Circulating Fat-Soluble Vitamin Concentrations and Nutrient Composition of Aquatic Prey Eaten by American Oystercatchers (Haematopus palliatus palliatus) in the Southeastern United States.

The American oystercatcher (Haematopus palliatus palliatus) is currently listed as a species of high concern by the United States Shorebird Conservation Plan. Because nutritional status directly impacts overall health and reproduction of individuals and populations, adequate management of a wildlife population requires intimate knowledge of a species' diet and nutrient requirements. Fat-soluble vitamin concentrations in blood plasma obtained from American oystercatchers and proximate, vitamin, and mineral composition of various oystercatcher prey species were determined as baseline data to assess nutritional status and nutrient supply. Bird and prey species samples were collected from the Cape Romain region, South Carolina, USA, and the Altamaha River delta islands, Georgia, USA, where breeding populations appear relatively stable in recent years. Vitamin A levels in blood samples were higher than ranges reported as normal for domestic avian species, and vitamin D concentrations were lower than anticipated based on values observed in poultry. Vitamin E levels were within ranges previously reported for avian groups with broadly similar feeding niches such as herons, gulls, and terns (eg, aquatic/estuarine/marine). Prey species (oysters, mussels, clams, blood arks [Anadara ovalis], whelks [ Busycon carica ], false angel wings [ Petricola pholadiformis ]) were similar in water content to vertebrate prey, moderate to high in protein, and moderate to low in crude fat. Ash and macronutrient concentrations in prey species were high compared with requirements of carnivores or avian species. Prey items analyzed appear to meet nutritional requirements for oystercatchers, as estimated by extrapolation from domestic carnivores and poultry species; excesses, imbalances, and toxicities-particularly of minerals and fat-soluble vitamins-may warrant further investigation.

Absorption and ocular deposition of dietary lutein in marine mammals.

Cataracts and ocular disease are common lesions of marine mammals in zoological collections. Lutein, an oxygenated carotenoid, may have therapeutic or prophylactic effects on ocular disorder. Therefore, this study examined the ability of marine mammals to absorb dietary lutein. Two preliminary trials examined lutein in two forms (beadlet or ester) in a small sample size of marine mammals representing pinnipeds and cetaceans. Lutein was fed daily in tablets providing 0.89-3.6 mg lutein/kg body weight(0.75) per day for 15 days to 2 years. A third study was conducted using lutein beadlet fed at 3.6 mg lutein/kg body weight(0.75) per day for 15-21 days. Blood was analyzed for lutein pre- and postsupplementation. In the preliminary trials, lutein beadlet was observed to result in greater blood lutein levels than lutein esters, and cetaceans had more noticeable responses than pinnipeds. In Study 3, serum lutein and zeaxanthin increased postsupplementation in beluga whales (P < 0.05), and serum lutein tended to increase postsupplementation in dolphins (P < 0.10), but little change was seen in serum lutein in pinnipeds or manatee. Opportunistic retinal samples demonstrated some detectable lutein in the retina of a dolphin and several harp seals. The lutein levels in dolphins after supplementation are similar to those reported in free-ranging animals. Ocular lutein in harp seals demonstrates that ocular deposition occurs despite low circulating lutein levels.

Molt-associated changes in hematologic and plasma biochemical values and stress hormone levels in African penguins (Spheniscus demersus).

Handling, including blood collection, has often been discouraged in molting penguins because it is considered an additional stress imposed on birds already experiencing major physiologic stress associated with molting. To evaluate the degree of physiologic stress posed by molting, we compared the hematologic and plasma biochemical values and hormone levels of molting and nonmolting African penguins, Spheniscus demersus. Five male and 5 female penguins randomly chosen were given complete physical examinations, were weighed, and blood samples were taken at 7 time points before, during, and after the molt. Data were analyzed by linear mixed-model analysis of variance. Throughout the study, behavior and appetite remained normal. Catecholamine levels were highly variable within and among subjects, whereas mean corticosterone levels were significantly different between baseline, molt, and postmolt values. Significant differences from baseline values were observed in many of the hematologic analytes; however, only decreases in hematocrit and red blood cell count values were considered clinically significant. Anemia due to experimentally induced blood loss as a possible cause of the significant hematologic changes was ruled out based on results of a follow-up control study during the nonmolt season, which showed no significant changes in hematocrit level or total red blood cell counts when using similar sampling protocols, which indicates that these changes were associated with molt.

