Hi ho, oceanographer called Paul here, reporting on the pteropod (pelagic marine snail) situation. It seems that there are many free-swimming marine snails! One in particular called Limacina helicina keeps coming up in Tucker trawls, which are deployed from the back of the research vessel. Limacina helicina can be found living near the ocean surface and up to 1600 meters of water depth. Limacina helicina looks like grains of sand until they are magnified, revealing beautiful sinistrally coiled and semi-transparent shells (photograph below).
Pteropods make their shells out of a type of calcium carbonate called aragonite. Aragonite is much like the calcium carbonate found in clams or mussels called calcite (another type). A pteropod's aragonite shell reflects the chemical properties of the seawater in which they live. So, with a little measuring of water column temperature and salinity with depth, along with a little measuring of stable isotopes of oxygen and carbon I can see at what depth(s) they make their shells and how ocean chemistry may influence them. This helps me to understand how changes in the ocean are exhibited in the pteropod’s shell, potentially making pteropods indicators of environmental change.
Pteropodologist Paul Suprenand signing out…