Oceanographic Conditions on Small Pelagic Fishery in the Gulf of Bone Waters

Author(s):  
Safruddin Safruddin ◽  
Rachmat Hidayat ◽  
Mukti Zainuddin

This study aimed to investigate the relationship between the dinamic oceanographic condition and fluctuation in the catch of small pelagic fish. Study on the dinamic oceanographic conditions were focused on the sea surface temperature (SST), chlorophyll-a concentration (SSC) and water depth. The study took place in the area of Gulf of Bone located, data collection was started from April to September 2017. The data were collected using experimental fishing metode (large liftnet) and applications of remote sensing in satellite oceanography, which then analysed using Geographic Information System (GIS) dan Generalized Additive Models (GAMs). The result showed that the distribution of small pelagic fish tends to be within the area of temperature ranging from 29.5 to 30.0oC, the chlorophyll-a from 0.7 to 0.9 mg.m-3 and concentrated within the coastal area with in waters depth maximum of 100 m.Keywords: Oceanography, small pelagic fish, distribution, fishing ground, Gulf of Bone

2019 ◽  
Vol 66 (4) ◽  
Author(s):  
P.H. Dhiju Das ◽  
C.G. Joshy ◽  
Leela Edwin

In this study, we attempted to identify and characterise the spatial variability of small pelagic fish abundance using geostatistical methods. The small pelagic fish abundance was estimated in terms of spatial parameters using generalised additive models (GAMs). The ring seine fishing grounds in the south-eastern Arabian Sea exhibited seasonal variability in distribution. Results of the study would help in prediction of the major pelagic fishing grounds for traditional fishers which would help in reducing fuel and time spent on searching for the fishing ground leading to sustainable exploitation. The prediction model can contribute to the management of pelagic fishery along the Kerala coast.


2017 ◽  
Vol 22 (2) ◽  
pp. 59-66
Author(s):  
Mukti Zainuddin ◽  
Safruddin Safruddin ◽  
Muhammad Banda Selamat ◽  
Aisjah Farhum ◽  
Sarip Hidayat

One of economically important fish in the Bay of Bone is Skipjack tuna which their distribution and migration are influenced by surrounding environment.  This study aims to investigate the relationship between skipjack tuna and their environments, and to predict potential fishing zones (PFZs) for the fish in the Bone Bay-Flores Sea using satellite-based oceanography and catch data. Generalized additive models (GAMs) were used to assess the relationship. A generalized linear model(GLM) constructed from GAMs was used for prediction. Monthly mean sea surface temperature (SST) and chlorophyll-a during the northwest monsoon (December-January) together with catch data were used for the year 2012-2013. We used the GAMs to assess the effect of the environment variables on skipjack tuna CPUE (catch per unit effort). The best GLM was selected to predict skipjack tuna abundance.  Results indicated that the highest CPUEs (fish/trip) occurred in areas where SST and chlorophyll-a ranged from 29.5°-31.5°C and 0.15 - 0.25 mg m-3, respectively. The PFZs for skipjack were closely related to the spatial distribution of the optimum oceanographic conditions and these mainly developed in three locations, northern area of Bone Bay in December, in the middle area of the bay (4°-5.5°S and 120.5°-121.5°E) during January and moved to the Flores Sea in February. The movement of skipjack concentration was consistent with the fishery data.  This suggests that the dynamics of the optimum oceanographic signatures provided a good indicator for predicting feeding grounds as hotspot areas for skipjack tuna in Bone Bay-Flores Sea during northwest monsoon. Keywords:  skipjack tuna, potential fishing zones, satellite based-oceanographic data, Northwest monsoon


2017 ◽  
Vol 569 ◽  
pp. 187-203 ◽  
Author(s):  
AM McInnes ◽  
PG Ryan ◽  
M Lacerda ◽  
J Deshayes ◽  
WS Goschen ◽  
...  

