scholarly journals Comparison of daily- and annual- increment counts in otoliths of bigeye (Thunnus obesus), yellowfin (T. albacares), southern bluefin (T. maccoyii) and albacore (T. alalunga) tuna

2013 ◽  
Vol 70 (7) ◽  
pp. 1439-1450 ◽  
Author(s):  
Ashley J. Williams ◽  
Bruno M. Leroy ◽  
Simon J. Nicol ◽  
Jessica H. Farley ◽  
Naomi P. Clear ◽  
...  
Keyword(s):  
Bluefin Tuna ◽  
Yellowfin Tuna ◽  
Older Age ◽  
Annual Increment ◽  
Daily Increments ◽  
Thunnus Obesus ◽  
Southern Bluefin Tuna ◽  
Meta Analyses ◽  
Age Estimates ◽  
Ageing Methods

Abstract Williams, A. J., Leroy, B. M., Nicol, S. J., Farley, J. H., Clear, N. P., Krusic-Golub, K., and Davies, C. R. Comparison of daily- and annual-increment counts in otoliths of bigeye (Thunnus obesus), yellowfin (T. albacares), southern bluefin (T. maccoyii) and albacore (T. alalunga) tuna. – ICES Journal of Marine Science, 70: . Information on the age of individuals is often required for models assessing the status of stocks. Techniques used to estimate age of tuna have varied across species and agencies, precluding meta-analyses of age and growth. We compared age estimates obtained from commonly used ageing techniques for four important tuna species: bigeye tuna, yellowfin tuna, southern bluefin tuna, and albacore tuna. Estimates of age from counts of annual increments in transverse-sectioned otoliths were generally higher than those from counts of daily increments in transverse and longitudinal sections for all species, particularly for fish older than two years. However, annual counts produced younger estimates, on average, relative to daily counts for bigeye and yellowfin tuna younger than one year. Estimates derived from daily increments in longitudinal and transverse sections were generally similar, although longitudinal sections produced relatively older age estimates for individuals older than two years. A linear or non-linear increase in the magnitude of differences between ageing methods was the best-approximating model in all cases except when comparing daily-increment counts between transverse and longitudinal otolith sections for southern bluefin tuna. These observations are consistent with a narrowing of daily increments with increasing age, resulting in underestimates of age relative to those derived from annual increments. We conclude that (i) daily increments are unsuitable for ageing individuals over two years, especially for southern bluefin and albacore, (ii) longitudinal sections are more precise and produce older age estimates than transverse sections for daily-age estimates, (iii) there are considerable differences in these trends between species, likely dependent on longevity, and (iv) parameter estimates and/or conclusions based on meta-analyses using age data derived from different ageing methods are likely confounded with methodological biases. This result demonstrates that greater effort is required to provide consistent, validated methods for routine age determination to support the assessment and management of these valuable populations.

scholarly journals Fishing ground and tuna productivity by tuna longline based on Benoa Bay, Bali, Indonesia

2021 ◽  
Vol 22 (2) ◽  
Author(s):  
Mohammad Imron ◽  
MUHAMMAD IRSYAD TAWAQAL ◽  
ROZA YUSFIANDAYANI
Keyword(s):  
Bluefin Tuna ◽  
Yellowfin Tuna ◽  
Fishing Ground ◽  
Bigeye Tuna ◽  
Productivity Analysis ◽  
Fishing Activity ◽  
Arafura Sea ◽  
Southern Bluefin Tuna ◽  
Timor Sea ◽  
Tuna Longline

