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Gift giving through the Holiday Season is a long tradition. Because necklaces, earrings, bracelets and other decorative objects and ornaments made from marine animals are among the gifts given in some places, the Ocean Health Index team hopes the following information will make your holidays happier and the ocean healthier.

We focus here on gifts made from corals and shells, perhaps the most beautiful and prized, since some of these animals are among nature’s loveliest creations---stunning ornaments on the tree of life.

A Little History

Wearing and displaying such exquisite objects has a long history. Shell beads found in a cave near Tofaualt, Morocco were collected from North African beaches by people 82,000 years ago and used for personal adornment. Shell jewelry roughly the same age has also been found in Algeria, Israel and South Africa, demonstrating the early and widespread importance of shells for personal ornamentation and possibly symbolic use. 

Other ancient examples include a shell necklace that someone wore 30,000 years ago in a cave at Cro Magnon, France, now on exhibit at the Smithsonian Institution and pins, amulets, shell beads and other body ornaments used by Native Americans for thousands of years.

Shells were the oldest marine-derived body ornaments known, probably because many washed ashore where they could easily be gathered.

In contrast, corals used for jewelry rarely appear on a beach, but only wash ashore if a severe storm tears them from the bottom or breaks off pieces of their branches. That could explain why coral is much less common than shells at archeological sites, although red coral (Corallium spp.) beads dating back 25,000 years were found in grave sites in Germany and both coral and shell beads dating from about 10,000 years ago were excavated in Anatolia.

Through most of human history, the coral and shells used for ornaments, tools, currency and other things were gathered by beachcombers, however people have also fished or hunted for them for thousands of years.

Targeted harvest of corals began about 5,000 years ago when Greek fishermen began using iron hooks to break off and bring up coral colonies. By 1,000 A.D., nets weighted with stones or heavy iron bars were being used to drag the bottom, break off corals and bring them to the surface. Most corals are still gathered in that inefficient and indiscriminate manner today, destroying both the corals and their habitats. 

Catching living mollusks for their shells (and flesh) probably began in tropical areas where clear water allowed divers to see shallow-living conchs, whelks, trumpets or other large or interesting species and warm temperatures enabled them to swim down and retrieve them. Capturing shells in baited traps also occurred. As equipment for helmet diving, snorkeling and SCUBA diving developed and boat transportation improved, hunting pressure on both shells and corals increased. 

Beautiful shells and corals were especially valued in inland areas where they did not occur naturally. Consequently, they were important components of trade routes that extended for thousands of miles in Asia, Europe, Africa the Americas, Australia and Oceania. 

The trade in shells and coral continues unabated today, providing benefits like jobs and income to harvesters and sellers, but also bringing serious threats to species, habitats and biodiversity. So here are some things to know about and balance when planning holiday gift-giving.

Corals

Corals (Phylum Cnidaria) are close relatives of sea anemones that protect their soft bodies with calcium carbonate structures.  You can learn more about their life cycles here and here.

Polyps that secrete calcium carbonate exoskeletons (Order Anthozoa), often called ‘hard corals’ or ‘stony corals’ include about 1,500 known species important for their role in building reefs. Though some are harvested for display in salt water aquariums or other purposes, they are not used for jewelry. 

In contrast, species used for jewelry are ‘soft corals’ (Order Alcyonacea), which do not make exoskeletons or form reefs, but whose polyps secrete tiny calcium carbonate crystals within their bodies for strength and support, producing gracefully branched or fan-like shapes. 

Red Coral and Pink Coral include 27 species of Corallium and Paracorallium in the Mediterranean, Japan and other Asian waters. Seven species are traded commercially and they are the most sought after and highly valued of all corals. Red Coral colonies grow slowly, increasing by less than 1 cm (0.5 in) in height each year and may live to be 100 years old. Overharvesting has severely reduced Red Coral populations in the Mediterranean and elsewhere.  Pink coral branches in Hawaii grew in radius about 170 μm per year, so it would require about 60 years to grow 1 cm (about 0.4 in). Colonies could be 60-or 70 years old. The other precious corals grow still more slowly! 

Black Corals (species of Antipathes, Leipathes and others) are deep-living species that grow extremely slowly. Carbon14 dating showed that colonies of one Hawaiian species used for jewelry, A. dichotoma, growing at 50 m (165 ft) depth were 12-32 years old and their branches took between 9 and 55 years to grow 1 cm (0.4 in) in radius.

Branches of another, A. glaberrima, from 500 m (1,600 ft) take nearly 2,000 years to grow 1 cm (about 0.4 in) in radius and colonies can live for at least 4,265 years --the oldest skeleton-forming species known!

The situation is similar for Gold Coral, which includes several species of Gerardia first discovered in 1971 in deep water (400 m, 1,200 ft) off Hawaii and several others. Recent experiments showed radial growth of branches to be only 36 μm per year, so it would take about 280 years to grow 1 cm (about 0.4 in). Colonies could be at least 2,700 years old. Harvest of Gold Coral still occurs, but it is strictly regulated because the species are so rare and slow growing.

The Problem

Despite the pleasure and meaning that precious corals have brought to people for millennia, these slow-growing species cannot fulfill human demand, especially if harvested by bottom-dragging that kills or breaks so many of the colonies. Traded corals originate in many countries, but the United States is the world’s largest importer.

There is no comprehensive global legal foundation for precious coral protection. None of the species are included in Appendix I of the Convention on International Trade in Endangered Species (CITES), which lists species that are endangered and for which commercial trade is illegal. Black Corals (Antipatharia spp.) and Blue Coral (Heliopora coerulea), a rare, infrequently traded species used mainly for aquariums, but sometimes for jewelry,  are included in Appendix II, which lists species that aren’t necessarily threatened, but require trade controls to prevent further decline. Marine species in Appendix II require both export and import permits.

