2. Quantitative Photo Quadrat Transects Having established the extent of the sponge in the bay using manta board swims, linear photo transects were used to establish quantitatively the areal coverage of Mycale armata and other dominant benthic biota along transects at 19 sites on 18 reefs throughout Kaneohe Bay. Digital photographs of bottom cover were taken along belt transects using an Olympus 5060 digital camera contained within an underwater housing and held on a fixed height camera stand, producing an image area of ca. 0.66 m2. Twenty-five photographs were taken on each of two transects per site for a total of 33 m2 reef surface measured per site. The start and end of each set of transects was recorded using GPS and mapped using ArcGIS.
Images obtained were enhanced and cropped to a consistent size of 0.66 m2 and processed using the Coral Point Count with Excel extension (CPCe) program available from the National Coral Reef Initiative (<http://www.nova.edu/ncri/research/a10.html>). Each quadrat was assigned 50 random points and the composition under each point was recorded, for a total of 1250 points analyzed per transect or 2500 points per site. These data were used to determine the percent cover of Mycale armata, macroalgae, corals and other invertebrates, and substratum types within the photoquadrats, which were averaged at each site.
3. Measurement of changes in sponge cover on control and removal quadrats
Twenty permanently marked photo quadrats were established in October 2004 on the reef slope along the southeast perimeter of Coconut Island to monitor sponge growth and competition with reef corals within the marked areas. The corners of each 0.165 m2 quadrat were marked with iron rebar or cable ties, enabling quarterly measurements of the same reef area for each quadrat throughout the year. No sponge was removed from 10 of the quadrats (Controls), while all the sponge that could be mechanically extracted from the remaining 10 quadrats (Removals) was removed. The amount of sponge removed averaged an equivalent of 1.85 kg dry wt per m2 for the ten quadrats. This was time-consuming and impacted corals within some of the quadrats, requiring an equivalent of 12.6-22.7 hr/ m2 for removal from a single quadrat and removing an equivalent 0.18-1.72 kg m2 of live coral skeleton as by-catch from six of the ten removal quadrats. Both sets of quadrats were photographed soon after sponge removal and quarterly thereafter in February, May, August, and November 2005 using a digital camera on a stand with a fixed photographic area of ca. 0.165 m2 .
After cropping to a consistent image area of 0.165 m2, the CPCe program was used to analyze the coverage of all components within the permanent photo quadrates for each quarter's determinations in a similar manner as was done for transect photo quadrats, except that 100 points evenly spaced in a grid were used for analysis of each permanent photo quadrat. This stratified approach provided greater sensitivity and probability that the same specific areas on a quadrat were being sampled each quarter, resulting in more replicability for time-series analyses of changes within the permanent photo quadrats.
4. Measurement of changes in weight and volume of sponge fragments
Twenty fragments of sponge were collected from near the HIMB pier on 3 December 2004, transferred to the laboratory, and held in flowing seawater under screen shade until 6 December. They were then photographed underwater with the digital camera held on a small quadrapod frame that provided a consistent image frame size of 412 cm2 . The sponges were then weighed underwater in a basket suspended from the bottom hook of an Ohaus Scout-Pro digital balance read to 0.001 g. Each sponge fragment was weighed twice and the results averaged. After weighing and photographing, each sponge was placed on a piece of underwater paper and both sponge and paper were attached to galvanized wire mesh platforms and deployed to the reef where they were held in place by cable ties attached to quadrat marker stakes or coral branches. The sponges were photographed and weighed quarterly thereafter in March, June, September, and December 2005. The projected areas of sponge images were determined using CPCe analysis software for determining the area of a irregular object. Duplicate area determinations were made and averaged for each sponge at each quarterly measurement. 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
Data are in the following directories. The originals were provided as MS Excel spreadsheets. Redundant ASCII CSV-format copies were made, with each unique sheet getting a unique file. Each spreadsheet is well-described within.
Directory /MantaSurveys Manta_Board_GPS_Data.xls Coordinates of stations Manta_Board_GPS_Data.csv ASCII CSV copy Manta_Survey_Data.xls survey data Manta_Survey_Data.csv ASCII CSV copy
Directory /Photoquadrats ControlsSummary.xls Summary of data from Control ControlsSummaryQuarter1.csv ASCII CSV copies of spreadsheets ControlsSummaryQuarter2.csv ASCII CSV copies of spreadsheets ControlsSummaryQuarter3.csv ASCII CSV copies of spreadsheets ControlsSummaryQuarter4.csv ASCII CSV copies of spreadsheets ControlsSummaryYear.csv ASCII CSV copies of spreadsheets
RemovalsSummary.xls Removal Summary Data RemovalsSummaryAllData.csv ASCII CSV copies of spreadsheets RemovalsSummaryQuarter1.csv ASCII CSV copies of spreadsheets RemovalsSummaryQuarter2.csv ASCII CSV copies of spreadsheets RemovalsSummaryQuarter3.csv ASCII CSV copies of spreadsheets RemovalsSummaryQuarter4.csv ASCII CSV copies of spreadsheets RemovalsSummaryRemovals.csv ASCII CSV copies of spreadsheets RemovalsSummaryYear.csv ASCII CSV copies of spreadsheets
TimeSeries.xls Change in time of control and removal quadrats TimeSeriesSheet1.csv ASCII CSV copy
Directories within /Photogradrats (each directory pertains to a given quadrat. In each, a ControlSummary and a RemovalSummary (*.xls) file is provided, which has been dumped into redundant ASCII CSV files for each sheet of each spreadsheet. The sheets hold the raw and the summary data).
Quadrat_1/ Quadrat_2/ Quadrat_3/ Quadrat_4/ Quadrat_5/ Quadrat_6/ Quadrat_7/ Quadrat_8/ Quadrat_9/ Quadrat10/
Directory /SpongeGrowth GrowthData.xls Growth analysis data GrowthData_Form.csv ASCII CSV copy GrowthData_Q1.csv ASCII CSV copy GrowthData_Q2.csv ASCII CSV copy GrowthData_Q3.csv ASCII CSV copy GrowthData_Q4.csv ASCII CSV copy GrowthData_TimeSeries.csv ASCII CSV copy GrowthData_year.csv ASCII CSV copy
Directory /TrasectData Photo_Transect_Data.xls Data from photo transects Photo_Transect_Data.csv ASCII CSV copy Photo_Transect_GPS_Data.xls Coordinates and dates Photo_Transect_GPS_Data.csv ASCII CSV copy TransectSummaries.xls Transect summary data TransectSummaries_Data.csv ASCII CSV copy TransectSummaries_Sheet2.csv ASCII CSV copy
Directories in /TrasectData (each directory pertains to a given location. The directory name includes the location, date, and depth (not all). In each, a summary file (*.xls) is provided, which has been dumped into redundant ASCII CSV files for each sheet of each spreadsheet. The sheets hold the raw and the summary data).