Pub Date : 2006-01-01DOI: 10.1163/157075406776984266
Christopher K. Dougherty, Geoffrey R. Smith
The application of road de-icing compounds during the winter has the potential to result in the contamination of nearby freshwater habitats and affect amphibians breeding in those habitats. We conducted a study of the effects of several de-icing and associated compounds (sodium chloride, magnesium chloride, calcium acetate, magnesium acetate, sodium ferrocyanide, and sodium formate) on the tadpoles of three species of anurans: African clawed frogs (Xenopus laevis), American toads (Bufo americanus), and green frogs (Rana clamitans). The survivorship of X. laevis tadpoles was negatively affected by MgCl2, but not by NaCl. The survivorship of R. clamitans tadpoles was negatively affected by both NaCl and MgCl2. The tadpoles of B. americanus were not affected by the concentrations of NaCl and MgCl2 used in this study. Our results suggest that contamination of freshwater habitats by de-icing and associated compounds could potentially adversely affect at least some anuran populations, but that this potential can vary from species to species, and from compound to compound.
{"title":"Acute effects of road de-icers on the tadpoles of three anurans","authors":"Christopher K. Dougherty, Geoffrey R. Smith","doi":"10.1163/157075406776984266","DOIUrl":"https://doi.org/10.1163/157075406776984266","url":null,"abstract":"The application of road de-icing compounds during the winter has the potential to result in the contamination of nearby freshwater habitats and affect amphibians breeding in those habitats. We conducted a study of the effects of several de-icing and associated compounds (sodium chloride, magnesium chloride, calcium acetate, magnesium acetate, sodium ferrocyanide, and sodium formate) on the tadpoles of three species of anurans: African clawed frogs (Xenopus laevis), American toads (Bufo americanus), and green frogs (Rana clamitans). The survivorship of X. laevis tadpoles was negatively affected by MgCl2, but not by NaCl. The survivorship of R. clamitans tadpoles was negatively affected by both NaCl and MgCl2. The tadpoles of B. americanus were not affected by the concentrations of NaCl and MgCl2 used in this study. Our results suggest that contamination of freshwater habitats by de-icing and associated compounds could potentially adversely affect at least some anuran populations, but that this potential can vary from species to species, and from compound to compound.","PeriodicalId":55499,"journal":{"name":"Applied Herpetology","volume":"3 1","pages":"87-93"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/157075406776984266","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64916416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-01-01DOI: 10.1163/157075406775247049
R. Rogers, J. Bacon, D. J. Fort, D. Linzey
Observations of abnormal adult cane toads ( Bufo marinus ) in Bermuda in 1998 prompted surveys of the island's mature and newly metamorphosed populations from 1999 to 2003. External examinations revealed eye and facial abnormalities, spinal and pelvic abnormalities, and a variety of limb malformations. Malformed toads were found in all nine of Bermuda's parishes and the incidence rate was high in both age classes. The annual abnormality frequencies were 19-30% for adults and juveniles, and 16-24% for metamorphs. Annual metamorph abnormality rates at particular ponds were as high as 58%, and abnormality rates for particular cohorts were as high as 81%. The frequency of hind limb abnormalities was significantly greater than that of forelimb abnormalities in both age classes. Most eye and limb abnormalities were unilateral. The most common limb malformation was brachydactyly, and few cutaneous fusions or examples of polymely were observed. Breeding sites that were natural or artificial ponds in parks or nature reserves, or lined ponds on golf courses, had significantly higher abnormality frequencies than lined or cement ponds in backyard settings. No encysted Ribeiroia metacercariae were found in 80 malformed metamorphs collected from four sites with high abnormality rates, suggesting that these parasites were not responsible for the malformations observed. Frog embryo teratogenesis assays demonstrated that water and sediment extracts from the same four breeding sites induced severe developmental malformations in B. marinus and three other amphibian species. These data suggested that many B. marinus breeding sites in Bermuda are potentially contaminated with developmental toxicants.
