Sandy beaches are home to many species, including tiny invertebrates which hold key ecological roles and functions. A new study warns that human activities, and especially tourism, pose a big threat to these minute organisms and the biodiversity they compose.
Coastal areas and sandy beaches are under increasing pressure from encroaching urbanisation and different sorts of human infrastructures, which promote bigger waves of tourism year after year.
While marine protected areas can aid the conservation of marine biodiversity, their effectiveness is likely to remain somewhat limited unless their protection is extended to beaches too. In fact, beaches are home to many organisms, amongst which are microscopic beings called meiofauna, which hold key ecological functions.
Examples of meiofauna. Figure credits: 1
These minute creatures recycle key nutrients, help prevent sediment erosion in sandy beaches, and are very important nutritionally to a variety of animals that could not survive without them. If meiofauna were to rapidly decrease, both marine and coastal ecosystems would be severely hit.
A new study1 by a group of European researchers, published in Nature Communications investigated whether tourism could negatively affect the microscopic biodiversity of coastal ecosystems whose taxonomic groups have thus far received little scientific attention.
“Most of the studies addressing the impact of human presence on beaches […] were performed on large invertebrates, which often present hard shells and cuticles and can dig into the sediment layers beyond the one that is directly affected by tourists” explain the authors, who then continue highlighting that “very few studies on the effect of tourists on meiofauna of sandy beaches are available”.
The authors, led by the molecular ecologist Dr Alejandro Martínez, based at the Water Research Institute (IRSA) in Italy, applied a specific genetic technique called DNA metabarcoding to conduct their research, which took place on Sardinia’s beaches, off the western coast of Italy.
The findings suggest that the presence of tourists on beaches does in fact significantly reduce the number of meiofauna species found at the shoreline.
“We suggest that the effect of presence of people could be assigned mostly to trampling, since walking on the beach […] is the major disturbance activity of humans in the sampled areas, where other more impacting recreational activities (e.g. access to motorized vehicles, camping, beach grooming, etc.) are forbidden”, the authors say.
The researchers also indicate that sunscreen cream used by tourists is likely to be another deleterious factor to the persistence of microscopic organisms in sandy beaches.
The study ends with practical indications on how policymakers and local governments could intervene to minimise the risk of destroying coastal biodiversity, including through implementing partial or full restrictions on public access to certain beaches whose ecosystems are particularly threatened.
“Since many meiofaunal taxa are restricted to sandy beaches and may be sensitive to trampling and other indirect influences from the mere presence of people, our results highlight the necessity of implementing management strategies including integral protection for specific sandy beaches for conservation purposes”.
“Protection can consist either of including certain beaches into areas of integral protection within marine protected areas […] or alternatively by defining specific zones within beaches in which tourist access is forbidden” conclude the authors.
As beaches become more crowded, even the conservation of coastal wildlife invisible to human eye is increasingly at stake.
If you enjoyed this read, and would like to receive a notification every time a new post comes out, enter your email address below and subscribe to Conservation in a Click.
- Martínez, A., Eckert, E.M., Artois, T., Careddu, G., Casu, M., Curini-Galletti, M., Gazale, V., Gobert, S., Ivanenko, V.N., Jondelius, U. and Marzano, M., 2020. Human access impacts biodiversity of microscopic animals in sandy beaches. Communications Biology, 3(1), pp.1-9. https://doi.org/10.1038/s42003-020-0912-6
Cover image credits: https://bit.ly/2x7ngXq