Many species of shorebirds migrate long distances from their overwintering grounds in the southern hemisphere to breeding grounds in the northern hemisphere. The coastal intertidal zone, consisting of sand and mud flats exposed at low tide and covered at high tide, is heavily used as a migratory stopover or overwintering habitat. Understanding the spatial distribution of sediment types at these stopover sites is a critical step for understanding habitat use by shorebird species. Due to their importance as overwintering and stopover habitat for the imperiled western Atlantic subpopulation of the shorebird, the red knot (Calidris canutus rufa), as well as other migratory shorebirds, the northern coast of Brazil between Pará and Maranhão, and Bahía Lomas in northern Tierra del Fuego, Chile, were selected for further investigation as to the applicability of remotely sensed characterization of the intertidal flat habitats. Examination of the Landsat 8 multispectral reflectance and Sentinel-1 SAR backscatter reveals that sand and mud represent endmembers at opposite ends of a continuous gradient in feature space. While remotely sensed data can be used to discriminate between mud and sand intertidal types, the spectral relationships varied between the two very different geographic locations. The inclusion of both multispectral and radar sensing imagery can lead to important insights about the physical properties of the sediment that would be omitted by using one data source alone. Spectral unmixing techniques in Google Earth Engine were used to map the intertidal zone into general sediment classes spanning the gradient (i.e., mud, sandy mud, muddy sand, and sand). Comparison of the mapped outputs with field reference data suggests that mapping of mud- vs. sand-dominated areas can be accomplished with reasonable accuracy (overall accuracy of 75%).

Migratory shorebirds are currently at significant risk, with populations of multiple species dropping globally, often due to habitat disruption and loss. The coast of northern Brazil, along the states of Pará and Maranhão, encompasses one of the broadest expanses of shorebird overwintering habitat for many shorebird species in the Atlantic Americas Flyway. Delineating how current management protects shorebird habitat is an important first step to identifying gaps in protections that then need to be prioritized. Different frameworks of conservation decision-making, such as focusing on flagship, umbrella, or biodiversity, can be used to prioritize what habitat needs to be protected. Understanding the effects of these different conservation perspectives is key to making informed management decisions. Multiple dates of Landsat 8 imagery at different tidal stages were used to identify intertidal habitats for further analysis. MaxEnt species distribution models were derived for each species using remote sensing and landscape metrics, as well as point-count survey data collected during the winters of 2016 and 2017. Landsat 8 and Sentinel 2 image data were included as direct inputs to the model rather than interpreted and mapped first into different habitat types. The resulting Maxent models successfully delineated between presence and absence locations for five of the eight target shorebird species. The model outputs were combined to map the intertidal habitat covered under several different management scenarios. These scenarios included using red knots as a flagship species, semipalmated sandpipers as an umbrella species, and species richness as a metric of shorebird diversity. Slightly more than 25% of delineated intertidal habitat was found to be included within a designated Marine Extractive Reserve, with three major gaps in current protections identified. The flagship, umbrella, and biodiversity perspectives result in different prioritizations of these distinct locations. While umbrella and diversity approaches are successful at protecting diverse communities, community assemblages of rarer or specialist species, such as the red knots, may fall outside their protective shadows. A hybrid approach that uses both diversity and the extent of rare flagship species produces results that best meet the management goals of identifying gaps in existing conservation to protect the most at-risk species while conserving the diverse assemblages they coexist with.

Las aves playeras incluyen varias especies asociadas a los humedales, muchas de las cuales son migratorias, las cuales son extremadamente dependientes de la Zona Costera. Se concentran en ambientes costeros para descansar y forrajear durante su ciclo migratorio, o para reproducirse en el caso de las especies residentes. El desarrollo de actividades socioeconómicas en la costa ha resultado en amenazas para las aves y la degradación de sus hábitats, lo que ha provocado una fuerte disminución de la población de muchas especies. Diferentes esfuerzos internacionales y nacionales han buscado incluir acciones para su conservación en la planificación territorial. En Brasil, el Plan Nacional para la Conservación (PAN) de las aves playeras migratorias identificó 43 áreas estratégicas de acción prioritaria hasta el año 2024, período de su segundo ciclo de implementación. En este trabajo proponemos que las áreas estratégicas sean especialmente consideradas en el Plan Nacional de Manejo Costero y en los Planes de Manejo Integrado. Describimos la historia del PAN y los criterios que llevaron a la identificación de las áreas. Presentamos las áreas estratégicas, contextualizándolas en cuanto a su ubicación y principales amenazas. Defendemos la combinación de diferentes instrumentos de planificación y políticas públicas que se centren en la conservación de las aves y la zona costera para resaltar las confluencias y la pertinencia de la integración de los diferentes planes. Finalmente, recomendamos un conjunto de iniciativas que pueden resultar en ganancias no solo para las aves playeras sino también para toda la sociedad que disfruta de los servicios ecosistémicos derivados de un territorio bien gestionado desde el punto de vista ambiental.

A criação de três Áreas de Proteção Ambiental Marinhas pela Secretaria de Meio Ambiente de São Paulo, em 2008, totalizando 1.138.067,68 hectares, estendendo-se de Ubatuba a Cananéia, na zona costeira marinha paulista fez emergir a questão da formalização das Águas Jurisdicionais em 15 municípios no Estado e os respectivos direitos e responsabilidades. Apresentamos proposta a esta divisão de interesses e deveres no Mar, com mapa estabelecendo divisas preliminares às futuras deliberações consentâneas na sociedade. Descrevemos o processo e as bases de proposição das Áreas de Proteção Ambiental Marinhas e apresentamos seus dados principais.

The creation of three Marine Environmental Protection Areas by the Secretary of the Environment of São Paulo, in 2008, totaling 1,138,067.68 hectares, extending from Ubatuba to Cananéia, in the coastal marine zone of São Paulo, raised the issue of formalizing the Waters Courts in 15 municipalities in the State and the respective rights and responsibilities. We present a proposal for this division of interests and duties at Sea, with a map establishing preliminary boundaries for future deliberations in society. We describe the process and bases for proposing Marine Environmental Protection Areas and present their main data. DOI:https://doi.org/10.56238/Connexpemultidisdevolpfut-110