The Diwal Harvest Seafood Festival is held every 2nd weekend of July. The Diwal is a rare bivalve found abundantly along the coastal waters of Roxas City and Capiz. Ten years ago it disappeared from the waters of the City and Province because of illegal harvesting practices and pollution. Now, ten years later, after intensive research, seeding, and strict fishing and harvesting legislation, the Diwal is again ready for harvest as the efforts of the City have once again caused its abundance. The festival was first celebrated this year and will be celebrated annually. The Diwal is known for its sweet and juicy qualities and its immaculately while elliptical shells, hence the name "Angel Wing" Shell. Every year during the festival, tons of the bivalve are harvested and sold in the open market and the seafood festival, with drinks and music, and lots of partying in thanksgiving to the Almighty for the great and rare bounty that is Diwal. Kasadyahan sa Capiz
The two-day celebration fits its national image as the seafood capital. Diwal, popularly known as "Angelwings" is one of the most sought after bivalve for it’s sweet, juicy and tender taste. It can be recalled that Diwal was first harvested in commercial quantity back in 1994. it’s abundance triggered wanton harvest that wrought havoc to its natural habitat. The destruction caused the absence of Diwal for almost a decade until a research team from the Institute of Aquaculture, College of Fisheries of the University of the Philippines in the Visayas came to the rescue in cooperation with the Philippine Council for Aquatic & Marine Research & Development (PCAMRD), the Bureau of Fisheries & Aquatic Resources (BFAR) and the Capiz Provincial Government. The city government funded study on "Habitat and Reproductive Biology of Angelwings, Pholas Orientalis (Gmelin)" eventually restored the natural habitat that brought back Diwal from years of absence. Kasadyahan sa Capiz