UV Project Update
Unfortunately due to funds and time restrictions, the UV project has been dropped. Now I will be completing the enrichment project for the rest of this academic year.
"Vitamin D3 in Captive Green Sea Turtles (Chelonia Mydas)." Abstract
Purgley, Hugh, Jack Jewell, James E. Deacon, Robert M. Winokur, and Vicki M. Tripoli. "Vitamin D3 in Captive Green Sea Turtles (Chelonia Mydas)." Chelonian Conservation and Biology 8.2 (2009): 161-67.<http://www.seaturtle.org/PDF/PurgleyH_2009_ChelonConservBiol.pdf>. Web. 19 Sept. 2012.
This is a reliable source since all of the authors are associated with a University, Aquarium (Purgley), or the National Center for Conservation Science and Policy (Tripoli). The authors begin by immediately informing the audience that “[m]ammals synthesize vitamin D3 in their epidermis, depending on ultraviolet B (UVB) from sunlight to accomplish critical portions of the synthesis” (161). On the next page the authors introduce the audience to sea turtle basking habits; “Sea turtles (family Cheloniidae) are known to bask out of water only occasionally” (162). During the AZA accreditation of the Shark Reef Aquarium (Mandalay Bay in Las Vegas, Nevada) the “reviewers expressed concern about the low light intensity and lack of basking opportunities for green turtles on display. [T]he Shark Reef Aquarium is an indoor facility where none of the animals on display have access to direct sunlight. AZA reviewers questioned whether such conditions might lead to abnormal or unhealthy conditions, particularly with respect to normal blood levels of vitamin D3 (25-OH-D) and Ca” (162). Due to this, the authors “decided to examine concentrations and variations of vitamin D3 and other blood parameters in the green turtles held at Shark Reef” as well as seeking to “obtain information regarding vitamin D3 levels in the blood of captive green turtles held at other facilities. This study therefore seeks to determine whether differences exist in concentration of vitamin D3 in the blood of green turtles held indoors compared to those maintained outdoors” (162).
The methods section begins by listing the exhibit dimensions as well as the UV lamp perimeters; “3 160-W UVB heat lamps (T-Rex Active UVHeat) placed 36 inches above the water surface. UVB intensity measured with a Solartech Digital Ultraviolet Radiometer (model 6.2-UVB) at the water surface directly under new lightbulbs was 100 mW/cm 2 ± 50 mW/cm 2. The heat lamps were replaced every 6 months” (162). For the rest of the day, the turtles weren’t exposed to UVB lighting (the light intensity from programmed metal halide lighting were measured); these programmed metal halide lighting structures were used to simulate light intensity differences over the course of a day. The authors then inform the audience that the green turtles were mainly fed vegetables, such as green pepper, a variety of seafood (such as squid and prawns) as well as weekly vitamin supplements. Later the amount of food decreased (in other words, they lowered the percentage of food given based on their body weight) due to fat appearing around the neck and flippers of the turtles. The authors then describe how the blood samples were drawn (i.e noting the angle of the syringe and the specific place between the head and the carapace). The blood samples were then allowed to clot in room temperature between thirty and sixty minutes followed being refrigerated for analysis. The authors then discuss when the blood samples were taken from specific individuals.
Personally I believed that the tables and the results sections were difficult to understand. Another minor issue with this journal article is that they collect data over several years while we only have approximately six months to collect and analyze data as well as our main case studies being loggerheads rather than greens.
This is a reliable source since all of the authors are associated with a University, Aquarium (Purgley), or the National Center for Conservation Science and Policy (Tripoli). The authors begin by immediately informing the audience that “[m]ammals synthesize vitamin D3 in their epidermis, depending on ultraviolet B (UVB) from sunlight to accomplish critical portions of the synthesis” (161). On the next page the authors introduce the audience to sea turtle basking habits; “Sea turtles (family Cheloniidae) are known to bask out of water only occasionally” (162). During the AZA accreditation of the Shark Reef Aquarium (Mandalay Bay in Las Vegas, Nevada) the “reviewers expressed concern about the low light intensity and lack of basking opportunities for green turtles on display. [T]he Shark Reef Aquarium is an indoor facility where none of the animals on display have access to direct sunlight. AZA reviewers questioned whether such conditions might lead to abnormal or unhealthy conditions, particularly with respect to normal blood levels of vitamin D3 (25-OH-D) and Ca” (162). Due to this, the authors “decided to examine concentrations and variations of vitamin D3 and other blood parameters in the green turtles held at Shark Reef” as well as seeking to “obtain information regarding vitamin D3 levels in the blood of captive green turtles held at other facilities. This study therefore seeks to determine whether differences exist in concentration of vitamin D3 in the blood of green turtles held indoors compared to those maintained outdoors” (162).
The methods section begins by listing the exhibit dimensions as well as the UV lamp perimeters; “3 160-W UVB heat lamps (T-Rex Active UVHeat) placed 36 inches above the water surface. UVB intensity measured with a Solartech Digital Ultraviolet Radiometer (model 6.2-UVB) at the water surface directly under new lightbulbs was 100 mW/cm 2 ± 50 mW/cm 2. The heat lamps were replaced every 6 months” (162). For the rest of the day, the turtles weren’t exposed to UVB lighting (the light intensity from programmed metal halide lighting were measured); these programmed metal halide lighting structures were used to simulate light intensity differences over the course of a day. The authors then inform the audience that the green turtles were mainly fed vegetables, such as green pepper, a variety of seafood (such as squid and prawns) as well as weekly vitamin supplements. Later the amount of food decreased (in other words, they lowered the percentage of food given based on their body weight) due to fat appearing around the neck and flippers of the turtles. The authors then describe how the blood samples were drawn (i.e noting the angle of the syringe and the specific place between the head and the carapace). The blood samples were then allowed to clot in room temperature between thirty and sixty minutes followed being refrigerated for analysis. The authors then discuss when the blood samples were taken from specific individuals.
