Merry Shellmas - I decided to make this post rebloggable so you can spread the word!
Anemone Vs. Nudibranch
Phyllidia ocellata gets tasted as well. Whether or not this nudi met it’s maker is unknown, it was neither consumed nor did it escape during observation. Scientists say these interactions highlight how little we know about the diets and interactions of marine species.
She shouldn’t sell seashells on the seashore.
As a budding marine biologist I used to wear shell jewellery to advertise to the world how much I loved the ocean. Many do. I don’t any more because I’ve learned the following:
Shell collection is a relatively unknown but drastic problem in marine conservation. We have such an obsession with the homes of pretty little molluscs that it is causing a severe imbalance in the eco-systems they are being collected from. Whether it be Cowries for jewellery and other decorations or Triton Shells for ornamental or traditional uses, there are visible changes because of our selfish demand for this pretty snail houses.
1. Hermit Crabs need a wide selection of shells to ‘move’ into when they get larger as the are not true crabs and have no protective shell of their own. We are seeing more and more ‘naked’ hermit crabs, or ones that have resorted to donning rubbish like bottle caps out of desperation.
2. The food web is a delicate balance of all within. Removing one level of that web, in this case, the grazers [mostly], there are knock-on effects that rock that eco-system. One telling example is that of the Triton Snail. So heavily sought after they are endangered and almost impossible to find. I have a marine biologist friend who has been diving in Asia for more than 3O years and has only ever seen 2. The Triton Snail is one of the few predators of the Crown-of-Thorns starfish which has a veracious appetite for Coral. Without one of it’s major predators, the starfishes population goes unregulated, and this has likely contributed to the over-whelming outbreaks of the COT all over the world. Though it should be noted that this is just one of many causes.
3. Ocean chemistry. Another delicate system that requires a balance of it’s components. Sea shells are made out of Calcium Carbonate, which sequesters Carbon, and is needed for the climate-regulating Carbon Cycle. An imbalance here can cause problems with Ocean Acidification, the study of this phenomena is gaining serious momentum in the Research world, including my own Masters dissertation.
4. Coral vs. Algae. A healthy coral reef has a an intricate equilibrium between Coral and Algae species. Coral is the tortoise, slow growing and eventually wins the race. Algae, the hare, is opportunistic and takes every chance it gets. The food web has those that eat both, but if the scales are tipped, Algae will grow like a maniac, and new Coral larvae has no where to settle and is out-competed. The grazers cannot keep up and eventually you have dead coral covered in tufts of algae and a crash in diversity as all that relies on coral for habitat, food and more are lost.
So please, next time you buy some earrings, or go on holiday and want a souvenier, please give the snails a break and don’t pick them. As consumers you have the power to change what is supplied to you. If no one buys shells, eventually people will stop harvesting them. Bonus for the snails because most of them are taken alive [and boiled or buried in the sand so the snail dies] to retain the perfect shell.
Think before you buy.