How did beach infilling become the messenger of summer?

Are our beaches beautiful and functional enough or is permanent beach infilling necessary?

Whether we reminisce about summer and the joy of the sea or winter walks along the coast that charge even the most depleted batteries, we all have wonderful memories of living by the sea. Everywhere in the world the seashore is the most attractive area for life and tourism (Kipson, 2021) so it does not surprise us that human activity in this area is strong and permanent. But do we preserve this treasure as every treasure should be preserved? Should we leave the opportunity to create memories like ours for the younger generations and preserve this irreplaceable resource?

Common sense tells us we should, but the events on our coast suggest otherwise. Today, the sea is a resource that we often unfairly take for granted and use so negligently, as if we were not aware that it is finite. Every spring excavators start tearing limestone pavement, trucks unload soil and stones into the shallows, mixers mix concrete that will devour every hump or pebble, all in order to make it “nice”. Beach infilling and nourishment have become a sure sign of the arrival of summer and tourist season. Sounds like a Croatian actuality, doesn’t it?

Surely, many will say that tourism is one of the biggest movers of change in coastal areas and that the touristic demand defines the direction of landscaping. It’s not disputable. What is controversial is how we reconcile the pursuit of a safe and healthy environment and at the same time a sustainable tourism industry that puts bread on our table.

Creating beaches in Croatia

The Association Sunce continuously warns that landscaping should be guided by environmental principles, with attention to the precautionary principle. This means that any human activity in the environment should first be assessed as safe for the environment. However, calls from citizens that we received through the Green Phone service in 2021 indicate that this is not the case. More than 50 calls were related to beach infilling or coastal construction without the necessary permits. Sometimes these are megalomaniac projects that are carried out inconsiderately towards the environment, and sometimes there are smaller infillings or seasonal replenishments that separately do not appear so problematic until we look at the bigger picture and add up the consequences that all these regular “arrangements” of the coast have on the environment.

The total length of beaches in Croatia is 619 km, while the average length of the coast of Croatian beaches is 370 m, which includes them among the shortest beaches in the world (Carević, 2020). Therefore, coastal municipalities and cities often choose to build an increasing number of new beaches and/or to expand the capacity of existing ones, in order to meet the needs of the growing number of tourists. Thus, the beaches are infilled or nourished. While infilling belongs to the category of construction (of new surfaces of the beach) and requires the implementation of environmental procedures and the issuance of building permits, nourishment belongs tothe category of technical maintenance of beaches in such a way that the position of the existing coastline does not change (substantially).

In the absence of funding for the preparation and implementation of a complete project for the construction of the beach, local self-government units regularly opt for the seemingly cheaper practice of forming beaches by ad hoc unloading of materials along the coastline, in places that are not necessarily the most suitable for such a procedure. Without elements to ensure their stability and resistance to the impact of the waves, such beaches, at best, last one summer season, and then winter storms, for the most part, simply wash them away. Then it becomes clear that nourishment on the basis of a professionally designed project, due to its durability, is more profitable and of higher quality in the long run. In addition, such treatment greatly reduces the negative impact of the added material on surrounding demersal marine habitats, as the amount of eroded nutrients is significantly lower in a well-designed and constructed beach and thus there is less need for repetitive replenishment (Coastal Plan of Split-Dalmatia County, 2021).

We are witnessing that many individuals who are infilling the coast have not obtained the necessary permits, and by examining the Coastal Plan of the SDC, it is evident that those who were entrusted to care for our coast are also adhering to cheaper and faster solutions that are unsustainable in the long run. Therefore, we wonder, until when will concreting and reckless infilling of the coast continue to be carried out, all without lasting consequences?

Analysis of the impact of infilling on the marine environment

When we had seen a truck releasing massive amounts of soil and rocks into the limestone pavement, we assumed something was not right, but we did not know exactly what was happening under the sea and why exactly was it wrong. As part of the SEAS project, we have embarked on exploring the impact of coastal infilling and nourishment of the beaches on sea demersal communities under the leadership of expert Dr. Silvija Kipson. Without entering into matters of issuance of permits and their legality, the review work of dr. sc. Kipson provides us with a window into the underwater world and gives examples of how the use of inadequate material to nourish the beach leads to various changes in the biogeochemistry of the environment, which thus ceases to be a suitable habitat for previous organisms.

