Relationship between catch, effort, CPUE and local abundance for non-target species, such as billfishes, caught by Indian Ocean longline fisheries

2003 ◽  
Vol 54 (4) ◽  
pp. 383 ◽  
Author(s):  
Alain Fonteneau ◽  
Nicolas Richard
Keyword(s):  
Indian Ocean ◽  
Generalized Additive Model ◽  
Additive Model ◽  
Fishing Effort ◽  
Potential Bias ◽  
Target Species ◽  
Catch Per Unit Effort ◽  
The Indian Ocean ◽  
Longline Fisheries ◽  
The Relationship

This paper analyses the local relationship between effort, catches, catch per unit effort (CPUE) and abundance of target species (such as tunas) and of non-target species (such as billfishes). The Indian Ocean longline fisheries are taken as an example. This paper evaluates the potential bias in the relationship between local CPUE and abundance when fisheries are increasing their fishing effort. A presentation of the Indian Ocean longline fisheries is carried out. A statistical analysis of CPUE is conducted using a generalized additive model which tends to indicate that the local effort is an important component in the statistical behaviour of the local CPUE. A migratory model in which both resources and fisheries are mobile was built. This model simulates the combined exploitation of two species, a target and a bycatch species, both fished at increasing intensity. This model confirms the potential bias as a result of the concentration of fishing effort in areas of high density of the target species. It also suggests that the CPUE of bycatch species may be more heavily biased because of their status. It is recommended that local fishing efforts should preferably be taken into account in order to calculate the CPUE of both target and non-target species.

Kinship as Politics

2017 ◽  
Author(s):  
Danna Agmon
Keyword(s):  
Indian Ocean ◽  
French Empire ◽  
Family Networks ◽  
Commercial Networks ◽  
The Indian Ocean ◽  
Kinship Ties ◽  
The Relationship

This chapter considers the role of family networks, both French and Tamil, in the development of French empire in India. It charts how two Tamil dynasties drew on their kinship ties to create commercial networks that spanned the Indian Ocean, and highlights the involvement of of one local woman in the relationship between French colonists and local familial institutions.

Indonesia and the Arab World, Then and Now

2021 ◽  
pp. 26-55
Author(s):  
Mirjam Lücking
Keyword(s):  
Middle East ◽  
Indian Ocean ◽  
Arab World ◽  
Seventh Century ◽  
Religious Leaders ◽  
Historical Overview ◽  
Islamic Culture ◽  
The Indian Ocean ◽  
The Relationship

This chapter provides a historical overview of ambivalent encounters between Indonesia and the Arab world through findings that show the relationship between Indonesia and the Middle East. It recounts the Indonesians' earliest encounters with Arab traders in the seventh century, from confrontations with Indo Persian Sufi up to the current democratization process that have been marked by contradictory dynamics. It also explains how Arabs have been acknowledged as teachers of Islam and allies in the postcolonial nonbloc movement. The chapter describes the gloomy counterimage of the Arab world against which Indonesian officials and religious leaders drew the picture of a tolerant, pluralist Indonesian Islam. It mentions the key role of the mobility across the Indian Ocean in the formation of Islamic culture in Indonesia.

Implications of interference among fishing vessels and the ideal free distribution to the interpretation of CPUE

1998 ◽  
Vol 55 (1) ◽  
pp. 37-46 ◽  
Author(s):  
D M Gillis ◽  
R M Peterman
Keyword(s):  
Ideal Free Distribution ◽  
Fishing Effort ◽  
Catch Per Unit Effort ◽  
Free Distribution ◽  
Fishing Vessels ◽  
Factor Interactions ◽  
The Relationship ◽  
Index Of Abundance ◽  
Ideal Free ◽  
The Ideal

Despite recognized biases, catch per unit effort (CPUE) statistics remain widely used for the estimation of fish abundance. Previous workers have shown that CPUE can be a misleading index of abundance due to fish behavior, the nominal effort units used, and increases through time in efficiency of fishing (catchability). We examine the theoretical implications of a different factor, interactions among fishing vessels, for the relationship between abundance and CPUE. Our model simulates a fishery that occurs in several adjacent fishing grounds. The spatial distribution of catch and effort is based on a simplification of the Baranov catch equation, the relationship between fishing efficiency and local fishing effort (interference), and the assumptions of the ideal free distribution. Our results indicate that (i) even low levels of interference among fishing vessels can cause a breakdown in the correlation between CPUE and local abundance and (ii) the influence of interference on this relationship is dependent on the correlation of abundances among adjacent areas. Our model suggests an alternative index of abundance, based on the proportion of fishing effort on a ground, that would be appropriate for cases where interference occurs among fishing gear.

scholarly journals Why Has the Relationship between Indian and Pacific Ocean Decadal Variability Changed in Recent Decades?