{"title":"Deformities in cane toad ( Bufo marinus ) populations in Bermuda: Part I. Frequencies and distribution of abnormalities","authors":"R. Rogers, J. Bacon, D. J. Fort, D. Linzey","doi":"10.1163/157075406775247049","DOIUrl":"https://doi.org/10.1163/157075406775247049","url":null,"abstract":"Observations of abnormal adult cane toads ( Bufo marinus ) in Bermuda in 1998 prompted surveys of the island's mature and newly metamorphosed populations from 1999 to 2003. External examinations revealed eye and facial abnormalities, spinal and pelvic abnormalities, and a variety of limb malformations. Malformed toads were found in all nine of Bermuda's parishes and the incidence rate was high in both age classes. The annual abnormality frequencies were 19-30% for adults and juveniles, and 16-24% for metamorphs. Annual metamorph abnormality rates at particular ponds were as high as 58%, and abnormality rates for particular cohorts were as high as 81%. The frequency of hind limb abnormalities was significantly greater than that of forelimb abnormalities in both age classes. Most eye and limb abnormalities were unilateral. The most common limb malformation was brachydactyly, and few cutaneous fusions or examples of polymely were observed. Breeding sites that were natural or artificial ponds in parks or nature reserves, or lined ponds on golf courses, had significantly higher abnormality frequencies than lined or cement ponds in backyard settings. No encysted Ribeiroia metacercariae were found in 80 malformed metamorphs collected from four sites with high abnormality rates, suggesting that these parasites were not responsible for the malformations observed. Frog embryo teratogenesis assays demonstrated that water and sediment extracts from the same four breeding sites induced severe developmental malformations in B. marinus and three other amphibian species. These data suggested that many B. marinus breeding sites in Bermuda are potentially contaminated with developmental toxicants.","PeriodicalId":55499,"journal":{"name":"Applied Herpetology","volume":"3 1","pages":"39-65"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/157075406775247049","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64915982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-01-01DOI: 10.1163/157075406778116203
G. Perry, G. Gerber
The British Virgin Islands (BVI) forms part of the Puerto Rican Bank and its fauna is closely related to that of the US Virgin Islands and Puerto Rico. Humans have inhabited the region for several thousand years and their impacts have continuously included habitat modification, hunting, and introduction of invasive species. Those are the three main causes of concern for the present-day herpetofauna of the BVI, which contains 34 amphibian and reptile species. Of these, five (15%) are common, three (9%) are at risk, eight (23%) are endangered, ten (29%) are data deficient, two (6%) are extinct, and six (18%) are introduced or cryptogenic. Several endemic species are only found on tiny islets where stochastic events can easily lead to their extinction. The native iguana, Cyclura pinguis , and the sea turtles found in the region are in an especially sensitive condition. Habitat destruction and fragmentation are ongoing and likely to accelerate. Invasive species are still arriving, establishing, and spreading. Thus, although the short-term conservation status of the BVI herpetofauna appears unlikely to change, we are more concerned about the mid-term outlook. We recommend some specific remedies intended to offset these pressures and provide long-term protection to the biota of the BVI.
{"title":"Conservation of amphibians and reptiles in the British Virgin Islands: Status and patterns","authors":"G. Perry, G. Gerber","doi":"10.1163/157075406778116203","DOIUrl":"https://doi.org/10.1163/157075406778116203","url":null,"abstract":"The British Virgin Islands (BVI) forms part of the Puerto Rican Bank and its fauna is closely related to that of the US Virgin Islands and Puerto Rico. Humans have inhabited the region for several thousand years and their impacts have continuously included habitat modification, hunting, and introduction of invasive species. Those are the three main causes of concern for the present-day herpetofauna of the BVI, which contains 34 amphibian and reptile species. Of these, five (15%) are common, three (9%) are at risk, eight (23%) are endangered, ten (29%) are data deficient, two (6%) are extinct, and six (18%) are introduced or cryptogenic. Several endemic species are only found on tiny islets where stochastic events can easily lead to their extinction. The native iguana, Cyclura pinguis , and the sea turtles found in the region are in an especially sensitive condition. Habitat destruction and fragmentation are ongoing and likely to accelerate. Invasive species are still arriving, establishing, and spreading. Thus, although the short-term conservation status of the BVI herpetofauna appears unlikely to change, we are more concerned about the mid-term outlook. We recommend some specific remedies intended to offset these pressures and provide long-term protection to the biota of the BVI.","PeriodicalId":55499,"journal":{"name":"Applied Herpetology","volume":"3 1","pages":"237-256"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/157075406778116203","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64916686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-01-01DOI: 10.1163/157075406778116195
R. W. Henderson, Craig S. Berg
Grenada and the politically associated Grenadines harbor 19 species of terrestrial herpetofauna, and four species of marine turtles either nest on their beaches or forage in the surrounding waters. The islands have a 2000-year history of human activity, but the past five centuries had the most adverse impact on the environment. Although some members of the herpetofauna have responded well to dramatically altered habitats (Anolis spp.), others have not (e.g., Eleutherodactylus euphronides). Similarly, the introductions of alien predators (most notably Herpestes javanicus) have likely impacted some species (e.g., Ameiva ameiva, Mabuya sp.), but not others. Several species appear to be genuinely rare (e.g., Clelia clelia, Typhlops tasymicris), and sharp declines in numbers have been documented for the arboreal boa Corallus grenadensis. The future of marine turtles in the area is threatened by habitat destruction (development of beachfront habitat for the tourist industry), slaughter of adults, and poaching of nests. Eco-tourism may hold the key for protection of forested habitats and the herpetofauna of this important group of islands.
