Introduction to Marine Biology: Hidden Corals - Mesophotic Reefs

These flashcards cover the key concepts discussed in the lecture on mesophotic reefs, including their ecological significance, environmental challenges, and research findings.

What are Mesophotic Coral Ecosystems (MCEs)?

Ecosystems found between 30-150 m depth, consisting of reef-building corals, soft corals, sponges, and algae.

Why are mesophotic reefs considered understudied?

Research was limited until the 1960s and 1970s due to safety issues with SCUBA at deeper depths and the expense of using ROVs and submersibles.

What light spectrum is available at mesophotic depths?

Mainly blue, green, and purple wavelengths, as longer wavelengths (red, orange, yellow) are absorbed first.

What temperature range do mesophotic coral ecosystems typically experience?

Typically between 20-26 °C.

What is the significance of the Deep Reef Refugia Hypothesis?

It suggests that MCEs may provide a refuge for shallow-water corals from disturbances, acting as a source of larvae for recovery.

What have studies shown about species diversity in mesophotic zones?

Diversity generally decreases with increasing depth, with a shift in community structure from shallow to deeper zones.

What factors impact community structure in MCEs?

Light availability and temperature are significant drivers influencing community composition as depth increases.

What types of species dominate in deeper mesophotic zones?

Sponges, gorgonians (sea fans), and azooxanthellate corals dominate at greater depths due to lower light availability.

What evidence supports the need to protect MCEs?

Studies show distinct communities in MCEs that provide valuable ecological services and may be relatively pristine.

What is a major concern regarding climate change and MCEs?

Increased frequency and severity of coral bleaching, which threatens the health of these ecosystems.