Seagrass-rafted large benthic foraminifera transported into the deep Red Sea

Area of Science:

• Marine Geology
• Paleoceanography
• Biogeography

Background:

• Large shallow-marine foraminifera are typically found in reef and seagrass habitats.
• Their presence in deep-sea sediments is unusual and requires explanation.

Purpose of the Study:

• To investigate the occurrence of shallow-marine foraminifera in deep-sea sediments of the northern Red Sea.
• To determine the transport mechanisms responsible for their deposition in off-platform environments.

Main Methods:

• Analysis of sediment cores from the northern Red Sea, Saudi Arabia.
• Identification of foraminifera taxa and associated organic remains (seagrass, macroalgae).
• Sedimentological and ecological context assessment of depositional environments.

Main Results:

• Several species of shallow-marine, symbiont-bearing foraminifera (Sorites, Amphisorus, Amphistegina) were identified at depths of 430-1,000 m.
• Foraminifera tests were found alongside pristine seagrass and macroalgae remains in the Umluj brine pool (approx. 638 m depth).
• Evidence suggests passive transport via rafting on floating vegetation.

Conclusions:

• Passive rafting on floating macrophytes is a significant mechanism for transporting shallow-marine foraminifera to deep-sea environments.
• Abundant seagrass and specific oceanographic conditions in the Arabian Peninsula facilitate offshore epiphyte transport.
• This mechanism is crucial for understanding sedimentary records and biogeographic patterns of marine organisms.