Impacts of Aquarium Fish Collecting and the
Brian Tissot, Washington State University, Vancouver, WA
The establishment of Marine Protected Areas (MPAs) is currently a major tool for coastal area management with the number of MPAs increasing rapidly around the world (Bohnsack, 1998). Although numerous studies have documented the benefits between the marine communities in MPAs and non-managed areas (e.g., Polunin and Roberts, 1993), very few studies have actually recorded baseline information on MPA-sites prior to their closure; the only true method of measuring their benefit to enhancing marine resource management (Jones et al., 1992).
The study proposed here represents an unique opportunity to investigate the effectiveness of MPAs as they apply to the management of aquarium fish collecting impacts in west Hawaii. We propose to continue the baseline monitoring initiated with previous funding of this subproject under the Hawaii Coral Reef Assessment and Monitoring Program (CRAMP). Continuation of this project will allow us to collect data both before and after the establishment of nine closed areas using a rigorous experimental design replicated along the 100 km west coastline of the big island of Hawaii. In addition, we propose to examine fine-scale fish recruitment patterns associated with MPAs to further understand how reserve design relates to biological function.
This study thus focuses on both the first and second priorities of the HCRI research program by: 1) continuing existing monitoring programs; 2) providing a large-scale assessment of aquarium fish collecting impacts, which builds on our earlier work, 3) expanding activities to better understand natural variability in reef ecosystems; and, 4) evaluating an ambitious reef fish management plan (Act 306).
The aquarium collecting industry in Hawaii has had a long contentious history. As early as 1973, public concern over collecting activities were first addressed by the Division of Aquatic Resources (DAR) by requiring monthly collection reports. However, the industry has been largely unregulated over the last 16 years despite dramatic increases in both the number of issued collecting permits and collected fishes. Further increases in fish collecting combined with growing public perception of dwindling fish stocks eventually developed into a severe multiple use conflict between fish collectors and the dive industry.
The severity of this problem and lack of reliable information on the extent of the impact prompted a joint investigation into the impacts of aquarium fish collecting in Kona by the University of Hawaii at Hilo and DAR between 1996-98 (Tissot and Hallacher, 1999). Utilizing two replicate pairs of control-impacts sites we monitored the abundance of twenty-one species of fish: seven collected species ("target species") and 14 species not subject to collection. Results of that investigation indicated that aquarium fish collectors can profoundly lower the abundance of fish species that they target. At Honokohau, six of the seven target species were frequently significantly lower in abundance compared to their density at control sites (Figure 1).
In response to these impacts and strong community angst, Act 306 was enacted in 1998 which established the West Hawaii Regional Fishery Management Area (WHRFMA). The major intent of the bill was to improve management of fish resources in west Hawaii by declaring a minimum of 30% of the west Hawaii coastline as aquarium Fish Replenishment Areas (FRAs), where fish collecting is prohibited. An additional component of the bill designates a portion of these areas as no fishing zones. In 1998, the West Hawaii Fishery Council, which consisted of representatives from the aquarium collecting industry, the dive tour industry, a Hotelier, commercial and recreational fishermen, shoreline gatherers, recreational divers, and several community representatives, proposed the location and size of the nine FRAs in the WHRFMA (Figure 2A). A public hearing was held in April 1999 on the management plan developed by the Council; there was very strong public support and we anticipate that the FRAs will be closed to aquarium fish collecting during 1999.
Purpose and Objectives of the project
During initial funding under CRAMP in 1998-99 we established 23 permanent study sites positioned in all of the proposed FRAs as well as eight sites where fish collecting is know to occur ("impact"), and six managed areas where aquarium fish collection is prohibited (three MLCDs and three FMAs or "control"). Initial surveys confirm that aquarium fish collecting impacts are significant but vary along the coastline (Figure 2B and C). The principle purpose of this project is to continue monitoring of these sites as Act 306 is implemented to provide an evaluation of the effectiveness of the FRA plan as a way to manage aquarium fish collecting impacts in Hawaii. In addition, examination of fish recruitment patterns will provide important information useful to the future establishment of MPAs in Hawaii.
Accordingly, the objectives of this proposal are to:
Approach and Methods
Our basic experimental design seeks to compare newly closed sites (FRA) to those which remain open (impact) and those that remain closed (control). The experimental design is as follows:
To implement this design, we have established 23 study sites where permanent transect lines have been installed. These include 9 FRAs, 8 Impact sites, and 6 controls (Figure 2). Thus, five of the FRAs have a balanced design with all three treatments which will allow precise and statistically powerful repeated-measure estimates of change in the abundance of aquarium fish species relative to both uncollected (control) and collected (impact) areas.
