Ichthyoplankton and decapod larvae taxonomic composition, density, relative abundance and frequency
of occurrence were determined to assess if Iloilo River tidal inlet is still a nursery ground during the Northeast
Monsoon. The sampling was conducted during the first quarter moon in the months of December 2016, January
and February 2017 by towing a conical plankton net in 3 stations, namely upstream, upper midstream and lower
midstream. A total of 7 taxonomic groups of ichthyoplankton and 7 decapod larvae taxa were recorded with
densities ranging from 70.8 to 404.2 individuals/100m3
and 112.7 to 1277.6 individuals/100m3
, respectively.
Ichthyoplankton in all 3 zones were dominated by Gobiidae (>70%). Sesarmidae and Dotillidae dominated
decapod larvae in all 3 zones (>65%). Ichthyoplankton and decapod larvae frequency of occurrence ranged
from 0.44 to 0.49 and 0.65 to 0.84, respectively. Compared to other coastal nursery grounds, Iloilo River shows
fewer taxa but similar densities. This implies that the river is a nursery ground, but is utilized by very few taxa
during the Northeast Monsoon. Clupeids was the only economically important ichthyoplankton group recorded,
although, it is unlikely this taxonomic group utilizes the river as a nursery ground. Portunidae, Penaeidae and
Palaemonidae were the only economically important decapod larvae taxa utilizing the river as a nursery ground.
Based on this information, further research exploring how to improve the ecological condition of the tidal inlet
should be conducted to hopefully increase the number of economically important taxa