{"title":"The herpetofauna of Grenada and the Grenada Grenadines: Conservation concerns","authors":"R. W. Henderson, Craig S. Berg","doi":"10.1163/157075406778116195","DOIUrl":"https://doi.org/10.1163/157075406778116195","url":null,"abstract":"Grenada and the politically associated Grenadines harbor 19 species of terrestrial herpetofauna, and four species of marine turtles either nest on their beaches or forage in the surrounding waters. The islands have a 2000-year history of human activity, but the past five centuries had the most adverse impact on the environment. Although some members of the herpetofauna have responded well to dramatically altered habitats (Anolis spp.), others have not (e.g., Eleutherodactylus euphronides). Similarly, the introductions of alien predators (most notably Herpestes javanicus) have likely impacted some species (e.g., Ameiva ameiva, Mabuya sp.), but not others. Several species appear to be genuinely rare (e.g., Clelia clelia, Typhlops tasymicris), and sharp declines in numbers have been documented for the arboreal boa Corallus grenadensis. The future of marine turtles in the area is threatened by habitat destruction (development of beachfront habitat for the tourist industry), slaughter of adults, and poaching of nests. Eco-tourism may hold the key for protection of forested habitats and the herpetofauna of this important group of islands.","PeriodicalId":55499,"journal":{"name":"Applied Herpetology","volume":"3 1","pages":"197-213"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/157075406778116195","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64916579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-01-01DOI: 10.1163/157075406776984248
Richard M. Lehtinen, J. Ramanamanjato
Habitat destruction in tropical forests often produces fragmented landscapes where relatively small forest remnants are present in a human-dominated matrix. To estimate rates of species loss after fragmentation and identify the traits of species which are most vulnerable to extinction, we assessed the distribution of amphibians and reptiles in an old (>50 yr) fragmented landscape in southeastern Madagascar. In the six rainforest fragments (10-457 ha) surveyed between 1999 and 2002, we detected forty-five species (28 reptiles, 17 amphibians). These species were not distributed randomly among the fragments but rather were very highly nested. The herpetofauna of small fragments consisted of smaller subsets of the species pool found in larger fragments. Species loss rates were high, with up to 64% of reptile and 88% of amphibian species lost when compared to the largest fragment. Species that were particularly prone to local extinction were generally rare, habitat specialists, and/or intolerant of the matrix habitat. Edge-avoidance was a good predictor of extinction vulnerability for frogs, but not for reptiles. Body size was generally not a good predictor of extinction proneness. In contrast with some other studies of amphibians and reptiles in fragmented landscapes, the results of this study indicate that species loss is a likely consequence of persistent isolation.