Fish densities are estimated by visual strip transect search along each permanent transect line. At each of the 24 sites, four 25 m transect lines are deployed using permanently installed eyebolts as geographic markers for the ends of each transect. Transects are located by differential GPS. Two pairs of divers survey the lines, each pair searching two of the 25 m lines. Each site is scheduled to be surveyed bi-monthly, weather permitting, for a total of six surveys per year.
The search of each line consists of two divers, swimming side-by-side on each side of the line, surveying a column 2 m wide. On the outward-bound leg, larger planktivores and wide-ranging fishes within 4 m of the bottom are recorded. On the return leg, fishes closely associated with the bottom, juveniles, and fishes hiding in cracks and crevices are recorded.
In addition, we propose to document recruitment patterns for selected aquarium and non-aquarium fish species at the Honokohau/Old Kona Airport design block (control-impact-FRA), an area in which we already have three years of data on adult patterns of abundance. The abundance of newly settled fishes will be estimated by using stationary circular plots, randomly allocated across a wide range of habitat types (reef flat, reef bench, reef slope) at each site. Recruitment patterns will be documented quarterly through an intensely time-replicated design whereby fine-scale temporal patterns in fish movement and abundance can be estimated at each site.
We will also estimate coral cover at each site by photographic analysis. We will utilize standard methods developed by CRAMP to estimate coral abundance, diversity and distribution. Currently these include digital video imaging to record 50 contiguous frames along each transect line (n=200 photographs for each site). We will also measure additional habitat measures, such as rugosity, which will provide habitat information consistent with Jim Parrishs proposed study on nearshore fishing impacts.
Facilities, equipment, and other resources
This investigation represents a cooperative effort between Washington State University at Vancouver, the University of Hawaii at Hilo, and the Hawaii Division of Aquatic Resources. Almost all aspects of the study, from development of the experimental design and methods to the field implementation of those methods are the result of cooperative interaction between WSU, UHH and DAR personnel, specifically: Leon Hallacher (UHH), Brian Tissot (WSU) and Bill Walsh, Bob Nishimoto, Pete Hendricks, and Brent Carmen of DAR. UH Scientific Divers, all UHH student divers specifically trained for the project, assist in field data acquisition. Equipment for the project, including Scuba equipment, transect lines, differential GPS, a research vessel, and underwater digital video cameras are available through DAR, UHH, and WSU. Image analysis of coral surveys and database management is handled at WSU.
Data management and dissemination of results
Original underwater data sheets are transcribed and copies are provided to all participating scientists (Hallacher, Tissot, and Walsh). Originals are archived in DARs west Hawaii facility under the supervision of Bill Walsh. Data are entered into a relational database developed by CRAMP under the supervision of Brian Tissot. This database will be accessible to each of the project participants through the Internet and will also be available to additional coral reef ecosystem managers through the CRAMP GIS database system.
We anticipate publishing several papers from these surveys in the peer-reviewed scientific literature based on the initial results of our baseline surveys and initial patterns of recruitment. The results of this study will be provided to the public through a series of community talks, educational videos, and on the Hawaii Coral Reef Network (http://coralreefs.Hawaii.edu).
The workplan, based on progress made this year and previous studies, will be to survey the primary study sites on a bi-monthly basis in order to assess temporal variation in adult and juvenile fish abundance. Coral and habitat surveys will be conducted concurrently during fish surveys in the summer on an annual basis. Recruitment patterns will be documented four times a year to estimate seasonal variation.
Anticipated outcomes and relevence to coral reef resource management
The results of these studies will have several direct outcomes that serve reef management. First, by comparing fish abundance between control, impact and FRA sites, the primary fish surveys will serve as an evaluation of the effectiveness of the West Hawaii Regional Fishery Management Area as mandated by Act 306. We anticipate that this outcome may take several years to fully develop. Second, by comparing fish abundances in control and impact sites, we will be providing ongoing estimates of aquarium fish collecting impacts. Third, by documenting recruitment patterns we will begin to understand the mechanisms whereby fish reserves alter population dynamics. This outcome is important as it will contribute to the design and function of future marine reserves which may be established in Hawaii. Finally, data from this study will contribute to and strengthen two additional proposed programs: Jokiels CRAMP, and Parrishs study on nearshore fishing impacts.