1998 Fourth Quarter Report

Largemouth Bass Habitat Use in the Belleville Pool of the Ohio River

Task 1: Adult Largemouth Bass Radio Telemetry

Jason Freund and Kyle Hartman
West Virginia University
Wildlife and Fisheries
320 Percival Hall
Morgantown WV 26506-6125

17 February 1999

Objectives

1. Determine largemouth bass (Micropterus salmoides) overwintering habitat selection and movements within the Belleville Pool of the Ohio River.
2. Determine seasonal water quality differences between major Ohio River habitat types (embayments, tributaries, and main channel). We will attempt to correlate water quality information to fish habitat preferences.
3. Determine pre- and post-spawn movements of largemouth bass, spawning habitat preferences and compare known spawning habitats with random locations.

Methods
A radio telemetry project on the Belleville Pool of the Ohio River was initiated on June 30, 1998. Fish used for radio tagging were captured through pulsed DC electrofishing or were obtained from bass tournaments. All bass were captured within the Belleville Pool. Fish were radio tracked within a week of release. Analysis of fish behavior and habitat use from 1-7 days post release will be used to determine at what point fish become re-acclimated. Only data from fish considered to be re-acclimated will be used in subsequent analysis.
Radio transmitters of no more than two percent of the fish's body weight were implanted into the visceral cavity. A summary of bass length, weight, tag weight, and tag percentage of body weight is found in Table 1. Fish were anaesthetized using a clove oil solution prior to surgery. A horizontal incision large enough to pass the radio transmitter was made anterior and dorsal to the anal vent. A needle was used to extend the 35-cm (14-inch) antennae out of the fish's body. The incision was surgically sutured and the fish was placed in an aerated tank for recovery. After recovering from surgery and anesthetic, the fish was released near its capture site.

Attempts were made to locate fish by radio telemetry a minimum of once a week beginning with initial searches conducted on 16 August 1998 . Fish were tracked using a large, boat mounted Yagi style antenna that is able to locate fish at a distance of up to 1 mile. Due to an outboard motor problem, the boat capable of utilizing the yagi antenna has not been in service since early October. The motor will be replaced in late February and will increase our searching efficiency. For short-distance locating of fish, or during times when the yagi antenna was disabled, a hand-held loop style antenna was used to obtain a more precise bearing on the fish's location. Low bridges and culverts in several embayments exclude access with the large Yagi antenna, requiring the use of the hand-held loop antenna. The loop antenna has an effective range of a quarter mile though bearings are taken as close to the fish as possible without startling the fish. Fish are located while motoring at less than 10mph using a scanning receiver. When a signal is detected, the loop antenna is used to record bearings taken at three different locations to triangulate the fish's position. Using a series of computer programs, GPS locations where the bearing was taken will be differentiated and the fish's location will be estimated. Computer programs will also be used to determine the fish's home range and to estimate its movement.

Water quality data was taken regularly to determine if fish use of habitat types was influenced by water quality differences. Water quality data collection coincided with radio telemetry searches or electrofishing efforts when possible. Water quality sampling efforts were concentrated in the lower 25-km (15 miles) of the Belleville Pool since it is believed to be the best largemouth bass habitat within the pool. Our electrofishing efforts in the upper pool yielded much lower catch per unit effort (CPUE) than the lower pool. Measurements of dissolved oxygen, conductivity, temperature, and turbidity were taken in embayments and tributaries. At each embayment or tributary, water quality measurements were taken at an adjacent main river site. Main river measurements were taken slightly upstream and at least 100 meters from the shoreline to ensure the embayments and tributaries would not affect main river water quality variables. All measurements were taken at a depth of 1 meter.

General habitat types, from which water quality was measured, were defined as main river, tributary, or embayment. Embayments were defined as small tributaries that were flooded by the impoundment of the Belleville Dam. Tributaries included the Hocking and Little Hocking Rivers, which are larger tributaries that do not have the pond-like areas associated with embayments. Main river encompasses the Ohio River located between the Ohio and West Virginia shorelines. A daily average for each water quality variable was determined by pooling measurements by habitat type.

Progress to Date
I.) Radio Telemetry

Ten wild fish and six hatchery-reared fish have been implanted with radio tags to this date. Six of the wild fish were captured by pulsed DC electrofishing and the remaining four were obtained from bass tournaments. Stocked fish were obtained from the Sprock Fish Hatchery on October 20, coinciding with the stocking of French Creek and Little Mill Creek. Very low largemouth bass electrofishing and local bass tournament CPUE has made obtaining a sufficient number of bass to tag difficult. Electrofishing efforts coincided with the juvenile largemouth bass project as well as additional efforts before and after the initiation of the juvenile bass project. Scott Morrison has indicated that electrofishing CPUE, particularly of fish large enough to tag, should increase in the pre-spawn period, hopefully enabling us to use our remaining tags.

Efforts to locate fish by radio telemetry have been largely successful. Dates on which we were successful in locating radio-tagged bass are shown in Table 4. Several other dates of effort have not been included because telemetry receivers failed. Efforts made to locate fish that we assumed had moved out of the area normally surveyed by radio telemetry have been unsuccessful on all occasions.

To determine possible differences in behavior between wild and stocked fish, we initiated a small experiment to coincide with the radio telemetry project being conducted in the Belleville Pool of the Ohio River. On 20 October 1998 we obtained six fish from the Sprock Fish Hatchery, the same source that was used to stock French and Little Mill Creeks. After implantation of radio transmitters and recovery of the fish, they were released in Lee Creek at the Robin Hood Road bridge. Our objectives are to determine if mortality, habitat utilization, and movement patterns differ between wild and stocked fish. It is hypothesized that stocked fish should behave similar to wild, locally adapted bass if they are to have a long-term impact on the fishery.

