Tracking River Smallmouth
Contact: Dave Mayers, (417)255-9561 x274
MISSOURI DEPARTMENT OF CONSERVATION
For more information contact:
Dave Mayers, Fisheries Regional Supervisor
Tracking River Smallmouth
Biologists use telemetry to learn more about Smallmouth bass
WEST PLAINS, Mo. -The smallmouth bass is one of Missouri's most popular game fish caught in Missouri's waters, and yet biologists continue to learn more about the species to help manage its habitat and regulate harvest.
Biologists from the Missouri Department of Conservation (MDC), National Park Service (NPS), University of Missouri (MU) and Missouri State University (MSU) are working together to gain information about smallmouth bass. These groups are conducting separate but complementary studies on the fish.
The MDC surveyed anglers by mail and tagged smallmouth bass in several rivers to gather angler catch and harvest information as well as angler's opinions. The groups used telemetry to monitor smallmouths' habitat use, and MU is conducting telemetry studies to determine behaviors of the fish such as what temperatures they prefer to live in. Although these studies are different, their combined results will give biologists a clearer picture of smallmouth habits and management needs.
"Working with other agencies enables us to easily share ideas about how to do the study and what the results mean," said Craig Paukert, leader of the Missouri Cooperative Fish and Wildlife Research Unit at the University of Missouri. "We help each other collect data and share equipment, and we can plan our studies to maximize the knowledge we gain while minimizing duplicate efforts."
Jennifer Girondo, MDC Fisheries Management Biologist and chair of the Smallmouth Bass Working Group, is working to measure harvest rates for smallmouth bass in streams of different sizes, as well as gather information about fishing pressure. Girondo said the group hopes to learn details about the fish's life history.
MDC's tag return study involves the Castor, Black and Current rivers, the North Fork of White River, and Courtois Creek, incorporating various sizes of waterways. Fisheries management biologists for the five streams place tags on wild-caught fish. Anglers are asked to report where and when they catch tagged fish and whether they were kept or released. They also provide measurements of the fish. Anglers can receive a reward for calling in that information to the number listed on the tag.
Girondo said the tag return study was prompted by the need to directly measure how much harvest occurs in streams.
"We need to ensure that our smallmouth bass fishing regulations are appropriate for providing quality fishing experiences for all Missouri stream anglers," Girondo said. "Appropriate regulations entail that we understand where and how smallmouth use our streams and where and how anglers use smallmouth bass."
The tags used in the MU study record the temperature the fish is experiencing at set time intervals.
"These tags tell us if the fish are using warmer or colder water than we expected them to," Paukert said. "We want to understand how fish growth may change if the climate changes."
To complement both of these studies, NPS biologists are working to understand how large springs influence aquatic life in adjacent streams.
Hope Dodd, of NPS, and MDC's Mike Siepker, conducted a fish telemetry study at Big Spring along the Current River to document the use of springs by smallmouth bass and the timing of their movement into and out of springs. Their group tagged and tracked 30 fish for a year, documenting the temperature and habitat used by smallmouth bass within the river and the spring.Dodd said the telemetry study data will help biologists understand the timing of movement and use of springs and river habitats by smallmouth bass, a fish species whose distribution and abundance in the Ozarks has declined due partly to increased water temperatures over the years.
"Combining the temperature data with the SMB telemetry work, we can assess the importance of springs in regulating water temperatures in the river and determine the importance of springs as refuges for fishes that require cooler temperatures," Dodd said.
Findings from all three studies are extensive. From the temperature data, the group found that each spring has a relatively constant temperature throughout the year, but not all springs have the same average temperature.From the telemetry study, they found that timing of movement from Big Spring into the river was influenced by temperature. Smallmouth bass inhabited the warmer water of Big Spring in late winter, and moved into the river once river temperatures warmed to similar temperatures of the spring.By late fall, when river temperatures cooled below that of Big Spring, fish began returning with five of 12 fish returning to Big Spring by the end of the study, Dodd said.
"One fish bypassed another large spring to overwinter in Big Spring," Dodd said. The fish returned to the same river location the following year, suggesting that SMB in the Current River may have site fidelity.
Check out these findings from Smallmouth bass (SMB) telemetry studies conducted by MDC, NPS and MU:
·The majority of SMB harvest occurred early in the season (eg: 32% of year's harvest was within the first 4 days of the season)
·Wade/bank fishing is the most popular method, next to float fishing (What else does that leave?) powerboat and jet boat
·82% of anglers responding fish for SMB
·High water and warming water temperatures DID trigger SMB movement in the Current River.
·SMB preferred deeper water of five feet or more.
·Open water, logs and boulders are used at different times of the day and year.
·SMB left Big Spring when river and spring temperatures were similar
·Fewer SMB returned to Alley Spring than to Big Spring.
This is just a sampling of information gained by these three intensive smallmouth bass studies. For more information about smallmouth bass in Missouri visit mdc.mo.gov/node/4057. For more information about these studies, contact your local MDC office.