Personally I believed that the tables and the results sections were difficult to understand. Another minor issue with this journal article is that they collect data over several years while we only have approximately six months to collect and analyze data as well as our main case studies being loggerheads rather than greens.
“The importance of physiological ecology in conservation biology” Abstract
Tracy, C. Richard; Nussear, K. E.; Esque, T. C.. “The importance of physiological ecology in conservation biology.” Integrative and Comparative Biology 46.6 (2006):1191-205 EBSCOhost. Web. 3 Sept. 2012. <http://web.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=4e0be940-bb96-4060-af62-36fed8b30ab4%40 sessionmgr110&vid=9&hid=7>
This is a credible source since all of the authors are associated with a university. The authors’ hypothesis was “If desert tortoises were to forage for nutrients rather than for particular plants, then tortoises would be predicted to obtain nutrients in proportions different from that obtainable via random foraging” (1193). In order to test this hypothesis, the authors defined a random diet where “ food items [that] are eaten [are] in proportion to their availability in the field” (1193). They note that due to this diet, it is assumed “that animals learn to avoid plants that could be toxic...or plants deficient or excessive in certain nutrients” (1193). By citing others, the authors also note that it may be through experience that animals can obtain diet preferences for specific nutrients (1193), however there’s a lack of experimental evidence to support this claim. Despite the lack of evidence, “[a] study on green iguanas (Iguana iguana) found modest preference for foods high in protein (var Marken Lichtenbelt and others 1993)” (1194). The authors later mention the important role that calcium plays within reptiles; “[a]dditionally calcium is required for maintenance of osmotic balance in cells, blood coagulation, nerve transmission and muscular activity (Despopoulos and Silbernagl 1991)” (1194). Deficiency of nutrients can lead to metabolic bone disease.
This is a credible source since all of the authors are associated with a university. The authors’ hypothesis was “If desert tortoises were to forage for nutrients rather than for particular plants, then tortoises would be predicted to obtain nutrients in proportions different from that obtainable via random foraging” (1193). In order to test this hypothesis, the authors defined a random diet where “ food items [that] are eaten [are] in proportion to their availability in the field” (1193). They note that due to this diet, it is assumed “that animals learn to avoid plants that could be toxic...or plants deficient or excessive in certain nutrients” (1193). By citing others, the authors also note that it may be through experience that animals can obtain diet preferences for specific nutrients (1193), however there’s a lack of experimental evidence to support this claim. Despite the lack of evidence, “[a] study on green iguanas (Iguana iguana) found modest preference for foods high in protein (var Marken Lichtenbelt and others 1993)” (1194). The authors later mention the important role that calcium plays within reptiles; “[a]dditionally calcium is required for maintenance of osmotic balance in cells, blood coagulation, nerve transmission and muscular activity (Despopoulos and Silbernagl 1991)” (1194). Deficiency of nutrients can lead to metabolic bone disease.
"Nutrition Research on Calcium Homeostasis. II. Freshwater Turtles
(with Recommendations)" Abstract
Williams, D. A. "Nutrition Research on Calcium Homeostasis. II. Freshwater Turtles (with Recommendations)." International Zoo Yearbook 39.1 (2005): 77-85. Web. 22 Aug. 2012. <http://www.caza-narg.ca/ref/ref200806-3.pdf>.
This journal article is a reliable source since it is written by the Secretary/Treasurer of the Nutrition Advisory and Research Group that is associated with the Canadian Association of Zoos and Aquariums. To begin Williams stresses the importance of calcium and vitamin D within carapace development by citing other sources. If a hatchling is deprived of these nutrients during its first year it can lead to metabolic bone disease (MBD) and deformation of the beak. Signs of MBD, shown in adult freshwater turtles, include “progressive mineral loss of the shell, shell and endoskeleton fractures, pyramidal shell growth, egg retention and concurrent hypovitaminosis A (Barten, 1996)” (77). Williams then discusses the factors that affect calcium and vitamin D metabolism: environmental temperature and humidity as well as photoreception and UV light. With the correct environment, turtles’ metabolic and digestion rates increase. Williams then notes that turtles “physiological[ly] need to bask in order to thermoregulate and synthesize vitamin D which, in turn, promote and maintain Ca homeostasis” (78). In addition to this “the isomerization of previtamin D to vitamin D3” (78), also known as vitamin D synthesis, is dependent on UV radiation exposure and temperature. With the wrong environment digestive efficiency can affect aquatic turtles, which in turn “ can inhibit or promote metabolic use of dietary factors essential for Ca homeostasis” (78). Williams then explains the differences between UVA and UVB radiation by noting their benefits and disadvantages; “UVA can cause cellular death, cellular mutation and DNA damage but, in reptiles, UVA also stimulates feeding, sexual and territorial behaviours (Coohill, 1995; Boyer, 1996). UVB light is necessary for vitamin D biosynthesis and photoreception in reptiles (Bernard & Ullrey, 1995; Bidmon & Stumpf, 1995; Gascon et al., 1995; Holick et al., 1995; Kohen et al., 1995; Dickinson & Fa, 1997)” (79). Since nothing else is really known about how UVA and UVB (and vitamin D biosynthesis) effects reptiles physiologically Williams suggest further research. Later calcium metabolism is discussed.
