Habitat preservation and management may play an important role in the conservation of the Puerto Rican crested toad, Peltophryne lemur, due to this species’ small geographic range and declining native wild population. Bioavailable water concentrations of Polycyclic Aromatic Hydrocarbon (PAH) contaminants within breeding pools at 3 sites were established using Passive Sampling Devices (PSDs) and gas chromatography-mass spectrometry (GC/MS). A more diverse population of PAH analytes were found in higher concentrations at the breeding site that allowed direct vehicular access, but calculated risk quotients indicated low risk to toad reproduction associated with the current PAH analyte levels. 1. Introduction The Puerto Rican crested toad, Peltophryne lemur, is the only native toad species of Puerto Rico and has become a subject of conservation concern due to its small population size, limited breeding sites, and small geographic range [1–3]. Although several new populations have been established in Puerto Rico through captive-breeding and release programs, reproduction of the naturally wild population of this toad species is considered limited to a small region of coastline located in Guanica, Puerto Rico [4–8]. Based on direct observation of breeding events during heavy rainfall, the number of observed mature individuals declined from 1984 to 2003, with only 80 mature individuals recorded in 2003 [1, 9]. The majority of breeding for the naturally wild population is thought to occur at three distinct breeding sites within a several kilometer radius, and each of these three breeding sites contains at least one ephemeral pool that fills with water under adequate rainfall conditions [2]. The volume, surface area, depth, and duration of each of these temporary pools is dependent on the amount and frequency of rainfall that the region receives. A portion of the largest and most significant site for toad reproduction, the Tamarindo site, is accessible for vehicular parking by members of the public when the breeding pools are dry. This parking occurs directly over areas where breeding pools form when it rains. Vehicular traffic is associated with a wide variety of contaminants including Polycyclic Aromatic Hydrocarbons (PAHs) from incomplete combustion, exhaust, oil leaks, tire abrasion, asphalt, and other lubricants [10–14]. PAHs have been linked with many undesirable health consequences in humans and animals including carcinogenic, immunotoxic, mutagenic, and teratogenic effects [15–18]. Environmental exposure of amphibians to PAHs may cause such broad effects
References
[1]
A. Angulo, “Peltophryne lemur,” in IUCN, IUCN Redlist of Threatened Species. Version 2012.1, 2012, http://www.iucnredlist.org/.
[2]
J. Matos-Torres, Habitat characterization for the Puerto Rican crested toad (Peltophryne [Bufo] lemur) at Guanica state forest, Puerto Rico [M.S. thesis], University of Puerto Rico, Puerto Rico, USA, 2006.
[3]
United States Fish and Wildlife Service, “Determination of threatened status for the Puerto Rican crested toad. Department of the Interior,” Federal Register, vol. 52, Doc 87-28828, no. 149, 1987.
[4]
D. Barber, “Cooperative Amphibian Programs in AZA: Puerto Rican Crested Toad SSP,” Connect, p. 13, 2007.
[5]
K. B. Beauclerc, B. Johnson, and B. N. White, “Genetic rescue of an inbred captive population of the critically endangered Puerto Rican crested toad (Peltophryne lemur) by mixing lineages,” Conservation Genetics, vol. 11, no. 1, pp. 21–32, 2010.
[6]
B. Johnson, “Recovery of the Puerto Rican crested toad,” Endangered Species Bulletin, vol. 24, no. 3, pp. 8–9, 1999.
[7]
T. J. Miller, “Husbandry and breeding of the Puerto Rican crested toad (Peltophryne lemur) with comments on its natural history,” Zoo Biology, vol. 4, no. 3, pp. 281–286, 1985.
[8]
PRCT SSP, The Puerto Rican Crested Toad Species Survival Plan Website, 2006, http://www.crestedtoadssp.org/.
[9]
CBSG, “Population and habitat viability assessment for the Puerto Rican crested toad final report,” Tech. Rep., IUCN/SSC Conservation Breeding Specialist Group, Apple Valley, Minn, USA, 2005.
