The environmental cost of collecting seashells

It’s a normal part of summer vacation: Head to the beach, pick up a few seashells, and take them home as keepsakes. But multiply this innocent activity by millions of tourists and we might have a big problem, researchers warn in PLOS ONE. Skyrocketing numbers of beachcombers are pocketing seashells, and the environmental effects could range from increased erosion to fewer building materials for bird nests.

“[S]eashores remain among the most alluring tourist destinations,” the authors write, and visitors often leave their mark by camping, driving, and trampling on beaches. But few scientists have thought to investigate whether seashell collection might be destructive as well. These pretty beach tokens play an important role in ecosystems; algae take shelter in shells, birds use them to build nests, and hermit crabs carry them as armor.

From 1978 to 1981, a research team surveyed seashells on Llarga Beach in Spain. So the authors of the current study returned to that site from 2008 to 2010, checking for the three most common bivalve species. In the intervening time, the beach hadn’t seen many changes in urban development, fishing activity, weather, or waves — but the number of tourists had nearly tripled.

The number of seashells was almost three times lower in the second round of surveys, the team reports. From 1978-81, researchers spotted an average of 1,506 seashells per transect; in 2008-10, that fell to 578 seashells per transect. The team also collected records of tourist visits from town hall reports and nearby hotels. The more tourists arriving in the area in a given month, the fewer seashells the researchers found.

The number of shells from three major bivalve species found per beach transect in 1978-1981 (top) and 2008-2010 (bottom).

Seashell declines could be even worse at more popular beaches. “Llarga Beach is not a highest-tier tourist destination,” the authors note, and its shells are “neither attractive to professional shell collectors nor spectacular enough to attract attention of every casual beachcomber.” Since tourist arrivals around the world have reached about a billion per year, the disappearance of seashells could be a global problem. Roberta Kwok | 9 January 2014

Source: Kowalewski, M., R. Domenech, and J. Martinell. 2014. Vanishing clams on an Iberian beach: Local consequences and global implications of accelerating loss of shells to tourism. PLOS ONE doi: 10.1371/journal.pone.0083615.

First image © Olaru Radian-Alexandru | Shutterstock

Second image: Kowalewski, M., R. Domenech, and J. Martinell. 2014. Vanishing clams on an Iberian beach: Local consequences and global implications of accelerating loss of shells to tourism. PLOS ONE doi: 10.1371/journal.pone.0083615.



  • scnehruroy January 18, 2014 at 11:20 am

    In many sea shore tourist spots, the locals collect seashells to make ornamental garlands and also some decorative items for sales unaware of the harmful effect to environment as a whole. It is high time . this matter is discussed globally and highlighted before the damage spirals.


  • J July 10, 2014 at 8:49 am

    The study itself points out that it’s not collection that seems to be the major problem at Llarga, but sand/beach maintenance. This article is misleading to say otherwise, and makes it sounds like the author didn’t finish reading the study and doesn’t realize.

    “In addition, beach maintenance, which can be expected to correlate with tourism intensity, often involves extensive cleaning and grooming of beach areas with heavy equipment [10], [29], [50], [51]. This is the case for Llarga Beach, where maintenance activities, using tractors with rakes, occurred daily during summer months of 2008–2010, but not during the 1978–1981 sampling interval. These maintenance activities may also explain the anomalously high decline observed for the 2008–2010 July-August months when comparing with the 1978–1981 time interval (Fig. 3B).”

    Where I live, you can the see difference in two major beaches we have. One with no sand cleaning is full of shells, you can find them everywhere. The other, a wealthy area full of vacation homes, has regular sand cleaning, and there is rarely a shell to be found. These places are no different otherwise.


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