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Humboldt Penguin (Spheniscus humboldti) population declines are attributable to several multifaceted anthropogenic impacts. At present, the exposure of Humboldt Penguins to high concentrations of heavy metals in the marine environment is a preeminent concern, due to mining along the Peruvian coast near key rookery sites. Metal and selenium concentrations were determined in eggs collected from September 2020 to April 2021 from a managed-care penguin population at the Brookfield Zoo to establish reference values for health indices conducted on wild populations. Concentrations of 16 elements, with emphasis on those found in mine efflux—arsenic, cadmium, copper, lead, mercury, selenium, and zinc—were assessed via inductively coupled plasma mass spectrometry in yolk, albumen, and eggshell. Data analyses indicate a clear delineation between egg constituents, with lipid-rich yolk displaying notably higher concentrations (lg/g) of arsenic (0.20 ± 0.064), chromium (0.086 ± 0.03), cobalt (0.01 ± 0.003), iron (238.65 ± 54.72), lead (0.32 ± 0.97), manganese (2.71 ± 0.66), molybdenum (0.57 ± 0.14), tin (3.29 ± 0.99), and zinc (64.03 ± 13.01) than other components (albumen and eggshell). These data confirm that heavy metals are partitioned differently across Humboldt Penguin egg components, which provides insight into the potential connection between embryonic nutrient source contamination and subsequent chick viability. [ABSTRACT FROM AUTHOR]

We assessed δ13C and δ15N profiles and endoparasite community composition in Great Egrets (Ardea alba), Great Blue Herons (A. herodias), and White Ibis (Eudocimus albus) from four wildlife rescue centers (two mainland, two on islands in the Florida Keys) in south Florida, USA to elucidate feeding ecology. We detected among-species differences for δ15N but not δ13C and noted decreased δ13C enrichment in Great Egrets and Great Blue Herons (but not White Ibis) from these centers. Parasite component community and infracommunity species richness were higher in Great Egrets and Great Blue Herons relative to White Ibis, and higher in birds of the same species from mainland centers. Multivariate analysis of parasite infracommunity structure detected co-occurring clusters of parasite taxa characteristic of Great Egrets and Great Blue Herons on the one part, and of White Ibis on the other; mainland Great Egrets and Great Blue Herons had similar parasite communities and clustered separately from conspecifics from the islands. We detected a significant (negative) correlation of infracommunity species richness with δ13C but not δ15N. Lastly, parasite infracommunity Bray-Curtis similarity correlated significantly with stable isotope Euclidean distances. We conclude that the two approaches converge towards similar outcomes, providing complementary and consilient information on host feeding ecology. [ABSTRACT FROM AUTHOR]

Six species of wading birds collected from wildlife centers throughout South Florida were dissected for parasites. Twenty-six species of parasites represent new host records and five parasite species represent new geographic range extensions. [ABSTRACT FROM AUTHOR]

Large, mesopelagic teleost fishes have a potentially keystone position in the ecology of the pelagic water column, yet remain relatively unstudied when compared with large, commercially important, epipelagic fishes. Here, the ecological roles of four, large, vertically migrating teleosts were examined. Stomach content analyses were performed on 48 oilfish ( Ruvettus pretiosis), 35 escolar ( Lepidocybium flavobrunneum), 32 snake mackerel ( Gempylus serpens) and seven lancetfish ( Alepisaurus spp.) collected from pelagic longline gear in the Western North Atlantic Ocean from 2007 to 2010. Of these specimens, stable carbon and nitrogen isotope analyses were also performed on white dorsal muscle tissue from 33 oilfish, 16 escolar, 27 snake mackerel and seven lancetfish. Based on literature length-at-maturity values, all escolar, snake mackerel and lancetfish specimens were mature, while 13 of the 33 oilfish were juveniles. Crustaceans, annelids, salps, cephalopods and teleosts were present in the stomachs and were presumed to be prey items. A Kruskal-Wallis test showed the four species to be isotopically segregated in both δ13C and δ15N. Escolar were the most depleted in δ13C, followed by adult oilfish, juvenile oilfish and lancetfish, with snake mackerel the most enriched. The depletion in δ13C of adult oilfish and escolar may have been attributable to high C/N values, which were strongly correlated with length in oilfish, weakly correlated with length in escolar and moderately correlated with length in snake mackerel and lancetfish. The high C/N was likely due to the high lipid concentration of these fishes. Other factors that may have contributed to the depletion in δ13C may include spawning or a change in carbon source within the ecosystem. Large escolar occupied the highest trophic level (δ15N = 10.20), followed by snake mackerel (δ15N = 9.66), adult oilfish (δ15N = 9.32), lancetfish (δ15N = 9.05) and juvenile oilfish (δ15N = 7.83). A marked change in oilfish δ13C and C/N at 30-35 cm fork length coincided with a presumed length-at-maturity. [ABSTRACT FROM AUTHOR]

