Line of action:

Status:

Execution date:

General:

Perform an initial diagnosis of Anemonia sulcata populations within the selected areas

Specific:

1. Collect and acclimatize the different selected population lines or clones under conditions of captivity, reproduction and culture.

2. To study the proximal composition, growth and nutritional indices at different stages of development of sea nettles cultivated in captivity and in their natural environment.

3. Determination of the welfare status and degree of gonadal ripeness of sea nettles cultivated in captivity and in their natural environment.

4. Carry out the transfer, installation and monitoring of the planting units, within the populations of the target areas.

5. Involve the harvesting sector in the importance of responsible use of the resource. Carry out awareness campaigns among the population, students, associations and volunteers. It is intended that this pilot experience will serve as a reference for future applications by the competent administrations, such as the design of a protocol for the reintroduction of illegally caught species.

6. To promote the dissemination of the results obtained in specialized journals and to the scientific community.

A1. Selection and collection of broodstock in captive conditions:

-Underwater expeditions for the selection of sampling areas and reintroduction of specimens.

-Collection of specimens from the selected sampling area

A2. Acclimatization, reproduction and cultivation of the different lines or clones:

-Acclimatization in facilities adapted to the species

-Sexual reproduction

-Asexual reproduction

-Fattening of juveniles

A3. Assessment and selection of mature individuals to ensure successful implementation in the natural environment:

-Growth analysis and biometrics

-Treatment and processing of samples for laboratory determinations

-Individual composition analysis

-Analysis of animal welfare parameters

-Histological evaluation of the degree of gonadal maturation

A4. Reintroduction of individuals and monitoring of planting units within populations in the target areas:

– Transfer of individuals to the areas selected for repopulation

– Control and monitoring of the sowing units

A5. Involvement in the collection sector. Awareness campaigns:

-Talks aimed at collectors, students, associations, volunteers in terms of environmental awareness and awareness.

-Informative workshops aimed at raising awareness of the importance of specific management of shellfish resources within protected areas

-Specific training for shellfish gatherers and administration staff.

A6. Scientific dissemination of results:

-Participation in congresses or conferences of a scientific and/or technical nature.

-Publications in scientific journals.

A study has been carried out in different areas of the coast of Granada where populations of anemones are found, capturing some specimens from the environment for breeding and reproduction using the culture system based on IMTA. This species was found distributed in the bathymetric range between 2-5 meters deep, with an acceptable degree of abundance of 10-15 individuals/m2. In all sampling stations, there is a considerable decrease in abundance at a depth greater than 5 meters. It was concluded that the three selected areas may be ideal areas for the repopulation of captive reproduced anemones and for the colonization of less populated areas due to shellfish overexploitation. The three areas presented very good environmental conditions, due to their hydrodynamic characteristics, type of substrate, bathymetry and incidence of light.

Similarly, a positive monitoring of the growth and survival rate of the individuals has been observed, indicative of their state of well-being, a key aspect for their optimal growth, maturation and reproduction (clones due to asexual reproduction).

The evolution in the composition and nutritional characteristics of the individuals, associated with the maturation process, has been studied and analyzed, and a protocol for the fixation and reintroduction of individuals in areas previously selected for their natural characteristics has been optimized for the repopulation of individuals. Some general conclusions are:

• The sea nettle is a species that has good prospects for its cultivation in order to conserve the fishery resource.
• It adapts very well to captive conditions, using IMTA (multi-trophic culture) technology that has the advantage of greater sustainability and animal welfare.
• During the nine months of the project, the stock has tripled.
• It is necessary to advance and consolidate sexual reproduction and larval breeding, although it is a slow process that requires two years to reach the minimum commercial size. However, this strategy is considered essential to achieve the conservation of the species, providing density of new individuals and genetic variability.
• Reintroduction operations into their natural habitat are feasible and allow the expansion of the resource in areas punished by overfishing.

Finally, a series of corrective measures are proposed to improve its management and sustainability:

• Delay the closed season to the period after spawning, so that the expansion into the environment of juveniles from sexual reproduction, responsible for providing genetic variability and, therefore, perpetuating the species, is allowed. It would be ideal to extend it by the three months in which spawning takes place -from March to May-; or failing that, two months.
• Measure the catch rate in units rather than kilograms. In this way, the capture of smaller specimens of their commercial size with the same allowed amount of 12 kg/collector/day would be avoided. Other alternatives would be to reduce the maximum quota of kg, or limit it to X days of capture/month.
• Increase the minimum commercial size from 15 to 25 grams, maintaining the catch rate of 12kg/day/harvester. The amount allowed would be reduced to 480 units.
• Reintroduce seized specimens from illegal captures into rocky areas of open and clean waters, avoiding port waters, where the lack of water transparency and adequate substrate, together with an inadequate flow and water quality, reduce their survival. It is also not appropriate to return them on the shore of the beach; the sandy substrate would not allow them to be fixed well, in addition to the fact that the waves would throw them back to the shore.