CINEMar/Open Ocean Aquaculture Annual Progress Report for the period 1/01/02 through 12/31/02
Project Duration: 9/01/01-8/31/03
Principal Investigator: Raymond E. Grizzle
Additional Investigators: Michael Chambers, Arthur Mathieson, Larry Harris
I. Accomplishments
A. Scheduled Tasks
Task 1 - Conduct preliminary net panel experiment (year 1)
This experiment was designed to provide preliminary data on the fouling process as well as adequacy of the experimental protocol. It consisted of deployment of experimental net panels 30 x 30 cm square to the top of each of the two fish cages. Panels were deployed and retrieved so as to yield fouling sequences ranging from 1 month to 6 months in duration. This protocol provided information for the engineering experiments (objective 2), and a test of the suitability of the initial design of the net panels for the full-year deployment during year 2 (Task 3).
Task 2 - Provide data for engineering and water quality studies (years 1 and 2)
This task represented a collaborative effort between the present project and two other projects: an engineering study to characterize cage behavior under different wind and wave conditions, and water quality studies conducted as part of the environmental monitoring program at the OOA site. The present objective was designed to yield biological data relevant to the engineering experiments and interpretation of data on water quality changes occurring as water flows through the cages.
Experimental net panels from Task 1 above were analyzed to meet this task. In the laboratory (on the day of retrieval or the next day), digital photos were taken of each panel after submersion in a small tank to allow the attached organisms to assume their normal life habit position. The percent blockage by the attached organisms of the cross-sectional area of the net material was computed using ArcView programming. After photos were taken, all plants and animals were carefully removed from the surface of the net material on each panel, sorted to species level when possible, counted, and weighed.
Task 3 - Design and initiate 1-year net panel experiment (year 2)
Information from Tasks 1 and 2 were used to design a 1-year experiment that will provide information on various aspects of the ecological successional sequences of fouling communities on the fish cages. The intent will be to characterize the overall annual successional sequence as well as 3-month, 6-month, and 9-month sequences. This will provide additional data for the engineering study (Task 2), as well as data useful in refining cage cleaning protocols. It is also anticipated that a new conceptual model describing ecological successional sequences of fouling communities will result from the project.
Environmental data (e.g. water temperature, current speed and direction) from the OOA oceanographic monitoring buoy will be used to interpret temporal variations in the fouling communities. Hobos will also be placed on the cages to monitor variations in temperature in the immediate area of the experimental net panels.
B. Progress on Tasks
Task 1 Conduct preliminary net panel experiment
The field component of this task was successfully completed as designed. During the experimental period (December 2001-June 2002), net panels were deployed and retrieved as planned so as to yield information on fouling communities ranging from 1 to 6 months in duration of development. Important information that led to design modifications in the experimental panels for the full year-long experiment were also obtained (see below).
Task 2 - Provide data for engineering and water quality studies
This task has only been accomplished in preliminary fashion because information relevant to the engineering and water quality studies that are part of separate research programs will be gathered during both years of the project. During the present reporting period, information relevant to net panel design and deployment were shared with the engineering group. Data on fouling communities that developed on the preliminary experimental net panels have been preliminarily assessed.
Task 3 - Design and initiate full 1-year net panel experiment
This task was fully accomplished and the 1-year experiment was initiated when panels were deployed to the tops of both cages on 30 November 2002 (see below for details).
C. Important Results or Findings
Task 1 yielded interesting and useful data on the plant and animal species involved in early successional stages, and it provided important information for design of the year-long experiment (Task 3). During the preliminary experiment, the two cages were fixed at different heights in the water column, resulting in dramatic differences between fouling communities of all durations on the net panels. Overall, plants dominated the fouling communities on the south cage (held near the surface) while animals dominated the north cage (held at 15 m water depth) for the entire 6-month deployment. The most dramatic differences in total community biomass occurred early on (Figure 1), but species composition differences persisted for the entire 6-month study.
Depending on the fish species being cultured and other factors, the cages can be deployed at different water depths. The preliminary experiment provided a quantification of how water depth (and thus light intensity and possibly temperature differences) can dramatically affect the fouling communities that develop. Such information can be used to design appropriate and cost-effective cage maintenance programs.
The preliminary experiment was of a non-replicated design (one panel per sampling interval per cage), and the net panels were relatively large (30 x 30 cm, inside dimensions of the CPVC frame). It was determined that making the experimental panels smaller (10 x 10 cm) would still result in adequate data on the fouling organisms. This change would also allow four replicates of each panel because a similar amount of processing time would be required, and the overall installation would occupy an acceptable surface area on the cages. Other changes were also incorporated into the final experimental design, which is illustrated in Figure 2. In brief, this design will provide data on monthly recruitment (bottom row of arrows in Figure 2), as well as successional sequences of 3 months duration (second row from bottom), 6 months duration (third row from bottom), 9 months duration (fourth row from bottom), and the community that develops after 1 full year.
As noted above, the year-long experiment was initiated on 20 September 2002 when net panel arrays were deployed to both fish cages. During the reporting period, two sets of monthly panels were retrieved but have not been fully processed. The results of this experiment will be described in the next progress report.
D. Difficulties Encountered
None.
E. Anticipated Success in Meeting Project Objectives on Schedule
It is anticipated that all project objectives will be met on schedule.
F. Reports, manuscripts, and presentations resulting from the project
During the reporting period, one poster presentation was made:
Greene, J.K. and R.E. Grizzle. 2002. Characterization of the Development of Fish Cage Fouling Communities. Benthic Ecology Meeting, 2002. Orlando, FL. 21-24 March.
It is also noted that the present project already has led to a collaborative study (funded through NOAA's Small Business Innovative Research program) with E Paint Corporation to assess the effectiveness of various anti-fouling compounds.
II. Tasks and Activities for Next Reporting period
A. Tasks for the next reporting period
The overall project consists of five major work tasks. In addition to the three tasks described above, two additional tasks will be addressed next year: (4) Characterize the year-long successional sequences of fouling communities on the fish cages, and (5) Preliminarily assess the effect of the fouling communities on water quality in the immediate area. Tasks 1 and 2 were completed during the present reporting period, the remaining three tasks are scheduled for completion during 2002/2003.
B. Brief work plan to accomplish tasks
The year-long experiment (Figure 2) has been deployed. Arrangements have been made for boat time and divers to deploy and retrieve panels. A protocol for taking water samples to address Task 5 has been developed and will be implemented.
C. Anticipated concerns or difficulties
None.
III. Expenditures
All expenditures were in the range anticipated for the work accomplished to date.