Mangrove ecosystems are very important for coastal waters, one of which is as a provider of food sources for biota in the surrounding waters. This study aims to determine the food habits of several types of fish found in the waters around the Lubuk Kertang mangrove ecosystem, Langkat, North Sumatra. The research location is a mangrove restoration area with the main species Rhizopora apiculata. The research was conducted in January 2021. The collection of fish samples was carried out using gill net with 1.5 inchi which is commonly used by fishermen. Sampling was carried out by spreading the net three times. The tested fish samples consisted of 46 individuals with 12 species, 9 families, and 6 orders. The highest number of fish caught was Clupeiformes with a percentage of 41.67%, while the order found with a low percentage was Beloniformes (2%). The families found in large numbers were Mugillidae, the families found in low numbers were Lutjanidae and Serranidae. The species caught the most is Chelon subviridis. Stomach contents analysis was performed with the Index of Preponderance (IP). Based on the type of food found in the stomach contents of the test fish, there were various types of food consisting of 11 types, namely phytoplankton, zooplankton, squid, fish (juvenile fish), crabs, shrimp, shellfish, litter, moss, pieces of insect bodies, and plant parts. The types of food that the plant fragments are found in are 9 fish species, phytoplankton (7 species), shrimp (7 species), and litter (5 species).  Ekosistem mangrove sangat penting bagi perairan salah satunya adalah sebagai penyedia sumber makanan biota pada perairan di sekitarnya. Penelitian ini bertujuan untuk mengetahui kebiasaan makanan beberapa jenis ikan yang ditemukan di perairan sekitar ekosistem mangrove Lubuk Kertang, Langkat, Sumatera Utara. Lokasi penelitian merupakan merupakan wilayah restorasi mangrove dengan vegetasi utama Rhizopora apiculata. Penelitian dilakukan pada bulan Januari 2021. Pengumpulan sampel ikan dilakukan dengan menggunakan jaring gill net dengan ukuran 1.5 inchi yang biasa digunakan oleh nelayan. Sampling dilakukan dengan melakukan tiga kali tebar jaring. Sampel ikan uji terdiri dari 46 individu dengan 12 spesies, 9 famili, dan 6 ordo. Jumlah ikan terbanyak yang tertangkap adalah Clupeiformes dengan persentase sebesar 41.67%, sedangkan ordo yang ditemukan dengan persentase yang rendah adalah Beloniformes (2%). Famili yang ditemukan dalam jumlah besar adalah Mugillidae, famili yang ditemukan dengan jumlah rendah adalah Lutjanidae dan Serranidae. Spesies yang paling banyak tertangkap adalah jenis Chelon subviridis. Analisis isi perut dilakukan dengan Indeks of Preponderance (IP). Berdasarkan jenis makanan yang ditemukan pada isi perut ikan uji, terdapat berbagai jenis makanan yang terdiri dari 11 jenis yaitu fitoplankton, zooplankton, cumi-cumi, ikan (juvenil ikan), kepiting, udang, cangkang kerang, serasah, lumut, potongan tubuh serangga, dan potongan tubuh tumbuhan. Jenis makanan potongan tumbuhan terdapat pada 9 spesies ikan, fitoplankton (7 spesies), udang (7 spesies) dan serasah (5 spesies).

The genus Panulirus is one of the important fishery commodities for Aceh Province. In the context of the sustainability of these resources, it is necessary to apply regulations properly. The purpose of the apprenticeship activity is to determine the type, number and origin of the lobster catching area that is trafficked through the Fish Quarantine Station for Quality Control and Safety of Fishery Products in Aceh. The activity is carried out from February to April 2022. The method used is by observing activities, and collecting data on the types of lobsters that are trafficked. There are 6 types of lobster that are trafficked at the Fish Quarantine Station for Quality Control and Safety of Fishery Products in Aceh, including; Panulirus homarus, Panulirus ornatus, Panulirus penicillatus, Panulirus polyphagus, Panulirus longipes and Panulirus versicolor. Every month the quarantine stations carry out inspections before shipping an average of 1929 individuals per month. The type of Panulirus versicolor is the type with the highest percentage (34%) sent through. The origin of lobster catching consists of 8 areas, namely Banyak Island (Aceh Singkil), Simeulue Island, Labuan Haji (South Aceh), Meulaboh (West Aceh), Calang and Lamno (Aceh Jaya), Banda Aceh and Sabang Island.