Phalacrocorax Brasilianus Research Articles

A new species of Andracantha Schmidt (Acanthocephala, Polymorphidae) parasite of Neotropical cormorants, Phalacrocorax brasilianus (Gmelin) (Aves, Phalacrocoracidae) from southern Brazil

A new species of the genus Andracantha Schmidt, 1975, parasite of Neotropical cormorants, Phalacrocorax brasilianus (Gmelin, 1789), is described and compared to the other six species currently placed in the genus. The new species differs from the previously known species of Andracantha by having two inflations in the anterior region of the trunk and by having the testes in tandem in the central region of the body. These differences were also responsible for the diagnosis emendation of the genus now proposed. The orange pigmentation of the acanthocephalans recently collected from the intestine is documented for the first time in a species of this genus. This is the first record of adult specimens of any species of Andracantha in South America.

The occurrence of Pontoporia blainvillei (Gervais & d'Orbigny) (Cetacea, Pontoporiidae) in an estuarine area in southern Brazil

The toninha, or franciscana, Pontoporia blainvillei (Gervais & D'Orbigny, 1844), is an endemic species of cetacean of the southwestern Atlantic Ocean. There is little information on the occurrence of this species in its natural environment due to the great difficulty in sighting it. Systematized and non-systematized observations of franciscanas were made from December 1996 through November 2001 at Babitonga Bay, on the northern coast of Santa Catarina State, southern Brazil. The observations were made from small motorboats. A total of 79 observations were made, totaling 561 individuals. Up to 59.5% of the groups consisted of over four individuals and the average group size was seven. Calves were present in 30.4% of the observations. The species was found throughout the year within the bay and preferential areas were identified. Calves were registered during all seasons. Data are presented on the behavior (feeding, traveling, aerial behavior and behavior relating to the boats) and on inter-specific interactions with terns, cormorants [Phalacrocorax brasilianus (Gmelin, 1789)] and brown boobies [Sula leucogaster (Boddaert, 1783)]. The species is sympatric with the estuarine dolphin Sotalia guianensis (P. J. Van Bénéden, 1864) in the bay, but there was no record of interaction between them. The area of the bay represents an important refuge for the franciscana species.

Nematode parasites of the digestive tract in Neotropic cormorant chicks (Phalacrocorax brasilianus) from the River Cruces Ramsar site in southern Chile

The neotropic cormorant (Phalacrocorax brasilianus) breeding colony of the Rio Cruces Nature Sanctuary and Ramsar site was surveyed for nematode parasites in southern Chile. Moribund chicks (n=128) of different ages were inspected for anchored nematodes using complete guts. We tested if chicks harbored the same parasites as the adults feeding them. Besides the known Contracaecum rudolphii, third or fourth stage larvae of Pseudoterranova sp. and Anisakis (type I and II) were obtained in this waterbird species for the first time. Most parasites were located in the stomach and C. rudolphii was the dominant species. The prevalence and mean intensity of C. rudolphii infections and the prevalence of Anisakis type I larvae were significantly less (P<0.05) in the youngest age group of the birds. The prevalence of Pseudoterranova sp. larvae infection was similar among birds of different age. The mean intensity with Pseudoterranova sp. was significantly less (P<0.05) in younger birds and in Anisakis type I it was similar in different age groups.

Seasonal and interannual variation in waterbird abundance and species composition in the Melincu� saline lake, Argentina

We conducted 14 bird surveys in the Melincue saline lake from 1992 to 2002 (7 in winter and 7 in summer), and we detected 223,643 individuals belonging to 71 species from 17 families. The more abundant species were Fulica leucoptera, Larus maculipennis, Phoenicopterus chilensis, Plegadis chihi, Anas platalea, Himantopus mexicanus, and Rollandia rolland. Bird abundance was similar in winter and summer, whereas species composition differed between seasons. We recorded 65 species in summer and 59 in winter. P. chilensis and A. sibilatrix were more abundant in winter, whereas Ajaia ajaja, Phalacrocorax olivaceus, Ardea ibis, Sterna nilotica, Egretta thula, Mycteria americana, Charadrius collaris, A. versicolor, Calidris fuscicollis, and Ciconia maguari were more abundant in summer. Bird abundance in each survey was positively associated with the lake level. In summer surveys, the highest variation in species composition through the years was associated with water level fluctuations. Shorebirds predominated in those years with lower level, whereas the species that fed mainly on plants or vertebrates predominated in years with higher levels. Those species that fed on invertebrates (not shorebirds) and those that fed on invertebrates and plants predominated in years with intermediate level. The omnivorous species predominated in years of lower level. There were differences among transects in the proportion of different trophic groups. Short-term studies that do not take into account the particular dynamic of these systems may lead to erroneous generalisations. Thus, the long-term information of this study may be useful for management and conservation of species and system.

