scholarly journals Spawning Potential Ratio (SPR) Approach as a Management Measure of Skipjack Sustainability Record from Cilacap Fishing Port, Central Java, Indonesia

2021 ◽  
Vol 13 (2) ◽  
pp. 199
Author(s):  
Yonvitner Yonvitner ◽  
Mennofatria Boer ◽  
Rahmat Kurnia

Highlight Research:Spawning potential ratio (SPR) based on the length and frequency data is a substitution approach for data-poor management in fisheriesGonad maturity is an indicator to ensure recruitment and stock sustainability. Therefore important to evaluate the impact of fishing capture on the size and length of fishSpawning potential ratio of skipjack relatively low and potential medium impact on risk sustainability AbstractWhen data is limited, management measurement from fisheries makes it possible to use natural history data to analyze the potential spawning ratio (SPR). This research aimed to determine skipjack fish management measure from the Indian Ocean landed at Cilacap Fishing Port through the SPR approach. The study was conducted in December 2014 to March 2015 using length and reproduction data. The analysis consisted of the size structure, growth rate, and asymptotic length that were analyzed using FISAT II program and length at fifty percent maturity (Lm50). The SPR analysis used SPR software from the application in http://barefootecologist.com.au/lbspr. The size distributions of skipjack obtained were a length of 220-790 mm and an average dominant length of 311-371 mm. The asymptotic length obtained was 831.57 mm, with growth rate and natural mortality of 1.1 and 1.44 per year respectively. The population proportion of 50% reaching gonad maturity (Lm50) was found at a length of 494.75 mm and (Lm95 = 522.39 mm) with an M/k ratio of 1.309. The length selectivity level was caught 50% (SL50 = 317.36 mm) and 95% (SL95 = 373.1 mm). The spawning potential ratio (SPR) ranged from 2-4 with an average of 4% during observation. The SPR potential, which is lower from the standardized threshold of 40%, indicates many young fish populations are caught, and the potential for overfishing is high, high risk, and low sustainability.

1996 ◽  
Vol 74 (4) ◽  
pp. 698-709 ◽  
Author(s):  
A. Cabanac ◽  
J. H. Himmelman

We examined changes in populations of Echinarachnius parma with depth on subtidal sediment slopes in the Mingan Islands. Size distributions showed the presence of two major groups measuring 1–21 and 37–62 mm in length, respectively. Intermediate-sized sand dollars were rare. Juveniles (< 28 mm in length) were extremely abundant at 16 and 20 m depth (460–660/m2) and decreased in number with decreasing depth, whereas the density of adults was relatively stable at different depths. Juveniles were more frequently buried (95%) than adults (30%). Analysis of growth lines and of shifts in juvenile cohorts indicated that growth rate increased with size up to a maximum between 20 and 40 mm and then decreased sharply. The bimodal size structure is possibly due to the accelerated growth rate at intermediate sizes. We hypothesize that sand dollars move to shallower water with increasing size to take advantage of food resources, possibly benthic diatoms, which are more abundant there. Large individuals are probably better adapted than juveniles to exploiting shallower water because they are less likely to be transported by water turbulence.


2016 ◽  
Vol 5 (4) ◽  
pp. 345-352
Author(s):  
Damar Nusawicaksono Kurniawan ◽  
Abdul Ghofar ◽  
Suradi Wijaya Saputra ◽  
Bram Setyadji

