Geology topics

Michael Gochfeld

Publications and source records attributed to Michael Gochfeld.

3 recordsLinked to original sources

USGS2023

Prevalence of Ophidiomyces ophidiicola and epizootiology of snake fungal disease in free-ranging Northern Pine Snakes (Pituophis melanoleucus melanoleucus) in New Jersey

Snake fungal disease, caused by Ophidiomyces ophidiicola , is recognized as a potential concern for North American snakes. We tested skin swabs from Northern Pine Snakes ( Pituophis melanoleucus melanoleucus ) in the New Jersey pinelands for the presence of O. ophidiicola before emergence from hibernation. We used qPCR to test the collected swabs for the presence of O. ophidiicola , then determined pathogen prevalence as a function of sampling year, sampling location (skin lesion, healthy ventral skin, healthy head skin) sex, and age . There were no temporal trends in O. ophidiicola detection percentages on snakes, which varied from 58 to 83% in different years. Ophidiomyces ophidiicola detection on snakes was highest in swabs of skin lesions (71%) and lowest in head swabs (29%). Males had higher prevalence than females (82% versus 62%). The fungus was not detected in hatchling snakes (age 0) in the fall, but 75% of juveniles tested positive at the end of hibernation (age 1 year). We also screened hibernacula soil samples for the presence of O. ophidiicola . Where snakes hibernated, 69% of soil samples were positive for O. ophidiicola , and 85% of snakes lying on positive soil samples also tested positive for the pathogen. Although a high proportion of snakes (73%) tested positive for O. ophidiicola during our 4-year study , the snakes appeared healthy except for small skin lesions. We conclude that O. ophidiicola prevalence is high on hibernating Northern Pine Snakes and in the hibernacula soil, with a strong association between snakes and positive adjacent soil. This is the first demonstration that snakes likely become infected during hibernation.

New Jersey↗

USGS1995

Estimating annual survival and movement rates of adults within a metapopulation of roseate terns

Several multistratum capture—recapture models were used to test various hypotheses about possible geographic and temporal variation in survival, movement, and recapture/resighting probabilities of 2399 adult Roseate Terns (Sterna dougallii) color—banded from 1988 to 1992 at the sites of the four largest breeding colonies of this species in the northeastern USA. Linear—logistic ultrastructural models also were developed to investigate possible correlates of geographic variation in movement probabilities. Based on goodness—of—fit tests and comparisons of Akaike's Information Criterion (AIC) values, the fully parameterized model (Model A) with time— and location—specific survival, movement, and capture probabilities, was selected as the most appropriate model for this metapopulation structure. With almost all movement accounted for, on average >90% of the surviving adults from each colony site returned to the same site the following year. Variations in movement probabilities were more closely associated with the identity of the destination colony site than with either the identity of the colony site of origin or the distance between colony sites. The average annual survival estimates (0.74—0.84) of terns from all four sites indicate a high rate of annual mortality relative to that of other species of marine birds.

Ecology↗

USGS1991

Effects of color on cadmium and lead levels in avian contour feathers

The use of feathers has been proposed as a noninvasive tissue for biomonitoring metal levels in birds and their ecosystems. We examined cadmium and lead levels in black and white contour feathers from common (Sterna hirundo) and sooty (S. fuscata) terns, and black skimmers (Rynchops niger) to determine if there were significant differences in metal levels related to the melanin content of the feathers. There were no significant differences in metals in black versus white body feathers in any of the three species; correlations between metal residues from individual birds were low. © 1991 Springer-Verlag New York Inc.

Archives of Environmental Contamination and Toxico↗