Tolerance of benthic foraminifer Calcarina gaudichaudii to polycyclic aromatic hydrocarbon pyrene: effects on photosynthesis

• Published in: Coral reefs Vol. 41; no. 6; pp. 1585 - 1594
• Main Authors: Akther, Shumona, Sun, Wenzhao, Suzuki, Jumpei, Fujita, Masafumi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.12.2022; Springer Nature B.V
• Subjects: Adsorption; Algae; Aromatic compounds; Aromatic hydrocarbons; Atolls; Benthos; Biomedical and Life Sciences; Calcarina; Cell density; Chlorophyll; Chlorophyll a; Coral reefs; Defence mechanisms; Diatoms; Exposure; Freshwater & Marine Ecology; Heavy metals; Identification; Islands; Laboratories; Life Sciences; Marine invertebrates; Metals; Oceanography; Photosynthesis; Photosystem II; Pollution; Polycyclic aromatic hydrocarbons; Population density; Pyrene; Seawater; Symbionts; Visual observation; Water quality; Water temperature; Large benthic foraminifera; Polycyclic aromatic hydrocarbons; Extracellular organic matrix; Symbiont; Pulse-amplitude-modulation fluorometry; Langmuir adsorption isotherm
• ISSN: 0722-4028; 1432-0975
• DOI: 10.1007/s00338-022-02318-8

Symbiont-bearing perforated large benthic foraminifers are vital to the formation of coral reef islands in the Pacific Ocean and are affected by the deterioration of reefal water quality in urbanized atolls. Recently, road traffic was identified as a notable source of heavy-metal pollution in the densely populated area of Majuro atoll in the Marshall Islands. However, the effects of polycyclic aromatic hydrocarbons (PAHs) on LBFs have not been investigated so far. In the present study, pyrene, a PAH, was selected, and its effects on photosynthesis were examined by using Calcarina gaudichaudii . The organisms were exposed to 0.02, 2.0, and 200 µg L −1 of pyrene for 8 d. The effective and maximum quantum yields did not change ( p  > 0.05). Chlorophyll- a content too remained constant ( p  > 0.05). The results indicate that pyrene does not damage the photosystem II and symbiotic algal cell in C. gaudichaudii . Although a previous study reported that the cell density of a marine diatom decreased on exposure to 125 µg L −1 of pyrene, the Langmuir adsorption isotherm model confirmed that pyrene was sufficiently adsorbed on the dried shell of C. gaudichaudii . Through visual observation, sticky materials such as the extracellular organic matrix around C. gaudichaudii were identified under exposure to pyrene. This extracellular organic matrix likely acted as a protective layer against the toxic effects of pyrene with different defense mechanisms found in coral. We conclude that C. gaudichaudii can tolerate short-term exposure to pyrene.