Author(s):  
Mark David Walker ◽  
Mihály Sulyok

Abstract Background Restrictions on social interaction and movement were implemented by the German government in March 2020 to reduce the transmission of coronavirus disease 2019 (COVID-19). Apple's “Mobility Trends” (AMT) data details levels of community mobility; it is a novel resource of potential use to epidemiologists. Objective The aim of the study is to use AMT data to examine the relationship between mobility and COVID-19 case occurrence for Germany. Is a change in mobility apparent following COVID-19 and the implementation of social restrictions? Is there a relationship between mobility and COVID-19 occurrence in Germany? Methods AMT data illustrates mobility levels throughout the epidemic, allowing the relationship between mobility and disease to be examined. Generalized additive models (GAMs) were established for Germany, with mobility categories, and date, as explanatory variables, and case numbers as response. Results Clear reductions in mobility occurred following the implementation of movement restrictions. There was a negative correlation between mobility and confirmed case numbers. GAM using all three categories of mobility data accounted for case occurrence as well and was favorable (AIC or Akaike Information Criterion: 2504) to models using categories separately (AIC with “driving,” 2511. “transit,” 2513. “walking,” 2508). Conclusion These results suggest an association between mobility and case occurrence. Further examination of the relationship between movement restrictions and COVID-19 transmission may be pertinent. The study shows how new sources of online data can be used to investigate problems in epidemiology.


2010 ◽  
Vol 68 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Henrik Jensen ◽  
Anna Rindorf ◽  
Peter J. Wright ◽  
Henrik Mosegaard

Abstract Jensen, H., Rindorf, A., Wright, P. J., and Mosegaard, H. 2011. Inferring the location and scale of mixing between habitat areas of lesser sandeel through information from the fishery. – ICES Journal of Marine Science, 68: 43–51. Sandeels are small pelagic fish that play an important role in the diet of a range of natural predators. Because of their limited capture by traditional survey gear, little is known about their large-scale distribution or the degree of mixing between habitat areas. Detailed information collected directly from the fishery was used to map fishing grounds, which were then assumed to reflect the foraging habitat of the species. Length distributions from individual hauls were used to assess differences in the distributions as a function of distance between samples. Sandeel foraging habitat covered some 5% of the total area of the North Sea. Mixing between neighbouring fishing grounds was too low to eliminate differences in length distributions at distances between grounds down to 5 km. Within fishing grounds, mixing was sufficient to eliminate differences in length distributions at scales <28 km but insufficient at greater distances. The lack of mixing between grounds may result in large differences in sandeel abundance among adjacent fishing grounds. Further, notable abundance at one end of an extensive fishing ground is not necessarily indicative of similar abundance at its other end.


Author(s):  
Marcos Samuel Matias Ribeiro ◽  
Lara de Melo Barbosa Andrade ◽  
Maria Helena Constantino Spyrides ◽  
Kellen Carla Lima ◽  
Pollyane Evangelista da Silva ◽  
...  

AbstractThe occurrence of environmental disasters affects different social segments, impacting health, education, housing, economy and the provision of basic services. Thus, the objective of this study was to estimate the relationship between the occurrence of disasters and extreme climate, sociosanitary and demographic conditions in the Northeast region of Brazil during the period from 1993 to 2013. Initially, we analyzed the spatial pattern of the incidence of events and, subsequently, generalized additive models for location, scale and shape were used in order to identify and estimate the magnitude of associations between factors. Results showed that droughts are the predominant disasters in the NEB representing 81.1% of the cases, followed by events triggered by excessive rainfall such as flash floods (11.1%) and floods (7.8%). Climate conditions presented statistically significant associations with the analyzed disasters, in which indicators of excess rainfall positively contributed to the occurrence of flash floods and floods, but negatively contributed to the occurrence of drought. Sociosanitary factors, such as percentage of households with inadequate sewage, waste collection and water supply, were also positively associated with the model’s estimations, i.e., contributing to an increase in the occurrence of events, with the exception of floods, which were not significantly influenced by sociosanitary parameters. A decrease of 19% in the risk of drought occurrence was estimated, on average. On the other hand, events caused by excessive rainfall increased by 40% and 57%, in the cases of flash floods and floods, respectively.


