Fisheries and Irrawaddy dolphin conservation in Malampaya inner sound, Palawan, Philippines

The critically endangered population of Irrawaddy Dolphin (Orcaella brevirostris) in Malampaya Inner Sound is continuously threatened by the activities of the human population, especially fishing activities. It is predicted that their local population will continue to decline and will be lost within seven years if current processes and fishing practices will continue to operate. Twenty-nine mortalities of Irrawaddy Dolphins were recorded between year 2001 and 2006. Five fishing gears identified to be associated with dolphin mortalities were studied: 1) to gather information on CPUE, catch trend, catch composition, spatial and temporal distribution of gears, and 2) to give recommendations for fisheries management in relation to the protection of Irrawaddy dolphins in the Inner Malampaya Sound. The high monthly fishing effort of shrimp gill net no.9, crab trap, and fish gill net no.12 is alarming, because there are reports of Irrawaddy Dolphins entanglement in their joining lines. Similarly gill net numbers 9 and 12 likewise create an additional risk of entanglement of Irrawaddy dolphins when soaked in longer periods, higher frequency and wider area. Except for fish gill net no.9, all fishing gears surveyed exhibited a declining trend in average catch per unit effort from August 2006 to January 2007. Top three fishing gears, with high monthly average CPUE, in decreasing order, are the fish gill net no.12, followed by fish gill net no.9, and then by the skimming net. Crab gill net no.4, crab pot, and shrimp gill net no.9 have distinct overlap in their fishing areas at the northern portion of the Inner Sound. While skimming net and crab pots partly overlap at the southern end of the Sound. The distribution of fishing gears shows that almost all of the areas of the Inner Sound are occupied by the gears related to Irrawaddy Dolphin conservation. The result shows how narrow is the swimming path left for the dolphins to move around freely with out encountering a net, while navigating in the water column. Fish gill net no.9, shrimp gill net no.9, crab gill net no.4, and crab pot are the most likely gears to be encountered by the Irrawaddy Dolphins in their frequent sighting areas. The current fisheries condition regarding Irrawaddy conservation are the following: 1) increasing number of Irrawaddy Dolphin mortality, 2) increase in kinds of gears associated with the mortality, 3) increasing efforts of Irrawaddy mortality associated fishing gears, and 4) co-occurrence