Jerome J. Lorenz (National Audubon Society)
The Big Cypress National Preserve Fish Monitoring and Assessment data collections for aquatic animals from BICY were begun in July 2004. The spreadsheet contains worksheets for Raccoon Point, L28, and Bear Island.
This project has several objectives, the foremost of which is to continue a program of aquatic study in BICY begun in 2002. Work will be performed in partnership with National Audubon Society (NAS) and the National Park Service to design and implement a spatially and temporally explicit, quantitative sampling program for aquatic animals in BICY. This program will 1) provide baseline data which may be used to track changes in hydrology as a result of CERP projects 2) document the distribution, composition, and habitat use by native and introduced aquatic animals to evaluate the effects of CERP on BICY aquatic habitats, and 3) provide ecological data for use in the ATLSS fish simulation model used to plan and evaluate restoration actions during CERP (presently, inappropriate data from the Everglades are being used in the model for cells that lie in BICY). The strategy used to accomplish these goals will be to employ techniques used by the co-principal investigators in establishing monitoring programs in the Everglades (since 1977) and the mangrove zone of Florida Bay (since 1989).
Quinn, J. F., Jr., Bogan, A. E., Coan, E. V., Hochberg, F. G., Lyons, W. G., Mikkelsen, P. M., Neves, R. J., Roper, C. F. E., Rosenberg, G., Roth, B., Scheltema, A., Thompson, F. G., Vecchione, M., Williams, J. D.
The diversity of habitat types in Big Cypress presents considerable challenges to the development of a comprehensive sampling regime, as the effectiveness of any given methodology varies between habitats. To compensate for this, numerous techniques were employed during this study. A variety of fish traps have been used extensively, as well as electrofishing gear, gill nets, cast nets, dip nets, and angling.
The location of each sampling site was recorded as universal transverse mercator (UTM) coordinates using a Garmin Etrex Vista GPS.
Project personnel collected and curated representative vouchers for all captured species whenever practical. Specimens too large to effectively preserve have been documented photographically using a digital camera. Vouchers have been collected independently for each habitat type sampled. Additionally, to ensure complete spatial coverage of the preserve, vouchers of each species have been collected from the north, central, and southern regions of Big Cypress. Information regarding each voucher was entered into the project Access database, and each was assigned a unique identifier to link with related sampling information. Voucher collection is an ongoing process and will continue for the duration of the study. Upon completion of this project, vouchers will be transferred to an NPS-identified repository.
40001 State Road 9336
Zokan, Marcus Loftus, William F. Lorenz, Jerome J.
Carlson, J. E. Meeder, J. F. Duever, L. C. Gunderson, L.H. Riopelle, L. A. Alexander, T. R. Myers, R. L. Spangler, D.P.
Opportunistic sampling was conducted using light-tackle, hook-and-line fishing with a variety of lures and live or dead baits. Lines of baited hooks were also occasionally deployed in canals in attempts to catch catfish, although hoop nets proved substantially more effective. Finally, sight records were kept for any species observed in the field that could be positively identified without being captured.
The diversity of habitat types in Big Cypress presents considerable challenges to the development of a comprehensive sampling regime, as the effectiveness of any given methodology varies between habitats. To compensate for this, numerous techniques have been employed during this study. A variety of fish traps have been used extensively, as well as electrofishing gear, gill nets, cast nets, dip nets, and angling.
TRAPS: Traps provide a means of sampling with a standardized unit of effort and are suitable for use in virtually any habitat. They are also relatively portable, and therefore suitable for work in remote locations. They have the disadvantage of having inherent selection biases, based both on trap construction, and size and behavior of targeted species. To attempt to minimize these, we deployed a variety of small-fish traps simultaneously. These included Gee-type minnow traps, box traps, collapsible mesh traps, and Breder traps. Soak times were generally 24 hours, although one-hour sets were also performed. Small-fish traps were consistently fished unbaited and relied on passive encounters to generate captures.
Hoop nets were used to sample larger fishes in deeper water. They were fished unbaited with or without leads, and were also baited with cheese to selectively target catfish species that had proved difficult to obtain otherwise. The hoop nets used here were 1.4 meters in overall length and were constructed from four 50-cm diameter fiberglass hoops and tar-coated twine with a 2.5 cm mesh size. The nets had two throats and an approximately 15 cm diameter aperture. Typically, hoop nets were deployed for 24-hour intervals.
Electrofishing: Electrofishing was conducted in locations where habitat composition allowed. Two electrofishing setups were used. The first utilized a boat-mounted Smith-Root type 6A electrofisher with a maximum current output of 1008 volts DC at 120 pulses per second or 720 volts AC at 60 hertz. It was used extensively for sampling in canals but was too large to penetrate into other habitats. Effort was generally standardized by conducting 100-meter transects, although opportunistic sampling around structures such as bridge pilings was conducted as well.
Forested habitats and marshes were sampled using a small barge carrying a Smith-Root model 2.5 GPP electrofisher with a maximum current of 1000 volts at either 120 pulses per second DC or 60 hertz AC. The barge drew only several centimeters of water and was only a meter wide, but still could not penetrate into heavily vegetated habitats. Samples were standardized to 300 seconds of total shock time.
NETS: Experimental gill nets were used to sample canal fishes. Two nets each composed of 4 242 cm deep x 180 wide cm panels were fished in tandem. The first had mesh sizes of 1.2, 2.5, 3.7, and 5 cm while the second was composed of panels with mesh of 6.2, 7.6, 8.8, and 11 cm. Nets were typically set from 1 to 4 hours. Reptile entanglements were problematic when using these nets. Encounters with alligators were particularly damaging, precluding longer sets.
While unsuitable for providing quantitative data, cast nets were used extensively in an opportunistic fashion to capture species sighted in canals. The cast nets had a radius of 180 cm and a 1.2 cm mesh size. Dip nets were used for sampling in dense vegetation. These nets had fine mesh (<1mm) and were the most effective method for collecting small species, such as least killifish (Heterandria formosa) and Everglades pygmy sunfish (Elassoma evergladei).
OTHER: Opportunistic sampling was conducted using light-tackle, hook-and-line fishing with a variety of lures and live or dead baits. Lines of baited hooks were also occasionally deployed in canals in attempts to catch catfish, although hoop nets proved substantially more effective. Finally, sight records were kept for any species observed in the field that could be positively identified without being captured.
Measurements
We recorded the location of each sampling site as universal transverse mercator (UTM) coordinates using a Garmin Etrex Vista GPS. For each sample, all specimens were identified to species, and total catch per species recorded. We measured total lengths for the first 20 randomly selected individuals of each species to obtain a representative size distribution. Water temperature, pH, salinity, and dissolved oxygen were measured for each site when possible, however, instrumentation problems precluded this for much of the year. We borrowed a Hydrolab 4a minisonde and datalogger from the BICY hydrology department to resolve these problems. For electrofishing expeditions, water conductivity was determined using a YSI-33 conductivity meter.
Voucher Specimens
We collected and curated representative vouchers for all captured species whenever practical. Specimens too large to effectively preserve have been documented photographically using a digital camera. Vouchers have been collected independently for each habitat type sampled. Additionally, to ensure complete spatial coverage of the preserve, vouchers of each species have been collected from the north, central, and southern regions of Big Cypress. Information regarding each voucher was entered into the project Access database, and each was assigned a unique identifier to link with related sampling information. Voucher collection ws an ongoing process and continued for the duration of the study. Upon completion of this project, vouchers will be transferred to an NPS-identified repository.
40001 State Road 9336
U.S. Department of the Interior, U.S. Geological Survey, Center for
Coastal Geology
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