Recopilación y análisis de la información científica disponible sobre Patella ferruginea

This document compiles and analyses the available scientific information on the ferruginous limpet (Patella ferruginea), a marine gastropod mollusc endemic to the western Mediterranean that lives on mediolittoral rocky substrata and is in danger of extinction. Its objective is to serve as a basis for adapting the conservation Strategy of the ferruginous limpet (Patella ferruginea) in Spain to the best available scientific knowledge.

A total of 310 references have been compiled and analysed, including articles published in research or scientific dissemination journals, books and monographs and book chapters, summaries of communications to congresses, doctoral theses, degree theses and equivalents, technical and scientific unpublished reports, and scientific research projects developed or in progress. The Internet has been used intensively to locate and collect bibliography and other information. One of the main difficulties encountered has been the great dispersion of information, generated in the countries where the ferruginous limpet is still present (Spain, France, Italy, Algeria, Tunisia and Morocco).

The results of the analysis of the information have been grouped into 11 chapters: scientific production, study methodology, morphology, geographical distribution, autoecology, reproduction, genetics, population dynamics, threats, management of the species and management and conservation measures.

Most of the scientific production of interest for the conservation of the ferruginous limpet has been generated in Spain during the last fifteen years. The largest number of scientific contributions corresponds to general or specific conservation issues, geographical distribution and study of populations. However, the level of knowledge of other aspects that are also fundamental for the management and conservation of the species, such as autoecology, reproduction, population genetics, larval development and recruitment, is still insufficient.

The funding dedicated to research oriented to management and conservation in the last 15 years is insufficient and much lower than that destined to other more charismatic species in danger of extinction. The port authorities and infrastructure companies have jointly contributed in these years a percentage of the total funding higher (44,5%) than that contributed by the organisms responsible for the conservation of the species (43,4%). This imbalance must be corrected to promote an investigation carried out independently of the interests of sectors not directly related to conservation and planned in the medium and long term.

The national and international coordination of the research on the ferruginous limpet is still incipient and very improvable. The presence on the Internet of the ferruginous limpet is reduced in comparison with another symbolic species threatened with extinction, such as the Iberian lynx, and even in relation to other non-threatened species of limpets. The publication of news in the digital press is also limited and often lacks scientific rigour. It is therefore essential to promote and improve the dissemination of the species in society, as a necessary and previous step to improve conservation policies and financing.

The results obtained from the analysis of the available information allow us to conclude:

1) The total population of Patella ferruginea in Spain seems stable in relation to the situation in 2008, but it is in an unfavourable state, with a very fragmented distribution consisting of a very small number of reproductively viable populations, which is why it remains in danger of extinction.

2) It is recommended to carry out a general assessment of the conservation status of the populations with a maximum periodicity of two years, and to monitor the main populations on an annual basis, by qualified biologists and following a homogeneous protocol.

3) It is recommended to propose the evaluation of the species for inclusion in the Red List of the International Union for Conservation of Nature (IUCN).

4) It is recommended to study the possibility of declaring additional marine protected areas for the protection of the species, at least in areas where a breeding population is present, to ensure connectivity between these areas and to protect them effectively.

5) It is recommended to establish collaboration agreements between environmental authorities and port authorities for the protection of ferruginous limpet populations on artificial substrates (ports, breakwaters, etc.).

6) It is recommended to approve the recovery plans of the species as soon as possible, which should include the designation of the critical areas. It is also recommended to incorporate the critical areas designated in those plans to the Network of Marine Protected Areas of Spain. It is proposed to consider critical areas at least the Chafarinas islands, Melilla, Ceuta, the island of Alborán, the bay of Algeciras and the rock of Vélez de la Gomera.

7) Except in Andalusia, the degree of compliance of the competent administrations in relation to the periodic evaluation of the state of conservation of the populations of Patella ferruginea throughout the nine years of validity of the Strategy has been generally insufficient for an adequate management of the species, which may be due to the general scarcity of human and financial resources.

8) The best available scientific evidence proves that translocation of Patella ferruginea specimens should not be considered as a conservation measure for the species.

9) It is recommended to prioritize and promote research in relation to reproduction, larval development, recruitment and population genetics of the species, given the insufficient information available on these issues and their importance for proper management .

10) In situ conservation measures should be complemented by ex situ conservation measures through captive breeding, in order to assess the possible reintroduction of the species into populations that are below a viable limit or to increase their area of distribution. The lines of research on ex situ conservation should be developed in the future in accordance with current legislation, following the guidelines of IUCN and in close international coordination .

11) It is also recommended to conserve genetic and biological material of the ferruginous limpet in the banks of genetic and biological material foreseen in Law 42/2007 .

12) Environmental monitoring should be improved both in marine protected areas and outside of them to avoid illegal shell-fishing, which is one of the main causes of loss of adult specimens in the populations .

13) Coordination among administrations should be greatly improved to eliminate or minimize the impacts of coastal works on Patella ferruginea populations .

14) Monitoring and prevention of pollution, especially of floating substances such as hydrocarbons, should be improved and, in areas where the ferruginous limpet is found, the species must be considered in the emergency plans .

15) Institutional cooperation should be improved, promoting the functioning of the Working Group for the implementation of the Strategy through joint work with the advisors appointed by Ministry for the Ecological Transition, optimizing coordination among public administrations, and increasing human and financial resources .

16) Finally, in order to reinforce the protection of the species, social awareness must be increased through an adequate policy of outreach and environmental education, the same as political will, both at a Spanish and international level.

Based on the results and conclusions obtained, a proposal has been drafted to update the current Strategy for the conservation of the ferruginous limpet (Patella ferruginea) in Spain.