ABSTRAK Pengkajian dan pendugaan status sumberdaya perikanan di suatu wilayah perairan dapat dilakukan dengan mengetahui laju eksploitasinya. Data frekuensi panjang merupakan salah satu data yang dapat digunakan untuk melakukan pendugaan tingkat eksploitasi tersebut. Penelitian ini bertujuan untuk menduga nilai mortalitas, laju pertumbuhan, ukuran pertama kali tertangkap dan tingkat eksploitasi. Penelitian dilakukan pada bulan April-Mei 2016 di Loka Penelitian Perikanan Tuna Pelabuhan Benoa, Denpasar, Bali. Metode yang digunakan adalah metode survei. Sementara data panjang ikan tuna sirip biru selatan tahun 2013-2014 kemudian diolah dengan perangkat lunak FISAT II. Hasil penelitian menunjukkan struktur ukuran ikan tuna sirip biru selatan 145 - 210 cmFL dengan modus di ukuran 170-174 cmFL, ukuran pertama kali tertangkap (Lc) 171 cmFL, hubungan panjang berat mendapat nilai W= 0,00006*FL2,792, faktor kondisi berada pada angka 1,86-2,00, laju pertumbuhan yang didapat yaitu Lt=220,50(1 - e 0,2(t+0,488)), dimana nilai dari L∞ yaitu 220,50 cmFL dan nilai t0 -0,49, laju mortalitas total (Z) sebesar 1,14/tahun, laju mortalitas alami (M) sebesar 0,36/tahun, dan laju mortalitas akibat penangkapan (F) sebesar 0,78/tahun, dan tingkat eksploitasi (E) 0,68/tahun, Hal ini menunjukan penangkapan  ikan tuna sirip biru selatan oleh kapal rawai tuna di Samudera Hindia dalam keadaan berlebih (overfishing) karena nilai tingkat eksploitasi yang didapat melebihi tingkat pemanfaatan optimum atau Eopt = 0,5/tahun (0,68 > 0,5). Kata Kunci : Ikan Tuna Sirip Biru Selatan, Tingkat Eksploitasi, Mortalitas, Pertumbuhan  ABSTRACT Stock assessment and prediction status of fisheries resources in the waters can be made by knowing the rate of exploitation. Length-frequency data is one can be used to suspect rate of exploitation . The aimed of this research was to suspect value of mortality, the growth rate, size at first capture and the level of exploitation. This research was conducted on April-May 2016 at the Loka Fishery Tuna's Research Benoa Port, Denpasar, Bali. This research used survey method.While data length of the southern bluefin tuna 2013-2014 was processed with FISAT II. The results showed size structure of southern bluefin tuna 145-210 cmFL with mode in sizes 170-174 cmFL, size at first capture (Lc) 171 cmFL, value of lenght and weight relationship W = 0,00006 *,792 FL2, condition factors 1,86-2.00, the growth rate Lt = 220,50 (1-e of 0.2 (t + 0,488)), where the value of L ∞ was 220.50 cmFL and value t0 -0.49 total mortality rate (Z) of 1.14/year, rate of natural mortality (M) of 0.36/year, and  rate of mortality due to the arrest of (F) amounted to 0.78/year, and the rate of exploitation (E) 0,68/year, it shows the fishing of southern bluefin tuna by the longline in the Indian Ocean was overfishing because level of exploitation value was over the optimum effort or Eopt = 0,5/year (0.68 > 0.5). Keyword: Southern Bluefin Tuna, exploitation rate, Mortality, growth,


1970 ◽  
Vol 32 (2) ◽  
pp. 139-146
Author(s):  
Dharmadi ◽  
K. Sumadhiharga ◽  
Fahmi

Study on biodiversity and size structure of sharks in the Indian Ocean was conducted at several landing sites and fish markets, i.e. Pelabuhanratu (West Java), Cilacap (Central Java), Kedonganan (Bali) and Tanjung Luar (East Lombok ). Field observation was done from April 2001 to March 2006. The results showed that there were 86 species of sharks belonging to 16 families in the Indian Ocean. The sharks were dominated by family of Carcharhinidae and Squalidae with 24 and 23 species, respectively. A high diversity of sharks was found at Kedonganan-Bali (49 species), at Tanjung Luar (47 species), at Cilacap (32 species) and at Pelabuhanratu (27 species). Size of sharks landed at those landing sites varied in length, the length of Carcharhinus amblyrhynchos was between 90 cm and 170 cm TL, C. sorrah (55-155 cm), C. obscurus (205-295 cm) and P glauca was caught at length between 205-300 cm.


Author(s):  
Mudasetia Hamid ◽  
Evy Rosalina Widyayanti

Yogyakarta is a city and the capital of Yogyakarta Special Region in Java, Indonesia. It is renowned as a center of tourism, education and culture. Yogyakarta is one of the foremost cultural centers of Java. This region is located at the foot of the active merapi vulcano. Yogyakarta is often called the main gateway to the Central Java as where it is geographically located. It stretches from Mount Merapi to the Indian Ocean. This province is one of the most densely populated areas of Indonesia. Yogyakarta is popular tourist destination in indonesia after Bali. These have attracted large number of visitors from across Indonesia and abroad to the city. This status makes Yogyakarta is one of the most heterogeneus cities in Indonesia. In edition, Yogyakarta has attracted large number of people to reside in this city for business. One of these comers is small entrepreneurs with their market munchies enterprise (specially a traditional snack trader). This business is one of famous business in Yogyakarta, we will find rows of pavement vendors selling market munchies. The students and tourists are their main target customers. Market munchies enterprise is part of small and medium enterprises SMEs as livelihood activities. SMEs has an important role in economic growth of Indonesia. Therefore, it is very important to develop and strengthen the micro enterprise empowerment. Micro enterprise empowerment is one of strategy to reduce the poverty rate in Indonesia. Major challenger in implement this program are that micro entrepreneurs are conventional and have satisfied with their revenue. It is very important to develop a comprehensive and sustainable micro enterprise empowerment which consist of strengthen the quality of human resources, maximize the government’s roles, empower the enterprise capital and strengthen the partnership and autonomous. Micro enterprise autonomy will contribute to the economic and investment climate. This will lead to establish an accountable enterprise both for the micro enterprise and customers which at the end will strengthen the development of the micro enterprise in Yogyakarta.Keyword: micro entreprise, human resources, government roles, capital, partnership and autonomous.


