DETECÇÃO DE DNA DE NEOSPORA CANINUM EM PARDELA-PRETA (PROCELLARIA AEQUINOCTIALIS) - RELATO DE CASO

A pardela-preta (Procellaria aequinoctialis) é uma ave procellariiforme, possui distribuição circumpolar ao longo de todo o oceano austral e migra para o hemisfério sul durante o inverno. É considerada uma espécie globalmente vulnerável pela União Mundial para a Conservação da Natureza (IUCN, 2020), devido a mortalidade acidental da espécie na pesca com espinhel e a degradação do seu habitat natural causando rápido declínio populacional. Neospora caninum é um protozoário intracelular formador de cisto que infecta aves e mamíferos. Os canídeos domésticos e silvestres são os hospedeiros definitivos e eliminam os oocistos nas fezes. As aves se infectam pela ingestão de alimentos e água contaminados com oocistos esporulados e por meio da ingestão de cistos em tecidos infectados (DONAHOE et al.,2015). O objetivo do presente estudo foi relatar a presença de DNA de Neospora caninum no coração de uma ave pardela-preta (P. aequinoctialis), fêmea e adulta. Amostras de tecidos (musculatura peitoral, cérebro e coração) foram coletadas para a realização do diagnóstico molecular de N. caninum e acondicionadas e fixadas em formalina 10% tamponada para análise histopatológica. A extração de DNA foi realizada com kit comercial. Para a amplificação de DNA N. caninum foi empregada a reação de cadeia da polimerase nested-PCR com os primers JS4, CT2c, JS4b e CT2b, que amplificam a região ITS1. Foi detectado DNA de N. caninum na amostra do coração. O produto da PCR foi submetido a purificação e sequenciamento. Foi obtida sequência nucleotídica (MW023246) que apresentou identidade de 99% com isolados de N. caninum depositados no Genbank. Na análise histopatológica os tecidos não apresentavam alteração macroscópica e a análise microscópica revelou congestão no miocárdio. O presente relato demonstra que a pardela-preta (P. aequinoctialis) pode ser naturalmente infectada por N. caninum e até o momento é primeira descrição nesta espécie de ave. Existem poucos estudos sobre a ocorrência de N. caninum na fauna marinha e as possíveis fontes de infecção ainda não foram bem elucidadas. Estudos demonstraram que mamíferos marinhos (lontras, morsas e golfinhos) estão expostos ao protozoário indicando uma possível contaminação das águas marinhas por oocistos O achado nesse relato sugere que as aves marinhas podem ser potenciais hospedeiros intermediários de N. caninum, atuando como sentinela e indicador de contaminação do ambiente marinho, além da sua participação no ciclo silvestre do parasito.

Incidental capture of seabirds in Argentinean side-haul trawlers

Summary Between April 2008 and July 2015, we conducted a total of 18 trips on five different side-haul trawlers fishing within the Argentine Exclusive Economic Zone, monitoring 486 hauls. We observed 100% of the hauls and monitored trawl cables for 136.7 hours, about 5% of the trawl effort, to identify the levels of seabird bycatch from net entanglements and collisions with trawl cables. A total of 35 net entanglements of White-chinned Petrels Procellaria aequinoctialis, Great Shearwaters Ardenna gravis, Black-browed Albatrosses Thalassarche melanophris and Southern Royal Albatross Diomedea epomophora were recorded, all of which occurred during the autumn and winter. Additionally, 656 seabird collisions against trawl cables were recorded including 39 heavy, 96 medium and 521 light. Further, we recorded nine Black-browed Albatrosses and two Great Shearwaters potentially dead. Although in the study fishery the number of deaths in the trawl cables could surpass the number of birds incidentally killed in nets, the mortality rate caused by the latter type of interaction far exceeds those observed in nets from other trawl fisheries operating in the Patagonian Shelf. Fortunately, 26% of the seabirds entangled in the net were recovered and released alive, which indicates that awareness and training in safe bird handling and release may improve captured seabird survival rates. The main objectives of this work is to highlight a little-studied source of seabird mortality by entanglement, to generate discussion on potential technical mitigation measures for side-haul trawl fisheries, and to propose crew training in safe handling and release of seabirds as an immediate mitigation measure.