Evaluation of potential variables contributing to the development and duration of plantar lesions in a population of aquarium-maintained African penguins (Spheniscus demersus).

Bumblefoot (pododermatitis), often described as the most significant environmental disease of captive penguins, is commonly due to excessive pressure or trauma on the plantar surface of the avian foot, resulting in inflammation or necrosis and causing severe swelling, abrasions, or cracks in the skin. Although not formally evaluated in penguins, contributing factors for bumblefoot are thought to be similar to those initiating the condition in raptors and poultry. These factors include substrate, body weight, and lack of exercise. The primary purpose of this retrospective study was to evaluate variables potentially contributing to the development and duration of plantar lesions in aquarium-maintained African penguins (Spheniscus demersus), including sex, weight, age, season, exhibit activity, and territory substrate. Results indicate that males develop significantly more plantar lesions than females. Penguins weighing between 3.51 and 4.0 kg develop plantar lesions significantly more often than penguins weighing between 2.5 and 3.5 kg, and because male African penguins ordinarily weigh significantly more than females, weight is likely a contributing factor in the development of lesions in males compared with females. Significantly more plantar lesions were observed in penguins standing for greater than 50% of their time on exhibit than swimming. Penguins occupying smooth concrete territories developed more plantar lesions compared with penguins occupying grate territories. Recommendations for minimizing bumblefoot in African penguins include training penguins for monthly foot examinations for early detection of plantar lesions predisposing for the disease, encouraging swimming activity, and replacing smooth surfaces on exhibit with surfaces providing variable degrees of pressure and texture on the feet.

Milk composition in free-ranging polar bears (Ursus maritimus) as a model for captive rearing milk formula.

The goals of this study were to have an improved understanding of milk composition and to help create a suitable milk formula for cubs raised in captivity. Milk samples were evaluated for fat, fatty acids, carbohydrate, vitamin D(3), 25(OH)D(3), vitamin A (retinol), vitamin E (α-tocopherol), protein, and amino acids. Total lipids in milk did not differ for cubs (mean ± SEM = 26.60 ± 1.88 g/100 ml vs. yearlings 27.80 ± 2.20 g/100 ml). Milk lipids were of 23.6% saturated fatty acid for cubs and 22.4% for yearlings. Milk consumed by cubs and yearlings contained 43.8 and 42.0% mono-unsaturated fatty acids and 23.4 and 21.9% polyunsaturated fatty acids, respectively. Carbohydrate content was higher in milk for cubs (4.60 ± 0.64 g/100 ml) than for yearlings (2.60 ± 0.40 g/100 ml). Vitamin D(3) concentration of milk was 18.40 ± 5.00 ng/ml in early lactation compared with 7.60 ± 2.00 ng/ml for mid-lactation. 25(OH)D(3) was lower in milk consumed by cubs (162.00 ± 6.70 pg/ml) than in milk consumed by yearlings (205.00 ± 45.70 pg/ml). Vitamin A concentrations were 0.06 ± 0.01 and 0.03 ± 0.01 µg/ml for cubs and yearlings, respectively. Vitamin E was higher in milk consumed by cubs (20.16 ± 4.46 µg/ml) than by yearlings (7.30 ± 1.50 µg/ml). Protein content did not differ in milk available to cubs (11.40 ± 0.80 g/100 ml compared with milk for yearlings 11.80 ± 0.40 g/100 ml). Taurine was the most abundant free amino acid at 3,165.90 ± 192.90 nmol/ml (0.04% as fed basis).

Evaluation of an alternative to feeding whole frozen fish in belugas (Delphinapterus leucas).

