Seagrass and Substrates

Based on the report culled from the Sagip Lingayen Gulf Project of the UPMSI, it was found out that the seagrass beds of Brgy. Victoria are relatively vast, and almost across the entire cove of the coastal barangay. Although shoot densities can range from low to high, it is generally dominated by thick Halodule and Cymodocea beds. The Halodule Univervis vertical rhizomes are high, assumed to assist plant exposure to light when waters are turbid. The substrate is sandy-silty and becomes turbid when substrate is agitated.

The major sea grass site in the  Hundred Islands can be found in the Shell Island where four (4) seagrass genera were observed vast during a most recent sampling. The percentage seagrass cover estimates were relatively high but plants notably consisted of new to young growth stages. It has  been observed that seagrasses in the whole area are all prone to vast uprooting and lost of cover during storm and surging wave action. Seagrass is dense in the area from January to August.

The muddy areas of Lucap  are dominated by Enhalus Acoroides whose tips are observable despite the highly turbid waters. Mixed sea grass densities were noted to be low. In the eastern tip of Alo Island, the area consist of either thick clumps of Enhalus,thick beds (high root densities) of Halodule Uninervis with long vertical shoots, or beds of Halodule interspersed with Enhalus.

Further, seagrass genera that are found in the coastal areas of the City are namely: Cymodocea, Enhalus, Halodule, Halophila and Thalassia. The substrate was likewise muddy and very turbid. For both Lucap and Alo Island, despite the high turbidity in the area, it is likely that sea grasses obtain light during low tide duration where plants are exposed. The high nutrient content of the waters (due to aquaculture feeds) exiting Tambac bay within the vicinity of Alo Island could be contributory  factor to dense seagrass growth in the area. The seagrass around Alo Island tend to be present throughout the year. According to anecdotes from fishermen, seagrass beds around the area, dominated by Enhalus are sites for shrimp harvest during low tides that mostly occur at night. (Seagrass Map of Alaminos City)