Temporal abundance of major macroinvertebrate phyla in Sto, Tomas Cove, La Union, Philippines

Abstract

The marine waters of the Philippines contain significant marine habitats- coral reefs, seagrass beds, mangrove forests and the deep seas. This study aimed to provide a status on the abundance and distribution of invertebrates in the body of water in Sto. Tomas Cove, La Union, Philippines.  A once a month survey was conducted using a modified trawl gear, locally known as karkar, by  dragging a net at each station for a distance of 1000 meters in four established sampling  stations in the cove: Station I at Brgy. Damortis-Tubod  (N16° 14.208’, E120° 23.377’); Station II at  Brgy. Casantaan-Ubagan (N16° 13.736, E119 49.905’); Station III at Brgy. Narvacan-Sungyot Point (N16° 14.25’ E120° 23.256’) and Station IV at Brgy. Tubod-Damortis (N16° 15.142’ E120° 23.219’).  From 2013 to 2016, collected samples were sorted, identified, and catergorized. The abundance and distribution of invertebrates in the area identified were: Mollusks, Arthropods, Echinoderms and Cnidarians. Results showed that the temporal distribution of these macromacroinvertebrates from 2013 to 2016 shows that of these macroinvertebrate phyla, mollusks were the most diverse, widespread and common group throughout the sampling months. The mollusks consist of three groups in the collections: Bivalves, Gastropods and Cephalopods.  Arthropods were also abundant in the collected samples and consisted primarily important species such as shrimps (Metapenaeus spp.); crabs: Charybdis sp., Portunus sp., S. serrata and other species of Portunidae.  S. mantis is also common and abundant in the collected samples. Others were collected in small quantity. Echinoderms were less common and represented by two species of sea cucumbers (H. ocellata & H. scabra). Few samples of Cnidarians were collected and may come from other source or carried by water currents into the cove.