Growth and survival of neotropic cormorant (Phalacrocorax brasilianus) chicks in relation to hatching order and brood size

We investigated chick development and feeding rate in the neotropic cormorant, Phalacrocorax brasilianus, in a colony in Central Chile. The year of our study was characterized by relatively good foraging conditions. Brood sizes varied from two to five chicks, and hatching was asynchronous, with gaps of 0 to 6 days between the youngest and the oldest chick. Egg size declined over laying order in three-egg clutches, but not in four-egg clutches. Hatch weight did not vary with hatching position, irrespective of brood size. Chicks increased mass on average by 60 g/day between 8 and 20 days of age. Growth rates and survival to fledging depended on hatching position only in broods of four, where D-chicks grew slower and showed a higher pre-fledging mortality. There was a non-significant tendency that also A-, B-, and C-chicks in broods of four grew slower than in smaller broods. Average number of fledglings was 2.76. Feeding frequency decreased with chick age between the ages of 10–40 days. Four-chick broods received more feeds per day than smaller broods, leading to a similar per-chick feeding frequency across all brood sizes. D-chicks were clearly disadvantaged in growth and survival, and facultative brood reduction occurred.

DIVING BEHAVIOR AND FORAGING AREAS OF THE NEOTROPIC CORMORANT AT A MARINE COLONY IN PATAGONIA, ARGENTINA

The Neotropic Cormorant (Phalacrocorax brasilianus) is a widespread and abundant species distributed throughout the Neotropics. We report on diving behavior and foraging areas of Neotropic Cormorants in inshore marine waters of Patagonia, Argentina. Mean dive duration was 18.9 ± 5.3 sec and differed significantly among birds. Maximum dive duration was 43 sec. Birds spent 58–79% of their time at sea underwater. Mean recovery time at the surface between successive dives was 6.7 ± 1.5 sec, and was also significantly different among individuals. Mean diving efficiency (mean dive duration time/mean recovery time) was 2.6 ± 0.5 (range: 0.5–4.6). We were able to locate birds while feeding on 112 of 215 occasions. Almost 90% of mapped locations (68 feeding trips) were within 2.5 km of the colony. However, we did not receive a signal on 103 occasions, suggesting that foraging may also occur in waters outside the inlet where the colony was located. High variability in dive duration and recovery time is congruent with flexible foraging techniques and diet, as Neotropic Cormorants feed on both bottom and pelagic schooling fish.

Seabird eggs as bioindicators of chemical contamination in Chile

Seabird eggs were used as bioindicators of chemical contamination in Chile. Brown-hooded Gull ( Larus maculipennis), Kelp Gull ( Larus dominicanus), Trudeau's Tern ( Sterna trudeaui), Neotropic Cormorant ( Phalacrocorax brasilianus), and Pink-footed Shearwater ( Puffinus creatopus) eggs were sampled at different breeding sites during the 1990s. Mercury and organochlorines (PCBs, DDT, HCB, HCH, and PCP) were quantified to reveal the interspecific differences, spatial and temporal trends in contamination levels. Trudeau's Tern displayed the highest levels of mercury (486 ng g −1 wet weight). The highest ΣDDT concentrations were measured in Brown-hooded Gulls (726 ng g −1). PCB levels were similar among the species (102–236 ng g −1), but the composition of the PCB mixture was different in Pink-footed Shearwaters. With the exception of the Brown-hooded Gull, all species studied presented similar and low levels of organochlorines (ΣOHa). Residues of PCB and related compounds were not detected in any of the seabird eggs analyzed in Chile. Geographical variation was low, although levels of industrial chemicals were slightly higher in eggs from Concepción Bay, and agricultural chemicals in eggs from Valdivia. Also interannual variation was low, but some evidence was found of decreasing levels in gull eggs throughout the time of the study. The causes of the low levels and small variability in space and time of environmental chemicals in Chilean seabirds are discussed. We propose the use of seabirds in future monitoring of the development of chemical contamination in Chile.