[10]
J. N. Brown and B. M. Peake, “Sources of heavy metals and polycyclic aromatic hydrocarbons in urban stormwater runoff,” Science of the Total Environment, vol. 359, no. 1–3, pp. 145–155, 2006.
[11]
P. J. Bryer, J. N. Elliott, and E. J. Willingham, “The effects of coal tar based pavement sealer on amphibian development and metamorphosis,” Ecotoxicology, vol. 15, no. 3, pp. 241–247, 2006.
[12]
Herrera Environmental Consultants, White Paper: Untreated Highway Runoff in Western Washington, Washington State Department of Transportation, Seattle, Wash, USA, 2007.
[13]
E. J. Hoffman, G. L. Mills, J. S. Latimer, and J. G. Quinn, “Urban runoff as a source of polycyclic aromatic hydrocarbons to coastal waters,” Environmental Science and Technology, vol. 18, no. 8, pp. 580–587, 1984.
[14]
B. Ngabe, T. F. Bidleman, and G. I. Scott, “Polycyclic aromatic hydrocarbons in storm runoff from urban and coastal South Carolina,” The Science of the Total Environment, vol. 255, no. 1–3, pp. 1–9, 2000.
[15]
P. Boffetta, N. Jourenkova, and P. Gustavsson, “Cancer risk from occupational and environmental exposure to polycyclic aromatic hydrocarbons,” Cancer Causes and Control, vol. 8, no. 3, pp. 444–472, 1997.
[16]
S. W. Burchiel and M. I. Luster, “Signaling by environmental polycyclic aromatic hydrocarbons in human lymphocytes,” Clinical Immunology, vol. 98, no. 1, pp. 2–10, 2001.
[17]
ENSR International, “Development of a standardized approach for assessing potential risks to amphibians exposed to sediment and hydric soils,” Tech. Rep. TR-2245-ENV, Naval Facilities Engineering Command, Port Hueneme, Calif, USA, 2004.
[18]
P. H. Langlois, A. T. Hoyt, P. J. Lupo, et al., “Maternal occupational exposure to polycyclic aromatic hydrocarbons and risk of neural tube defect-affected pregnancies,” Birth Defects Research A, vol. 94, no. 9, pp. 693–700, 2012.
[19]
J. E. Djomo, V. Ferrier, L. Gauthier, C. Zoll-Moreux, and J. Marty, “Amphibian micronucleus test in vivo: evaluation of the genotoxicity of some major polycyclic aromatic hydrocarbons found in a crude oil,” Mutagenesis, vol. 10, no. 3, pp. 223–226, 1995.
[20]
M. Fernandez, L. Gauthier, and A. Jaylet, “Use of newt larvae for in vivo genotoxicity testing of water: results on 19 compounds evaluated by the micronucleus test,” Mutagenesis, vol. 4, no. 1, pp. 17–26, 1989.
[21]
M. Fernandez, J. L'Haridon, L. Gauthier, and C. Zoll-Moreux, “Amphibian micronucleus test(s): a simple and reliable method for evaluating in vivo genotoxic effects of freshwater pollutants and radiations. Initial assessment,” Mutation Research, vol. 292, no. 1, pp. 83–99, 1993.
[22]
A. C. Hatch and G. A. Burton, “Effects of photoinduced toxicity of fluoranthene on amphibian embryos and larvae,” Environmental Toxicology and Chemistry, vol. 17, no. 9, pp. 1777–1785, 1998.
[23]
O. Marquis, A. Millery, S. Guittonneau, and C. Miaud, “Toxicity of PAHs and jelly protection of eggs in the Common frog Rana temporaria,” Amphibia Reptilia, vol. 27, no. 3, pp. 472–475, 2006.
