Project name: UCRA – Use of Rolled Pebbles in the Azores, Characterization, Diagnosis and Management Plan
Duration: 13 months
Framework: Coastal zones accommodate transitional areas between land and sea. The variability of the (often extreme) environmental conditions to which they are subjected, coupled with the rapid morphological evolution that characterizes them, due to their permanent exposure to a variety of natural agents, make them unique environments, of considerable vulnerability and in need of specific management measures. Such features give them the status of complex and dynamic systems with an extremely important ecological function – that of linking terrestrial and marine ecosystems. The intensification of population growth in coastal zones and economic expansion, with consequent concentration of anthropic activities (industry and tourism / leisure), have successively created conflicts of interest of use and occupation and between these and the natural processes of coastal systems, threatening this form the delicate dynamic equilibrium of the latter and worryingly contributing to the degradation of their biodiversity.
In the Azores Archipelago the presence of a limited territory, along with the physiographic contrast between the coastal fringe of the islands and their interior areas, has conditioned human fixation since the settlement of the islands in the 2nd quarter of the century XV, and more recently, government decisions on territorial planning.
Since the coast is a constant presence in Azorean daily life, the population has, over time, systematically enjoyed the vast amount of resources available on it. The need to manage the uses and activities developed in coastal areas has led to the emergence of successive legal instruments, strategies and action plans, which are often inarticulate with the needs and limitations of the population.
This project aims to address the problem of regular collection (and not always respecting the natural and legal constraints) of beach ballasts in the Autonomous Region of the Azores (RAA), locally designated by the regionalisms “calhau rolado”, “pedra lisa” or “ rolo ”, in accessible places of the coastal strip, where the natural accumulation of these sedimentary deposits occurs. The collection of these sediments is mainly motivated by their usefulness in commercial fishing as sinkers in traditional demersal fishing gear (longlines and handlines), and is occasionally intended for ornamental or artistic purposes, such as application to walls and gardens. The lack of alternative (material equivalent with similar physical characteristics and serving the purpose) to the use of that sediment has justified the persistence of its search, particularly by the fishing community.
Sedimentary depletion with anthropic origin commonly results in irreversible changes in shoreline morphology and modification of sedimentary shifts (eg Borges, 2003; 2009) that tend to favor coastal erosion processes, with a consequent contribution to shoreline retreat. Historical cases of anthropic sedimentary depletion on beaches in the Azores archipelago show us how this activity is likely to disrupt the sedimentary recovery of the system, with repercussions on the beach verge narrowing (reduction of the transverse extension of the beach) and consequent intensification of the retreat process of the adjacent coastal cliff (Borges et al., 2002; Borges, 2003; Borges et al., 2009). Thus, there is a need to assess the actual impacts of coarse sediment extraction activity on the Azores Islands coastal strip, with a view to assessing the relevance of adapting existing legal regulations to the reality and needs of the Azorean population, namely the which is affected by fishing activity, and the search for material alternatives to the geological resource sought, which are in line with the use in question.
This project aims to contribute to the knowledge of the technical-scientific nature that helps in the decision-making process in public policies of strategic and sustainable management of coastal erosion, in line with the defense of coastal financial resources and safeguarding the interests of user population. In this context, the general objective of the UCRA project – Calculated Rolled Use in the Azores – was defined as providing information to support decision making on issues related to:
(1) sustainable management of areas of very coarse sediment (commonly known as beach gravel) in the RAA coastal zone, implemented and regulated by the competent authorities, and to be considered in a territorial and regulatory model adapted to the specificities of the region;
(2) global reordering of the land / sea interface space through the assessment and review of existing special land management instruments (e.g. Coastal Planning Plans – POOC) to assess their efficiency and effectiveness and to decide on the need to amend them, in particular in matters relating to the regulation on the extraction of geological materials;
(3) implementation of measures to mitigate the possible adverse effects of excessive beach ballast extraction from RAA coastal areas, in line with the new European-wide water resources management paradigms, as provided for in the Water Framework Directive, and addressed by the Azores Hydrographic Region Management Plan (PGRHA) and the Island Water Resource Management Plans (PGRHI);
(4) management of natural hazards in the RAA coastal zone, in particular related to the increased risk of flooding in coastal areas by extreme marine invasions, to be imperatively considered in the RAA – PGRIA Flood Risk Management Plan, as provided for in Floods Directive – Regulatory framework for flood risk assessment and management in the European Union (EU) area;
(5) implementation of the Regional Climate Change Plan (PRAC), in accordance with the Regional Climate Change Strategy, namely in the materialization of strategies aimed at reconciling the AAR’s experience with climate change, given the islands’ intrinsic vulnerability to this phenomenon;
(6) creation of legislative structures defining the licensing and supervision of beach ballast extractive activity in the RAA coastal zone.
(1) obtain a detailed characterization of the use and extraction activity of the beach ballast mineral resource:
- a) estimated average amount of “pebble rolled” extracted annually for use in fishing activity per island;
- b) estimated average amount of “pebble rolled” extracted annually by fishing gear – longline and handline – per island;
- c) location of preferred extraction sites by fishing communities;
- d) regularity of the extractive activity;
- e) losses of “pebble rolled” by fishing gear per year per island;
- f) financial costs of the extraction activity;
- g) profile (morphometric, dimensional and lithological characteristics) of the “standard rolled pebble” extracted for use in fishing activity.
(2) Obtain a detailed characterization of the specifically sought-after mineral resource, hereinafter referred to as standard ballast, naturally available in very coarse (gravel) coastal sedimentary deposits:
- a) lithological, morphometric and dimensional characteristics;
- b) natural processes / parameters that control their occurrence;
- c) geographical dispersion within the target study sites;
- d) volume of the non-metallic “pebble” mineral resource in the target study sites;
(3) Diagnose the impacts of extraction on depleted sites;
(a) annual morphodynamic evolution (potential imbalances);
- b) estimate of shoreline indentation magnitudes;
- c) proposal for monitoring methodology.
Some considerations on mineral resource management solutions, are also foreseen, which will include, among other things, suggestions for altering the legal framework governing its extraction activity.