Evaluating Underwater Light Availability for Phytoplankton: Mean Light Intensity in the Mixed Layer versus Attenuation Coefficient

Domingues, Rita B.; Barbosa, Ana B.

doi:10.3390/w15162966

Cited by 3 publications

(1 citation statement)

References 39 publications

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“…The higher Chl-a at the innermost stations can be explained by higher nutrient concentrations, also associated with WWTP discharges, higher mean light intensity in the turbid but shallower water column [139], lower advective losses at these stations compared to the outer station, and even direct importation of phytoplankton from the WWTP effluent or Almargem stream. At ALM 1750, the intense exchange with coastal waters, with the Chl-a generally below 1 µg L −1 , further contributed to the dilution of the phytoplankton biomass.…”

Section: Spatial-temporal Variability In Phytoplankton Biomass and Ab...mentioning

confidence: 97%

Patterns and Predictors of Phytoplankton Assemblage Structure in a Coastal Lagoon: Species-Specific Analysis Needed to Disentangle Anthropogenic Pressures from Ocean Processes

Lima,

Barbosa,

Correia

et al. 2023

Water

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Phytoplankton are dominant primary producers and key indicators in aquatic ecosystems. Understanding the controlling factors on the structure of phytoplankton assemblages is fundamental, but particularly challenging at the land–ocean interface. To identify the patterns and predictors of phytoplankton assemblage structure in the Ria Formosa coastal lagoon (south Portugal), this study combined phytoplankton abundance along a transect between the discharge point of a wastewater treatment plant and a lagoon inlet, over two years, with physico-chemical, hydrographic, and meteo-oceanographic variables. Our study identified 147 operational taxonomic units (OTUs), and planktonic diatoms (60–74%) and cryptophyceans (17–25%) dominated the phytoplankton in terms of abundance. Despite strong lagoon hydrodynamics, and the lack of spatial differences in the phytoplankton abundance and most diversity metrics, the multivariate analysis revealed differences in the assemblage structure between stations (p < 0.001) and seasons (p < 0.01). Indicator analysis identified cryptophyceans as lagoon generalists, and 11 station-specific specialist OTUs, including Kryptoperidinium foliaceum and Oscillatoriales (innermost stations) and potentially toxigenic species (Pseudo-nitzschia and Dinophysis; outer lagoon station, p < 0.05). Water temperature, pH, and nutrients emerged as the variables that best explained the changes in the phytoplankton assemblage structure (p < 0.001). Our findings provide insight into the relevance of local anthropogenic and natural forcings on the phytoplankton assemblage structure and can be used to support the management of RF and other coastal lagoons.

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Section: Spatial-temporal Variability In Phytoplankton Biomass and Ab...mentioning

confidence: 97%

Patterns and Predictors of Phytoplankton Assemblage Structure in a Coastal Lagoon: Species-Specific Analysis Needed to Disentangle Anthropogenic Pressures from Ocean Processes

Lima,

Barbosa,

Correia

et al. 2023

Water

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Phenotypic variability of Montastraea cavernosa and Porites astreoides along a depth gradient from shallow to mesophotic reefs in the Cayman Islands

Doherty,

Chequer,

Mass

et al. 2024

Coral Reefs

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Phenotypic variability is the ability of the same species to express different phenotypes under different environmental conditions. Several coral species that exist along a broad depth distribution have been shown to differ in skeletal morphology and nutrient acquisition at different depths, which has been attributed to variability in response to differing levels of light availability. This study examined the phenotypic variability of two common depth generalist corals, Montastraea cavernosa and Porites astreoides, along a gradient from 10 to 50 m in the Cayman Islands, by examining changes in skeletal morphology, photophysiology, symbiont cell density, and chlorophyll concentration. Skeletal features of M. cavernosa were found to increase in size from 10 to 30 m, but returned to smaller sizes from 30 to 50 m, while P. astreoides skeletal features continued to increase in size from 10 to 40 m. No differences were observed in either symbiont density or chlorophyll concentration across depths for either species. However, all photophysiological parameters exhibited significant depth-dependent variations in both species, revealing adaptive strategies to different light environments. These results suggest that both species have high variability in response to depth. Patterns of skeletal morphology and photophysiology, however, suggest that M. cavernosa may be more variable in regulating photosynthetic efficiency compared to P. astreoides, which likely facilitates the broader depth distribution of this species.

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Beam attenuation coefficient for different water turbidities

Lodovisi,

Gerardi,

Moriconi

et al. 2024

Appl. Opt.

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Interest in underwater optical communications has grown in recent years. A key aspect for the development of such systems is the modeling of light signal propagation in turbid water. In this paper, we present an experimental estimation of the light beam attenuation coefficient by varying the turbid water conditions with pollutants and also considering sea and lake water. The estimation of the beam attenuation coefficient c is based on laboratory measurements of the optical signal-to-noise ratio (SNR) for underwater transmissions and an analytical model of c as a function of SNR. To assess the reliability of the estimation procedure, c has been estimated in the case of clear water and the value obtained is very close to that reported in many studies. Next, c has been estimated for different water conditions. In particular, the results show that the value of c for polluted waters varies between 2.875m−1 and 15.675m−1. In addition, the values of c for lake and clear sea water are 0.6m−1 and 0.9m−1, respectively.

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Evaluating Underwater Light Availability for Phytoplankton: Mean Light Intensity in the Mixed Layer versus Attenuation Coefficient

Cited by 3 publications

References 39 publications

Patterns and Predictors of Phytoplankton Assemblage Structure in a Coastal Lagoon: Species-Specific Analysis Needed to Disentangle Anthropogenic Pressures from Ocean Processes

Patterns and Predictors of Phytoplankton Assemblage Structure in a Coastal Lagoon: Species-Specific Analysis Needed to Disentangle Anthropogenic Pressures from Ocean Processes

Phenotypic variability of Montastraea cavernosa and Porites astreoides along a depth gradient from shallow to mesophotic reefs in the Cayman Islands

Beam attenuation coefficient for different water turbidities

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