{"title":"Effects of rainforest fragmentation and correlates of local extinction in a herpetofauna from Madagascar","authors":"Richard M. Lehtinen, J. Ramanamanjato","doi":"10.1163/157075406776984248","DOIUrl":"https://doi.org/10.1163/157075406776984248","url":null,"abstract":"Habitat destruction in tropical forests often produces fragmented landscapes where relatively small forest remnants are present in a human-dominated matrix. To estimate rates of species loss after fragmentation and identify the traits of species which are most vulnerable to extinction, we assessed the distribution of amphibians and reptiles in an old (>50 yr) fragmented landscape in southeastern Madagascar. In the six rainforest fragments (10-457 ha) surveyed between 1999 and 2002, we detected forty-five species (28 reptiles, 17 amphibians). These species were not distributed randomly among the fragments but rather were very highly nested. The herpetofauna of small fragments consisted of smaller subsets of the species pool found in larger fragments. Species loss rates were high, with up to 64% of reptile and 88% of amphibian species lost when compared to the largest fragment. Species that were particularly prone to local extinction were generally rare, habitat specialists, and/or intolerant of the matrix habitat. Edge-avoidance was a good predictor of extinction vulnerability for frogs, but not for reptiles. Body size was generally not a good predictor of extinction proneness. In contrast with some other studies of amphibians and reptiles in fragmented landscapes, the results of this study indicate that species loss is a likely consequence of persistent isolation.","PeriodicalId":55499,"journal":{"name":"Applied Herpetology","volume":"3 1","pages":"95-110"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/157075406776984248","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64916322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-01-01DOI: 10.1163/157075406775247067
E. Sánchez, J. Pérez, Randy L. Powell
Facilities that maintain and extract venom from venomous snakes were located worldwide. Information concerning numbers, distribution, years in operation, ownership (private or government), facilities open to the public for display of animals or educational programs, number of snakes and species maintained, prevalence of captive breeding programs, venom extraction frequency, and occupational hazards was collected. A total of 34 facilities in 21 countries were located. Information (all or in part) was obtained on 32 of these facilities. Forty-four percent of the facilities existed in countries as the sole venom extraction enterprise. The length of time they have been in operation ranged from 1 to over 90 years and are 56% private and 44% government owned. Thirty-five percent of the facilities are open to the public for display of animals or educational purposes. Most facilities maintained animal totals between 50 and 1500. However, the number of species maintained at these facilities varied greatly, ranging from 1 to 70. The majority of facilities have some type of captive breeding program, with some reporting as high as 80% of their total animals captive born. While some facilities maintain both exotic and native species, most (68%) house native species only. The majority of the facilities reported that venom was collected or "extracted" from snakes on 14 to 30 day intervals. Occupational hazards of employees regarding accidental envenomation or "snakebite" varied. Envenomation frequencies at facilities ranged from zero to as high as one accident every eight months. Only one death was reported due to an envenomation accident.
{"title":"Farming for venom: Survey of snake venom extraction facilities worldwide","authors":"E. Sánchez, J. Pérez, Randy L. Powell","doi":"10.1163/157075406775247067","DOIUrl":"https://doi.org/10.1163/157075406775247067","url":null,"abstract":"Facilities that maintain and extract venom from venomous snakes were located worldwide. Information concerning numbers, distribution, years in operation, ownership (private or government), facilities open to the public for display of animals or educational programs, number of snakes and species maintained, prevalence of captive breeding programs, venom extraction frequency, and occupational hazards was collected. A total of 34 facilities in 21 countries were located. Information (all or in part) was obtained on 32 of these facilities. Forty-four percent of the facilities existed in countries as the sole venom extraction enterprise. The length of time they have been in operation ranged from 1 to over 90 years and are 56% private and 44% government owned. Thirty-five percent of the facilities are open to the public for display of animals or educational purposes. Most facilities maintained animal totals between 50 and 1500. However, the number of species maintained at these facilities varied greatly, ranging from 1 to 70. The majority of facilities have some type of captive breeding program, with some reporting as high as 80% of their total animals captive born. While some facilities maintain both exotic and native species, most (68%) house native species only. The majority of the facilities reported that venom was collected or \"extracted\" from snakes on 14 to 30 day intervals. Occupational hazards of employees regarding accidental envenomation or \"snakebite\" varied. Envenomation frequencies at facilities ranged from zero to as high as one accident every eight months. Only one death was reported due to an envenomation accident.","PeriodicalId":55499,"journal":{"name":"Applied Herpetology","volume":"3 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/157075406775247067","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64915748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-01-01DOI: 10.1163/EJ.9789004194083.I-439.158
R. Platenberg, R. Boulon
The United States Virgin Islands (USVI) are situated along the Puerto Rico Bank near the eastern terminus of the Greater Antilles in the northern Caribbean, and comprise four major inhabited islands and more than 50 satellite cays. The small sizes of the islands, their relative isolation, and unpredictable weather events such as hurricanes make natural populations vulnerable to human-induced impacts of habitat loss and the introduction of invasive exotic species. There are currently 30 extant species of reptiles and amphibians in the USVI, 24 of which are native. Four species have been extirpated from all or part of their former distribution, four species are endangered, one is threatened, and eight are considered data deficient. Five reptiles and amphibians are fairly recent (within the last 150 years) introductions. Species of particular conservation concern are the St. Croix ground lizard (Ameiva polops), Virgin Islands tree boa (Epicrates monensis granti), and sea turtles, and recovery efforts are underway for these species. Habitat protection and reduction of exotic predators are important conservation actions required to protect herpetofauna, combined with ecological studies and population monitoring.