Breeding distribution and abundance of seabirds on islands off north-central Chile

Between 1999 and 2003 we collected information on the breeding distribution and abundance of 12 seabird species occurring on nine islands off the coasts of north and central Chile (27°-33°S). The Peruvian booby Sula variegata was the most abundant seabird with a breeding population of ca. 18,000 pairs concentrated in two islands, followed by the Humboldt penguin Spheniscus humboldti with ca. 9,000 pairs, the largest colony being at Chanaral Island with ca. 7,000 pairs. Kelp gulls Larus dominicanus bred at all the surveyed sites in colonies of variable size, ranging from 40 to 2,000 pairs. Peruvian diving-petrels Pelecanoides garnotii and Peruvian pelicans Pelecanus occidentalis bred at restricted sites, but generally in large colonies. Magellanic penguins Spheniscus magellanicus, wedge-rumped storm-petrels Oceanodroma tethys, Neotropical cormorants Hypoleucos brasiliensis, guanay cormorants Leucocarbo bougainvillii, red-legged cormorants Stictocarbo gairmardi, band-tailed gulls Larus belcheri and Inca terns Larosterna inca nested at few sites forming small colonies (from a few to 150 pairs). Two new breeding sites are reported for the Peruvian diving-petrel and nesting of the wedge-rumped storm-petrel is confirmed on the Chilean coast for the first time. Despite protective status, most of the islands showed human disturbance, derived mainly from guano harvesting, egging and tourism. On at least five of these islands we were able to confirm introduced mammals including rats, rabbits and cats. These factors are likely to be detrimental to seabirds and thus demand detailed assessment. Further comprehensive ornithological surveys in other areas are needed so as to improve the scarce knowledge that we currently have on the seabird populations along the Chilean coast

The life cycle of Clinostomum complanatum Rudolphi, 1814 (Digenea, Clinostomidae) on the floodplain of the high Paraná river, Brazil.

The life cycle of the digenetic trematode Clinostomum complanatum was studied on the floodplain of the high Paraná river, Brazil. Sampling was done between June 1999 and June 2000. The mollusc Biomphalaria peregrina was the first intermediate host with a prevalence of infection of 0.75%. The fish Loricariichthys platymetopon, Hoplosternum littorale, Parauchenipterus galeatus, Hoplias malabaricus and Loricaria sp. were second intermediate hosts, with the prevalence varying from 2.45% ( H. malabaricus) to 60.8% ( L. platymetopon). The birds Ardea cocoi, Phalacrocorax brasilianus, Egretta alba and Egretta thula were definitive hosts, with the prevalence ranging between 5.5% ( E. thula) and 95% ( A. cocoi). The high prevalences in birds, especially in A. cocoi, suggest some kind of mechanism facilitating the predation of infected fish. The importance of the various hosts is discussed, and it is concluded that the floodplain of the high Paraná river has suitable conditions for the maintenance of the life cycle of C. complanatum.

Flutuações sazonais na abundância de Phalacrocorax brasilianus (Gmelin) no estuário do Saco da Fazenda, Itajaí, Santa Catarina, Brasil

The Neotropic cormorant is one of the most comm on estuarine birds along SantaCatarina's shore, especially in artisanal fishery areas, where it obtains food easily. During the period from January, 1996 to December, 1999, and of January to December, 2001, the cormorants were monitored monthly in the estuary. The population P. brasilianus (Gmelin, 1789) presented seasonal changes with the same annual pattern of increment of the abundance. Significant differences were recorded between the seasons and the medium abundance of birds. Those differences can be attributed to the events of the life cicle of the species and the oscillations in the estuary water temperature.

Cestodes of the family Dilepididae (Cestoda:Cyclophyllidea) from fish-eating birds in Mexico: a survey of species.

