ABSTRACT The Paranaguá Estuarine Complex (PEC) is internationally recognized for its economic, social, and environmental relevance. It is designated as a World Heritage site and part of selected wetland areas that protect and conserve biodiversity, especially waterbirds. However, it has historically been under pressure from human activities, and the information about waterbirds that use the region is fragmented. Thus, with this study, we sought to establish a baseline for the waterbirds using the bays of the PEC, considering aspects such as species richness, abundance, and conservation status. On board a boat, we conducted monthly surveys from March 2020 to February 2021 along 36 transects equally distributed among the three main bays of the PEC. We recorded 46 species distributed across 17 families and eight orders. The order Charadriiformes displayed the highest number of species, totaling 19. Among them, the Neotropic Cormorant, identified as Nannopterum brasilianum, stood out with the highest number of occurrences. Furthermore, we documented eight migratory species from the Northern Hemisphere, including Calidris pussilla, the Semipalmated Sandpiper, considered near threatened by the International Union for Conservation of Nature Red List. Additionally, we observed seven other species classified under some threat of extinction. Our results revealed that the PEC harbors a rich and diverse assemblage of waterbirds consisting of resident and migratory species, many of which are at some risk of population decline. Therefore, we reinforce the importance of continuous monitoring in the region, which can serve as a basis for public policies, supporting management and conservation strategies focused on waterbirds and the wetlands on which they depend. (PEC economic social relevance biodiversity However activities fragmented Thus study richness abundance status boat 202 3 4 1 orders 19 them Cormorant brasilianum occurrences Furthermore Hemisphere pussilla Sandpiper List Additionally extinction decline Therefore policies depend 20 2

Resumo As capturas incidentais de peixes no arrasto do camarão representam um recurso abundante para a alimentação de muitas aves, sobretudo para a gaivota Larus dominicanus. O presente estudo avaliou a influência do defeso da pesca de arrasto do camarão sobre a dieta de L. dominicanus no litoral do estado do Paraná. Entre dezembro de 2013 e agosto de 2014 foram coletados 10 pellets alimentares por mês em duas áreas distintas, em períodos sem e com a influência do defeso do camarão sete-barbas. Ao todo, foram identificados 920 peixes, divididos em quatro famílias e 15 espécies, com destaque para a família Sciaenidae, com 11 espécies. Foram identificadas diferenças na abundância e biomassa das espécies entre as áreas e entre os períodos de pré-defeso, defeso e pós-defeso. Diferenças em relação ao comprimento total médio das espécies só foram encontradas entre o pré-defeso e defeso em uma das áreas. Com este trabalho, foi possível observar a forte relação entre L. dominicanus e a pesca de arrasto do camarão, a composição das espécies identificadas nos pellets e as estimativas de comprimento seguem o mesmo padrão do que a literatura traz para os peixes descartados nas atividades de arrasto.

Abstract Fish that are incidentally caught by shrimp trawling represent a predictable and abundant resource for feeding several bird species, especially for the gull Larus dominicanus. This fishing activity is subject to disruptions throughout the year during closed fishing seasons, when other fishing modalities are exercised, which can alter the composition, abundance and size of the fish bycatch. This study evaluated the influence of the restriction of fishing period of shrimp (closed season) on the diet of L. dominicanus, on the Paraná State coast. From December 2013 to August 2014, 10 pellets were collected per month in two distinct areas that have shrimp trawl fishery as the main economic activity: one continental and another in an estuarine island. In total, 920 fish were identified, divided into four families and 15 species, especially the family Sciaenidae with 11 species. There were differences in abundance and biomass of species between areas and between seasons of pre-closure, closure and post-closure. Differences for the mean total length of the species were only detected between the pre-closed and closed seasons in one area. This study evidenced the strong relationship between L. dominicanus and the shrimp trawl fishery, the species composition identified in the pellets and their respective morphometric measurements follow the same pattern of the literature for fish discarded in trawling activities.