{"title":"Conservation Status Of Reptiles And Amphibians In The U.S. Virgin Islands","authors":"R. Platenberg, R. Boulon","doi":"10.1163/EJ.9789004194083.I-439.158","DOIUrl":"https://doi.org/10.1163/EJ.9789004194083.I-439.158","url":null,"abstract":"The United States Virgin Islands (USVI) are situated along the Puerto Rico Bank near the eastern terminus of the Greater Antilles in the northern Caribbean, and comprise four major inhabited islands and more than 50 satellite cays. The small sizes of the islands, their relative isolation, and unpredictable weather events such as hurricanes make natural populations vulnerable to human-induced impacts of habitat loss and the introduction of invasive exotic species. There are currently 30 extant species of reptiles and amphibians in the USVI, 24 of which are native. Four species have been extirpated from all or part of their former distribution, four species are endangered, one is threatened, and eight are considered data deficient. Five reptiles and amphibians are fairly recent (within the last 150 years) introductions. Species of particular conservation concern are the St. Croix ground lizard (Ameiva polops), Virgin Islands tree boa (Epicrates monensis granti), and sea turtles, and recovery efforts are underway for these species. Habitat protection and reduction of exotic predators are important conservation actions required to protect herpetofauna, combined with ecological studies and population monitoring.","PeriodicalId":55499,"journal":{"name":"Applied Herpetology","volume":"3 1","pages":"215-235"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64595375","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-01-01DOI: 10.1163/157075406776984239
J. Bacon, R. Rogers, D. J. Fort
An alarming high incidence of deformities in mature and newly metamorphosed Bufo marinus was identified in 2002 (29% in adults and 21% in metamorph specimens) in Bermuda. Suspicion of multiple chemical stressors in many of the effected ponds warranted identification of potential causative agents. Short-term embryo-larval, chronic exposure studies through hind limb development, and a battery of toxicity identification studies were performed with B. marinus and the surrogate species, Xenopus laevis, using sediment and water collected from four target ponds and one reference pond in Bermuda. Short-term embryo larval developmental toxicity studies based on a modified FETAX method indicated that samples from each of the target sites were capable of inducing abnormal development. Malformations induced in the early developmental tests were consistent amongst the species and included abnormal development of the craniofacial region, eye, mouth, and gut. Limb reduction deficit defects were identified in the chronic exposure studies with B. marinus and X. laevis. Toxicity characterization studies found that the toxicity of sediment extracts was variably filterable and reduced by C18-SPE, cation exchange, and zeolite treatments. Developmentally toxic samples contained elevated levels of petroleum hydrocarbons, metals (Al, As, Sn, Cd, Cr, Cu, Fe, Pb, Hg, Mn, Ni, and Zn), and ammonia. Sediment spiking studies with reference sediment confirmed that the levels of petroleum hydrocarbons and metals were capable of inducing developmental toxicity individually. Joint mixture interaction studies with sediment extracts prepared from the individually spiked reference sediment suggested however, that these extracts were potentially capable of acting synergistically, producing a greater level of toxicity than would normally be predicted based on the response to the individual spiked samples.