Feeding fish to captive piscivores can be challenging owing to cost, availability, variability in nutrient, and caloric composition, as well as handling and storage concerns. This trial evaluated the response of three belugas to being fed Fish Analog, an alternative to frozen fish. Body condition, gut transit time, serum chemistry and metabolic hormone analytes, immune function, and behavioral motivation were the dependent variables. Belugas (n=3) were fed various levels of Fish Analog (0-50%) over a 6-month period, and follow-up studies were conducted to further examine several dependent variables. When provided in gradually increasing amounts, belugas consumed the Fish Analog, with only minor fecal consistency changes and without behavioral responses indicative of gastric discomfort. Axillary girth and blubber thickness were positively correlated, and did not differ significantly with changes in the percentage of Fish Analog fed. Individual animal variation in initial passage time, some serum chemistry analytes, and immune function differences were noted following feeding of Fish Analog. Feeding Fish Analog reduced blood n9 fatty acids compared with captive belugas fed no Fish Analog. Feeding a DHA-enriched Fish Analog increased several n3 fatty acids, including eicosapentaenoic acid, but not DHA, compared with whales fed no Fish Analog or non-DHA-enriched Fish Analog. Fish Analog was shown to be a viable alternative to feeding fish at up to 50% of the dietary caloric density.

Health assessment of free-ranging alligator snapping turtles (Macrochelys temminckii) in Georgia and Florida.

The Alligator Snapping Turtle (Macrochelys temminckii) is a large freshwater turtle endemic to river systems that drain into the Gulf of Mexico. Turtle populations were sharply reduced by commercial harvest in the 1970s and 1980s; however, the species has yet to be protected under the Endangered Species Act. While anthropogenic stressors such as habitat fragmentation and degradation and illegal capture continue to threaten populations, the degree to which disease may be contributing to any decline of the Alligator Snapping Turtle is unknown. Data were collected from 97 free-ranging Alligator Snapping Turtles in nine waterways in Florida and Georgia from 2001 to 2006. Eleven turtles were captured more than once, resulting in a total sample pool of 123. Reference ranges were established for complete blood count, plasma biochemistry values, trace metals (mercury, zinc, copper, lead, and arsenic), and nutrient parameters (vitamins A, E, D, and selenium). Variations by capture location, sex, and season were detected and likely resulted from external factors such as habitat and diet. Turtles sampled in one location were positive for tortoise herpesviral antibodies. Blood mercury values also differed among populations. This study provides justification for the use of these long-lived aquatic turtles as biologic monitors of the health of local freshwater ecosystems.

Comparison of the somatotropic axis in free-ranging and rehabilitated harbor seal pups (Phoca vitulina).

The somatotropic axis, including growth hormone (GH), insulin-like growth factor (IGF)-I, and IGF binding proteins (IGFBP), is a bridge between growth physiology, developmental age, and nutritional status in domestic animals. However, the importance of the somatotropic axis in nutrition, growth, and development of harbor seals has not been previously explored. Given the difficulty of conducting longitudinal studies in free-ranging harbor seals, this study focused on the potential use of harbor seals in rehabilitation facilities as a model for free-ranging seals. The purpose of this research was to compare concentrations of components of the somatotropic axis in free-ranging versus rehabilitated harbor seal pups. The hypothesis was that measurements of the somatotropic axis will be similar between individuals of comparable age and nutritional status (fasting versus feeding). To investigate this hypothesis, harbor seal pups (n=8) brought to The Marine Mammal Center (Sausalito, California, USA) or Mystic Aquarium (Mystic, Connecticut, U.S.A.) were initially assessed and determined to be healthy but abandoned. All pups were less than 2 wk of age upon arrival at rehabilitation facilities. Standard length was assessed at the time of arrival and again at release. Body mass was measured every week and blood samples were collected from each pup at 0, 4, and 8 wk of rehabilitation. Blood was collected and morphometrics assessed in free-ranging harbor seal pups (n=8) from the Gulf of Maine. Sera were analyzed for GH, IGF-I, and IGFBP concentrations. Concentrations of GH, IGF-I, and IGFBP-2 and -3 in rehabilitated pups were within a similar range compared with free-ranging pups when considered in the context of presumed nutrient intake. These data suggest that rehabilitated harbor seals may provide a useful model to investigate the effects of nutrient intake on growth and development of harbor seals, and will provide insight into phocid endocrinology and metabolism.