Commercial harvest probably will not drive these species to extinction globally, because harvest becomes unprofitable when corals become scarce. However, local populations (or species) could disappear or become more vulnerable to other pressures, including sea temperature change, ocean acidification, disease or competition from native or invasive species. Since many of these corals shelter fish and other species, severely decreased populations would reduce biodiversity and marine benefits that depend on it. Moreover, slow re-growth would eliminate harvest and trade at those locations for decades or centuries to come.

Steps Toward a Solution

Aquaculture cannot help precious corals. Though some hard corals are successfully cultured for use in aquariums or repopulation of damaged reefs, precious corals grow too slowly for culture to be economic. 

More stringent management of deep water corals and their habitats is urgently needed. Adding precious corals to CITES has been controversial, but without such listing there is no regulatory framework to guide or assure consumers.  Being mindful about purchasing precious corals may be the best thing an individual can do at this time.    

Before you purchase coral read this excellent article. If buy, be certain that your product has come from a sustainable source --and that won’t be easy. Sustainability information is not provided for most products, although Maui Divers Jewelry states that they carefully harvest black coral at rates that are renewable.    

Colorful substitutes for corals are available --and at much lower cost: carnelian, agate or garnet for Red Coral; Hematite, Obsidian and Onyx for Black Coral; or glass for Gold Coral or others. Beautiful coral-like ornaments have also been made from painted metal, for example the candle holder shown at the beginning of this article.  

Many environmentally concerned companies, including world renowned U.S. jeweler, Tiffany & Co. refuse to use real corals in their collections and have a formal “No Coral Sales” policy. Many work with SeaWeb’s Too Precious to Wear campaign to create demand among consumers and retailers for coral conservation and to press for addition of all precious corals to Appendix II of CITES.

Shells

Shells of mollusks have a long history of use as tools (scrapers, bowls, lamps, combs, pins), components for many industrial processes, money, sacred or symbolic objects, trumpets, curios and jewelry.  

The 85,000 known species of living mollusks include some that live on land or in fresh water, so shells for crafts, jewelry and other decorative objects come from many sources, though marine species are the most important.

Marine species such as mussels, clams, oysters, scallops and others are so abundant and widespread that use of their shells---when allowed--- does not cause ecological problems. 

Similarly, beachcombing for shells is probably ecologically benign. Famous shell beaches in the United States, Western Australia, the Caribbean and Africa draw tourists and collectors from all over the world.

The Problem

Harvest of many large, showy, less common species, including Helmet Shells, Tritons, Trochids, Volutes, Spider Conchs, Murids, Melons, Nautiloids and others is of more concern. Some, such as Queen Conchs or Abalone are taken primarily for food, with shells sold later as secondary products; others, are taken as bycatch by fisheries draggers. Still others are targeted exclusively for their shells. 

Photographs of some of these remarkable shells can be seen on Web sites of shell shops in the UK (here or here), Australia and India, for example. Some shops state that they only stock shells obtained from reputable sources who certify that harvest was sustainable, but definitions and standards for sustainability vary. Only two types of mollusks have international protection, the Queen Conch and all Giant Clams in the Family Tridacnidae, which are both listed in Appendix II of CITES.

Harvests for food or shells have severely depleted local populations not only of Queen Conchs and Giant Clams, but also of some more prolific species. Local populations of Pearl Oysters (Pinctada spp.) from Asia, Australia, the Mediterranean, Gulf of Mexico and elsewhere are harvested exclusively for pearls and the lustrous inner shell layer (‘nacre’ or ‘mother of pearl’) used for buttons and inlay. Overfishing extirpated populations throughout their ranges.  As one example, John Bailey’s book, The White Divers of Broome describes the frenzied pearl hunting in Western Australia during the early 1900s and the social injustices that accompanied it.

Steps to a Solution

The widespread decline of wild populations stimulated efforts to culture Pearl Oysters. In 1893, Kokichi Mikimoto created the first cultured pearl in his laboratory near Toba, Japan, and slowly built a world famous company.  Thousands of sites in Japan, the South Seas and Tahiti now culture Pearl Oysters and pearls. Tahiti is famous for its lustrous black pearls, often with green, blue or purple overtones.  Other types and shapes of pearls are grown in freshwater mussels at inland facilities in China, Japan and the United States. Sustainable Pearls hosts a wealth of information, photos and videos on all aspects of Pearl Oyster and pearl culture, practices that have made enormous strides for the sustainability of this industry.

Mariculture may also help repopulate Queen Conch and Giant Clams in some areas. Both are being been successfully raised for sales to aquariums and wild release. But it seems unlikely that mariculture could have equal potential for many of the other spectacular species involved in the shell trade, because much less is known about their ecology and growth requirements.

The American Malacological Society’s conservation goals can also guide gift giving:

• ensure that fisheries and collecting activities impacting natural populations of mollusks are conducted only on a sustainable basis;
  
• restrict shell-collecting for commercial gain, especially for rare or endangered species; and minimize habitat destruction and prevent destructive collecting practices such as the use of toxic chemicals and explosives;
  
• encourage awareness among shell-collecting hobbyists that their activities may impact natural populations of mollusks, and that they should focus their collecting activities on the more common species and/or dead specimens, consider substituting photography for collection of live specimens, and avoid damage to habitats;
  
• encourage awareness among professional and professional-level amateur researchers that their activities may impact natural populations of mollusks, and that they should restrict their collecting activities to the minimum necessary to address the specific research needs, and that these research needs should be evaluated against a background of the status of the mollusk species in question, and of potential damage to habitats.