How to Find Shells

Jo O'Keefe Copyright 2010. 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.

Disk Dosinia, Dosinia discus, 2.75 inches or 70 mm
Lettered Olive, Oliva sayana, 2.55 inches or 65 mm
Marsh Periwinkle, Littoraria irrorata, 0.21 inches or 5.5 mm
Atlantic Nutclam, Nucula proxima, 0.19 inches or 5 mm

The shells in the first row are scattered on the beach. Those in the lower row are found in both sea drift and seaweed.

The Lettered Olive and Marsh Periwinkle are gastropods, univalves or snails. They have one shell. The Disk Dosinia and Atlantic Nutclam, with two shells, are bivalves or clams.

My system has become elaborate and complicated. Yours does not need to be this way.

It is worthwhile to examine the fine debris and sea drift because scores of species are beautiful microshells. There also are newborns and juveniles of the larger species that you see when walking. The simplest method is to take seaweed and sea drift back to your beach cottage in 2-quart containers and gallon bags. Although plastic bags from the grocery store do not work well, they can be used.

Rinse the seaweed and/or sea drift in a sieve or colander to remove sand. Let it drain. Then spread it on paper towels 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 that you want to preserve, immerse them in alcohol for several days. Later dry them out. The arms of curled sea stars and brittle stars will relax if you soak them in water for 15 minutes. Dry them between paper towels with a light item such as a tissue box over them. Set a timer for 30 minutes. After that, remove the box and the top paper towel.

Below is my elaborate process, still evolving after two years of collecting and inspecting seaweed and sea drift.

Sea Drift and Sea Grit

There are two types of sea drift on the eastern point of Sunset Beach -- worm casings and fine grit. On many -- but not all -- 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.

Sea Drift -- soft debris that washes up at the edges of tide pools and scallops
Sea Grit -- small shells and fragments of shells at edges of tide pools

The fine grit has delicate shells 1/16 to 1/4 inch wide. In it are countless minute shells.

The most important step of my system is using containers that prevent damage. I carry margarine containers for sand dollars, crabs and fragile shells. For delicate shells I use medicine bottles with a small amount of tissue in the bottom for padding. I bring at least four quart containers with lids to fill with sea drift. Although Zip-lock bags can be used, they increase the risk of breakage.

I gather sea drift and sea grit at the ends of the "scallops" made by the lapping water at the eastern point of Sunset Beach.

At home, I rinse the material in sieves.

I spread the material on several layers of newspaper to dry. A blow dryer on a low setting or a fan would help. 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. It can be the plastic lid of a bin used to bring items to the beach. I pour a pile of dry sea drift on the back edge of a 12 X 15 piece of dark posterboard and then gently move a small amount forward at a time to inspect. Using forceps (tweezers) or a toothpick, I push it around to expose mollusks and other invertebrate animals. I pick up each find with forceps, 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, shells 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. I seldom walk in the ocean.

At home, before I begin inspecting seaweed, I place dishes to my right with ocean water in them. 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. Finally I save specimens for scientists.

I have extracted as many as a thousands shells from seaweed from 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. Despite their demise, I save shells for educational facilities.

Bryozoa, Hydrozoa and Tunicates

Often clumps of solitary tunicates and large colonial tunicates have minute shells and small crabs in their crevices. I tear apart solitary tunicates, often releasing squishy guts, to find the beautiful juvenile shells growing in the shelter between them. I tear apart clumps of bryozoans that look like short dried brooms. Many are growing on large barnacles. Fragile mussels and some gastropods are in the crevices along with crabs, marine worms and other surprises.

My Mollusk Mentor

After realizing that I needed help identifying the many species of mollusks that I found in sea drift and sea weed, I learned of Harry Lee, the scientific advisor of the phenomenal website. For nearly two years he has worked with me to identify the Shells of Sunset Beach. I can never thank him for his patience and work. Although compared to Dr. Lee I know nothing, I have learned a phenomenal amount about shells during our partnership.