A survey of adults of dilepidid tapeworms (Cyclophyllidea) from piscivorous birds from Mexico is presented on the basis of the taxonomic evaluation of freshly collected and voucher specimens. The following species are reported (first records from Mexico marked with an asterisk): Cyclustera capito (Rudolphi, 1819); *C. ibisae (Schmidt & Bush, 1972); *Dendrouterina ardeae Rausch, 1955; *D. herodiae Fuhrmann, 1912; *D. papillifera (Fuhrmann, 1908); Glossocercus auritus (Rudolphi, 1819); *Neogryporhynchus cheilancristrotus (Wedl, 1855); Paradilepis caballeroi Rysavy & Macko, 1973; Paradilepis sp.; Parvitaenia cochlearii Coil, 1955; and Valipora mutabilis Linton, 1927. Dendrouteria herodiae is reported from America for the first time. New definitive hosts are Phalacrocorax olivaceus for C. capito, N. cheilancristrotus and P. caballeroi; Casmerodius albus and Egretta thula for G. auritus; and E. thula for D. herodiae. Data on the morphology of the rostellar hooks of all species, their hosts and distribution in Mexico are provided.

A Study of Neotropic Cormorants in Central Chile: Possible Effects of El Nino

-In 1997, one of the strongest recorded El Niiio-Southern Oscillation (ENSO) events occurred in the eastern Pacific. It caused strong oceanic and climatic anomalies, such as high sea surface temperatures (SST) and heavy rainfall along the eastern Pacific coast. We investigated the effects of this event on the reproductive ecology of the Neotropic Cormorant (Phalacrocorax brasilianus) in central Chile (36037'S; 73'03'W) by comparing the preEl Nifio season in 1996 with the 1997 El Nifio year. Fish landings immediately prior to the 1997 breeding season were notably lower and rainfall increased. In 1997, the number of breeding pairs declined by 71% from the previous year. During El Nifio, laying started 15 days later, was less synchronized and ended 35 days later. Although egg size, clutch size and hatching success did not differ significantly between the two years, the decrease in the breeding numbers in 1997 would have caused a considerable drop in offspring production. We suggest that poor environmental conditions may have caused young or poor quality birds to miss breeding in the El Nifio year. Since it appears that large El Nifio events are becoming more frequent, it is important to undertake more research into the ability and mechanisms of seabirds to cope with them. Received 12 February 2001, accepted 26June 2001.

Porphyrin Levels in Excreta of Sea Birds of the Chilean Coasts as Nondestructive Biomarker of Exposure to Environmental Pollutants

In this preliminary study on sea birds we propose the use of porphyrins in excreta as a biomarker of exposure to contaminants. Samples of excreta were obtained from colonies of brown pelicans (Pelecanus occidentalis thagus), neotropic cormorants (Phalacrocorax olivaceus), and kelp gulls (Larus dominicanus) in three areas of the south coast of Chile with different human impact (Tubul, Talcahuano, and Valdivia). They were analyzed for porphyrin content (copro-, uro-, and protoporphyrins and total porphyrins) by a rapid fluorimetric method and by HPLC. The main outcomes of the study were: (a) kelp gulls and neotropic cormorants living in areas with high human impact showed a clear capacity to accumulate and eliminate porphyrins in the excreta; (b) species-related accumulation capacities are likely, as shown by the different levels found in different species living in the same area; (c) the porphyrin profile obtained by fluorimetry and HPLC showed a higher percentage of protoporphyrin than the other porphyrins; (d) although the fluorimetric method of Grandchamp is semiquantitative, it was found to be sensitive enough to detect differences in samples from field studies. The positive results of this preliminary study make it possible to propose this nondestructive method for a variety of field applications.

Descartes da pesca do camarão sete-barbas como fonte de alimento para aves marinhas

From July 1996 to June 1997, in Armacao do Itapocoroy, Penha, Santa Catarina State, Brazil, monthly census were done in three areas of traditional fishery and Itacolomis islands. A total of 10021 seabirds were registered, belonging to eight species, five genus and four families. The average number of seabirds per dragging varied between 80,2 and 113,6. Sterna spp, appeared at first in 43,3% of the released by-catch, followed by Larus dominicanus Lichtenstein, 1823, Fregata magnificens Matheus, 1914, Phalacrocorax brasilianus (Humboldt, 1805) and Sula leucogaster Boddaert, 1783. The average size of the fish consumed by the seabirds oscillated from 8,3 cm (Sterna spp.) to 18,5 cm (F. magnificens), with an average time from 6,12 to 7,55 minutes per by-catch released. In general, seabirds use 84,0% of the by-catch fish as a feeding source.