2002 ◽  
Vol 4 (1) ◽  
Author(s):  
Suadi Suadi

The aims of this research were to know the state of small pelagic fishery and social economic aspect of resources exploitation. To examine these issues, the research combined survey and descriptive analytic methods. Gordon-Schaefer model was applied to analyze the state of fishery and analytical descriptive to explained the relationship of the phenomena's. Data collection was based on indepth interview and recording of District Fishery Service's. Samll pelagic fisheries that been analyzed were anchovies (Stolephorus sp.), squids (Loligo sp.), and mackerels (Rastrelliger sp.).There are two main problems of fisheries in the area, firstly, the conflict on coastal zone between marine capture fisheries and mariculture. The second one is the intensive exploitation of fisheries resources. Pelagic fisheries at Sape Bay have been exploited above maximum TAC mainly 80% of MSY. MSY of anchovies (Stolephorus sp.) reached 2324,9 ton at number of effort 56534 trip and MEY 2172,3 ton at number of effort 42144 trips. MSY of squids (Loligo sp.) is 455,0 ton at number of effort 12183 trip and MEY 449,0 ton at number of effort 10780 trips equal to Bagan Perahu  trips. The model was not applicable to predict the MSY and MEY of mackerels (Rastrelliger sp.). The continuing increase of effort will depleted the stock and decreased economic rent. In addition, the increasing of competition on fishing ground with pearl culture, have resulted fishermen stress. The integrated policy and management are needed to solve these problems and to avoid social riots. 


2017 ◽  
Vol 4 (1) ◽  
pp. 109 ◽  
Author(s):  
I Gusti Agung Bagus Wisesa Sastra ◽  
I Wayan Gede Astawa Karang ◽  
Abd. Rahman As-syakur ◽  
Yulianto Suteja

Mackerel fish that classified pelagic fish and an export commodity in Indonesia. Distribution of mackerel fish are foundn all Indonesian waters, one of them in the Bali Strait. Distribution of mackerel fish influenced by oceanographic condition such as sea surface temperature (SST) and chlorophyll-a concentration. SST and chlorophyll-a concentrations are environmental parameters that can provide information on fishing ground. The purpose of this research is explained the temporal fluctuation and relationship between SST and chlorophyll-a concentration with mackerel fish had been catch in Bali Strait waters during 2011-2016. Data were analyzed using simple correlation analysis with 95% confidence interval. Temporally, the highest average SST occurred during the transition season I (March-May) and the lowest in the east season (June-August). The highest average chlorophyll-a concentration occurs in the east season and the lowest in the west season (December-February). The highest catch of mackerel fish occurred during transitional season II (September-November) and lowest in west season. The association between SST and chlorophyll-a concentration on mackerel fish catch showed low correlation with significant relationship, whereas concentration between SST and chlorophyll-a concentration strong with significant correlation


Risks ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 91
Author(s):  
Jean-Philippe Boucher ◽  
Roxane Turcotte

Using telematics data, we study the relationship between claim frequency and distance driven through different models by observing smooth functions. We used Generalized Additive Models (GAM) for a Poisson distribution, and Generalized Additive Models for Location, Scale, and Shape (GAMLSS) that we generalize for panel count data. To correctly observe the relationship between distance driven and claim frequency, we show that a Poisson distribution with fixed effects should be used because it removes residual heterogeneity that was incorrectly captured by previous models based on GAM and GAMLSS theory. We show that an approximately linear relationship between distance driven and claim frequency can be derived. We argue that this approach can be used to compute the premium surcharge for additional kilometers the insured wants to drive, or as the basis to construct Pay-as-you-drive (PAYD) insurance for self-service vehicles. All models are illustrated using data from a major Canadian insurance company.


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