Lake Pandan is one of the lakes located in Tapanuli Tengah district. Morphometry can explain the biological and chemical processes of the lake, regulate nutrient load, productivity and the influence of input loads from the surrounding area. Therefore, the morphometry of lake was needed as a basis for lake utilization and management. This is what underlies the morphometric research of Lake Pandan, where there has been no research on this topic. The purpose of this study was to determine the morphometry of Lake Pandan. This research was conducted on April 2019. The results of measurements of lake surface dimensions obtained that Lake Pandan has an area of ± 103 Ha with a maximum length of 2,034.60 m, a maximum width of 1,033.38 m, and a length of around the lake of 5,395 m. With an edge (Sl) of 5.395 m so that the Lake Development Index (LDI) was obtained at 0.302. The LDI value of 0.302 illustrates that the lake has an irregular shape. LDI can be used to describe the level of productivity of water if the value is greater, the waters are more fertile. The subsurface dimension found that the average depth (Z) of Lake Pandan was 0.21 m with maximum depth (Zmax) 1.7 m. The morphometric parameters of lake influence the physical, chemical and biological processes in the waters of Lake Pandan, such as depth. Based on depth, Lake Pandan has low stability and easy to experience stirring.

Pengunaan Generalized Additive Model (GAM) sudah umum digunakan di beberapa wilayah laut Indonesia dengan tingkat akurasi yang lebih baik. Tujuan dari penelitian adalah untuk memprediksi daerah penangkapan ikan tuna sirip kuning melalui pendekatan statistik Generalized Additive Model (GAM). Data yang digunakan dalam penelitian ini berupa data penangkapan ikan tuna sirip kuning yang didapatkan dari logbook Pelabuhan Perikanan Samudera Bungus dan data oseanografi berupa data suhu permukaan laut, klorofil-a, salinitas dan tinggi muka laut. Analisis kelimpahan ikan dinyatakan dalam nilai laju pancing (hook rate) tuna longline. Laju tangkap merupakan indeks kepadatan stok. Didalam pemodelan, dataset dibagi menjadi 2 bagian yaitu training data yang digunakan untuk pembentukan model dan evaluation data digunakan untuk memvalidasi hasil prediksi dari pemodelan. Pada penelitian ini, data tahun 2015 digunakan sebagai training data dan data tahun 2016 digunakan sebagai evaluation data. Hasil penelitian menunjukkan bahwa, sebanyak 14 model prediksi telah dihasilkan melalui pendekatan model GAM berdasarkan parameter oseanografi. Model variabel SPL+Salinitas+TML+Chl-a merupakan yang terbaik dengan nilai AIC terkecil yaitu sebesar 658,1 dan nilai deviance terbesar yaitu 56,9%. Nilai deviance memberikan pengertian model GAM tersebut dapat menjelaskan data hook rate sebesar 56,9%. Berdasarkan model GAM, daerah penangkapan ikan yang potensial pada tahun 2016 terdapat pada perairan Pulau Siberut dan Sipora.

Yellowfin tuna (Thunnus obesus) is one of the most important and most caught fish in the eastern Indian Ocean off west Sumatera and has extensive migration. To develop an appropriate prediction model and to understand the contribution of oceanographic parameters in the potential habitat of Yellowfin tuna, remotely sensed data and habitat modeling were used. Daily data of sea-surface temperature (SST), sea-surface salinity (SSS) and sea-surface height (SSH) were downloaded from the marine copernicus website, meanwhile fishing vessel position for Yellowfin tuna were obtained from fishing port Samudera, Bungus, west Sumatera, from January through December 2015. Daily fishing vessel position and environmental parameters were used for maximum entropy model construction. The model predictive performance was then evaluated using a threshold-independent metric, the area under the curve (AUC) metric of the receiver operating characteristic (ROC). Maximum entropy model results (AUC > 0.90) indicated its potential to figure out the spatial distribution of Yellowfin tuna. In general, SST (50.5%) is the most affective variable in the Yellowfin tuna distribution, followed by SSS (37%) and SSH (12.5%). This study showed that integration multi remotely sensed data and a modeling approach provide an innovative way to decide the potential fishing zones of the Yellowfin tuna in the eastern Indian Ocean off west Sumatera.

The exploitation of tuna in the Indian Ocean is increasing due to the high demand of its resources. This research aims to predict the fishing ground of the yellowfin tuna (Thunnus albacares) using Maximum entropy models (MaxEnt) based on oceanographic satellite data and tuna fishing data obtained from Aceh waters, from June-August 2015. The highest MaxEnt (AUC) model in the transition season 1 occurred in May with AUC values of 0.9612, followed by March (0.8200) and April (0.6780). The high AUC value shows the potential to know the spatial distribution of tuna yellowfin tuna which can be interpreted as the level of accuracy of the model produced. Environmental parameters have a major contribution to the prediction of tuna fishing ground. In March the SST variable (64.4%) had the largest contribution, followed by SSH (8.4%) and Salinity (7.2%). Then in April the SST variable (62.4%) also had the largest contribution, followed by SSH (22.9%) and Salinity (17.6%). Similar to May SST (60.5%) had the largest contribution, followed by SSH (12.6%) and Salinity (7.0%). Based on the Maxent model, potential fishing grounds in the transition season 1 of 2015 are found in the waters of north and south of the Aceh Province.

Barracuda Fish in the Central Tapanuli region is known as Teter Fish (Sphyraena barracuda) which is still relatively cheap and easy to get throughout the year. Teter fish has many health benefits, but not everyone likes this fish. Based on this, various processed forms are needed in order to attract other people to continue consuming tethered fish. One of these processed forms is fish nuggets. The purpose of this community service activity is to provide education to the community, especially mothers in the Indonesian Family Welfare Guidance Program or PKK in Sorkam District, Central Tapanuli Regency about the use of Teter Fish meat as a processed material for making fish nuggets. The method used is the delivery of material and direct practice in making fish nuggets. The result of this community service activity is the ability of PKK women to make processed fish nuggets and package the product properly. In the future, fish nuggets can increase family income and are sold as a typical food of Central Tapanuli.