While in captivity aquatic turtles receive the required amount of calcium through dietary supplements. Calcium deficiency can lead to “Hypercalcaemia... caused by hypervitaminosis D can impede growth and cause soft-tissue mineralization and shell pyramiding” (80)- ultimately “bone thinning” (81) in addition to “reduced neurological functioning and heart failure (Barten, 1996)” (81). Williams then discusses the importance of vitamin D3; “Vitamin D3 is essential for the functioning of the immune system and the stimulation of the active-transport process of Ca from the small intestine into the plasma (Lemire, 1992; Bernard & Ullrey, 1995; Dierenfeld & Barker, 1995; Boyer, 1996)” (82). The most efficient way to receive vitamin D3 is through suitable air temperature and exposure to UV radiation. Without enough vitamin D3 (due to UV supplemental sources giving the correct wavelengths or intensity), also known as hypovitaminosis, deficiency can lead to hypercalcaemia as well as “fatigue, weakness, anorexia and abdominal pain with osteoporosis and calcification of...tendon sheaths and periarticular structures (Barten, 1996; Boyer, 1996; Williams, 1996)” (82). Williams then mentions that there is not enough information provided within this journal article to have husbandry protocols based off of it, in addition to not enough overall research-based data about appropriate environments and diets regarding vitamin D3 and calcium. Another issue is that this article only focuses on red earred slider turtles and snapping turtles (between the hatchling stage and one year) while there are hundreds of other aquatic turtle species in zoological institutions across the globe. Williams also notes that research into calcium homeostasis on aquatic turtles can differ in length due to the species growth rate, leading to the possible issue of funding a long-term project for a species that might take more than a year to demonstrate results.
Overall this journal article was somewhat difficult to understand since it used zoological terminology in multiple places. Despite this, I now have gained a better understanding of calcium homeostasis, biosynthesis of vitamin D3, and how an aquatic turtle could be affect by calcium and/or vitamin D3 deficiency.
This journal article is a reliable source since it is written by the Secretary/Treasurer of the Nutrition Advisory and Research Group that is associated with the Canadian Association of Zoos and Aquariums. To begin Williams stresses the importance of calcium and vitamin D within carapace development by citing other sources. If a hatchling is deprived of these nutrients during its first year it can lead to metabolic bone disease (MBD) and deformation of the beak. Signs of MBD, shown in adult freshwater turtles, include “progressive mineral loss of the shell, shell and endoskeleton fractures, pyramidal shell growth, egg retention and concurrent hypovitaminosis A (Barten, 1996)” (77). Williams then discusses the factors that affect calcium and vitamin D metabolism: environmental temperature and humidity as well as photoreception and UV light. With the correct environment, turtles’ metabolic and digestion rates increase. Williams then notes that turtles “physiological[ly] need to bask in order to thermoregulate and synthesize vitamin D which, in turn, promote and maintain Ca homeostasis” (78). In addition to this “the isomerization of previtamin D to vitamin D3” (78), also known as vitamin D synthesis, is dependent on UV radiation exposure and temperature. With the wrong environment digestive efficiency can affect aquatic turtles, which in turn “ can inhibit or promote metabolic use of dietary factors essential for Ca homeostasis” (78). Williams then explains the differences between UVA and UVB radiation by noting their benefits and disadvantages; “UVA can cause cellular death, cellular mutation and DNA damage but, in reptiles, UVA also stimulates feeding, sexual and territorial behaviours (Coohill, 1995; Boyer, 1996). UVB light is necessary for vitamin D biosynthesis and photoreception in reptiles (Bernard & Ullrey, 1995; Bidmon & Stumpf, 1995; Gascon et al., 1995; Holick et al., 1995; Kohen et al., 1995; Dickinson & Fa, 1997)” (79). Since nothing else is really known about how UVA and UVB (and vitamin D biosynthesis) effects reptiles physiologically Williams suggest further research. Later calcium metabolism is discussed.
While in captivity aquatic turtles receive the required amount of calcium through dietary supplements. Calcium deficiency can lead to “Hypercalcaemia... caused by hypervitaminosis D can impede growth and cause soft-tissue mineralization and shell pyramiding” (80)- ultimately “bone thinning” (81) in addition to “reduced neurological functioning and heart failure (Barten, 1996)” (81). Williams then discusses the importance of vitamin D3; “Vitamin D3 is essential for the functioning of the immune system and the stimulation of the active-transport process of Ca from the small intestine into the plasma (Lemire, 1992; Bernard & Ullrey, 1995; Dierenfeld & Barker, 1995; Boyer, 1996)” (82). The most efficient way to receive vitamin D3 is through suitable air temperature and exposure to UV radiation. Without enough vitamin D3 (due to UV supplemental sources giving the correct wavelengths or intensity), also known as hypovitaminosis, deficiency can lead to hypercalcaemia as well as “fatigue, weakness, anorexia and abdominal pain with osteoporosis and calcification of...tendon sheaths and periarticular structures (Barten, 1996; Boyer, 1996; Williams, 1996)” (82). Williams then mentions that there is not enough information provided within this journal article to have husbandry protocols based off of it, in addition to not enough overall research-based data about appropriate environments and diets regarding vitamin D3 and calcium. Another issue is that this article only focuses on red earred slider turtles and snapping turtles (between the hatchling stage and one year) while there are hundreds of other aquatic turtle species in zoological institutions across the globe. Williams also notes that research into calcium homeostasis on aquatic turtles can differ in length due to the species growth rate, leading to the possible issue of funding a long-term project for a species that might take more than a year to demonstrate results.