{"title":"Deformities in cane toad (Bufo marinus) populations in Bermuda: Part II. Progress towards characterization of chemical stressors","authors":"J. Bacon, R. Rogers, D. J. Fort","doi":"10.1163/157075406776984239","DOIUrl":"https://doi.org/10.1163/157075406776984239","url":null,"abstract":"An alarming high incidence of deformities in mature and newly metamorphosed Bufo marinus was identified in 2002 (29% in adults and 21% in metamorph specimens) in Bermuda. Suspicion of multiple chemical stressors in many of the effected ponds warranted identification of potential causative agents. Short-term embryo-larval, chronic exposure studies through hind limb development, and a battery of toxicity identification studies were performed with B. marinus and the surrogate species, Xenopus laevis, using sediment and water collected from four target ponds and one reference pond in Bermuda. Short-term embryo larval developmental toxicity studies based on a modified FETAX method indicated that samples from each of the target sites were capable of inducing abnormal development. Malformations induced in the early developmental tests were consistent amongst the species and included abnormal development of the craniofacial region, eye, mouth, and gut. Limb reduction deficit defects were identified in the chronic exposure studies with B. marinus and X. laevis. Toxicity characterization studies found that the toxicity of sediment extracts was variably filterable and reduced by C18-SPE, cation exchange, and zeolite treatments. Developmentally toxic samples contained elevated levels of petroleum hydrocarbons, metals (Al, As, Sn, Cd, Cr, Cu, Fe, Pb, Hg, Mn, Ni, and Zn), and ammonia. Sediment spiking studies with reference sediment confirmed that the levels of petroleum hydrocarbons and metals were capable of inducing developmental toxicity individually. Joint mixture interaction studies with sediment extracts prepared from the individually spiked reference sediment suggested however, that these extracts were potentially capable of acting synergistically, producing a greater level of toxicity than would normally be predicted based on the response to the individual spiked samples.","PeriodicalId":55499,"journal":{"name":"Applied Herpetology","volume":"3 1","pages":"143-172"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/157075406776984239","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64916254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-01-01DOI: 10.1163/157075406776984211
Michelle M. Gooch, Aubrey M. Heupel, M. Dorcas, S. Price
Recent declines in amphibian populations have created an urgent need for large-scale, long- term monitoring efforts and many anuran monitoring programs have been established that utilize calling surveys. Calling surveys can be effective monitoring tools; however, differences among survey protocols may bias survey results. Failure to take into account detection probabilities when monitoring anurans can lead to inaccurate inferences about site occupancy, since non-detections in survey data do not necessarily mean that a species is absent unless the probability of detection is 1. We used a likelihood-based method, in the form of the computer program PRESENCE, to estimate detection probabilities and site occupancy rates for summer-breeding anurans in the Western Piedmont of North Carolina. Using detection data from calling surveys, we evaluated how detectability and site occupancy for five anuran species were influenced by 1) time spent listening at each site, 2) number of surveys per site, and 3) sample- and site-specific covariates. We found considerable variation among species with regards to detection probability and site occupancy across survey duration and sampling occasion. Although 13% of all species detection occurred after 3 min, longer surveys did not significantly increase detectability of individual species. We found that detectability varied more with sampling occasion than with survey duration for each species. Covariates had differing effects on occupancy and detectability among individual species. Multiple surveys per site within a season are necessary to eliminate biased detection probabilities, but we found that 3- or 5-min surveys were adequate for detecting all species breeding at the time of the survey.
{"title":"The effects of survey protocol on detection probabilities and site occupancy estimates of summer breeding anurans","authors":"Michelle M. Gooch, Aubrey M. Heupel, M. Dorcas, S. Price","doi":"10.1163/157075406776984211","DOIUrl":"https://doi.org/10.1163/157075406776984211","url":null,"abstract":"Recent declines in amphibian populations have created an urgent need for large-scale, long- term monitoring efforts and many anuran monitoring programs have been established that utilize calling surveys. Calling surveys can be effective monitoring tools; however, differences among survey protocols may bias survey results. Failure to take into account detection probabilities when monitoring anurans can lead to inaccurate inferences about site occupancy, since non-detections in survey data do not necessarily mean that a species is absent unless the probability of detection is 1. We used a likelihood-based method, in the form of the computer program PRESENCE, to estimate detection probabilities and site occupancy rates for summer-breeding anurans in the Western Piedmont of North Carolina. Using detection data from calling surveys, we evaluated how detectability and site occupancy for five anuran species were influenced by 1) time spent listening at each site, 2) number of surveys per site, and 3) sample- and site-specific covariates. We found considerable variation among species with regards to detection probability and site occupancy across survey duration and sampling occasion. Although 13% of all species detection occurred after 3 min, longer surveys did not significantly increase detectability of individual species. We found that detectability varied more with sampling occasion than with survey duration for each species. Covariates had differing effects on occupancy and detectability among individual species. Multiple surveys per site within a season are necessary to eliminate biased detection probabilities, but we found that 3- or 5-min surveys were adequate for detecting all species breeding at the time of the survey.","PeriodicalId":55499,"journal":{"name":"Applied Herpetology","volume":"3 1","pages":"129-142"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/157075406776984211","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64916299","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2006-01-01DOI: 10.1163/157075406778116186