Abstract. Imron M, Tawaqal MI, Yusfiandayani R. 2021. Fishing ground and tuna productivity by tuna longline based on Benoa Bay, Bali, Indonesia. Biodiversitas 22: 961-968. The success of a longline fishing operation depends on several things such as the skill of the crew, bait used, fishing season, fishing operation, the total of fish caught, the price of the fish, productivity, and fishing grounds. Information about productivity and fishing ground becomes important to increase effectiveness and optimal profit. The methodology is carried out by conducting a survey to collect data to be processed and analyzed using productivity analysis based on Landing per Unit Effort (LPUE) and fishing activity analysis from the Vessel Monitoring System (VMS) to determine the Fishing Ground. We calculate tuna productivity from catch production (landing) per effort, meanwhile fishing ground use VMS data. Production tuna was landed at Benoa Bali from 2016-2018 fluctuated. In 2016 production of tuna albacore took a portion of 34.60%, yellowfin tuna 43.56%, bigeye tuna 15.44%, and southern bluefin tuna 6.26%. Production of tuna albacore took a portion of 35.61%, yellowfin tuna 42.64%, bigeye tuna 12.49%, and southern bluefin tuna 9.26% in 2017. Production albacore took a portion of 36.41%, yellowfin tuna 41.56%, bigeye tuna 11.79%, and southern bluefin tuna 10.24% in 2018. The highest productivity of albacore was in August 2018 with LPUE value 1.0099, yellowfin tuna was in July 2018 with LPUE value 1.2431, big eye tuna was in November 2018 with LPUE value 0.5538, and bluefin was at December 2017 with LPUE value 0.3864. The result of VMS data processing showed that tuna longline vessel based at Benoa has several locations of fishing grounds based on fishing activity for example Hindia High Seas, WPP NRI 714 (Telo gulf and Banda Sea), WPP NRI 718 (Aru Sea, Arafura Sea, and Timor Sea), ZEEI WPP NRI 718.

scholarly journals Rapid growth of wahoo (Acanthocybium solandri) in the Coral Sea, based on length-at-age estimates using annual and daily increments on sagittal otoliths

2013 ◽  
Vol 70 (6) ◽  
pp. 1128-1139 ◽  
Author(s):  
Mitchell T. Zischke ◽  
Shane P. Griffiths ◽  
Ian R. Tibbetts
Keyword(s):  
Rapid Growth ◽  
Growth Parameter ◽  
Age And Growth ◽  
Parameter Estimates ◽  
Annual Increment ◽  
Important Species ◽  
Daily Increments ◽  
Growth Increments ◽  
Coral Sea ◽  
Age Estimates

Abstract Zischke, M. T., Griffiths, S. P., and Tibbetts, I. R. 2013. Rapid growth of wahoo (Acanthocybium solandri) in the Coral Sea, based on length-at-age estimates using annual and daily increments on sagittal otoliths. – ICES Journal of Marine Science, 70: 1128–1139. The wahoo (Acanthocybium solandri) is an economically important species incidentally caught in oceanic fisheries targeting tuna and coastal fisheries targeting mackerels. The age and growth of wahoo was examined using whole and sectioned otoliths from 395 fish (790–1770 mm LF) sampled from the Coral Sea. Growth increments were more reliably assigned on whole otoliths than sectioned otoliths. Edge analyses revealed that growth increments were deposited annually, primarily between October and February. Furthermore, analysis of presumed daily microincrements showed that ∼90% of fish had deposited the first “annual” growth increment by the 365th day, thereby indirectly validating annual increment formation. Wahoo were aged at between 108 d and 7 years, with 76% of fish being <2-year old. The specialized von Bertalanffy growth function provided the best fit to length-at-age data, with parameter estimates (sexes combined) of L∞ = 1499 mm LF, K = 1.58 year−1, and t0 = −0.17 years. The growth performance index for wahoo in the Coral Sea (φ′ = 4.55) was one of the highest of all pelagic fish, with their growth and maximum size most similar to dolphinfish. This study suggests that wahoo are one of the fastest growing teleosts and provides growth parameter estimates that may facilitate future stock assessments and guide fisheries management.

scholarly journals TEKNOLOGI PENANGANAN DAN PENYIMPANAN IKAN TUNA SEGAR DI ATAS KAPAL

2008 ◽  
Vol 3 (2) ◽  
pp. 41
Author(s):  
Hari Eko Irianto
Keyword(s):  
Bluefin Tuna ◽  
Yellowfin Tuna ◽  
Bigeye Tuna ◽  
Southern Bluefin Tuna

