The spatio-temporal distribution of epiphytic and planktonic microalgae coupled with environmental factors was investigated for a one-year period in the Gulf of Tunis (northeastern Tunisia). Harmful microalgae assemblages were dominated by three toxic epiphytic dinoflagellates: Ostreopsis sp., Prorocentrum lima and Coolia monotis. They were observed, both on macrophytes (1.03 × 10⁵ cells g⁻¹ FW ; 1.3 × 10⁴ cells g⁻¹ FW and 865 cells g⁻¹ FW, respectively) and in the water column (2.35 × 10⁴ cells L⁻¹; 3.72 × 10³ cells L⁻¹; 1.04 × 10³ cells L⁻¹, respectively). Species abundances decreased with depth and maximum concentrations were found in shallow waters (0.5–1 m). The highest species abundance was registered both on macroalgae and seagrass with no special preference observed for either of these substrates. Redundancy analyses (RDA) show significant changes in these species abundances according to sites and seasons. The proliferation of Ostreopsis sp. is widespread in summer, when water temperature is warm, and especially in bay zones. The occurrence of P. lima and C. monotis blooms was mainly correlated to nutrients. In this study, macrophyte beds in the Gulf of Tunis were a reservoir of potentially toxic species that could pose a real threat, both to ecosystems and to public health.

在突尼斯湾（东北突尼斯），研究了附生和浮游微藻的时空分布以及环境因素，为期一年。有害的微藻组合以三种有毒的附生鞭毛藻为主导：Ostreopsis sp。，Prorocentrum lima和Coolia monotis。他们观察到，无论在水生植物（1.03×10 ⁵细胞克^-1 FW; 1.3×10 ⁴细胞克^-1 FW和865个细胞克^-1 FW，分别地）和在水柱（2.35×10 ⁴传感器L ^{- 1} ; 3.72×10 ³单元格L ^-1; 分别为1.04×10 ^3个单元格L ^-1）。物种的丰度随着深度的增加而降低，在浅水区（0.5-1 m）中发现最大浓度。在大型藻类和海草上都记录了最高的物种丰度，但对这些底物中的任何一种都没有观察到特别的偏好。冗余分析（RDA）显示，这些物种的丰度根据地点和季节而发生了显着变化。Ostreopsis sp。的增殖。在水温高的夏季尤其普遍，尤其是在海湾地区。利马假单胞菌和monotis的发生花朵主要与养分相关。在这项研究中，突尼斯湾的大型植物床是潜在有毒物种的储存库，可能对生态系统和公共健康构成真正威胁。