Vitamin A and E tissue distribution with comparisons to organochlorine concentrations in the serum, blubber and liver of the bowhead whale (Balaena mysticetus).

Vitamin A and E concentrations were determined in liver (n=51), blubber (n=23) and serum (n=53) of subsistence-hunted bowhead whales (Balaena mysticetus), between 1998 and 2001. Retinol and alpha-tocopherol were the major forms of vitamins A and E detected, respectively. Liver contained the highest mean concentrations of vitamin A, followed by epidermis, blubber, and serum. Liver also contained the highest mean concentration of vitamin E, followed by serum, epidermis, and blubber. Stratification of retinol and tocopherol was examined throughout the blubber cores collected. Retinol concentrations were significantly higher in the epidermis than in the deeper blubber layers. Tocopherol concentrations were similar for epidermis and the intermediate layer of blubber. Both the epidermis and the intermediate layer of blubber had significantly higher tocopherol concentrations than the innermost and outermost blubber layers. Vitamin A and E concentrations were investigated with respect to gender and reproductive status of females (males, non-pregnant females, pregnant females), age groups and season of harvest. Certain persistent organic contaminants are known to have a negative effect on retinol concentration in serum of pinnipeds and cetaceans. Bowhead whales have relatively low concentrations of organochlorines (OCs) in comparison to other mysticete species. The relationships between serum, liver and blubber retinol and serum and blubber OC concentrations were examined with no significant correlations noted.

Tissue heavy metal concentrations of stranded California sea lions (Zalophus californianus) in Southern California.

Concentrations of nine heavy metals (As, Cd, Cu, Fe, Hg, Pb, Mn, Mo and Zn) were determined in the hepatic and renal tissues of 80 stranded California sea lions (Zalophus californianus). Significant age-dependant increases were observed in liver and kidney concentrations of cadmium and mercury, and renal zinc concentrations. Hepatic iron concentrations were significantly higher in females than males. Animals with suspected domoic acid associated pathological findings had significantly higher concentrations of liver and kidney cadmium; and significantly higher liver mercury concentrations when compared to animals classified with infectious disease or traumatic mortality. Significantly higher hepatic burdens of molybdenum and zinc were found in animals that died from infectious diseases. This is the largest study of tissue heavy metal concentrations in California sea lions to date. These data demonstrate how passive monitoring of stranded animals can provide insight into environmental impacts on marine mammals.

Iron indices in bottlenose dolphins (Tursiops truncatus).

Bottlenose dolphins can have iron overload (that is, hemochromatosis), and managed populations of dolphins may be more susceptible to this disease than are wild dolphins. Serum iron, total iron-binding capacity (TIBC), transferrin saturation, and ferritin were measured in 181 samples from 141 dolphins in 2 managed collections and 2 free-ranging populations. Although no iron indices increased with age among free-ranging dolphins, ferritin increased with age in managed collections. Dolphins from managed collections had higher iron, ferritin, and transferrin saturation values than did free-ranging dolphins. Dolphins with high serum iron (exceeding 300 µg/dL) were more likely to have elevated ferritin but not ceruloplasmin or haptoglobin, demonstrating that high serum levels of iron are due to a true increase in total body iron. A time-series study of 4 dolphins with hemochromatosis that were treated with phlebotomy demonstrated significant decreases in serum ferritin, iron, and TIBC between pre- and posttreatment samples; transferrin saturation initially fell but returned to prephlebotomy levels by 6 mo after treatment. Compared with those in managed collections, wild dolphins were 15 times more likely to have low serum iron (100 µg/dL or less), and this measure was associated with lower haptoglobin. In conclusion, bottlenose dolphins in managed collections are more likely to have greater iron stores than are free-ranging dolphins. Determining why this situation occurs among some dolphin populations and not others may improve the treatment of hemochromatosis in dolphins and provide clues to causes of nonhereditary hemochromatosis in humans.