2017 ◽  
Vol 30 (6) ◽  
pp. 1971-1983 ◽  
Author(s):  
Lu Dong ◽  
Michael J. McPhaden
Keyword(s):  
Pacific Ocean ◽  
Indian Ocean ◽  
Climate Models ◽  
Climate Model ◽  
Decadal Variability ◽  
Negative Phase ◽  
External Forcing ◽  
Indian Ocean Basin Mode ◽  
The Indian Ocean ◽  
The Relationship

Abstract Both the Indian and Pacific Oceans exhibit prominent decadal time scale variations in sea surface temperature (SST), linked dynamically via atmospheric and oceanic processes. However, the relationship between SST in these two basins underwent a dramatic transformation beginning around 1985. Prior to that, SST variations associated with the Indian Ocean basin mode (IOB) and the interdecadal Pacific oscillation (IPO) were positively correlated, whereas afterward they were much less clearly synchronized. Evidence is presented from both observations and coupled state-of-the-art climate models that enhanced external forcing, particularly from increased anthropogenic greenhouse gases, was the principal cause of this changed relationship. Using coupled climate model experiments, it is shown that without external forcing, the evolution of the IOB would be strongly forced by variations in the IPO. However, with strong external forcing, the dynamical linkage between the IOB and the IPO weakens so that the negative phase IPO after 2000 is unable to force a negative phase IOB-induced cooling of the Indian Ocean. This changed relationship in the IOB and IPO led to unique SST patterns in the Indo-Pacific region after 2000, which favored exceptionally strong easterly trade winds over the tropical Pacific Ocean and a pronounced global warming hiatus in the first decade of the twenty-first century.

The relationship between Indian Ocean sea–surface temperature and East African rainfall

2005 ◽  
Vol 363 (1826) ◽  
pp. 43-47 ◽  
Author(s):  
Emily Black
Keyword(s):  
Indian Ocean ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Southern Oscillation ◽  
Sea Surface ◽  
East African ◽  
African Rainfall ◽  
The Pacific ◽  
The Indian Ocean ◽  
The Relationship

Knowledge of the processes that control East African rainfall is essential for the development of seasonal forecasting systems, which may mitigate the effects of flood and drought. This study uses observational data to unravel the relationship between the Indian Ocean Dipole (IOD), the El Niño Southern Oscillation (ENSO) and rainy autumns in East Africa. Analysis of sea–surface temperature data shows that strong East African rainfall is associated with warming in the Pacific and Western Indian Oceans and cooling in the Eastern Indian Ocean. The resemblance of this pattern to that which develops during IOD events implies a link between the IOD and strong East African rainfall. Further investigation suggests that the observed teleconnection between East African rainfall and ENSO is a manifestation of a link between ENSO and the IOD.

scholarly journals KOMPOSISI HASIL TANGKAPAN SAMPINGAN DAN IKAN TARGET PERIKANAN RAWAI TUNA BAGIAN TIMUR SAMUDERA HINDIA (Catch Composition of By-Catch and Target Species on Tuna Longline Fisheries in Eastern Indian Ocean)

2016 ◽  
Vol 5 (2) ◽  
pp. 119
Author(s):  
Dian Novianto ◽  
Budi Nugraha
Keyword(s):  
Indian Ocean ◽  
Eastern Indian Ocean ◽  
Target Species ◽  
Olive Ridley ◽  
Lepidochelys Olivacea ◽  
Bony Fishes ◽  
By Catch ◽  
Catch Composition ◽  
Longline Fisheries ◽  
Tuna Longline