Indonesia merupakan negara produsen ikan tuna terbesar kelima di dunia. Terdapat  beberapa jenis ikan tuna  yang banyak diperdagangkan di pasar internasional, terutama bluefin tuna, southern bluefin tuna, bigeye tuna, yellowfin tuna, albacore, dan skipjack.  Ikan tuna termasuk komoditas yang cepat mengalami proses kemunduran mutu bila tidak disimpan pada suhu rendah dan juga dapat menghasilkan senyawa histamin yang berbahaya bagi manusia yang mengkonsumsinya. Ikan tuna segar bermutu baik dapat diperoleh dengan menerapkan teknik penanganan dan penyimpanan yang benar segera setelah ikan ditangkap. Cara penanganan ikan tuna setelah ditangkap yang sering diterapkan adalah penggancoan, pendaratan ke atas kapal, pematian, perusakan saluran saraf dengan alat Taniguchi, pembuangan darah, pembuangan insang dan isi perut,  pembersihan, serta penyimpanan dingin. Mutu ikan tuna dipengaruhi oleh faktor-faktor biologis dan non-biologis. Faktor-faktor biologis yang berpengaruh meliputi spesies, umur, ukuran, tingkat kematangan seksual, dan adanya parasit atau penyakit, sedangkan faktor-faktor non-biologis adalah metode penangkapan, teknik penanganan, teknik pendinginan, dan teknik penyimpanan.

Age validation of yellowfin (Thunnus albacares) and bigeye (Thunnus obesus) tuna of the northwestern Atlantic Ocean

2020 ◽  
Vol 77 (4) ◽  
pp. 637-643 ◽  
Author(s):  
Allen H. Andrews ◽  
Ashley Pacicco ◽  
Robert Allman ◽  
Brett J. Falterman ◽  
Erik T. Lang ◽  
...  
Keyword(s):  
Growth Zone ◽  
Yellowfin Tuna ◽  
Age And Growth ◽  
Thunnus Albacares ◽  
Bigeye Tuna ◽  
Age Validation ◽  
Thunnus Obesus ◽  
Bomb Radiocarbon ◽  
Age Estimates ◽  
Age Reading

Estimates of age and growth of yellowfin (Thunnus albacares) and bigeye (Thunnus obesus) tuna remain problematic because validation of growth zone deposition (opaque and translucent) has not been properly evaluated. Otolith growth structure (zone clarity) can be poorly defined for tropical tunas, but the use of bomb radiocarbon dating has validated age estimates to 16–18 years for yellowfin and bigeye tuna. Use of the radiocarbon decline period — defined by regional coral and otoliths — provided valid ages through ontogeny. Yellowfin tuna aged 2–18 years (n = 34, 1029–1810 mm FL) and bigeye tuna aged 3–17 years (n = 12, 1280–1750 mm FL) led to birth years that were coincident with the bomb radiocarbon decline. The results indicate there was no age reading bias for yellowfin tuna and that age estimates of previous studies were likely underestimated for both species.

scholarly journals Small scale tuna fisheries profiles in the Indonesia archipelagic waters

2021 ◽  
Vol 869 (1) ◽  
pp. 012017
Author(s):  
U Muawanah ◽  
F Y Arthatiani ◽  
P A Soedjarwo ◽  
N Kurniasari ◽  
Y D Sari ◽  
...  
Keyword(s):  
Revenue Sharing ◽  
Bluefin Tuna ◽  
Yellowfin Tuna ◽  
Coastal Communities ◽  
Small Scale ◽  
Access To Finance ◽  
The World ◽  
Southern Bluefin Tuna ◽  
Thunnus Alalunga ◽  
Tuna Fisheries

Abstract Indonesia is one of the largest tuna producers in the world, which contributes 16% to world tuna production. The dominant tuna species catched in Indonesia are Albacore Tuna (Thunnus alalunga), Madidihang/Yellowfin Tuna (T. albacares), Big Eye Tuna (T. obesus) dan Southern Bluefin Tuna (T. maccoyii). The tuna fisheries have contributed significant jobs or livelihood to the coastal communities. Profit and revenue sharing is a common remuneration system found on tuna fisheries though out Indonesia. However, these fishers are vulnerable given their economic and welfare conditions and of usually limited options of others livelihood. Small fishers have limited access to livelihoods, access to finance and access to skills or fishing technology. Therefore, the inclusion of socio-economic performance or indicators into the tuna fisheries management is crucial in Indonesia.