II.) Water Quality

Water quality can be an important influence in largemouth bass habitat selection. Within the Ohio River, there can be great differences between the main river, tributaries and embayments that will affect the season distribution of largemouth bass.

Turbidity
On all dates, turbidity of embayments was greater than main river or tributary turbidity. Turbidities of the main river and tributaries were similar. Turbidity varied greatly among embayments and very little among main river locations or tributaries. Turbidity in embayments may be directly related to land usage within the drainage basin. Embayments have smaller drainage basins and are more effected by sources of erosion within their basin than are tributaries and the Ohio River. An area of non-point source pollution has less affect on rivers with larger drainage areas.

Temperature
Temperature differences between habitat types were not statistically different. However, temperatures varied more between embayments than main river locations or tributaries. While embayments were cooler on average during the summer, some embayment sites had maximum temperatures exceeding main river maximums. It was hypothesized that the embayments would be warmer than the main river in the summer due to higher turbidities and their smaller, shallower nature. Springs and other freshwater inputs and shading from steep bluffs and forested watersheds may help keep some of the embayments cooler. The main river was found to thermally stratify vertically, but only slightly.

Dissolved Oxygen
Dissolved oxygen (DO) did not vary between any of the habitat types and all DO concentrations to date were sufficient for largemouth bass. DO concentrations have never been recorded under 6 mg/L. As bass are able to tolerate DO levels of 2 mg/L for short times and fully function at 4 mg/L, the DO in the Ohio River appears to be adequate for largemouth bass during the period studied.

Conductivity
Conductivity did not vary between habitat types.

Special Considerations
A significant proportion of stocked fish were never located after their release (three of the six hatchery-reared fish) despite large-scale searches conducted within the lower half of the Belleville Pool. To date, we can only speculate why they have not been located. In Eric Janney's research with stocked fish in the Racine and Willow Island pools, bass made significant movements after stocking and some fish have been reported to have moved into the pool below. Lee Creek, the stocked fish release site, is located 3.7 km (2.2 miles) upstream of the Belleville Lock and Dam making movements out of the study site quite possible. Fish that have moved into another pool would not be located in this study. Since the study was implemented to study the Belleville Pool, we have not made radio-tracking efforts outside of the pool. In the future, we will make periodic efforts outside of the pool to determine if any tagged fish have migrated through the Belleville or Willow Island dams.

We have been unable to quantify angler harvest of tagged fish. The fish implanted with 49.111 is known to be kept by an angler. Through a conversation with the manager of Haas Marine in Marietta, Ohio, it was learned a fish was caught by an angler who kept the fish not realizing it had a transmitter until he had returned home with the fish. The angler did not turn the tag in nor call Dr. Hartman or the West Virginia Department of Natural Resources with the information about the fish's capture. Despite the radio transmitters bearing Dr. Hartman's name, address, and phone number, no transmitters have been recovered from anglers. It is likely that anglers keeping radio tagged fish assume they are doing something wrong or even illegal. Anglers keeping tagged fish may make up a significant proportion of the fish that can not be located.

The fish that was tagged with a frequency of 49.034 was lost between 10 October 1998 and 11 October 1998. This tag has either failed to transmit after 10 October or was caught by an angler. On 10 October, the fish was located in the Little Kanawha River. A search conducted on 11 October did not locate the fish despite tracking efforts of four miles in all directions from the previous location.

Several uncontrollable events have reduced our radio tracking efforts. Radio telemetry receiver failures have occurred on three occasions, delaying telemetry efforts. However, loaned receivers are easily obtained and delays in tracking fish are rarely more than one week. Weather has also deterred efforts occasionally. Barring atypical winter weather, efforts should not be greatly effected by winter weather. Ice covered boat launches and floating ice has deterred efforts, but not substantially. Additionally, rain has caused the receiver to malfunction on one occasion. Thus, tracking in heavy rains is now avoided to protect the receiver from malfunction.

Future Efforts
Our future efforts include analyzing much of our radio telemetry data and preliminary fish movements and home range structure will be analyzed early this year. This will help define what areas are critical to largemouth bass and if habitat use is dependent upon seasons or water quality variables. Difficulties in obtaining fish for radio transmitter implantation may require us to devise new survey methods to strengthen our study. We may use an angler survey card as a way to get more information about where fishermen are catching bass at various times of the year.

The angler survey card is seen as a way to obtain more data to supplement our radio telemetry efforts. Using Ohio Department of Natural Resources' side-scan maps, which will soon be available in a GIS format, we will be able transpose our triangulated fish locations on the substrate map to help determine habitat use.
Our low CPUE rates during summer and fall have coincided with periods of low susceptibility of largemouth bass to electrofishing gear. Largemouth bass in a pre-spawn pattern, moving to the warm, shallow water, are highly susceptible to electrofishing.

The highest largemouth bass CPUE of the season is typically during the pre-spawn season, which should coincide with Late March through early May in the Ohio River. During this season, water temperatures should approach or exceed 60°F (15.6°C), which is the coldest water in which largemouth bass should be tagged, according to John Pitlo of the Iowa Department of Natural Resources (personal communication). Through his observations, bass tagged in water below 60°F had substantially higher mortality rates than bass tagged in warmer water. We will make greater efforts to electrofish adult bass during this time. If CPUE is sufficient, we should be able to implant the twenty remaining radio transmitters before the largemouth bass spawn. The transmitters, which have a guaranteed life of 300 days, would also enable those fish to provide us with over-wintering data in 2000.