Over the holidays, I do a lot of traveling. Packing and unpacking is a chore, and often I do not take as much as care as I should folding up my belongings and putting them back in their spots. That is the reason, I sat on my bed this morning, untangling the delicate gold chain I wanted to wear to work. Squinting, I followed the links, tugging gently at knots trying to identify the path. Every once in a while, I would hit the jackpot, and one tug would result in a chain reaction and release of a few interconnected knots. Inevitably though, there were further knots that needed attention.
This mundane task reminded me of ecology works. We have a big problem—understanding how coastal ecosystems work—that is analogous to that knotted chain. As a researcher, I spend a lot of time figuring out one small knot. For example, as a master’s student, many years ago, I spent a lot of time trying to understand the role of a specific family of clams—the lucinids—play in seagrass sediment biogeochemisty. I took cores, found out where they lived and in what densities. I did careful experiments and calculations showing that because they have bacteria in their gills that oxidize sulfides—an ion toxic to seagrasses themselves—they alter the sediment chemistry in a way that makes the sediments a better place for seagrasses to thrive. That was a chain reaction for me…a greater understanding of an awesomely intricate relationship. There are bacteria that live in the gills of clams, protected from the outside world. Those bacteria made their own food through chemosynthesis (using the energy produced from oxidizing sufides instead of light energy used in photosynthesis to fuel sugar production), and the clams benefited from the food produced so much that they have a very reduced gut of their own. Those clams live in seagrass meadows, and the seagrass belowground tissue provides a hiding place—a protection for those clams from predators. Finally, that chemosynthesis changes the sediment chemistry by reducing sulfide concentrations and increasing ammonium concentrations. Those conditions and changes are good for seagrasses! Woah, how cool. Read about it here: link.springer.com/article/10.1007/BF02819394 .
This week a new paper came out. The authors showed that these same clams contributed a significant amount to the diet of spiny lobster —I guess those seagrasses don’t protect them 100% from predation! This is cool for a whole bunch of reasons. We already know that the primary production makes these meadows some of the most productive systems on earth. It turns out that, even so, we were failing to account for the chemosyntheic production that in large part fuels an economically important fishery. Another reason to appreciate and work to conserve seagrass meadows. Also, just a moment to stand back and appreciate the intricacies and interactions that make coastal ecosystems work. How cool!
There are lots of questions left. How do these lobsters dig up these clams? Are there other animals eating them? What other roles do these clams play in these systems? How do these clams alter the carbon accumulation in the sediment?
Instead of that delicate, knotted chain, I wore a different necklace to work today. I have some more work to do untangling that mess, just as there is more work to do untangling the web of important interactions shaping seagrass systems.
A marine ecologist and her colleagues hoping to engage both stakeholders and the public in an effort to identify pressing environmental problems and to collaborate on creative, effective solutions based in sound science.