D. J. Fort, R. Rogers, Brody O. Buzzard, G. Anderson, J. Bacon
Short-term embryo-larval, limb development, and a battery of toxicity identification studies using sediment and water collected from selected ponds found that developmentally toxic samples contained elevated levels of petroleum hydrocarbons and As, Cu, Pb, Cr, Cd, Hg, Fe, and Zn. Sediments spiked with diesel fuel or metals confirmed that the levels of petroleum hydrocarbons and metals found in the sediment were capable of inducing developmental toxicity individually. However, joint mixture interaction studies indicated that the metals and petroleum hydrocarbons acted synergistically. To more rigorously evaluate exposure pathways and the effects induced, chronic laboratory-based microcosm experiments were performed using B. marinus from early embryo to metamorphosis. Results from these microcosm studies indicated that reasonably consistent frequencies of malformations were induced by exposure to contaminated media samples from four contaminated sites compared with frequencies found in field-collected specimens. The frequencies of specific types of deformities in newly metamorphosed organisms from the microcosm studies and in free-roaming field-collected specimens were also similar. Exposure to contaminated media from three of the four sites decreased the frequency of metamorphic completion and at one site reduced the metamorphic rate, compared to exposure to laboratory controls or reference media. Elevated whole body petroleum hydrocarbons and metals tissue residues were detected in organisms from the laboratory microcosms, as well as in the free-roaming specimens collected. To evaluate the impact of maternal contaminant transfer as an exposure route, cross-over exposure studies in which reference organisms were raised, from embryos through metamorphosis, in contaminated media and organisms from a contaminated site were cultured in reference media were conducted. Results from these studies indicated that environmental exposure and maternal toxicant transfer were the potential exposure routes. Overall, the present studies suggested the petroleum hydrocarbons and metals that accumulated in B. marinus during development in microcosms corresponded with increased frequencies of malformation.
{"title":"Deformities in cane toad (Bufo marinus) populations in Bermuda: Part III. Microcosm-based exposure pathway assessment","authors":"D. J. Fort, R. Rogers, Brody O. Buzzard, G. Anderson, J. Bacon","doi":"10.1163/157075406778116186","DOIUrl":"https://doi.org/10.1163/157075406778116186","url":null,"abstract":"Short-term embryo-larval, limb development, and a battery of toxicity identification studies using sediment and water collected from selected ponds found that developmentally toxic samples contained elevated levels of petroleum hydrocarbons and As, Cu, Pb, Cr, Cd, Hg, Fe, and Zn. Sediments spiked with diesel fuel or metals confirmed that the levels of petroleum hydrocarbons and metals found in the sediment were capable of inducing developmental toxicity individually. However, joint mixture interaction studies indicated that the metals and petroleum hydrocarbons acted synergistically. To more rigorously evaluate exposure pathways and the effects induced, chronic laboratory-based microcosm experiments were performed using B. marinus from early embryo to metamorphosis. Results from these microcosm studies indicated that reasonably consistent frequencies of malformations were induced by exposure to contaminated media samples from four contaminated sites compared with frequencies found in field-collected specimens. The frequencies of specific types of deformities in newly metamorphosed organisms from the microcosm studies and in free-roaming field-collected specimens were also similar. Exposure to contaminated media from three of the four sites decreased the frequency of metamorphic completion and at one site reduced the metamorphic rate, compared to exposure to laboratory controls or reference media. Elevated whole body petroleum hydrocarbons and metals tissue residues were detected in organisms from the laboratory microcosms, as well as in the free-roaming specimens collected. To evaluate the impact of maternal contaminant transfer as an exposure route, cross-over exposure studies in which reference organisms were raised, from embryos through metamorphosis, in contaminated media and organisms from a contaminated site were cultured in reference media were conducted. Results from these studies indicated that environmental exposure and maternal toxicant transfer were the potential exposure routes. Overall, the present studies suggested the petroleum hydrocarbons and metals that accumulated in B. marinus during development in microcosms corresponded with increased frequencies of malformation.","PeriodicalId":55499,"journal":{"name":"Applied Herpetology","volume":"3 1","pages":"257-277"},"PeriodicalIF":0.0,"publicationDate":"2006-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1163/157075406778116186","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"64916493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：