Author(s):  
Beta Asteria

This research deals with the impact of Local Tax and Retribution Receipt to Local Government Original Receipt of Regency/City in Central Java from 2008 to 2012. This research utilizes the data of actual of local government budget from Directorate General of Fiscal Balance (Direktorat Jendral Perimbangan Keuangan). Methods of collecting data through census. The number of Regency/City in Central Java are 35. But the data consists of 33 of Regency/City In Central Java from 2008 to 2012. Total of samples are 165. Karanganyar Regency and Sukoharjo Regency were not included as samples of this research because they didn’t report the data of actual of local government budget to Directorate General of Fiscal Balance in 2009.The model used in this research is multiple regressions. The independent variables are Local Tax and Retribution Receipt, the dependent variable is Local Government Original Receipt. The research findings show that Local Tax and Retribution give the significant impact partially and simultaneusly on Local Government Original Receipt at real level 5 percent. All independent variables explain 91,90 percent of the revenue variability while the rest 8,10 percent is explained by other variables.Keywords: Local Tax, Retribution, and Local Government Original Receipt


2019 ◽  
pp. 79-91 ◽  
Author(s):  
V. S. Nazarov ◽  
S. S. Lazaryan ◽  
I. V. Nikonov ◽  
A. I. Votinov

The article assesses the impact of various factors on the growth rate of international trade. Many experts interpreted the cross-border flows of goods decline against the backdrop of a growing global economy as an alarming sign that indicates a slowdown in the processes of globalization. To determine the reasons for the dynamics of international trade, the decompositions of its growth rate were carried out and allowed to single out the effect of the dollar exchange rate, the commodities prices and global value chains on the change in the volume of trade. As a result, it was discovered that the most part of the dynamics of international trade is due to fluctuations in the exchange rate of the dollar and prices for basic commodity groups. The negative contribution of trade within global value chains in 2014 was also revealed. During the investigated period (2000—2014), such a picture was observed only in the crisis periods, which may indicate the beginning of structural changes in the world trade.


Author(s):  
Francisco Pozo-Martin ◽  
Heide Weishaar ◽  
Florin Cristea ◽  
Johanna Hanefeld ◽  
Thurid Bahr ◽  
...  

AbstractWe estimated the impact of a comprehensive set of non-pharmeceutical interventions on the COVID-19 epidemic growth rate across the 37 member states of the Organisation for Economic Co-operation and Development during the early phase of the COVID-19 pandemic and between October and December 2020. For this task, we conducted a data-driven, longitudinal analysis using a multilevel modelling approach with both maximum likelihood and Bayesian estimation. We found that during the early phase of the epidemic: implementing restrictions on gatherings of more than 100 people, between 11 and 100 people, and 10 people or less was associated with a respective average reduction of 2.58%, 2.78% and 2.81% in the daily growth rate in weekly confirmed cases; requiring closing for some sectors or for all but essential workplaces with an average reduction of 1.51% and 1.78%; requiring closing of some school levels or all school levels with an average reduction of 1.12% or 1.65%; recommending mask wearing with an average reduction of 0.45%, requiring mask wearing country-wide in specific public spaces or in specific geographical areas within the country with an average reduction of 0.44%, requiring mask-wearing country-wide in all public places or all public places where social distancing is not possible with an average reduction of 0.96%; and number of tests per thousand population with an average reduction of 0.02% per unit increase. Between October and December 2020 work closing requirements and testing policy were significant predictors of the epidemic growth rate. These findings provide evidence to support policy decision-making regarding which NPIs to implement to control the spread of the COVID-19 pandemic.


Author(s):  
Weiqi Xu ◽  
Chun Chen ◽  
Yanmei Qiu ◽  
Conghui Xie ◽  
Yunle Chen ◽  
...  

Organic aerosol (OA), a large fraction of fine particles, has a large impact on climate radiative forcing and human health, and the impact depends strongly on size distributions. Here we...


2021 ◽  
Vol 10 (4) ◽  
pp. 214
Author(s):  
Lihua Yuan ◽  
Xiaoqiang Chen ◽  
Changqing Song ◽  
Danping Cao ◽  
Hong Yi

The Indian Ocean Region (IOR) has become one of the main economic forces globally, and countries within the IOR have attempted to promote their intra-regional trade. This study investigates the spatiotemporal evolution of the community structures of the intra-regional trade and the impact of determinant factors on the formation of trade community structures of the IOR from 1996 to 2017 using the methods of social network analysis. Trade communities are groups of countries with measurably denser intra-trade ties but with extra-trade ties that are measurably sparser among different communities. The results show that the extent of trade integration and the trade community structures of the IOR changed from strengthening between 1996 and 2014 to weakening between 2015 and 2017. The largest explanatory power of the formation of the IOR trade community structures was the IOR countries’ economic size, indicating that market remained the strongest driver. The second-largest explanatory power was geographical proximity, suggesting that countries within the IOR engaged in intra-regional trade still tended to select geographically proximate trading partners. The third- and the fourth-largest were common civilization and regional organizational memberships, respectively. This indicates that sharing a common civilization and constructing intra-regional institutional arrangements (especially open trade policies) helped the countries within the IOR strengthen their trade communities.


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