Abstract Cyanobacterial blooms are a potential threat to human communities and ecosystems. Since the late 1980s, researchers have reported harmful cyanobacterial colonies in Patos Lagoon (PL), the largest coastal lagoon in South America. Most studies concerning harmful blooms in PL have focused on its biology and on its southernmost estuarine region, with little information about its displacement inside the lagoon and the influence of physical forces on its dynamics. This study uses satellite-derived information (normalized difference chlorophyll-a index – NDCI), river discharge data, and meteorological data (wind speed and direction, rainfall, and air temperature) to analyze two bloom episodes in PL, during the austral summer of 2019/2020, specifically in its larger, limnic portion. A 30-year meteorological time series was used to contrast the same summer period. Two remote sensing images from Sentinel-2 were taken of PL margins, near their central portion. The summer of 2019/2020 was drier when compared with the historical data, characterizing low river discharge. This environmental condition was coupled with high temperature, which implies thermal stratification in summer even at 2-m depth sites, which might have promoted cyanobacterial growth and accumulation inside PL. Moreover, weak winds (<<6 m s−1) seemed to accumulate cyanobacterial patches on the water surface, including after vertical mixing caused by strong winds (>6 m s−1). The NDCI values represented the two days of blooms, with higher values occurring under higher water temperatures and low wind speeds.

Neste trabalho foi estudada a biologia floral do cacaui (Theobroma speciosum). Os botões florais romperam a suas sépalas às 14h com a maior freqüência às 22h, estando completamente abertas às 6 h da manhã seguinte. Os braços estigmáticos apresentaram exsudato, com o nível máximo entre 06 e 10 horas da manhã do mesmo dia. As lígulas mais as cógulas foram as partes florais com odor mais intenso. As flores estavam receptivas durante toda a manhã e à tarde do dia da antese. Aproximadamente 65% das flores foram naturalmente polinizadas, mas somente 0,85% formou fruto. A abscisão ocorreu com maior frequência às 6 h do segundo dia após a antese. Polinizações controladas mostraram que o cacauí é uma espécie auto-incompatível.

In the present work, cacauhy's (Theobroma speciosum) floral biology was studied. Flower buds split their sepals at 14h reaching its maximum at 22h, but all flowers were fully opened at 6:00 h of the following morning. Stigmatic branches showed exudates, reaching maximum between 6:00 h and 10:00 h at the same day. Ligules and petal hoods were the floral parts with highest intensity of odour. Flowers were receptive along all the morning and noon of the anthesis day. Approximately 65% of the flowers were naturally pollinated, but only 0.85% of them set a fruit. Abscission occurred on its higher frequency at 6:00 h of the second day after anthesis. Controlled pollinations showed that cacauhy was self-incompatible species.