VOLUME 18 NUMBER 2 (July to December 2025)

Ecophysiology and community ecology studies of Philippine seaweeds: Insights, research opportunities, and possible implications for cultivation and management

Seaweeds are vital to the marine ecosystem as primary producers and it serves as a widely consumed food source for humans. Some species of these marine resources are mainly mass cultivated due to the increased demand for raw materials and derived products. In the Philippines, studies on seaweed community ecology, reproductive biology, and growth began around the 1970s. Studies on seaweed photosynthesis are relatively new, beginning in the 1990s, and have since progressed through advancements in physiological and molecular analyses. This review paper examined a total of 123 studies, encompassing ecophysiology and community ecology in Philippine seaweeds, dating back to the 1970s and continuing up to 2025, from public and unrestricted access on scientific databases, including grey literature and the author’s personal collection. This also analyzed and synthesized literature to determine the cumulative knowledge we have, the gaps that require attention, and the research opportunities to be prioritized. Generally, rocky substrates with wider intertidal zones have higher seaweed abundance and diversity than sandy substrates, which is attributed to local and regional hydrodynamics and meteorological phenomena, and is largely unaffected by physicochemical parameters due to minimal yearly variation. Seaweed communities exhibited a declining trend in composition, possibly due to anthropogenic pressure, and can serve as a biomonitoring tool. On the other hand, reproductive biology, growth, and photosynthetic studies have mainly focused on economically utilized eucheumatoid, agarophytes, and alginophyte species to improve production. Utilizing new cultivars/strains as planting materials in seaweed farming, especially those produced from tetrasporophytes, and applying organic fertilizer could enhance their growth rate and carrageenan content. Unfortunately, there are still limited photosynthetic studies, yet information can be significantly valuable for culturing and maintaining economically important seaweed in the laboratory and outdoor hatchery. This review paper recommends continuous monitoring to provide comprehensive insights into the variations in seaweed community ecology over time and to quantify the different ecological services offered by seaweed communities. Furthermore, continuous studies on photosynthesis, growth, and reproduction are necessary to provide baseline information for improving and developing seaweed farming techniques, ensuring effective and efficient farming practices.