…..that is the question being asked about many sandy beaches around the world.
Should beaches be mechanically cleared (or groomed) with tractors and raking equipment? Or is this creating more problems than it solves?
Beaches both in Scotland and on an international level are being groomed because it is a quick, effective way of removing litter. In order to attain beach awards such as the highly prized Blue Flag, beach managers feel they need to keep their beaches litter free and looking pristine (Llewellyn and Shackley, 1996). The problem with this is that grooming also removes everything else on the beach including stranded seaweed and any small animals (macro-invertebrates) that are associated with it.
A lot of people don’t particularly like stranded seaweed with its notorious aroma and its accompanying flies. But seaweed is a vital part of the coastal ecosystem. It provides food and shelter for a large number of macro-invertebrates which in turn provide food for birds and mammals. It plays an important part in biogeochemical processes by providing nutrient re-mineralisation and recycling. The macro-invertebrates play a significant role in nutrient recycling and most of the nutrients are returned to the marine environment. Fewer fish fry (including many commercial species) are found adjacent to groomed beaches (Orr, 2013). Stranded seaweed also stabilises and fertilises sand dunes. Grooming therefore not only affects strandline ecosystems but also near shore marine ecosystems and dune systems.
Most people agree that sand dunes are magical places.
Valued for their wilderness they play an important part in our cultural heritage. Sand dunes provide us with many important Environmental Services. Soil formation, nutrient cycling and provision of habitat sit alongside their role as a natural coastal defence (Everard et al, 2010). With rising sea levels reported around the world, sand dunes really shouldn’t be ignored. We need them.
So the answer surely is to just stop all this mechanical grooming nonsense, pick the litter by hand, sit back with an ice cream and enjoy the beach and dunes in all their natural glory. Or is it? The answer unfortunately is not that simple.
Recent research has discovered that seaweed washed up on beaches is a possible source of faecal bacteria. Seaweed (or macro-algae) may potentially enable faecal bacteria to survive for extended periods and these bacteria are then washed back into the water column leading to an increased risk for people swimming, paddling or enjoying water-sports. The increased bacterial loads can play havoc with bathing water quality meaning that some beaches may fail to meet the Bathing Water Directive’s standards which will obviously have a knock on effect for the tourism industry.
With this in mind the question of whether to groom or not to groom becomes more complicated.
Is seaweed a good thing or a bad thing?
Clearly more research is needed into the role stranded macro-algae plays in harbouring harmful bacteria. It may be a very fine balancing act that needs to be worked out between the Environmental Services provided by the sand dunes and the Environmental Services provided by clean bathing water. The seaweed issue needs to be solved, before our sand dunes are pushed to the limit.
Everard, M, Jones, L, Watts, B. 2010. Have we neglected the societal importance of sand dunes? An ecosystem services perspective. Aquatic Conservation: Marine and Freshwater Ecosystems 20: 476-487.
Llewllyn PJ, Shackley SE. 1996. The Effects of Mechanical Beach-Clearing on Invertebrate Populations. British Wildlife 7 (3): 147-156
Orr KK. 2013. Predicting the ecosystem effects of harvesting beach-cast kelp for bio-fuel. PhD Thesis. University of Aberdeen.