<p>ABSTRACT<br />Tuna longline operations also capture other than tuna species are known as by-catch are caught accidentally due to the ecological linkages. This study aims to identify the species composition of by-catch and try to analyzed the interaction of non-target species with tuna species as the target species on tuna longline fishery in the eastern Indian Ocean. Surveillance was conducted on February 2013-January 2014 by following 7 commercial tuna longliners vessel with fishing operations for 226 days. The results showed there were 36 species, where the target species consists of 4 tuna species (26.11%) and 32 by-catch species consist of by-product (24.08%) and that is not utilized (discards, 49.74%). The Results of by-catch are consists of a lancetfish (Alepisaurus spp., 42.87%), pelagic stingray (Pteroplatytrygon violacea, 22.05%), escolar (Lepidocybium flavobrunneum, 10.22%) and sickle pomfret (Taractichthys steindachneri, 8.21%), while for other species consists of are billfishes (6 species), shark and rays species (10 species), bony fishes (11 species) and turtles (olive ridley).</p><p>Keywords: by-catch, tuna longline, Indian ocean</p><p>-------</p><p>ABSTRAK</p><p>Pengoperasian rawai tuna juga menangkap jenis-jenis lain selain tuna yang dikenal dengan sebutan hasil tangkap sampingan (HTS atau by-catch) yang tertangkap secara tidak sengaja dikarenakan adanya keterkaitan secara ekologi. Penelitian ini bertujuan untuk mengidentifikasi komposisi jenis hasil tangkap sampingan dan mencoba menganalisis hubungan interaksi ikan hasil tangkap sampingan dengan ikan tuna sebagai tangkapan utama (target species) pada perikanan rawai tuna di bagian timur Samudera Hindia. Pengamatan dilakukan pada bulan Februari 2013-Januari 2014 dengan mengikuti kegiatan operasi penangkapan 7 kapal rawai tuna komersial dengan selama 226 hari operasi penangkapan. Hasil penelitian menunjukkanterdapat 35 jenis ikan dan 1 jenis penyu dimana target utama terdiri dari 4 jenis ikan (26,11%) dan hasil tangkapan sampingan 31 jenis ikan dan 1 jenis penyu dimana yang dimanfaatkan (by-product) (24,08%) dan yang tidak dimanfaatkan (discards) (49,74%). Hasil tangkapan sampingan berturut-turut didominasi oleh ikan naga (Alepisaurus spp., 42,87%), pari lemer (Pteroplatytrygon violacea, 22,05%), ikan setan (Lepidocybium flavobrunneum, 10,22%) dan bawal sabit (Taractichthys steindachneri, 8,21%), selanjutnya juga tertangkap jenis paruh panjang (billfish, 6 spesies), jenis cucut dan pari (elasmobranchii, 10 spesies), jenis teleostei (bony fishes,11 spesies) dan penyu lekang (Lepidochelys olivacea).</p><p><br />Kata kunci: Hasil tangkap sampingan, rawai tuna, Samudera Hindia</p>

scholarly journals ASPEK BIOLOGI DAN DAERAH PENANGKAPAN CUCUT BOTOL (Squalus sp.) YANG TERTANGKAP DI PERAIRAN SAMUDERA HINDIA

2017 ◽  
Vol 13 (1) ◽  
pp. 35
Author(s):  
Dharmadi Dharmadi ◽  
Fahmi Fahmi
Keyword(s):  
Indian Ocean ◽  
Deep Water ◽  
Fishing Season ◽  
Total Length ◽  
Study Results ◽  
The Indian Ocean ◽  
Dogfish Shark ◽  
Males And Females ◽  
The Relationship ◽  
Fishing Area

Penelitian mengenai keragaman jenis Elasmobranchi dilakukan pada bulan Januari sampai dengan Desember 2002 di pelabuhan-pelabuhan perikanan PPI Cilacap, TPI Palabuhanratu, TPI Kedonganan-Bali, dan PPI Tanjung Luar-Lombok Timur. Cucut botol Squalus sp. merupakan jenis cucut laut dalam yang paling sering dijumpai selama penelitian berlangsung. Hasil penelitian menunjukkan bahwa cucut botol betina lebih sering tertangkap dibandingkan cucut jantan pada setiap waktu pengamatan. Frekuensi panjang cucut botol tertinggi dijumpai pada bulan Juni danAgustus yaitu berkisar antara 62 sampai dengan 68 cm. Nisbah kelamin cucut botol antara jantan betina selama pengamatan adalah 1:1,83. Hubungan antara panjang total tubuh dan panjang klasper cenderung linier dengan nilai R2=0,634326. Puncak musim penangkapan cucut botol terjadi sekitar bulan Agustus. Sedangkan daerah penangkapan cucut botol adalah di perairan Samudera Hindia. A study on diversity Elasmobranchi of was conducted using market surveys method from January to December 2002 at several fish landings in southern Indonesia, i.e. the Cilacap, Palabuhanratu, Kedonganan- Bali, and Tanjung Luar-East Lombok landing sites.A deep water shark, Indonesian shortnose spurdog (Squalus sp.), was the most common deep water sharks captured in the area during the study. Results show that females sharks were caught more frequent at every observation than those of males. The most abundant of Indonesian shortnose spurdog was recorded in June and August ranging from 62 to 68 cm in total length. Sex ratio between males and females of Squalus sp. during the study was 1:1.83, and the relationship between total length and claspers length of dogfish shark was linier (R2=0.634326). The peak fishing season of Indonesian spurdog was occurred in August with the fishing area was in the Indian Ocean.

