Line of action:

Status:

Execution date:

General Objective:

To increase and improve the technical and scientific knowledge of the shrimp fishery (Penaeus Kerathurus) to achieve its environmental sustainability, reducing the discards of juveniles of other commercial species and those of high ecological interest such as the seahorse, as well as the accidental catches of eel. To reduce the loss of biodiversity in both commercial species and those of high ecological interest.

Specific objectives:

1. Current knowledge of the farm and the bioecological parameters of the shrimp (Penaeus Kerathurus) population.
2. To reduce the discards that occur as a cause of the capture of juveniles of other commercial species such as Sparus aurata, Lithognathus mormyrus, Solea senegalensis, Dicetrarchus labrax, Diplodus spp., as well as those of high ecological interest, such as the seahorse (Hippocampus guttulatus), as well as accidental captures on the eel (Anguilla anguilla).
3. To offer advisory services to the Fishermen’s Guilds of San Pedro del Pinatar, Santa Pola and Guardamar del Segura involved in the shrimp fishery (Penaeus Kerathurus).
4. Dissemination of results and exchange of knowledge to all sectors involved in the environmental sustainability of the shrimp fishery (Penaeus Kerathurus).

The project has begun with a first bibliographic and data search in public research organizations and fisheries administrations, from which the survey and sampling statistics (fish market and boat) have been designed and prepared.

Subsequently, sampling campaigns have been carried out in the SCI and SPA Mar Menor and in the SPA Espacio Marítimo Tabarca – Cabo de Palos and the following results have been obtained:

• The exploitation of the shrimp is carried out through trammel in Guardamar del Segura and charamita (paranza) in San Pedro del Pinatar.
• The fishing season in San Pedro del Pinatar occurs in two campaigns (spring and autumn) and in Guardamar del Segura only in one season (April-July).
• Shrimp catches in 2018, for all the areas studied, totalled 27,191 kg. 89% correspond to catches made in San Pedro del Pinatar and 11% in Guardamar del Segura – Santa Pola.
• The distribution of sizes indicates that the months where the most smaller individuals are captured are those between September and November (autumn campaign). The charamita captures the smallest females in the months of October-November and the males in June-July. For trammel gear, it is the month of May for both females and males.
• The reproductive biology of the shrimp shows that the development of ovarian maturity advances from June to July, when the highest percentages of mature females are observed. Males mature sexually earlier than females. The first maturity size for females has been calculated at LC50= 32 mm and for males at LC50= 23.5 mm
• The sex ratio obtained in 2018 is 51.29% for females and 48.71% for males.
• The exploited population of shrimp, both in females and males, is made up of specimens up to 3.5-4 years of age. The catches in both sexes are mainly made up of adult specimens, 1 and 2 years old.
• The values of natural and total mortality in males is slightly higher than in females.

Based on the data obtained, the state of exploitation of the resources and their evolution have been studied. The results estimated indirectly with the Recruitment Performance analyses show a trend that coincides with the actual results, observed directly in the fishery. It is concluded that the resource is subject to an adequate exploitation pattern.

Four prototypes were designed and evaluated aimed at facilitating triage, reducing the time spent separating juveniles and non-target species in the shrimp fishery and favoring the recovery of individuals when they are returned to the sea. The test of the box prototypes for triage showed that it was not practical due to the high number of prawns caught. From the survival cage model, it was observed that the fry are capable of reintroducing themselves to the sea if they have been handled quickly by the fishermen during triage.