Overall this journal article was somewhat difficult to understand since it used zoological terminology in multiple places. Despite this, I now have gained a better understanding of calcium homeostasis, biosynthesis of vitamin D3, and how an aquatic turtle could be affect by calcium and/or vitamin D3 deficiency.
"Effects of UV Radiation on 25-hydrovitamin D3 Synthesis in Red-earred Slider Turtles (Trachemys Scripta Elegans)." Abstract
Acierno, Mark J., Mark A. Mitchell, Marlana K. Roundtree, and Trevor K. Zachariah. "Effects of UV Radiation on 25-hydrovitamin D3 Synthesis in Red-earred Slider Turtles (Trachemys Scripta Elegans)." AJVR 67.12 (2006): 2046-9. Web. 21 Aug. 2012. <http://vetmed.illinois.edu/mmitch/pdf/red%20eared%20slider.pdf>.
This journal article is a reliable source since it was published by the Department of Veterinary Clinical Sciences, School of Veterinary Medicine, of Louisiana State University while all of the authors are veterinarians. The article begins by demonstrating the importance of vitamin D3 such as a “hormone [in] the regulation of calcium metabolism, which is needed for the development and maintenance of healthy bones” (2046). Vitamin D3 can be received through the skin during UVB basking or through dietary supplements. The authors then stress the importance of UVB basking for tortoises and turtles while in captivity. The reason for their study is to “determine whether red-eared slider turtles (Trachemys scripta elegans) exposed to UV-B radiation under controlled conditions would have increased concentrations of 25-hydroxyvitamin D3 concentrations, compared with concentrations for control turtles” (2046). The authors determined this through testing three factors: seeing if UVB radiation would increase “the concentration of 25-hydroxyvitamin D3 compared with concentrations for control turtles” (2046), versus the concentration of 25-hydroxyvitamin D3 increasing due to dietary supplements over time, or whether the amount of UVB radiation from commercial sources would decrease over time (leading to a lower concentration of the 25-hydroxyvitamin D3).
The authors then begin discussing their methods by introducing the twelve-year old red-earred turtles that were used in the study as well as various controls such as the turtles’ container dimensions and water temperature. After being transferred from an outside environment, the turtles were given a week in order to adjust to the laboratory setting after which blood samples were drawn. Immediately the “blood samples were stored in lithium heparin microtainers [and then] centrifuged within 60 minutes after collection. [The p]lasma was [later] harvested and frozen. Plasma samples were submitted on frozen gel packs to a university laboratory for measurement of 25-hydroxyvitamin D3 concentrations.” (2047). The turtles were split into two groups- one with supplemental UVB radiation (for twelve continuous hours each day) and one without supplemental radiation (however did use a basking stone). In order to collect data from the supplemental sources the radiation was measured with a radiometer-photometer, taken 2.54 and 22.86cm from the bulb’s surface while the radiation measurements were taken from the basking stones’ surface. “Amounts of UV-A and UV-B [radiation] were measured on a weekly basis at the same time of day during each successive week, with the exception of the first measurement, which was recorded immediately after the lights were turned on” (2047). In addition to this the turtles were weighed weekly after the bulbs were on for four hours. After thirty days blood samples of the twelve turtles were taken again and prepared the same way that the previous samples were stored. The data was analyzed by through the relationship between concentration of 25-hydroxyvitamin D3 and body weight of each group. After the study it is evident that the mean concentrations of 25-hydroxyvitamin D3 changed significantly (as well as an increase in body weight) throughout the thirty day period for both groups. They also saw significant differences between the amount of UVB radiation at the bulbs’ surface and the basking stones’ surface during the study (in addition to significance of UVA radiation from the bulbs’ surface despite not having a significant difference with UVA radiation from the basking stones’ surface).
The concentrations of 25-hydroxyvitamin D3 increased significantly in both groups over the course of the study; however since one group weren’t receiving UVB radiation directly from a bulb, it is thought that the increase was purely based on dietary supplements. Due to this, the group that was exposed to the supplemental UVB radiation during the study demonstrated a pronounced increase of 25-hydroxyvitamin D3 concentration. The reason why the authors examined body weight within this study is due to vitamin D3 being important during the bone development process. However, since “these turtles were all from the same colony and had been housed outdoors, it seems unlikely that measurable differences in body weight from bone demineralization or changes in general health would be detectable in such a short study (ie, 4 weeks). Even had the study period been longer, we would have needed to conduct a more sensitive measure of bone density to detect weight attributable to demineralization of bone” (2048). The authors note that supplemental UVB bulbs were used in the study rather than full-spectrum fluorescent tubes since the bulbs provide “greater quantities of UV-B radiation at the bulb surface and distances of 15 and 30 cm” (2048) as well as the UVB radiation from full-spectrum fluorescent tubes decrease over time. Due to this study the authors suggest further investigation of the longevity of UVA and UVB radiation bulbs as well as how they affect human caregivers (since red-earred slider turtles are a common house pet in Louisiana). They also suggest that husbandry protocols of aquatic turtles should include basking from the sun “ that is unobstructed by UV-B filtering material or an artificial source of UV-B radiation (290 to 320 nm) that is located no more than 23 cm from the basking area” (2049).
After reading this journal article I want to primarily base our study of UVA/B radiation of loggerhead sea turtles (Caretta caretta) on this study since their methods to analyze the concentration of 25-hydroxyvitamin D3 though blood samples as well as assessing UVA/B supplemental sources seemed adequate. However I did have some trouble interpreting the tables that were provided for the data and results despite the overall wording of the article easy to understand.
