The average lethal concentration of un-ionized ammonia (48-h LC 50 NH 3 ) has been determined by the static assay for larvae (0·48 mg l 1 ) and alevins (0·92 mg l 1 ) of ' pacamã ' Lophiosilurus alexandri. Studies by light and scanning electron microscopes at the greatest concentration of NH 3 (0·99 mg l 1 for larvae and 1·5 mg l 1 for alevins) have shown that the changes in the cells and branchial tissue were more intense in the alevins. 1996 The Fisheries Society of the British Isles

This study analysed sea turtle strandings on the coast of Paraíba State, Northeastern Brazil, from August 2009 to July 2010. A total of 124 strandings were recorded in this period: green turtle Chelonia mydas (n = 106), hawksbill Eretmochelys imbricata (n = 15), olive ridley Lepidochelys olivacea (n = 2) and loggerhead Caretta caretta (n = 1). Of all turtles for which the Curved Carapace Length (CCL) was measured (n = 122), only 12 individuals (9.7%) were adults. Twenty individuals had synthetic anthropogenic debris in the gastrointestinal tract. Other traces of human interactions were observed in 43 individuals, such as injuries caused by entanglement in fishing lines or nets, collisions with vessels, direct contact with oil spills and lesions caused by sharp or spiked objects. Moreover, in 28.5% of the stranded turtles, the presence of external tumors was noticed, suggestive of fibropapillomatosis and in 9.7%, shark bite marks were observed. Of the 107 individuals that were sexed, 76 were females and 31 were males. Most turtles (72.6%) became stranded during the spring/summer (between October and March). We found evidence of human interactions (injuries) in half of the strandings, but in most cases it was not possible to determine if such interactions were the cause of death. A logistic regression found a significant relationship between CCL, ingestion of debris and lesions caused by sharks or spiked objects. Systematic data collection from stranded sea turtles can provide useful biological information, such as seasonal and spatial patterns in their occurrence and mortality, age structure, sex ratio and diet, as well as possible mortality causes.Keywords: threatened species, human impact, beach strandings, green sea turtle. Padrões e inferências associadas com encalhes de tartarugas marinhas no Estado da Paraíba, Nordeste do Brasil ResumoEste estudo analisou encalhes de tartarugas marinhas na costa do Estado da Paraíba, Nordeste do Brasil, de agosto de 2009 a julho de 2010. Neste período, 124 encalhes foram registrados: tartaruga-verde Chelonia mydas (n = 106), tartaruga-de-pente Eretmochelys imbricata (n = 15), tartaruga-oliva Lepidochelys olivacea (n = 2) e cabeçuda Caretta caretta (n = 1). Dentre todas as tartarugas que tiveram o Comprimento Curvilíneo da Carapaça (CCC) medido (n = 122), apenas 12 indivíduos (9,7%) foram considerados adultos. Vinte indivíduos tinham detritos antropogênicos sintéticos no trato gastrointestinal. Em 43 indivíduos, outros vestígios de interações humanas foram observados, tais como lesões causadas por emaranhamento em linhas ou redes de pesca, colisões com embarcações, contato direto com derramamentos de óleo e lesões causadas por objetos perfurocortantes. Além disso, em 28,5% das tartarugas encalhadas, foi observada a presença de tumores externos sugestivos de fibropapilomatose e em 9,7%, foram observadas marcas de mordidas de tubarão. Dos 107 indivíduos sexados, 76 eram fêmeas e 31 eram machos. A maioria das tartarugas (72,6%) encalhou durante a primavera/verão (entre ...

ABSTRACT. Currently, plastics are recognized as a major pollutant of the marine environment, representing a serious threat to ocean wildlife. Here, we examined the occurrence and effects of plastic ingestion by sea turtles found stranded along the coast of Paraíba State, Brazil from August 2009 to July 2010. Ninety-eight digestive tracts were examined, with plastic found in 20 (20.4%). Sixty five percent (n = 13) of turtles with plastic in the digestive tract were green turtles (Chelonia mydas), 25% (n = 5) were hawksbills (Eretmochelys imbricata), and 10% (n = 2) were olive ridley (Lepidochelys olivacea). More plastic was found in the intestine (85%) than in other parts of the gastrointestinal tract. We observed complete blockage of the gastrointestinal tract due to the presence of plastic in 13 of the 20 turtles that had ingested plastic. No correlation was found between the curved carapace length (CCL) and the number or mass of the plastic ingested items. Significant differences were found between the intake of hard and soft plastic and the ingestion of white/transparent and colored plastic, with soft and white/transparent plastics being more commonly ingested. This study reveals the serious problem of plastic pollution to sea turtles at the area. KEYWORDS. Marine debris ingestion, gastrointestinal blockage, Chelonia mydas, Eretmochelys imbricata, Lepidochelys olivacea.RESUMO. Ingestão de plástico por tartarugas marinhas no estado da Paraíba, Nordeste do Brasil. Atualmente, os plásticos são reconhecidos como um dos principais poluentes do ambiente marinho, representando uma séria ameaça para a vida marinha. Neste trabalho, nós examinamos a ocorrência e os efeitos da ingestão de plástico por tartarugas marinhas encontradas encalhadas ao longo da costa do estado da Paraíba, Brasil, de agosto de 2009 a julho de 2010. Noventa e oito tratos gastrointestinais foram examinados e plásticos foram encontrados em 20 (20,4%). Sessenta e cinco por cento (n = 13) das tartarugas com plástico no trato gastrointestinal eram da espécie verde (Chelonia mydas), 25% (n = 5) eram da espécie pente (Eretmochelys imbricata) e 10% (n = 2) eram da espécie oliva (Lepidochelys olivacea). Foi encontrado mais plástico no intestino (85%) do que em outras partes do trato gastrointestinal. Observou-se o completo bloqueio do trato gastrointestinal, devido à presença de plástico, em 13 das 20 tartarugas que ingeriram plástico. Não foi encontrada correlação entre o comprimento curvilíneo de carapaça (CCC) e o número ou massa dos itens plásticos ingeridos. Diferenças significativas foram encontradas entre a ingestão de plástico rígido e flexível e entre a ingestão de plástico branco/ transparente e colorido, com os flexíveis e brancos/transparentes sendo ingeridos com mais frequência. Este estudo revelou o grave problema da poluição por resíduos plásticos para as tartarugas marinhas nesta área. PALAVRAS-CHAVE. Ingestão de lixo marinho, bloqueio gastrointestinal Chelonia mydas, Eretmochelys imbricata, Lepidochelys olivacea.