Structural variation of potentially toxic epiphytic dinoflagellates on Thalassia testudinum from two coastal systems of Colombian Caribbean

Natalia Arbeláez M; José Ernesto Mancera-Pineda; Beatriz Reguera

doi:10.1016/j.hal.2019.101738

Structural variation of potentially toxic epiphytic dinoflagellates on Thalassia testudinum from two coastal systems of Colombian Caribbean

Harmful Algae. 2020 Feb:92:101738. doi: 10.1016/j.hal.2019.101738. Epub 2020 Jan 8.

Authors

Natalia Arbeláez M¹, José Ernesto Mancera-Pineda², Beatriz Reguera³

Affiliations

¹ Marine and Coastal Research Institute, INVEMAR. Calle 25 No. 2-55, Playa Salguero. Rodadero, Santa Marta, Colombia. Electronic address: nar_nmc@hotmail.com.
² Universidad Nacional de Colombia, sede Bogotá, Carrera 45 No 26-85, Bogotá D.C., Colombia.
³ Instituto Español de Oceanografía (IEO), Centro Oceanográfico de Vigo, Subida a Radio Faro 50, 36390 Vigo, Spain.

PMID: 32113597
DOI: 10.1016/j.hal.2019.101738

Abstract

Some benthic dinoflagellates produce toxins that can affect other organisms including humans, and their proliferation seems to be related to the environmental variability. For this reason, the present study aims to compare the structural variation of potentially toxic dinoflagellates associated with the seagrass Thalassia testudinum from two nearby systems, with different environmental characteristics in Colombian Caribbean, corresponding to a brackish water coastal lagoon and an adjacent bay. Between January 2014 and December 2015, leaves of T. testudinum were collected monthly to obtain the dinoflagellates. Salinity, temperature, dissolved oxygen, pH, nutrients and total suspended solids (TSS) were measured, and precipitation data and the Oceanic Niño Index (ONI) were obtained. Dinoflagellates were detached from the leaves, morphologically identified by analyzing their thecal plates arrangements, and quantified using a Sedgewick-Rafter chamber. The information was analyzed using standard statistics and regression models. Fourteen species of potentially toxic epiphytic dinoflagellate belonging to four genera were recorded, being Prorocentrum the most representative in number of species. The maximum density, dominated by P. lima, were found in Bahía Chengue during the rainy season of 2014 (18452 and 20109 cells g^-1 w.w.), with salinity of 35.50, high temperatures (>29.60 °C), dissolved oxygen >6 mg L^-1, pH close to 8 and TSS >85 mg L^-1. Densities at the Lagoon were lower than 80 cells g^-1 w.w. with the highest values of Prorocentrum sp.1 under different environmental conditions. With the statistical relationships between the most abundant species and the main environmental variables, fundamental niche models were proposed in which cells could proliferate. The degree of risk to human health due to the presence of these potentially toxic epiphytic dinoflagellates will not be resolved until their toxicity discarded.

Keywords: Colombian Caribbean; Epiphytic dinoflagellates; Seagrasses; Toxigenic microalgae; bHABs.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Caribbean Region
Colombia
Dinoflagellida*
Hydrocharitaceae*
Salinity