Nuʻalolo Kai Reef Algal Survey and Well Algal Growth
September 2006

Nuʻalolo Kai Reef Algal Survey

The reef seems to be in good condition in regards to algae, considering the location and its exposure to extreme stresses throughout the year; high wave activity during winter months, low light levels during winter months, sediment coverage from up-current land run-off, high tourist traffic during summer months, and complete surface exposure at low tide during summer months. Many types of fish were seen and presumably contribute to algal grazing.

The area surveyed was very small considering the entire reef system. However, a high level of diversity was observed in this small area. Many species were observed around crevice openings or on rock edges. The other areas were covered with a yellowish-gray-brown sediment. Once the sediment was removed, the underlying algal mat was exposed, and several types were seen in these areas as well. The area surveyed was the reef/coral head complex on the left side of the channel near the landing, facing makai. A brief survey was done in the area to the right of the channel near the landing, facing makai.

Some specimens were collected and pressed while others were transported to Oʻahu in water. Some were not able to be collected or not collected at all due to few numbers. An attempt was made to photograph these species (some not yet identified). Some specimens were identified on location while others, pressed or live, were shown to and identified by graduate student Thomas Sauvage and/or Dr. Celia Smith at UHM. A follow-up report will be prepared that will include pictures of the photographed algae and coral. Hopefully some more identification will be made at that time.

In the future, a map of the reef should be used to label the locations of the algae present. This would allow for continued monitoring and perhaps inference of reef health over time. The entire reef system in the valley should be thoroughly surveyed and mapped. Fish surveys should also be conducted in conjunction with algal surveys to identify potential grazers. A coral survey also need to be conducted.

Left of the landing:

Dictyosphaeria verslusii – found in many patches and was one of the main species present.

Neomeris sp. – only 3 specimens were observed on one slanted rock face near the landing and 1 was gone and 1 was damaged by the end of the visit, presumably disturbed by tourists.

Dictyota sandvicensis - iridescent, small and decumbent.

Turbinaria ornata – only one specimen was observed and seemed to have been highly grazed.

Valonia trabeculata - several specimen were observed in crevices growing among the Amansia. Large, green masses. Amansia glomerata - large, healthy, swaying specimens were observed in almost every crevice. Red and branched. Pressed.

Tolypiocladia glomerulata – identified from fragment. Red, brush-like, growing decumbently in several areas.

Acanthophora pacifica – red, flat, branched. Pressed.

Ceramium sp. – identified from fragment. Phylodicton sp. – identified from fragment.

Bryopsis sp. – identified from fragment.

Laurencia sp. - ? small, red, branched, flat with blunt ends. Pressed.

Jania adhaerens – ? pink, branched, articulated coralin. Pressed.

Pterocladiella capillacea - ? flat, branched, red. Pressed.

Pterocladiella caerulescens - red with green flattened axes. Turf of this species dominated the reef under the sediment. Pressed.

Martensia/Neomartensia - ? Pressed.

Peysonnellia sp. – red crust, some very attached. Pressed. Blue-green tufts of cyanobacteria – many patches.

Right of the landing:

Amansia glomerata - red and branched in most crevices.

Bornetella sphaerica - 3 spheres were observed in a single patch cleared of sediment.

Acetabularia sp. – 1 flower was observed next to the Bornetella in the cleared area.

Branched coralins – medium to large patches of pink specimens were observed in a variety of crevices. Most likely Jania.

Peysonnellia sp. – red crusts.

Blue-green tufts of cyanobacteria – many patches.

Well Algal Growth

The well water was covered by an algal mat that was 3-4 inches thick. A specimen was collected and pressed. The alga was bright green, thin and wiry. The dried specimen was given to Dr. Alison Sherwood of UHM and identified as Pithophora sp. in the order Cladophorales.

The presence of algae in the well was not seen in the two previous years. The alga might have been introduced by human contamination or brought in by the wind. It is possible that algal tissue was already present in the well but the condition of the water was not fit for growth until this last season. The well should be inspected next year and the loʻi area should be surveyed as well.