunci: glass eel, ukuran, kelimpahan, Sungai Poigar.

scholarly journals Feeding Habits of the Glass Eel Anguilla japonica Determined by C and N Stable Isotopes in the Nakdong River Estuary of the Korean Peninsula

The Sea ◽  
2016 ◽  
Vol 21 (1) ◽  
pp. 36-43
Author(s):  
JEONG BAE KIM ◽  
WON-CHAN LEE ◽  
HYUNG CHUL KIM ◽  
SOKJIN HONG ◽  
KYEONG DONG PARK
Keyword(s):  
Stable Isotopes ◽  
Korean Peninsula ◽  
Feeding Habits ◽  
River Estuary ◽  
Anguilla Japonica ◽  
Nakdong River ◽  
Glass Eel ◽  
C And N ◽  
The Nakdong River

scholarly journals Recruitment and abundance estimation of glass eel genus Anguilla in three large estuaries on the coast of Sukabumi West Java

2021 ◽  
Vol 322 ◽  
pp. 01037
Author(s):  
Triyanto ◽  
Gadis Sri Haryani ◽  
Mohammad Mukhlis Kamal ◽  
Iwan Ridwansyah ◽  
Fauzan Ali ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Rainy Season ◽  
Dominant Species ◽  
Water Discharge ◽  
Abundance Estimation ◽  
West Java ◽  
Glass Eel ◽  
The Indian Ocean ◽  
Glass Eels

The rivers on the Sukabumi Coast flow into the Indian Ocean. Three major rivers, namely the Cimandiri River, Cikaso River, and Cibuni River, are sources of glass eel fishing. This study aims to determine the recruitment and estimate of glass eel abundance for future glass eel management. The study was conducted from November 2020-April 2021. Estimation of glass eel abundance was carried out using a fyke net. The glass eel calculation is determined based on the number of glass eels caught, the water discharge entering the fyke net, the water discharge in the estuary, and other variables. The results showed that glass eel recruitment began at the beginning of the rainy season in November 2020 and lasted at the end of the study in April 2021. Anguilla bicolor bicolor is a dominant species of glass eel found in the three river estuaries. The estimated abundance of glass eel was approximately 2,583,438-13,556,650 ind./year or 326,24-1,812 kg/year. The abundance of glass eels at the estuary of Cimandiri River was higher than that of the estuary of Cibuni River and the estuary of Cikaso River.

scholarly journals Isolation and identification of bacteria and parasites in glass eel (Anguilla spp.)

2021 ◽  
Vol 322 ◽  
pp. 02012
Author(s):  
Septyan Andriyanto ◽  
Hessy Novita ◽  
Tuti Sumiati ◽  
Taukhid
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Prevalence Rate ◽  
Bacterial Species ◽  
Bacterial Identification ◽  
Biochemical Method ◽  
Isolation And Identification ◽  
Glass Eel ◽  
Pathogenic Agent ◽  
Identification Of Bacteria ◽  
Glass Eels

The disease is the main agent that causes mortality of fish, especially during seed stages. The research aimed to find out bacteria and parasitic speciesin glass eel, Anguilla spp. Bacterial identification was carried out by a biochemical method. The prevalence of bacterial species was calculated using the El-Gohary et al. (2020) formula, while the results of bacterial identification from glass eel were Aeromonas spp., Vibrio spp., Enterococcus spp., Staphylococcus spp., Planococcus spp., Lactobacillus spp., Listeria spp., Citrbacterfreundii, Neisseria spp., Pseudomonas aeruginosa, Kurthia spp., Streptococcus spp., and Corynebacterium spp. It was found that the five highest prevalence rate was for Listeria spp. (39.64%), followed by Aeromonas spp. (26.13%), Staphylococcus spp. (16.22%), Corynebacterium spp. (5.41%), Lactobacillus spp. (2.70%), and the lowest prevalence rate was Streptococcus spp. (0.90%). The type of parasitic pathogen obtained was Trichodina spp. (2,70%), Dactylogyrus spp. (2,70%) and Gyrodactylus spp. (2,70%). Bacterial and parasites identified in glass eels need further verification on the epizootiology characteristic of each pathogenic agent.

scholarly journals The effects of differences in water exchange on the productivity of glass eel stage in Anguilla bicolor bicolor culture

2021 ◽  
Vol 322 ◽  
pp. 02006
Author(s):  
Eri Setiadi ◽  
Adang Saputra ◽  
Imam Taufik
Keyword(s):  
Water Quality ◽  
Blood Glucose ◽  
Survival Rate ◽  
Quality Management ◽  
Water Exchange ◽  
Water Quality Management ◽  
Economic Value ◽  
Culture Technique ◽  
Glass Eel ◽  
Survival And Growth

Eel, Anguilla bicolor bicolor has an economic value for export commodity. Eel farming has been developed both of home to industries scales. However, the main problem during the glass eel culture is the low survival rate, characterized by high mortality. This condition is related to the culture technique that has not been established yet, especially water quality management. The research aims to determine the best water exchange during the culture of the glass eel on the survival, growth, and blood glucose. The different percentages of water exchange as a treatment were followed A) control (without water exchange); B) 20% of water exchange; C) 40% of water exchange; and D) 60% of water exchange. The water exchange has affected the survival, growth, and blood glucose (P<0.05). The ammonia, nitrite, and nitrate values during the culture period showed that the control was higher compared to the others. The water exchange of 40% is suitable for glass eel stage culture to obtain the best survival and growth.

Sign in / Sign up

Export Citation Format

Share Document