This journal article is a reliable source since it was published by the Department of Veterinary Clinical Sciences, School of Veterinary Medicine, of Louisiana State University while all of the authors are veterinarians. The article begins by demonstrating the importance of vitamin D3 such as a “hormone [in] the regulation of calcium metabolism, which is needed for the development and maintenance of healthy bones” (2046). Vitamin D3 can be received through the skin during UVB basking or through dietary supplements. The authors then stress the importance of UVB basking for tortoises and turtles while in captivity. The reason for their study is to “determine whether red-eared slider turtles (Trachemys scripta elegans) exposed to UV-B radiation under controlled conditions would have increased concentrations of 25-hydroxyvitamin D3 concentrations, compared with concentrations for control turtles” (2046). The authors determined this through testing three factors: seeing if UVB radiation would increase “the concentration of 25-hydroxyvitamin D3 compared with concentrations for control turtles” (2046), versus the concentration of 25-hydroxyvitamin D3 increasing due to dietary supplements over time, or whether the amount of UVB radiation from commercial sources would decrease over time (leading to a lower concentration of the 25-hydroxyvitamin D3).
The authors then begin discussing their methods by introducing the twelve-year old red-earred turtles that were used in the study as well as various controls such as the turtles’ container dimensions and water temperature. After being transferred from an outside environment, the turtles were given a week in order to adjust to the laboratory setting after which blood samples were drawn. Immediately the “blood samples were stored in lithium heparin microtainers [and then] centrifuged within 60 minutes after collection. [The p]lasma was [later] harvested and frozen. Plasma samples were submitted on frozen gel packs to a university laboratory for measurement of 25-hydroxyvitamin D3 concentrations.” (2047). The turtles were split into two groups- one with supplemental UVB radiation (for twelve continuous hours each day) and one without supplemental radiation (however did use a basking stone). In order to collect data from the supplemental sources the radiation was measured with a radiometer-photometer, taken 2.54 and 22.86cm from the bulb’s surface while the radiation measurements were taken from the basking stones’ surface. “Amounts of UV-A and UV-B [radiation] were measured on a weekly basis at the same time of day during each successive week, with the exception of the first measurement, which was recorded immediately after the lights were turned on” (2047). In addition to this the turtles were weighed weekly after the bulbs were on for four hours. After thirty days blood samples of the twelve turtles were taken again and prepared the same way that the previous samples were stored. The data was analyzed by through the relationship between concentration of 25-hydroxyvitamin D3 and body weight of each group. After the study it is evident that the mean concentrations of 25-hydroxyvitamin D3 changed significantly (as well as an increase in body weight) throughout the thirty day period for both groups. They also saw significant differences between the amount of UVB radiation at the bulbs’ surface and the basking stones’ surface during the study (in addition to significance of UVA radiation from the bulbs’ surface despite not having a significant difference with UVA radiation from the basking stones’ surface).
The concentrations of 25-hydroxyvitamin D3 increased significantly in both groups over the course of the study; however since one group weren’t receiving UVB radiation directly from a bulb, it is thought that the increase was purely based on dietary supplements. Due to this, the group that was exposed to the supplemental UVB radiation during the study demonstrated a pronounced increase of 25-hydroxyvitamin D3 concentration. The reason why the authors examined body weight within this study is due to vitamin D3 being important during the bone development process. However, since “these turtles were all from the same colony and had been housed outdoors, it seems unlikely that measurable differences in body weight from bone demineralization or changes in general health would be detectable in such a short study (ie, 4 weeks). Even had the study period been longer, we would have needed to conduct a more sensitive measure of bone density to detect weight attributable to demineralization of bone” (2048). The authors note that supplemental UVB bulbs were used in the study rather than full-spectrum fluorescent tubes since the bulbs provide “greater quantities of UV-B radiation at the bulb surface and distances of 15 and 30 cm” (2048) as well as the UVB radiation from full-spectrum fluorescent tubes decrease over time. Due to this study the authors suggest further investigation of the longevity of UVA and UVB radiation bulbs as well as how they affect human caregivers (since red-earred slider turtles are a common house pet in Louisiana). They also suggest that husbandry protocols of aquatic turtles should include basking from the sun “ that is unobstructed by UV-B filtering material or an artificial source of UV-B radiation (290 to 320 nm) that is located no more than 23 cm from the basking area” (2049).
After reading this journal article I want to primarily base our study of UVA/B radiation of loggerhead sea turtles (Caretta caretta) on this study since their methods to analyze the concentration of 25-hydroxyvitamin D3 though blood samples as well as assessing UVA/B supplemental sources seemed adequate. However I did have some trouble interpreting the tables that were provided for the data and results despite the overall wording of the article easy to understand.
"The Biology of Basking in the green turtle (Chelonia mydas)" Abstract
Swimmer, J. Yonat, and George H. Balazs. "The Biology of Basking in the green turtle (Chelonia mydas)" PROCEEDINGS OF THE EIGHTEENTH INTERNATIONAL SEA TURTLE SYMPOSIUM (1998): 256-7. Web. 17 July 2012. <http://www.scribd.com/doc/87926319/Turtle-Symposium-1998>.