scholarly journals DEVELOPING RECOMMENDATIONS FOR UNDERTAKING CPUE STANDARDISATION USING OBSERVER PROGRAM DATA

2012 ◽  
Vol 18 (1) ◽  
pp. 19
Author(s):  
Lilis Sadiyah ◽  
Natalie Dowling ◽  
Budi Iskandar Prisantoso
Keyword(s):  
Statistical Modelling ◽  
Bluefin Tuna ◽  
Yellowfin Tuna ◽  
Confounding Factors ◽  
Modelling Framework ◽  
Tweedie Distribution ◽  
Southern Bluefin Tuna ◽  
The Common ◽  
High Degree ◽  
Program Data

Abundance indices based on nominal CPUE do not take into account confounding factors such as fishing strategy and environmental conditions, that can decouple any underlying abundance signal in the catch rate. As such, the assumption that CPUE is proportional to abundance is frequently violated. CPUE standardisation is one of the common analyses applied. The aims of this paper were to provide a statistical modelling framework for conducting CPUE standardisations using the Observer Program data for bigeye tuna, yellowfin tuna, albacore and southern bluefin tuna, and provide a comparison in the trends between the nominal CPUEs and their standardised indices obtained. The CPUE standardisations were conducted on the Observer Program collected between 2005 and 2007, by applying GLM analysis using the Tweedie distribution. The results suggested that year, area, HBF and bait factors significantly influenced the nominal CPUEs for the four tuna species of interest. Some extreme peaks and troughs in the nominal time series were smoothed in the standardised CPUE time<br />series. The high degree of temporal variability that is still shown in the standardised CPUE trends suggests that the data are too sparse to give any meaningful indication of proxy abundance. Nevertheless, this may also suggest that variables used in the GLMs do not sufficiently account for all<br />of the confounding factors, or abundance may indeed be truly variable.

QUANTIFICATION OF TUNA FISH TARGET STRENGTH USING QUANTITATIVE ECHO SOUNDER

2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Henry M. Manik
Keyword(s):  
Wave Reflection ◽  
Fork Length ◽  
Research Programme ◽  
Yellowfin Tuna ◽  
Target Strength ◽  
Bigeye Tuna ◽  
Tuna Fish ◽  
Thunnus Obesus ◽  
The Relationship ◽  
Echo Sounder

A preliminary research programme was carried out in order to study the acoustic wave reflection or target strength (TS) of tuna fish using a quantitative echo sounder (QES). The relationships between TS to fork length (FL) and swimbladder volume, for bigeye tuna (Thunnus obesus) and yellowfin tuna (T. albacares) are investigated. The TS of bigeye tuna was about 3 dB higher than yellowfin tuna when comparing species at the same size. The result can be correlated to the swimbladder volume differencebetween species. The relationship between TS and swimbladder volume was quantified for both species.Keywords: tuna fish, target strength, quantitative echo sounder

Parental Bereavement in Older Age: A Scoping Review

2021 ◽  
pp. 105413732199581
Author(s):  
Patricia Moyle Wright
Keyword(s):  
Older Adults ◽  
Scoping Review ◽  
Adult Child ◽  
Older Age ◽  
Parental Bereavement ◽  
Older Parents ◽  
Physical Decline ◽  
Scoping Reviews ◽  
Cultural Mores ◽  
Meta Analyses

A scoping review of parental bereavement in older age was conducted to identify the unique needs of older adults after the loss of an adult child. Inclusion and exclusion criteria were developed in accordance with the stated objectives of this review, which was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). In total, 26 research studies were included. The data were then analyzed using a systematic approach for organizing and synthesizing key data. The results indicated that some consequences and mediators of parental bereavement are similar regardless of age. But, older adults experience greater loneliness, isolation, and stigma than their younger counterparts. Older parents are also at greater risk for physical decline, mortality, and institutionalization following the death of an adult child. Religious and cultural mores also have influence on the bereavement process.

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