How to Find Shells
Jo O'Keefe Copyright 2012. Photos may be used for educational purposes only. Contact me with inquiries.
On Sunset Beach, NC, there are two types of shells and two sizes of shells. You see average-size shells when you are on the beach. You see minute shells when you bend or kneel down to look at fine material. Below are photos demonstrating the two differences. The four photos are to scale to demonstrate the significant difference in size.
The shells in the first row are scattered on the beach. Those in the lower row are found in sea drift, sea grit and seaweed.
The Disk Dosinia and Atlantic Nutclam on the left, with two shells, are bivalves or clams. The Lettered Olive and Marsh Periwinkle are gastropods, univalves or snails. They have one shell.
My system has become elaborate and complicated. Yours does not need to be this way.
Examining seaweed, sea drift and sea grit is exciting. Scores of species of shells are beautiful microshells. In material that washes up there also are newborns and juveniles of the larger species that you see when walking. Collect seaweed, sea drift and sea grit in 2-quart containers and gallon Ziplock bags. Although plastic bags from the grocery store do not work well, they can be used.
Back home, rinse the material in a sieve or colander to remove sand. Let it drain. Then spread it on paper towels or newspaper on the kitchen counter. Plug in a lamp next to it; perhaps remove the shade. You should find many things. Details are below.
If you find small animals such as brittle stars, sea spiders and live mollusks that you want to preserve, immerse them in alcohol for several days. Later dry them out. That prevents them from rotting and smelling.
Below is my elaborate process, still evolving after several years of collecting and inspecting seaweed, sea drift and sea grit.
The most important step of my system is using containers that prevent damage. I carry margarine containers for fragile items that I see while walking such as sand dollars, crabs and fragile shells. For delicate shells I use medicine bottles with a small amount of tissue in the bottom for padding. On each walk I bring at least four quart containers from yogurt with lids to fill with sea drift and sea grit.
Sea Drift, Sea Grit and Seaweed
Sea Drift is mostly worm casings. On many days, there are large patches of worm casings. Amidst those empty tubes there usually are Rainbow Tellins, Jackknife Clams, Southern Surfclams, Atlantic Abra, mussels and arks. There are small crabs and crab carapaces, sea urchin tests, and other invertebrates. Sea drift has far more bivalves than gastropods. Each item in sea drift is extremely fragile. Transporting sea drift in plastic containers is much better than using bags. Because I collect crab shells, I love finding sea drift.
Sea Grit is crushed shards of shells with intact shells in it. They are 1/16 to 1/2 inch wide. Sea grit contains countless microscopic shells. It should be placed in firm plastic containers. Picture this shell in sea grit. It is thinner than and no longer than the tip of a pencil. It could break in a plastic bag.
I gather sea drift and sea grit at the ends of the "scallops" made by the gentle lapping waves at the eastern point of Sunset Beach during during the two hours preceding the moment of low tide.
At home, I rinse the material in stacked sieves that separate them into sizes.
I spread the material on several layers of newspaper over plastic to dry. One friend "roasts" his at a low temperature in his oven. I wait several days for it to dry before inspecting it.
Perhaps you have seem detectives on crime shows using illuminating magnifiers to examine material for evidence. I use a 5X illuminating magnifier to inspect dry sea drift. An important element is a solid, colored background. The item on which you inspect shells should be poster board or plastic -- not cloth. You can use the inside of the plastic lid of a bin. I pour a pile of dry sea drift at the back edge of a 12 X 15 piece of dark poster board. Then I gently move a small amount at a time forward to inspect. Using a toothpick, I push the material around to expose mollusks and other invertebrate animals. I pick up each item that I find with forceps -- tweezers, the wet tip of a fine artist's paint brush, or by licking my finger and touching it. I place each specimen in a Petri dish.
Here is a photo of a sand dollar from sea grit. It is less than a half inch in diameter. This photo is the exact size of the sand dollar.
Each time sea drift is handled, items in it break. Minimize contact. Protect the minute, fragile specimens that you find.
Seaweed is very different than sea drift. You might find animals such as sea spiders, tunicates, bryozoans, sponges, brittle stars, crabs, barnacles, eggs, isopods and scores of amphipods. You will find many small gastropods. Most will host a hermit crab. Some are juveniles of species that you find on the beach such as Knobbed Whelks and True Tulips.
In the ocean, seaweed and egg cases get tangled with man-made objects such as fishing line or an elastic hair band. Soon there is a big clump bursting with marine life.
I gather seaweed on the beach near the water. It is also in the ocean. I put seaweed into Zip-lock bags.
At home, before I begin inspecting seaweed, I place dishes to my right with ocean water in them. I get it from the bottom of the Zip-lock bag. After I remove an animal from the seaweed, I dip my finger into the water to release the small animal or shell. Later I photograph animals through my microscope. If they are moving too much to photograph, I place the dish containing them and a small amount of sea water into the refrigerator for 20 minutes to slow their metabolism. They are easier to photograph afterward. After finding and photographing specimens, I save them for teachers and researchers.
I have extracted as many as a thousands shells from seaweed collected during a single beach walk.
I knowingly take home seaweed with small hermit crabs inside shells because I am researching. After I spend up to four hours going to the beach, walking, and coming home, and then several more hours inspecting seaweed, the animals are not in good enough health to return to the ocean. I send them to universities, museums and schools afterwards.
Bryozoa, Hydroids and Tunicates
Often clumps of solitary tunicates and large colonial tunicates have minute shells and small crabs in their crevices. I separate solitary tunicates to find beautiful juvenile shells growing in the shelter between the tunicates. I tear apart clumps of bryozoans that look like short dried brooms. Many are growing on barnacles. Fragile mussels and some gastropods are in the crevices along with crabs, marine worms and other surprises.
A cluster of solitary tunicates, bryozoa and hydrozoa with shells and barnacles