Swimmer is associated with the School of Natural Resources and environment within the University of Michigan while Balazs is with the National Marine Fisheries Service,Southwest Fisheries Science Center, Honolulu Laboratory. The article dives right in by discussing how the green sea turtle is the primary species known for atmospheric basking. Their purpose for their study was to “determine the physiological roles that this behavior serves.” (256) Based on data collection from wild and captive populations basking is connected with the air and substrate temperature, making it evident that basking plays a significant role within the thermoregulation of green sea turtles. In the end Swimmer and Balazs realized that basking “serves as an energy-conserving mechanism” (257) as well as playing a role within reproduction. Based on the important physiological roles that basking serves it is evident this behavior is extremely important to the biology of green sea turtles as well as the importance to conserve basking areas of green sea turtles (such as Hawaii).
Overall this article was more like an abstract while not displaying data collection tables, graphs, etc or their calculations of how Swimmer and Balazs concluded and analyzed their results of their study. The article was extremely easy to understand; this article confirms the significant role that basking plays within green sea turtle thermoregulation and their lives.
Swimmer is associated with the School of Natural Resources and environment within the University of Michigan while Balazs is with the National Marine Fisheries Service,Southwest Fisheries Science Center, Honolulu Laboratory. The article dives right in by discussing how the green sea turtle is the primary species known for atmospheric basking. Their purpose for their study was to “determine the physiological roles that this behavior serves.” (256) Based on data collection from wild and captive populations basking is connected with the air and substrate temperature, making it evident that basking plays a significant role within the thermoregulation of green sea turtles. In the end Swimmer and Balazs realized that basking “serves as an energy-conserving mechanism” (257) as well as playing a role within reproduction. Based on the important physiological roles that basking serves it is evident this behavior is extremely important to the biology of green sea turtles as well as the importance to conserve basking areas of green sea turtles (such as Hawaii).
Overall this article was more like an abstract while not displaying data collection tables, graphs, etc or their calculations of how Swimmer and Balazs concluded and analyzed their results of their study. The article was extremely easy to understand; this article confirms the significant role that basking plays within green sea turtle thermoregulation and their lives.
"Diving, Basking, and Foraging Patterns of a Sub-Adult Green Turtle at Punalu'u, Hawaii” Abstract
"Diving, Basking, and Foraging Patterns of a Sub-Adult Green Turtle at Punalu'u, Hawaii”."PROCEEDINGS OF THE EIGHTEENTH INTERNATIONAL SEA TURTLE SYMPOSIUM(1998): 256-7. Web. 17 July 2012. <http://www.scribd.com/doc/87926319/Turtle-Symposium-1998>.
The authors of this article are either associated with the Hawaii Preparatory Academy, National Marine Fisheries Service, Southwest Fisheries Science Center, Honolulu Laboratory, or the Marine Option Program through the University of Hawaii at Hilo. The article begins with a description of Punalu’u, Hawaii and how green sea turtles vegetate on the red algae throughout the area. Then foraging behaviors are described through several literary references. The authors then inform the audience about the difficulty of observing basking behavior of green sea turtles, due to the majority of their basking takes place at night. Rice and the others performed a series of experiments in order to determine the distinct times of each of “the three major behaviors(diving, basking and foraging) over an extended period of time.” (252)
The data was collected between the fall of 1996 through the summer of 1997 from a sub-adult green sea turtle that was captured (in shallow waters) within Punalu’u through a TDR (time-depth recorder) and a sonic tag. In the end Rice and his team discovered that the turtle only basked for approximately 3.2% of the total observed time for an average length of 130 minutes. 25% of the total basking time occurred during night. Due to these findings, it is evident that this green sea turtle spent a significant amount of time basking. Within the end of the article Rice and his team suggest that more studies are done in the future with the TDR across Hawaii in order to clarify and discover more about green sea turtle behavior.
The main thing that I didn’t like about this article was that only one case study was tested and analyzed. Despite this major flaw the article was somewhat easy to understand as a whole as well as the table. Through this article I have learned that green sea turtles bask during the day as well as the night and will figure out, sometime in the near future, how that will play a part within the data collection section of this project.
The authors of this article are either associated with the Hawaii Preparatory Academy, National Marine Fisheries Service, Southwest Fisheries Science Center, Honolulu Laboratory, or the Marine Option Program through the University of Hawaii at Hilo. The article begins with a description of Punalu’u, Hawaii and how green sea turtles vegetate on the red algae throughout the area. Then foraging behaviors are described through several literary references. The authors then inform the audience about the difficulty of observing basking behavior of green sea turtles, due to the majority of their basking takes place at night. Rice and the others performed a series of experiments in order to determine the distinct times of each of “the three major behaviors(diving, basking and foraging) over an extended period of time.” (252)
The data was collected between the fall of 1996 through the summer of 1997 from a sub-adult green sea turtle that was captured (in shallow waters) within Punalu’u through a TDR (time-depth recorder) and a sonic tag. In the end Rice and his team discovered that the turtle only basked for approximately 3.2% of the total observed time for an average length of 130 minutes. 25% of the total basking time occurred during night. Due to these findings, it is evident that this green sea turtle spent a significant amount of time basking. Within the end of the article Rice and his team suggest that more studies are done in the future with the TDR across Hawaii in order to clarify and discover more about green sea turtle behavior.
The main thing that I didn’t like about this article was that only one case study was tested and analyzed. Despite this major flaw the article was somewhat easy to understand as a whole as well as the table. Through this article I have learned that green sea turtles bask during the day as well as the night and will figure out, sometime in the near future, how that will play a part within the data collection section of this project.
