Offshore Creel Survey
Introduction
Effective management of the island's offshore fishery resources requires the collection and analysis of boat-based offshore data on participation, fishing effort, methods used, and harvest. The Fisheries section at the Department of Agriculture's Division of Aquatic and Wildlife Resources (DAWR) has been monitoring offshore fishing activities for the past 26 years in order to identify trends in fishing activities. During this period, survey and analysis methodologies have changed in response to fluctuations in budget and staff, changes in the fishery, and the development of computer hardware and software.
The Agana Boat Basin, centrally located on the western leeward coast, is the island's primary launch site for boats fishing areas off the central and northern leeward coasts and the northern banks. Most commercial fishing boats operates from here.
The Merizo boat ramp, Seaplane Ramp in Apra Harbor, Umatac boat ramp, and Agat Marina are launch sites which provide access to the southern coast, Apra Harbor, Cocos Lagoon, and the southern banks.
The Agat Marina, located between the Agana Boat Basin and the Merizo boat ramp, provides trailered boats from the northern and central areas of the island a closer and more convenient launch site to the southern fishing grounds.
A makeshift ramp at Ylig Bay provides access to fishing areas on the eastern side of the island, and is heavily used during periods of calm weather. Surveying the Ylig ramp during the summer has been proposed since significant quantities of BMUS species are landed there by bottomfishing or spearfishing. However, a lack of adequate lighting, no public phone for emergencies, and other safety issues make surveying this area challenging.
Participation
At present, DAWR conducts its Offshore Creel Survey participation counts and interviews at the Agana Boat Basin, the Agat Marina, and the Merizo boat ramp.
Data is collected at these places for 8 randomly selected days each month. The Agana Boat Basin was sampled 4 times a month on 2 weekdays and 2 weekend/holidays, while the Agat Marina and the Merizo boat ramps were each sampled twice in a month on one weekday and one weekend\holiday.
Agana Boat Basin surveys consist of two survey periods a day, from 0500 -1200 hrs and from 1600 - 2400hrs. The Agat Marina is surveyed from 0530-1200 hrs in the morning and Merizo boat ramp facility is surveyed from 0600-1100hrs in the morning. The evening survey for these places is the same as for the Agana Boat Basin.
Participation data from the field is entered on an Offshore Survey Boat Log Form before being entered into the computer. The partcipation data includes Interviewer's name, Sample Date, Start and Stop Time, Location and type of day. For each boat logged, its depart time, return time, registration number or name, whether or not it is fishing, whether or not it is a charter boat, the type of activity or fishing method and the vehicle license number for trailered boats is entered on the form. The Agat Boat Basin Survey Map and the Agat Marina Survey Map forms help the data collectors identify which berthed boats are not at their pier and hence out fishing.
On 2 weekdays and 2 weekend/holidays a month a vehicle/trailer census is done using an Offshore Vehicle/Trailer Participation Census Form. All public boat launching areas and accessible makeshift launching sites are surveyed by counting the number of vehicles with trailers (VTs) attached. A percentage of boats operating out of Agat Boat Basin, the Agat Marina and the Merizo boat ramp versus boats operating out of all areas is computed. This percentage is used to expand the participation counts in Agat Boat Basin, the Agat Marina and the Merizo boat ramp to account for island wide activity.
Interviews
DAWR conducts its Offshore Creel Survey interviews at the Agana Boat Basin, the Agat Marina, and the Merizo boat ramp at the same time that it is doing participation counts as described above
Originally all completed interviews on Offshore Creel Census Forms included interviewer name, interview time and date, weekday or weekend\holiday, landing where survey was done, fishing location and method, (See Offshore Location and Method Codes and Offshore Area Codes), number of fishermen, number of gear, number of hours fished, use of a FAD, boat number , the type of bait used and meteorological data such as wind direction and speed, rain, cloud cover and phase of the moon.
For each species the length or weight of up to three samples can be entered and the weight of remaining fish of that species can be calculated from the average of these three samples.
When the Offshore Creel Census Form was firsrt revised, charter boat information such as number of people on board and number of guests was added. The meteorological data was expanded to include typhoon conditions, small craft and high surf warnings. Information on the towing vehicle's license number and bething information was added. Disposition data such as % sold, % kept and the buyer's name was added.
The current version of the Offshore Creel Census Form added information on bycatch or fish that was releasd or thrown back such as species, fishing method, length and weight data and whether it was released alive or dead.
For most interviews, it was possible to identify the entire catch to the species level. However, an estimated total weight was occasionally used, depending on the level of fishermen cooperation. A small percentage of fishers declined interviews and although obtaining survey data is voluntary on Guam, the vast majority of them were cooperative and supportive of our staff and program.