scholarly journals The Effect of the COVID-19 Vaccine on Daily Cases and Deaths Based on Global Vaccine Data

Vaccines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1328
Author(s):  
Zhiwei Li ◽  
Xiangtong Liu ◽  
Mengyang Liu ◽  
Zhiyuan Wu ◽  
Yue Liu ◽  
...  
Keyword(s):  
Random Effects ◽  
Generalized Additive Model ◽  
Meta Analysis ◽  
Additive Model ◽  
Global Pandemic ◽  
Daily Data ◽  
Fair Distribution ◽  
The Impact ◽  
The Relationship

Background: Coronavirus disease 2019 (COVID-19), a global pandemic, has caused over 216 million cases and 4.50 million deaths as of 30 August 2021. Vaccines can be regarded as one of the most powerful weapons to eliminate the pandemic, but the impact of vaccines on daily COVID-19 cases and deaths by country is unclear. This study aimed to investigate the correlation between vaccines and daily newly confirmed cases and deaths of COVID-19 in each country worldwide. Methods: Daily data on firstly vaccinated people, fully vaccinated people, new cases and new deaths of COVID-19 were collected from 187 countries. First, we used a generalized additive model (GAM) to analyze the association between daily vaccinated people and daily new cases and deaths of COVID-19. Second, a random effects meta-analysis was conducted to calculate the global pooled results. Results: In total, 187 countries and regions were included in the study. During the study period, 1,011,918,763 doses of vaccine were administered, 540,623,907 people received at least one dose of vaccine, and 230,501,824 people received two doses. For the relationship between vaccination and daily increasing cases of COVID-19, the results showed that daily increasing cases of COVID-19 would be reduced by 24.43% [95% CI: 18.89, 29.59] and 7.50% [95% CI: 6.18, 8.80] with 10,000 fully vaccinated people per day and at least one dose of vaccine, respectively. Daily increasing deaths of COVID-19 would be reduced by 13.32% [95% CI: 3.81, 21.89] and 2.02% [95% CI: 0.18, 4.16] with 10,000 fully vaccinated people per day and at least one dose of vaccine, respectively. Conclusions: These findings showed that vaccination can effectively reduce the new cases and deaths of COVID-19, but vaccines are not distributed fairly worldwide. There is an urgent need to accelerate the speed of vaccination and promote its fair distribution across countries.

scholarly journals Temperature variability and trend estimates at tropopause and UT-LS over a subtropical site: Reunion (20.8° S, 55.5° E)

2010 ◽  
Vol 10 (4) ◽  
pp. 10113-10143
Author(s):  
N. Bègue ◽  
H. Bencherif ◽  
V. Sivakumar ◽  
G. Kirgis ◽  
N. Mzé ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Temperature Variability ◽  
Lapse Rate ◽  
Temperature Trends ◽  
Oceanic Forcing ◽  
The Indian Ocean ◽  
Cooling Trend ◽  
Main Component ◽  
Cold Point ◽  
The Relationship

Abstract. This paper mainly focuses on the trends and variability of the tropopause and UT-LS temperature using radiosonde observations carried out over 16 years (January 1993 to December 2008) from a southern subtropical site, Reunion Island (20.8° S, 55.5° E), using a linear-regression fitting model. Two kinds of tropopause definitions, namely, cold point tropopause (CPT) and lapse rate tropopause (LRT) are used. In the purpose to characterize and quantify the relationship between the regional oceanic forcing and temperature at tropopause and UT-LS, we take into account the Indian Ocean Dipole (IOD) for the estimation of temperature trends. Results show that the main component is the Annual Oscillation (AO), particularly at tropopause (CPT, LRT) and in the lower stratosphere (LS) where more than 26% of the variability of temperature can be explained by AO. As a result, the influence of IOD on the variability of the temperature is at highest ratio at CPT and LS, with respectively 12.3% and 13.1%. The results show a low correlation between IOD and the temperature anomalies at tropopause (LRT, CPT) and UT-LS, in the range of 0.08–0.15, with the maximum of correlation at CPT (0.15). In addition, trend estimates at CPT and in the LS suggests that the IOD forcing contributes enhancing the rate of cooling of about 0.1 K per decade. Indeed a trend analysis reveals a cooling of about 0.90±0.40 K per decade at LS and a cooling trend of about 0.36±0.48 K per decade at CPT. The cooling trend at LS is found to be in good agreement with the others studies. These results support the assumption that the Indian Ocean may have a slight impact on temperature variability and on temperature change at CPT and in the LS over Reunion.

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