"Ultraviolet Light and Reptiles, Amphibians" Abstract
Adkins, Elizabeth, Todd Driggers, Gary Ferguson, William Gehrmann, Zoltan Gyimesi, Elizabeth May, Michael Ogle, Tommy Owens, and Eric Klaphake. "Ultraviolet Light and Reptiles, Amphibians." .Journal of Herpetological Medicine and Surgery 12.4 (2003): 27-37. Web. 26 June 2012. <http://www.reptileuvinfo.com/docs/ultraviolet-light-and-reptiles-amphibians.pdf>.
All of the authors of this article are credible due to either being a veterinarian, University biology professor, or work for the department of herpetology in a zoological facility. Within this journal article all of the ‘authors’ are asked a series of questions about ultraviolet light and how it affects reptiles and amphibians. The first question is a definition of ultraviolet light. Gyimesi provides the simplest one “Ultraviolet light is radiation just beyond the violet end of the visible spectrum. UV radiation is the spectrum extending from 100 - 400 nm, which made up of shorter wavelengths than visible light (400 - 700 nm) and infrared radiation (700 - 3,200 nm)” (2). Question three asks “Why is ultraviolet light important for reptiles?”. Gehrmann and Ferguson provide the best answer by describing the benefits of (primarily) UVB, and UVA light. UVB is beneficial towards reptiles and amphibians however they can cause “tissue damage, potentially causing death, and vitamins A and D degradation (Kiesecker and Blaustein, 1995, Blaustein, et al, 1996, Tang, et al, 1994, Webb, et al, 1989, Remenyek et al, 1999)” (3). Some benefits include playing a significant role “ in the photobiosynthesis of vitamin D3 (Holick, et al, 1995, Ferguson, et al, 2003), which ironically it can also degrade (Webb, et al, 1989), and possibly the disinfecting of pathogenic external parasites from a reptile's skin (Pritchard and Greenhood, 1968)...UVB [can also be] useful for vitamin D photoregulation (Ferguson, et al, 2003)” (3). They also list that “UVA has been documented to be beneficial for social communication but may be detrimental regarding predator detection. UVA can cause degradation of vitamin A in the skin (Tang, et al, 1994), which could lead to vitamin A deficiency” (3). In short, both UVA and UVB light are good for reptiles and amphibians but can be harmful if their amount is too high. The authors then list various radiometers and how they measure UV light as well as discussing various UV products for reptiles and amphibians. The questionnaire then continues to ask how UV light affects specific reptiles and amphibians, signs of UV deficiency, how it’s treated and how to prevent it in the future as well as signs, treatment, and how to prevent overexposure to UV light.
The main issue that I had with this article is that it didn’t really focus on turtles, let alone ones that are being rehabilitated and/or captive in zoos (rather than in homes). Despite this frustration I did learn about the benefits and disadvantages of reptiles basking in UVA and UVB light which will help me greatly while I continue to research basking rehabilitation in sea turtles.
All of the authors of this article are credible due to either being a veterinarian, University biology professor, or work for the department of herpetology in a zoological facility. Within this journal article all of the ‘authors’ are asked a series of questions about ultraviolet light and how it affects reptiles and amphibians. The first question is a definition of ultraviolet light. Gyimesi provides the simplest one “Ultraviolet light is radiation just beyond the violet end of the visible spectrum. UV radiation is the spectrum extending from 100 - 400 nm, which made up of shorter wavelengths than visible light (400 - 700 nm) and infrared radiation (700 - 3,200 nm)” (2). Question three asks “Why is ultraviolet light important for reptiles?”. Gehrmann and Ferguson provide the best answer by describing the benefits of (primarily) UVB, and UVA light. UVB is beneficial towards reptiles and amphibians however they can cause “tissue damage, potentially causing death, and vitamins A and D degradation (Kiesecker and Blaustein, 1995, Blaustein, et al, 1996, Tang, et al, 1994, Webb, et al, 1989, Remenyek et al, 1999)” (3). Some benefits include playing a significant role “ in the photobiosynthesis of vitamin D3 (Holick, et al, 1995, Ferguson, et al, 2003), which ironically it can also degrade (Webb, et al, 1989), and possibly the disinfecting of pathogenic external parasites from a reptile's skin (Pritchard and Greenhood, 1968)...UVB [can also be] useful for vitamin D photoregulation (Ferguson, et al, 2003)” (3). They also list that “UVA has been documented to be beneficial for social communication but may be detrimental regarding predator detection. UVA can cause degradation of vitamin A in the skin (Tang, et al, 1994), which could lead to vitamin A deficiency” (3). In short, both UVA and UVB light are good for reptiles and amphibians but can be harmful if their amount is too high. The authors then list various radiometers and how they measure UV light as well as discussing various UV products for reptiles and amphibians. The questionnaire then continues to ask how UV light affects specific reptiles and amphibians, signs of UV deficiency, how it’s treated and how to prevent it in the future as well as signs, treatment, and how to prevent overexposure to UV light.
The main issue that I had with this article is that it didn’t really focus on turtles, let alone ones that are being rehabilitated and/or captive in zoos (rather than in homes). Despite this frustration I did learn about the benefits and disadvantages of reptiles basking in UVA and UVB light which will help me greatly while I continue to research basking rehabilitation in sea turtles.
Sea Turtles: An Ecological Guide Abstract
Gulko, D., and Dr. Karen L. Eckert. Sea Turtles: An Ecological Guide. Honolulu, HI: Mutual 6.19Pub., 2004. 56-57. Print.