Persistent organochlorine pollutants in eggs of colonial waterbirds from Galveston Bay and East Texas, USA

Eggs of neotropic cormorants (Phalacrocorax brasilianus), black-crowned night herons (Nycticorax nycticorax), and great egrets (Ardea alba) nesting on several locations in Galveston Bay (TX, USA) and at two control sites outside the bay were collected during April-May 1996 and analyzed for chlorinated pesticides, PCBs, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans. Additionally, concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQs) were determined by use of relative potency factors (TEQs) or the H4IIE-luc bioassay TCDD-EQs. Concentrations of 1,1,-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) were greater in eggs of neotropic cormorants from Alexander Island (mean = 1,040 ng/g wet wt) in the Houston Ship Channel (Houston, TX, USA) and in those from Telfair Island (mean = 1,460 ng/g wet wt), a reference location outside the bay, than in most locations inside the bay (mean range = 119-453 ng/g wet wt). Mean PCB concentrations were greater in eggs of neotropic cormorants from Alexander Island (mean = 5,720 ng/g wet wt) than in eggs of cormorants from areas farther away from the ship channel, including two reference sites outside the bay (mean range = 404-3,140 ng/g wet wt). The TCDD was the main dioxin congener detected in eggs from all locations within Galveston Bay. Instrumental TEQs in eggs ranged from 67 pg/g wet weight at control sites to 452 pg/g wet weight at Alexander Island. Concentrations of TCDD-EQs determined in the H4IIE assay were correlated with instrumental TEQs and were greater in eggs of cormorants from islands within the bay, although these were farther away from the ship channel. Overall, concentrations of DDE, PCBs, TCDD, and TCDD-EQs were less than the threshold levels known to affect reproduction. However, some eggs contained concentrations of total PCBs or DDE greater than what would elicit adverse effects on birds. No identifiable deformities or abnormalities were detected in embryos collected from all sites.

PERSISTENT ORGANOCHLORINE POLLUTANTS IN EGGS OF COLONIAL WATERBIRDS FROM GALVESTON BAY AND EAST TEXAS, USA

Eggs of neotropic cormorants (Phalacrocorax brasilianus), black-crowned night herons (Nycticorax nycticorax), and great egrets (Ardea alba) nesting on several locations in Galveston Bay (TX, USA) and at two control sites outside the bay were collected during April–May 1996 and analyzed for chlorinated pesticides, PCBs, polychlorinated dibenzo-p-dioxins, and polychlor-inated dibenzofurans. Additionally, concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQs) were determined by use of relative potency factors (TEQs) or the H4IIE-luc bioassay TCDD-EQs. Concentrations of 1,1,-dichloro-2,2-bis(p-chlo-rophenyl)ethylene (DDE) were greater in eggs of neotropic cormorants from Alexander Island (mean = 1,040 ng/g wet wt) in the Houston Ship Channel (Houston, TX, USA) and in those from Telfair Island (mean = 1,460 ng/g wet wt), a reference location outside the bay, than in most locations inside the bay (mean range = 119–453 ng/g wet wt). Mean PCB concentrations were greater in eggs of neotropic cormorants from Alexander Island (mean = 5,720 ng/g wet wt) than in eggs of cormorants from areas farther away from the ship channel, including two reference sites outside the bay (mean range = 404–3,140 ng/g wet wt). The TCDD was the main dioxin congener detected in eggs from all locations within Galveston Bay. Instrumental TEQs in eggs ranged from 67 pg/g wet weight at control sites to 452 pg/g wet weight at Alexander Island. Concentrations of TCDD-EQs determined in the H4IIE assay were correlated with instrumental TEQs and were greater in eggs of cormorants from islands within the bay, although these were farther away from the ship channel. Overall, concentrations of DDE, PCBs, TCDD, and TCDD-EQs were less than the threshold levels known to affect reproduction. However, some eggs contained concentrations of total PCBs or DDE greater than what would elicit adverse effects on birds. No identifiable deformities or abnormalities were detected in embryos collected from all sites.

