ISLAND OF MOLOKAI

PUKOO HARBOR/REEF

Several sites were surveyed at this location in an attempt to cover all of the different habitat types that were found here. The furthest west area that was sampled was a large and very protected lagoon/embayment where aquaculture of the alga Gracilaria cornopifolia is taking place. Several large cages containing this plant were suspended in the water column within this area. The majority of the substrate here was soft sediment and sand however, some large boulders line both sides of this lagoon. Huge mats of the alien alga Gracilaria salicornia and Acanthophora spicifera were found throughout this rocky area. This was the first site that G. salicornia was found and this population is actually a new record for Molokai. As we moved further out of the lagoon from this very calm watered area, coral colonies become apparent but were heavily dusted with sediment. Maroalgae was abundant on just about every hard surface available for colonization, including the bubble alga Dictyosphaeria cavernosa which was seen overgrowing live coral. The visibility in this area was very poor- not more than 1 meter of horizontal distance. Large mats of Halimeda opuntia were found all over the bottom in this area along with Spyridia filamentosa and several species of coralline algae. The abundance of Dictyosphaeria cavernosa in this area may be approaching an invasive categorization. 

In general the area within this lagoon seems to be  impacted by some sort of anthropogenic influence leading to macroalgal growth and sedimentation. We also surveyed outside of the lagoon and this habitat seemed more similar to most other reef flats in the area. The substrate was soft sediment intermixed with sand, coral rubble and small rocks that were colonized by macroalgae. Close to shore large seagrass beds (both the endemic species and a new unidentified species) proliferated. There were many houses, a fire station, some boat launch facilities and the aquaculture activities all occurring on the shore surrounding this site.

Table 1.  Information regarding site characteristics and alien species abundances. The  number recorded for each alien species of algae is a ranking of the abundance of that species at each given site. Impact ranking values range from 0 (not present) to 10 (100% cover). 

Table 2.  Species list of all of the algal samples that were collected at this site. Alien species are displayed in green.  

Table 3.  Species list and relative abundance of herbivores at this location.