Dave Gulko is a coral reef ecologist for Hawaii's Department of Land and Natural Resources who has written numerous scientific articles about tropical marine ecosystems and natural resource management as well as a popular book, Hawaiian Coral Reef Ecology. Dr. Karen L. Eckert has been an activist in the fields of sea turtle research and international conservation policy for over two decades and is currently the Executive Director of the Wider Caribbean Sea Turtle Conservation Network (WIDECAST). Based on their backgrounds in marine ecosystems and sea turtle conservation, these are a credible authors.
They begin the basking behavior section of their guide by defining it; “Basking behavior, where turtles lie motionless, and [and where they] soak-up the heat of the sun...basking behavior allows the animal to absorb large amounts of solar radiation....increased body temperature from solar radiation may limit the time the animal can spend basking” (56). Then the page discusses what has been observed with green and other sea turtles within the Northwestern Hawaiian Islands (NWHI). Males and female green sea turtles have been observed basking day and night on beaches. Basking during the day is thought to play a “significant role within thermoregulation; solar raising of internal body temperature would increase rates of metabolism, which in turn could lead to faster digestion and possibly increasing the rate of egg maturation in the female” (56). They then discuss basking behaviors during night; “...captive studies in Hawai’i have shown that metabolic rates drop during basking behavior, suggesting that perhaps this nocturnal behavior in parts of Hawai’i may function to both decrease predation pressure from tiger sharks and to conserve energy” (56). Sea turtles also bask while in the water (‘“surface basking’” (56)) in order to conserve energy, avoiding predators, and raising body temperature. On the next page heat exchange and other functions of basking are discussed through a diagram that demonstrates the different ways in which a sea turtle can gain (and lose) heat while basking on a beach as well as a description of other ways sea turtles can intake heat while basking on a beach. Examples include increased heat within the turtle’s lungs which are located underneath the carapace (also known as shell), fatty tissues can insulate the turtle’s body and be used for “increased mobilization” (57), as well as subadult sea turtles in the NWHI being observed to use their front flippers to flip sand onto their carapaces as a sign of heat stress. The authors then conclude the basking section of their guide by listing the main benefits sea turtles gain while basking on beaches;
“The very act of basking would serve to eliminate natural predation risk on the animal from sharks for the period that the turtle is out of the water. Basking also prevents males from mating with unreceptive females, and may dry out and kill epiphytic algae growing atop the carapace. Other possible functions of basking include the increasing the rate of digestion or serving as an alternative to more traditional underwater reef resting sites, such as caves, reef holes, and ledges” (57).
I found this section of the guide easy to understand and analyze for this abstract based on basic wording and an easy-to-understand diagram highlighting heat exchange of sea turtles. I now have a better understanding of basking behavior(s) and heat exchange of sea turtles. I believe that this section of the guide will aid me in the future as a reminder of heat exchange of sea turtles while continuing to research basking rehabilitation of sea turtles.
Dave Gulko is a coral reef ecologist for Hawaii's Department of Land and Natural Resources who has written numerous scientific articles about tropical marine ecosystems and natural resource management as well as a popular book, Hawaiian Coral Reef Ecology. Dr. Karen L. Eckert has been an activist in the fields of sea turtle research and international conservation policy for over two decades and is currently the Executive Director of the Wider Caribbean Sea Turtle Conservation Network (WIDECAST). Based on their backgrounds in marine ecosystems and sea turtle conservation, these are a credible authors.
They begin the basking behavior section of their guide by defining it; “Basking behavior, where turtles lie motionless, and [and where they] soak-up the heat of the sun...basking behavior allows the animal to absorb large amounts of solar radiation....increased body temperature from solar radiation may limit the time the animal can spend basking” (56). Then the page discusses what has been observed with green and other sea turtles within the Northwestern Hawaiian Islands (NWHI). Males and female green sea turtles have been observed basking day and night on beaches. Basking during the day is thought to play a “significant role within thermoregulation; solar raising of internal body temperature would increase rates of metabolism, which in turn could lead to faster digestion and possibly increasing the rate of egg maturation in the female” (56). They then discuss basking behaviors during night; “...captive studies in Hawai’i have shown that metabolic rates drop during basking behavior, suggesting that perhaps this nocturnal behavior in parts of Hawai’i may function to both decrease predation pressure from tiger sharks and to conserve energy” (56). Sea turtles also bask while in the water (‘“surface basking’” (56)) in order to conserve energy, avoiding predators, and raising body temperature. On the next page heat exchange and other functions of basking are discussed through a diagram that demonstrates the different ways in which a sea turtle can gain (and lose) heat while basking on a beach as well as a description of other ways sea turtles can intake heat while basking on a beach. Examples include increased heat within the turtle’s lungs which are located underneath the carapace (also known as shell), fatty tissues can insulate the turtle’s body and be used for “increased mobilization” (57), as well as subadult sea turtles in the NWHI being observed to use their front flippers to flip sand onto their carapaces as a sign of heat stress. The authors then conclude the basking section of their guide by listing the main benefits sea turtles gain while basking on beaches;
“The very act of basking would serve to eliminate natural predation risk on the animal from sharks for the period that the turtle is out of the water. Basking also prevents males from mating with unreceptive females, and may dry out and kill epiphytic algae growing atop the carapace. Other possible functions of basking include the increasing the rate of digestion or serving as an alternative to more traditional underwater reef resting sites, such as caves, reef holes, and ledges” (57).
I found this section of the guide easy to understand and analyze for this abstract based on basic wording and an easy-to-understand diagram highlighting heat exchange of sea turtles. I now have a better understanding of basking behavior(s) and heat exchange of sea turtles. I believe that this section of the guide will aid me in the future as a reminder of heat exchange of sea turtles while continuing to research basking rehabilitation of sea turtles.
