Variability in magnesium content in Arctic echinoderm skeletons.

Area of Science:

• Marine Biology
• Biogeochemistry
• Echinoderm Ecology

Background:

• Echinoderm skeletons exhibit variable magnesium (Mg) content.
• Understanding Mg incorporation is key to interpreting paleoenvironmental proxies.
• Arctic echinoderms inhabit unique environmental conditions influencing skeletal composition.

Purpose of the Study:

• To quantify Mg concentration variation in Arctic echinoderm skeletons.
• To determine if Mg levels are driven by biological or environmental factors.
• To identify patterns of Mg variation across echinoderm classes and species.

Main Methods:

• Compiled 235 Mg concentration measurements from 30 Arctic echinoderm species.
• Analyzed skeletal samples from 216 specimens collected in the Barents Sea.
• Compared Mg content across different echinoderm classes (asteroids, ophiuroids, crinoids, holothuroids, echinoids).

Main Results:

• Mg concentration was characteristic for echinoderm classes and often species-specific.
• Asteroids showed the highest Mg content, followed by ophiuroids, crinoids, and holothuroids.
• Echinoids exhibited the lowest Mg concentrations among the studied groups.

Conclusions:

• Biological factors significantly control Mg incorporation into echinoderm skeletons.
• Skeletal Mg content is a reliable indicator of echinoderm class and species.
• These findings have implications for using echinoderms as paleoenvironmental indicators.