Influence of abiotic factors on phytoplankton diversity and distribution in an atoll environment

Abstract

Taxonomic investigations of phytoplankton community structure are very important for understanding the dynamics of these organisms in places like reefs, which present broad hydro-biological variation. This study aimed to determine and investigate phytoplankton community composition and biomass in natural pools of Atol das Rocas (3°51' S; 33°49' W), and to evaluate the possible influences of abiotic variables throughout different seasons. The oceanographic parameters used to assess the phytoplankton community and its biomass were chlorophyll a, salinity, water temperature, dissolved oxygen and dissolved inorganic nutrient content, namely ammonia, nitrate, nitrite, phosphate and silica. A total of 109 species were identified, distributed among four groups: Ochrophyta (52.3 %), Dinophyta (37.6 %), Cyanobacteria (7.33 %) and Haptophyta (2.75 %). Although none of the hydrological parameters were found to be statistically determinant, phytoplankton composition in all the studied pools was primarily associated with nutrient salts and there was a qualitative and quantitative increase in phytoplankton in the rainy season. This increase was due to the positive relationship between phytoplankton composition and nutrient salts when associated with local hydrodynamics, which provides more favorable conditions for the enrichment of diversity with emphasis on species that compose the benthic microflora.

Critical factors driving spatiotemporal variability in the phytoplankton community structure of the coral habitat in Dongshan Bay, China

“…This suggests that this heterotrophic dinoflagellate prefers waters with lower nutrient concentrations. The phytoplankton diversity and distribution in the atoll were primarily associated with nutrients concentration (Jales et al, 2022). Under favorable nutrient conditions, including the presence of dissolved inorganic nitrogen, dissolved inorganic phosphorus and a suitable optimal temperature, phytoplankton exhibited high growth rates throughout the upwelling process from Shanwei to Shantou-Dongshan (Hu et al, 2015).…”

“…Najmi et al (2022) have verified that the presence of a substantial amount of phytoplankton is crucial for the survival of zooplankton, and together, they play a vital role in maintaining the sustainability of coral reefs. In coral atolls like the central South China Sea, the south of the Atlantic Ocean, and the Gulf of Aqaba (Red Sea), diatoms and dinoflagellates emerge as the predominant groups (Ke et al, 2018;Jales et al, 2022;Şahin et al, 2022). These findings align with our own research, highlighting the interconnectedness of phytoplankton, zooplankton, and coral reefs.…”

“…Recently, there have been multiple studies on the phytoplankton community structure of coral reefs in various bays and oceans worldwide (Sournia and Ricard, 1976;Jales et al, 2022;Şahin et al, 2022;Soondur et al, 2023). Some research findings (Soondur et al, 2023) indicate that diatoms and dinoflagellates are more abundant in non-degraded coral reefs, whereas cyanobacteria exhibit higher densities in degraded coral reefs.…”

“…The abundance of phytoplankton tends to be the highest nearshore (Sournia and Ricard, 1976;Şahin et al, 2022). Phytoplankton composition in an atoll environment is primarily associated with nutrient salts (Jales et al, 2022). Shallow-water coral reefs will be affected more often by episodic smothering conditions caused by harmful algal blooms.…”

Temporal and spatial distribution of plankton community in three Indonesian salt pond environments

“…Aside from physical and biological environmental factors, Wei et al (2022) found that variations strongly influence the abundance and composition of phytoplankton in predatory factors. As Jales et al (2021) stated, biological and physical factors such as environmental changes, nutrients, and the presence of herbivorous zooplankton affect the species composition and diversity of phytoplankton in the ecosystem. Furthermore, the zooplankton community had a low diversity index (H') of 0.81±0.16 at Tuban salt ponds (TSS), a moderate diversity index (H') of a level 1.64±0.04 at Brebes salt ponds (BSR), a depressed evenness index (E) that ranged from 0.18-0.22; and a low dominance index (C) that ranged from 0.03-0.30 at the three salt pond locations.…”