Beach nourishment causes:

▪ Pollution with heavy metals, polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCBs) and others, if the material used contains them (Speybroeck et al., 2006; Pit et al., 2017);

▪ Suffocation of stationary organisms, and consequences on mobile species that depend on them, e.g. those that feed on them (Aragones et al., 2015);

▪ The reduction of feeding possibility of herbivorous species because of the blocking of the photosynthesis due to turbidity. (Goatley and Bellwood, 2013);

▪ The appearance of slimy algae clusters which are accumulated on stationary seabed organisms and prevent them from performing photosynthesis and feeding (see González-Correa, Fernández Torquemada and Sánchez Lizaso, 2008; “Long-term effect of beach replenishment on natural recovery of shallow Posidonia oceanica meadows”.  Estuarine, Coastal and Shelf Science 76 (4): 834-844.);

▪ The inability to adequately feed, reproduce and/or recruit new individuals due to the accumulation of unloaded material on the natural habitat of these organisms (Avissar, 2006);

▪ Negative impact on individual plants and animals due to increased presence of people, increased noise and inappropriately disposed waste during the use of beaches (Ekoinvest, 2020).

Bearing in mind that all links of an ecosystem are important, we conclude that beach infilling can cause significant imbalances.

Poniente beach case study and nature response

In order to illustrate what was previously stated, bearing in mind the constant aspiration for economic progress in tourism, we cite the example of infilling of Poniente beach in Benidorm (Valencia, Spain) represented by Dr. Sc. Kipson:

“Poniente Beach in Benidorm on Spain’s Mediterranean coast is an important tourist attraction in Valencia. It stretches over almost 3 km of coastline and is formed by fine sand (0.3 mm). In response to the impact of storms, which caused structural damage to the wall of the coastal promenade, in 1991 a solution was adopted that included the infilling/nourishment of the eastern part of the beach in the length of 1350 m. The total amount of unloaded sand, excavated from the seabed near the Helada Mountains, was 710847 m³, so more than 500 m³ was spent for each required meter of beach. This resulted in the expansion of the beach from an initial 20 m to 100 m wide and it was necessary to build a feather that would hold back the sand and prevent the bottom in the nearby harbor from getting filled in.

The infill buried part of the Posidonia that was in front of the beach and was the main cause of its death. With the disappearance of Posidonia, the ecosystem services it provided, in the form of sediment stabilization and wave energy mitigation, have also disappeared, which further caused the extraction of the unloaded material. Due to the extremely slow growth of Posidonia, any destruction can be considered irreversible, at least during the lifespan of an average human. The trend of Posidonia disappearance resulted in a decrease in the width of the beach by more than 20 m over a period of two years after the infilling.

Thus, inadequate infilling caused ecological and economic damage, and the expansion of the beach in the outlined dimensions was not achieved in the long term.

An alternative calculation showed that the expansion of the beach to 60 m (instead of the 100 m performed) in the first phase would satisfy the functionality regarding its public use for recreation purposes, etc. It would also avoid the destruction of Posidonia, maintain the stability of the beach profile and reduce the initial losses of unloaded sand. Only after 20 years it would be necessary to infill the beach again in order to expand it again to 60 m. Both phases would require a total of 341630 m³ of sand, that is, 52 % less than the amount spent in 1991, and for the same period of beach functionality. With all this, the natural heritage, in the form of settlements of Posidonia potentially several hundred to thousands of years old, would not be destroyed.”

They managed to lose the touristic and local value they intended to create, all because nature answered to human actions with the simple act of moving one “seaweed” just a little deeper into the sea.

We need it natural and healthy!

But we do not need to travel to Spain to witness how the mismanagement of the coast leads to economic and environmental losses. Let’s take a walk along our coast this spring, see what we want to conquer. Do we need a perfectly flat coastline with perfectly uniform stones? Do our tourists need it or do they appreciate authenticity and come from countries that have already destroyed their shores, which makes them amazed by the unique moments of our Adriatic?

The Association Sunce doesn’t think we need it. We believe that we need it to be natural, healthy and unique. We would trade all the comfort of towels on the concrete plateau for the experience of diving into the sea full of life. This does not put us in conflict with the development of the economy; in fact, with our work we offer solutions for reconciliation of economic development and environment preservation.

Some of the possible steps for coastal management, which offer to meet the needs of the local community while preserving the environment and financial viability, are offered by dr. sc. Kipson in his research:

1. develop or amend/supplement legislation that would define methods and ways of feeding, including the necessary standards on the quality of beach material (Carević, 2020)

2. promote ‘good practice’ related to the issue of beach erosion (highlighted e.g. in the SDC Coastal Plan)

3. advocate adequate supervision in the execution of works (e.g. method, quantity and quality of unloaded material)

4. advocate alternative, more sustainable solutions, e.g.:

a. the concept of increasing beach capacity, which provides for measures that have a minimal impact on the natural balance and includes extending the beach into the hinterland or setting up ‘seasonal’ sunbathing areas (potentially from artificial materials) that can be removed after the summer season (Carević, 2020);

b. nature-based solutions (see Morris et al., 2021), e.g. Maintain good conservation status of sea flowering plants that stabilize sediment with their roots while reducing wave energy with leaves, thereby preventing, or at least diminishing, coastal erosion and acting as “natural beach keepers”.