Clustered or dispersed: testing the effect of sampling strategy to census burrow-nesting petrels with varied distributions at sub-Antarctic Marion Island

We compared systematic and random survey techniques to estimate breeding population sizes of burrow-nesting petrel species on Marion Island. White-chinned (Procellaria aequinoctialis) and blue (Halobaena caerulea) petrel population sizes were estimated in systematic surveys (which attempt to count every colony) in 2009 and 2012, respectively. In 2015, we counted burrows of white-chinned, blue and great-winged (Pterodroma macroptera) petrels within 52 randomized strip transects (25 m wide, total 144 km). Burrow densities were extrapolated by Geographic Information System-derived habitat attributes (geology, vegetation, slope, elevation, aspect) to generate island-wide burrow estimates. Great-winged petrel burrows were found singly or in small groups at low densities (2 burrows ha−1); white-chinned petrel burrows were in loose clusters at moderate densities (3 burrows ha−1); and blue petrel burrows were in tight clusters at high densities (13 burrows ha−1). The random survey estimated 58% more white-chinned petrels but 42% fewer blue petrels than the systematic surveys. The results suggest that random transects are best suited for species that are widely distributed at low densities, but become increasingly poor for estimating population sizes of species with clustered distributions. Repeated fixed transects provide a robust way to monitor changes in colony density and area, but might fail to detect the formation/disappearance of new colonies.

Year-round movements of white-chinned petrels from Marion Island, south-western Indian Ocean

White-chinned petrelsProcellaria aequinoctialisL. are the most frequently recorded procellariiform species in the bycatch of Southern Hemisphere longline fisheries. Our study investigated the year-round movements of ten adult white-chinned petrels (seven breeders, three non-breeders/suspected pre-breeders) from Marion Island tracked with global location sensor (GLS) loggers for three years. Additionally, 20 global positioning system (GPS) tracks were obtained from breeding white-chinned petrels during incubation (n=9) and chick-rearing (n=11). All GLS-tagged birds remained, year-round, in the area between southern Africa and Antarctica, not making any major east/west movements. Three core areas (50% kernels) were utilized: around the Prince Edward Islands (PEI; incubation and early chick-rearing),c. 1000 km west of PEI (pre-breeding and early incubation) and around South Africa (non-breeding birds). The only area where 50% utilization kernels overlapped with intensive longline fishing effort was off the Agulhas Bank (non-breeding season). Our results confirm the lack of foraging overlap between the two subspecies; nominate birds (South Georgia/south-western Indian Ocean) utilize separate areas toP. a. steadi(New Zealand/sub-Antarctic islands), and thus should be treated as separate management units. Knowledge of the year-round movements of a vagile species, such as the white-chinned petrel, is important for its continued conservation.

Acuariidae (Nematoda) in Procellariiformes (Aves) on the southern coast of Rio Grande do Sul, Brazil

Acuariidae nematodes are normally found in the digestive tract of aquatic birds, including Procellariiformes. Were examined Calonectris borealis (n = 4), Diomedea exulans (n = 1), Macronectes giganteus (n = 8), Thalassarche chlororhynchos (n = 5), Thalassarche melanophrys (n = 15), Procellaria aequinoctialis (n = 4), Puffinus gravis (n = 2) and Puffinus puffinus (n = 6), collected on the southern coast of RS, Brazil. A total of 16 birds (35.5%) were parasitized by two species of Acuariidae. Stegophorus diomedeae and Seuratia shipleyi were identified, with prevalences of 26.1% and 21.7%, respectively. Few studies on nematodes in Procellariiformes have been conducted. Here, the acuariids Seuratia shipleyi in Calonectris borealis and Procellaria aequinoctialis and Stegophorus diomedeae in Diomedea exulans, Procellaria aequinoctialis and Thalassarche chlororhynchos were reported for the first time.

Mouse predation affects breeding success of burrow-nesting petrels at sub-Antarctic Marion Island

We report the breeding success of four species of burrow-nesting petrels at sub-Antarctic Marion Island where house miceMus musculusare the sole introduced mammal. Feral catsFelis catuswere present on Marion for four decades from 1949, killing millions of seabirds and greatly reducing petrel populations. Cats were eradicated by 1991, but petrel populations have shown only marginal recoveries. We hypothesize that mice are suppressing their recovery through depredation of petrel eggs and chicks. Breeding success for winter breeders (grey petrelsProcellaria cinerea(34±21%) and great-winged petrelsPterodroma macroptera(52±7%)) were lower than for summer breeders (blue petrelsHalobaena caerulea(61±6%) and white-chinned petrelsProcellaria aequinoctialis(59±6%)) and among winter breeders most chick fatalities were of small chicks up to 14 days old. We assessed the extent of mouse predation by monitoring the inside of 55 burrow chambers with video surveillance cameras (4024 film days from 2012–16) and recorded fatal attacks on grey (3/18 nests filmed, 17%) and great-winged petrel chicks (1/19, 5%). Our results show that burrow-nesting petrels are at risk from mouse predation, providing further motivation for the eradication of mice from Marion Island.