Invasion and establishment of Ceratium furcoides (Dinophyceae) in an urban lake in Porto Alegre, RS, Brazil

Abstract

Ceratium furcoides has received attention due its invasive behavior in South America and consequent alterations in local phytoplankton communities. Pedalinhos Lake had been dominated by chlorophytes until 2015, when the first occurrence of this dinoflagellate was detected. In order to investigate the colonization process of this species, we monitored the meteorological variables and phytoplankton abundance of this urban lake on a weekly basis from September 2015 to September 2018. At the beginning of the invasion process (Year 1), a peak density of 10,170 ind.mL-1 was recorded, with a significant decrease to 23 ind.mL-1 , indicating an initial, unstable process of adaptation, with notable oscillation and reduction of cyanobacterial blooms. At this time, abundance of C. furcoides revealed inverse correlations with cyanobacteria, temperature, and insolation. In Year 2 there were a stabilization of the density of C. furcoides accompanied by increased cell size. Year 3 (starting in September 2017) was again marked by oscillations in the density of this dinoflagellate. This study contributes to improved understanding of the adaptation process of this dinoflagellate in an invaded environment and its effects on the local phytoplankton community.

Invasion strategies and establishment of Ceratium dinoflagellate in subtropical watersheds of Southern Brazil and its interaction with Microcystis cyanobacteria: I. Hydrographic Region of Uruguay

“…Keeping the cell levels within the standard ranges is essential to ensuring drinking water quality, as CORSAN provide domestic water supply to almost six million people. For the company and public health, it is much easier and low cost to do water treatment with not harmful Ceratium than with Microcystis and its possible toxicity.ConclusionsSince its introduction on the Southern Brazil in 2011(Cavalcante et al, 2013), C. furcoides has been establishing itself in the state, with an increasing number of records(Cavalcante et al, 2016;Silva et al, 2019). In our study, we showed that the species tended to stabilize and remain in most of the monitored water bodies of the HR Uruguay, and this has to be carefully considered by water management bodies, as this area is suitable, and the reservoirs are used to supply water to human populations.…”

“…These results suggest that local environmental characteristics (abiotic conditions and biotic interactions) are key for the development of C. furcoides in this Hydrographic Region, as these features can act as ecological lters, determining if the species can survive, reproduce, and persist in the habitat(Incagnone et al, 2015). Studies in other aquatic ecosystems in South America reveal that the presence of species differs in relation to the local conditions, ranging from a single record(Silva et al, 2018;Macêdo et al, 2021) to permanent frequency(Silva et al, 2012;Silva et al, 2019).…”

Influence of Environmental Factors on Occurrence of Cyanobacteria and Abundance of Saxitoxin-Producing Cyanobacteria in a Subtropical Drinking Water Reservoir in Brazil

“…In the Itupararanga reservoir, the cyanobacterial biomass declined when C. furcoides occurred, and the lowest cyanobacterial biomass (<1.00 µg chl a L −1 ) coincided with the riverine bloom of C. furcoides in October 2017. Invasion of C. furcoides has previously been shown to overturn the cyanobacterial dominance in a eutrophic tropical reservoir [61], and cause oscillation and reduction in cyanobacterial blooms in an urban lake [62]. These authors correlated the increased biomass of C. furcoides to a high-water transparency and high concentrations of N and P. Their observations appear to support the phytoplankton community modulations in the Itupararanga reservoir.…”

“…C. furcoides has been found in many Brazilian freshwater systems [56][57][58][59] and in the Itupararanga reservoir since 2010 [60]. Yet, few studies have dealt with the influence of C. furcoides on cyanobacterial population dynamics [61,62]. In the Itupararanga reservoir, the cyanobacterial biomass declined when C. furcoides occurred, and the lowest cyanobacterial biomass (<1.00 µg chl a L −1 ) coincided with the riverine bloom of C. furcoides in October 2017.…”

Spatial and temporal variability of cyanobacteria in two subtropical reservoirs: community composition, molecular and cyanotoxin analyses

“…furcoides has previously been shown to overturn the cyanobacterial dominance in a eutrophic tropical reservoir (Crossetti et al, 2018), and cause oscillation and reduction of cyanobacterial blooms in an urban lake (Silva et al, 2019). These authors correlated the increased biomass of C. furcoides to a high-water transparency and high concentrations of N and P. Their observations appear to support the phytoplankton community modulations in the Itupararanga reservoir.…”