The relationship between a dolphin mother and her calf has been well studied, but details regarding tactile exchanges within these dyads are limited. Contacts between five adult female bottlenose dolphins (Tursiops truncatus) and their calves, with data from three pairs analyzed statistically, were examined from video collected in October 2017, 2018, 2019, and in January 2018. Of 289 contact events, calves initiated 65.7% (n = 190), of which 82.6% (n = 157) were affiliative; 77.8% (n = 77) of mother-initiated contacts were categorized similarly. Thus, the overall trend for mother-calf contacts was affiliative. Mothers initiated contact with the dorsal fin less often (n = 3), while calves initiated with their dorsal fin more often (n = 40), especially one-year-old (C1) calves (n = 33). The body was used to initiate contact more by three-year-old (C3) calves (n = 47) and less by C1 calves (n = 22). Both results are likely an artifact of the infant position used by calves at different developmental stages. Only two-year-old (C2) calves initiated agonistic contact with their rostrum (n = 4); 75% of these contacts were initiated by one male calf. Mothers used the body to initiate contact with most calf ages, though contact by pectoral fin occurred more often than expected with their C2 calves (n = 11). Since 72.7% of these contacts came from one mother, a specific maternal style may be present. Only one mother used her rostrum with her C3 calf to initiate agonistic contacts; all others used the fluke. Several variables, including individual preference, calf sex, and maternal experience, may explain some of the contact patterns, but a larger sample size is needed to illustrate potential patterns among pairs. Still, these results support the notion that mother-calf dyads share more affiliative than agonistic contacts, expanding our knowledge on the tactile relationships of mother-calf pairs. [ABSTRACT FROM AUTHOR]

Due to increasing recognition of the benefits provided by mangrove ecosystems, protection policies have emerged under both wetland and forestry programs. However, little consistency remains among these programs and inadequate coordination exists among sectors of government. With approximately 123 countries containing mangroves, the need for global management of these ecosystems is crucial to sustain the industries (i.e., fisheries, timber, and tourism) and coastal communities that mangroves support and protect. To determine the most effective form of mangrove management, this review examines management guidelines, particularly those associated with Integrated Coastal Zone Management (ICZM). Five case studies were reviewed to further explore the fundamentals of mangrove management. The management methodologies of two developed nations as well as three developing nations were assessed to encompass comprehensive influences on mangrove management, such as socioeconomics, politics, and land-use regulations. Based on this review, successful mangrove management will require a blend of forestry, wetland, and ICZM programs in addition to the cooperation of all levels of government. Legally binding policies, particularly at the international level, will be essential to successful mangrove management, which must include the preservation of existing mangrove habitat and restoration of damaged mangroves. [ABSTRACT FROM AUTHOR]

Sea lion and seal populations in Alaskan waters underwent various degrees of decline during the latter half of the twentieth century and the cause(s) for the declines remain uncertain. The stable carbon (13C/12C) and nitrogen (15N/14N) isotope ratios in bone collagen from wild Steller sea lions (Eumetopias jubatus), northern fur seals (Callorhinus ursinus) and harbor seals (Phoca vitulina) from the Bering Sea and Gulf of Alaska were measured for the period 1951–1997 to test the hypothesis that a change in trophic level may have occurred during this interval and contributed to the population declines. A significant change in δ15N in pinniped tissues over time would imply a marked change in trophic level. No significant change in bone collagen δ15N was found for any of the three species during the past 47 years in either the Bering Sea or the Gulf of Alaska. However, the 15N in the Steller sea lion collagen was significantly higher than both northern fur seals and harbor seals. A significant decline in δ13C (almost 2 ‰ over the 47 years) was evident in Steller sea lions, while a declining trend, though not significant, was evident in harbor seals and northern fur seals. Changes in foraging location, in combination with a trophic shift, may offer one possible explanation. Nevertheless, a decrease in δ13C over time with no accompanying change in δ15N suggests an environmental change affecting the base of the foodweb rather than a trophic level change due to prey switching. A decline in the seasonal primary production in the region, possibly resulting from decreased phytoplankton growth rates, would exhibit itself as a decline in δ13C. Declining production could be an indication of a reduced carrying capacity in the North Pacific Ocean. Sufficient quantities of optimal prey species may have fallen below threshold sustaining densities for these pinnipeds, particularly for yearlings and subadults who have not yet developed adequate foraging skills. [ABSTRACT FROM AUTHOR]

Trophic levels of 1,105 humpback whales from six geographically and isotopically distinct North Pacific feeding groups were calculated using δ15N of humpback whales and regional primary consumers. The overall mean trophic level for North Pacific humpback whales was 3.6 ± 0.02, indicating a diet of both fish and zooplankton, and, thus, supporting assumptions of humpback whales as generalist predators. The highest mean trophic level was calculated for the north Gulf of Alaska group (4.0 ± 0.03), while the lowest was found for the Russian and the western Aleutian Islands group (3.3 ± 0.08). Differences in mean trophic levels suggest that feeding groups differ in the proportion of fish and zooplankton in their diets. [ABSTRACT FROM AUTHOR]