Aves acuáticas del estero La Manzanilla, Jalisco, México

Con la finalidad de conocer la distribución temporal y el uso del hábitat por las especies de aves acuáticas costeras del estero La Manzanilla, Jalisco, México, se realizaron censos mensuales de marzo de 1997 a febrero de 1998, excepto septiembre. En las once visitas realizadas en el estero se observó un total de 4180 aves (95.24% residentes y 4.76% migratorias), distribuidas en 45 especies (29 residentes y 16 migratorias). Las aves migratorias y residentes presentaron fluctuaciones estacionales en su abundancia; en el primer grupo la mayor abundancia se observó en enero y febrero y estuvo determinado principalmente por la presencia del Cormorán Bicrestado (Phalacrocorax auritus) y el Petrel Mínimo (Oceanodroma microsoma), mientras que en el segundo grupo las mayores abundancias fueron observadas en marzo y junio, y en todos los casos fueron influenciadas por el Cormorán Neotropical (Phalacrocorax brasilianus) y la Cigüeña Americana (Mycteria americana). El estero no fue un paradero importante para las aves migratorias. Sin embargo, para las aves residentes fue apostadero durante la mayor parte del año.

Infection by Contracaecum rudolphii (Nematoda: Anisakidae) in the Neotropic cormorant Phalacrocorax brasilianus, and fishes from the estuary of the Valdivia river, Chile

Seasonal parameters of infection by the nematode Contracaecum rudolphii in the Neotropic cormorant Phalacrocorax brasilianus (Phalacrocoracidae) and their relation with feeding and infection in fishes from River Valdivia, Chile, were determined. The prevalences of infection in birds were similar during seasons, whereas mean intensity and percentages of adult gravid females were higher in spring and summer, respectively. For fishes no seasonal differences were found in infection. Cormorant diet varied seasonally in relation to fish prey consumed and this can be related to seasonal differences in infection parameters of birds. The high infection in birds should be considered as a potential risk for salmoniculture.

Records of the bird capillariid nematode Ornithocapillaria appendiculata (Freitas, 1933) n. comb. from freshwater fishes in Mexico, with remarks on Capillaria patzcuarensis Osorio-Sarabia et al., 1986.

Re-examination of capillariid specimens collected from the freshwater fish Chirostoma estor Jordan from Lake Pátzcuaro in 1985-1986 and deposited as paratypes of Capillaria patzcuarensis Osorio-Sarabia, Pérez-Ponce de León & Salgado-Maldonado, 1986 showed that their morphology was in contradiction with the description of this species and, in fact, they could be identified as the species originally described as C. appendiculata Freitas, 1933 from cormorants Phalacrocorax brasilianus (Gm.) in Brazil; conspecific capillariid specimens were later recorded from Chirostoma estor and Cyprinus carpio L. from the same locality. This species and two others are transferred to Ornithocapillaria Barus & Sergeeva, 1990 as O. appendiculata (Freitas, 1933) n. comb., O. carbonis (Dubinin & Dubinina, 1940) n. comb., and O. phalacrocoraxi (Borgarenko, 1975) n. comb. This is the first record of O. appendiculata in Mexico. Its occurrence in fishes suggests that these nematodes may be acquired by their fish hosts accidentally while feeding on cormorant excrement containing mature nematodes. A female capillariid collected from one of 110 Chirostoma estor examined from this locality in April, 1998 was identified as Capillaria patzcuarensis. Both capillariid species are briefly described and illustrated.

Nondestructive biomarkers of exposure to endocrine disrupting chemicals in endangered species of wildlife

This paper explores the problem of endocrine disrupting chemicals (EDCs) from the ecotoxicological point of view, focusing on nondestructive biomarkers of exposure to EDCs for risk assessment of endangered species of wildlife. Several EDCs, such as polyhalogenated aromatic hydrocarbons and toxic metals, tend to be biomagnified in the terrestrial and particularly the marine food chains. Top predators tend to accumulate high concentrations of these contaminants which places them in a situation of high toxicological risk. Hence, there is a need to develop nondestructive techniques, such as nondestructive biomarkers, for hazard assessment, protection, and conservation of endangered species exposed to EDCs. The biological materials proposed for this approach (for example blood, faeces, fur, skin biopsy specimens) are easily obtained with minimal stress for individuals and populations. Some validation data are reported on porphyrins in sea bird excreta ( Larus dominicanus, Phalacrocorax olivaceus, Pelecanus occidentalis thagus), as nondestructive biomarkers of exposure to organochlorines, and on benzopyrene monooxygenase activities in marine mammal skin biopsy specimens ( Stenella coeruleoalba, Balaenoptera physalus), as early indicators of exposure to p,p′-DDE and other endocrine disrupting organochlorines.