[24]
P. D. Monson, D. J. Call, D. A. Cox, K. Liber, K. G. T, and Ankley, “Photoinduced toxicity of fluoranthene to Northern leopard frogs (Rana pipiens),” Environmental Toxicology and Chemistry, vol. 18, no. 2, pp. 308–312, 1999.
[25]
S. E. Walker, D. H. Taylor, and J. T. Oris, “Behavioral and histopathological effects of fluoranthene on bullfrog larvae (Rana catesbeiana),” Environmental Toxicology and Chemistry, vol. 17, no. 4, pp. 734–739, 1998.
[26]
A. R. Blaustein, J. M. Romansic, J. M. Kiesecker, and A. C. Hatch, “Ultraviolet radiation, toxic chemicals and amphibian population declines,” Diversity and Distributions, vol. 9, no. 2, pp. 123–140, 2003.
[27]
D. Sparling and Donald, “A review of the role of contaminants in amphibian declines,” in Handbook of Ecotoxicology, D. J. Hoffman, B. A. Rattner, and G. A. Burton, Eds., pp. 1099–1128, Lewis Publisheers, Boca Raton, Fla, USA, 2003.
[28]
Ministry of Environment of British Columbia, Environmental Protection Division, Water Quality: Ambient Water Quality Criteria for Polycyclic Aromatic Hydrocarbons (PAHs), 1993, http://www.env.gov.bc.ca/wat/wq/BCguidelines/pahs/pahs_over.html.
[29]
G. W. Suter II and C. L. Tsao, “Toxicological benchmarks for screening potential contaminants of concern for effects on aquatic biota: 1996 revision,” Tech. Rep. ES/ER/TM-96/R2, U.S. Department of Energy,, Oak Ridge, Tenn, USA, 1996.
[30]
Canadian Council of Ministers of the Environment, “Canadian water quality guidelines for the protection of aquatic life: summary table,” in Canadian Environmental Quality Guidelines, 1999, Canadian Council of Ministers of the Environment, Winnipeg, Canada, 2007.
[31]
United States Environmental Protection Agency, “Office of water and office of science and technology,” National Recommended Water Quality Criteria Report 4304T, 2009.
[32]
J. N. Huckins, J. D. Petty, and K. Booij, Monitors of Organic Chemicals in the Environment: Semipermeable Membrane Devices, Springer, New York, NY, USA, 2006.
[33]
A. Opperhuizen, V. D. E. W. Velde, and F. A. P. C. Gobas, “Relationship between bioconcentration in fish and steric factors of hydrophobic chemicals,” Chemosphere, vol. 14, no. 11-12, pp. 1871–1896, 1985.
[34]
K. Booij, H. M. Sleiderink, and F. Smedes, “Calibrating the uptake kinetics of semipermeable membrane devices using exposure standards,” Environmental Toxicology and Chemistry, vol. 17, no. 7, pp. 1236–1245, 1998.
[35]
J. N. Huckins, J. D. Petty, J. A. Lebo, C. E. Orazio, R. C. Clark, and V. L. Gibson, SPMD Technology Tutorial, USGS, 3rd edition, 2002, http://wwwaux.cerc.cr.usgs.gov/SPMD/SPMD-tech_tutorial.htm.
[36]
Y. Lu, Z. Wang, and J. Huckins, “Review of the background and application of triolein-containing semipermeable membrane devices in aquatic environmental study,” Aquatic Toxicology, vol. 60, no. 1-2, pp. 139–153, 2002.
[37]
D. R. Luellen and D. Shea, “Calibration and field verification of semipermeable membrane devices for measuring polycyclic aromatic hydrocarbons in water,” Environmental Science and Technology, vol. 36, no. 8, pp. 1791–1797, 2002.
[38]
Garmin International, GPSMAP 60CSx with Sensors and Maps Owner’s Manual, 2006.
[39]
D. Shea, “Environmental risk assessment,” in A Textbook of Modern Toxicology, E. Hodgson, Ed., pp. 501–517, John Wiley & Sons, Hoboken, NJ, USA, 3rd edition, 2004.
