The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris)...
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Transcript of The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris)...
![Page 1: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/1.jpg)
The Effects of temperature and Density on year of young (YOY) Rock Bass
(Ambloplites rupestris) Growth in Gull Lake
![Page 2: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/2.jpg)
Biotic and abiotic Factors that affect fish growth and survival
• Food availability
• population density
• other potential competitors
• predation pressure
• temperature
![Page 3: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/3.jpg)
Temperature
• Temperature affects environment of YOY fish, which in turn affects growth rates, metabolism and ingestion
• Therefore growth is dependant on temperature, for which there is an Optimum temperature for Growth (Kelly,99)
• Optimum Temp is calculated 2-3 degrees below temp where intake of food and metabolism is greatest
![Page 4: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/4.jpg)
Density
• Definition: estimated # of fish in population
• if population is high, competition and search for food s more intense therefore limiting growth in YOY (Leslie,93)
• fish growth is influenced by quantity of energy expended for activity
• activity levels are expected to rise with increasing population (Holm,99)
![Page 5: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/5.jpg)
Temperature Dependant Model
• Only above a given temp. will fish begin to gain mass and promote growth (Kelly,99)
• therefore as temperature increases so should YOY growth
• must find the YOY length for Rock bass using Peterson Method, due to high variability std deviations were calculated
• max length cut off was 55mm
![Page 6: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/6.jpg)
Temperature Dependant Model
• Daily temperatures must be converted to Growing Degree Days (mean daily temp- base temp), 12c air temperature was used for base temperature for rock bass
![Page 7: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/7.jpg)
Density Dependant Model
• Use seine haul results to estimate catch per unit effort
• catch per unit effort gives an estimation on density of a population (Bagenal, 78)
• its expected that a negative relationship would be shown between density and average fish length or as density increased, fish length decreased
![Page 8: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/8.jpg)
Results
• 1992,96,97 had lowest amount of Growing degree days, 2000 was 856.1 GDD’s
• 41mm was found to be average YOY length over ten years, 2000 YOY length was 42mm
• 1992,96,97 showed YOY lengths below average
• 1992,96,97 also showed low density numbers
![Page 9: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/9.jpg)
Interpretation of Data
• Problems with a high degree of variability within data and small sample set, try to increase sample size in future
• 1992,96,97 years that had smaller YOY lengths and the fewest GDD’s this would support the positive correlation that with increased GDD’s we should see increase in fish length
![Page 10: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/10.jpg)
Interpretation of Data
• McClendon and Rabeni found that temperature has a major impact on fish growth when its below the fishes preferendum
• Minden never reached this temp of 25 c set by Carlander for rock bass, therefore temperature dependant growth was obeserved, substatiating the temperature Dependant Model
![Page 11: The Effects of temperature and Density on year of young (YOY) Rock Bass (Ambloplites rupestris) Growth in Gull Lake.](https://reader036.fdocuments.us/reader036/viewer/2022072013/56649e695503460f94b6650a/html5/thumbnails/11.jpg)
Interpretation of Data
• Density dependant model was rejected, because we should have observed a increase in fish length as density decreased
• however 1992,96 and 97 showed low densities and the fish size decreased
• seine hauls should be increased for larger sample sizes
• perhaps openings in nets at to small for YOY