The Negombo Lagoon has an area of 3 164 hectares and is situated some 40 km north of Colombo. It is part of a much larger Muthurawajawela Marsh-Negombo Lagoon coastal wetland. Apart from at the single narrow opening to the sea at its northern end, the water depth within the lagoon is less than 2 m. Six principal gears are used for catching shrimp inside the lagoon. Trammel nets are the most common, which along with cast nets are operated across the central portion of the lagoon. Stake nets are used immediately inside the entrance. Around the perimeter, lagoon seines (drag nets) and brush pile are the common gears. Fyke nets are also used at the southern end of the lagoon. Outside the lagoon, nonmechanized shrimp trawlers are operated north of the entrance, while mechanized shrimp trawlers are used 5 - 10 km to the south. The estimated catch from all gears operated inside the lagoon in 1997 was 613 t of shrimp and 1 044 t of others (mostly fish). The production from trawlers operated outside the lagoon was 270 t of shrimp and 239 t of others. Fourteen species of shrimp were identified, with six of these being major contributors to the catches. Penaeus indicus and to a lesser extent, P. semisulcatus were the most important in the trammel net and cast net catches. P. indicus was also the main species from brush piles. The stake nets set at the entrance caught mainly Metapenaeus dobsoni and M. moyebi.