The study was continued for a second year to determine whether changes in sponge coverage and distribution in the bay could be detected, whether the first year's rates of increase in sponge cover on permanent quadrats would continue, and whether a more effective method of sponge control could be devised. Photo-transects repeated at 11 of the 19 sites from Year 1 indicated increased sponge cover at all sites with significant increases at 7 of the 11 sites, and highest sponge coverage still occurring in the vicinity of Coconut Island. The permanent control photo-quadrats remaining from the first year were re-photographed quarterly and showed a further non-significant increase of 1.7% during Year 2. Re-growth of sponge on the remaining removal quadrats averaged a non-significant increase of 6.3%. Four more photoquadrats were deployed in March 2006 and sponge surfaces on two of these were mechanically removed, followed by injection of the sponge with air delivered by a 10 cm long bone necrosis needle. This treatment resulted in mean reduction from initial values of sponge cover of up to 73% a month later. Four more quadrats were deployed in May and these were treated by air injection alone, which showed little visible effect one month later. Sponge on these quadrats were re-injected with air, and one month later showed mean reductions in sponge of 57%. Some regrowth of sponge occurred on these removal quadrats, resulting in a net average reduction of 42% below pretreatment conditions for the five of the six quadrats that remained by the end of the study.
Overall, the two-year study suggests that growth and spread of Mycale armata on Kaneohe Bay reefs and may now be slowly but steadily extending beyond its area of highest concentration in the south bay. The air injection method may provide a means for reducing the range expansion and impact of the sponge if substantial resources are directed toward controlling this highly invasive species. Before a large-scale control effort is considered, a pilot study of reducing the sponge by air injection should be conducted and results monitored to determine the effectiveness of this means of control in both the area of highest sponge abundance and at the boundary of present sponge occurrence.
Resource Description: NODC Accession Number 0033380
Coles, S.L. and H.Bolick, 2006. Assessment of Invasiveness of the Orange Keyhole Sponge Mycale armata in Kaneohe Bay, Oahu, Hawaii. Final Report, Year 1. The Hawaii Coral Reef Initiative. Contribution No. 2006-02 to the Hawaii Biological Survey.
Coles, S.L., and Marchetti,J., Bolick,H, Montgomery,A., 2007. Assessment of Invasiveness of the Orange Keyhole Sponge Mycale armata in Kaneohe Bay, Oahu, Hawaii. Final Report, Year 2. The Hawaii Coral Reef Initiative. Contribution No. 2006-02 to the Hawaii Biological Survey.
Directories: data/0-data files and filenames as received from originator data/1-data renamed or redundant ASCII (CSV) copies of originals as prepared for the archive by NODC
The original data is primarily provided as MS Excel spreadsheets. Redundant ASCII CSV-format copies were made, with each unique sheet getting a unique file. The name of the file for each sheet in a spreadsheet is
In other words, the name of each sheet is concatenated onto the name of the spreadsheet for each of the CSV files.
Image files are all given in JPEG format.