SOME BIOLOGICAL PARAMETERS OF THE COMMON SOLE; SOLEA SOLEA FROM THE BARDAWIL LAGOON EGYPT

Attia A.O. EL-Aiatt¹ and Shymaa A.A. Omar²

¹ National Institute of Oceanography and Fisheries NIOF.

² General Authority for Fish Resources Development.

ABSTRACT

Due to the economic importance of Common sole, S. solea, and the importance of fish biological measurements in managing the fisheries of Bardawil Lake, the study was conducted on Common sole S. solea, during the fishing season 2019. The most important measurements: The length – weight relationship of solea solea described by the power equation W= 0.0091L^3.0104, W= 0.0059 L^3.1495 and W= 0.0067 L^3.1056 for males, females and combined sexes respectively The back-calculated length of combined sexes of solea soleasexes17.8, 22.2, 25.7 and 27.9 cm for1^st, 2^nd, 3^rd and 4^th years of life respectively. Growth parameters of the common sole Solea solea from Bardawil lagoon as L∞ = 33.76cm; K= 0.55 year−1 and t0 = -1.24 years for combined sexes, L∞ = 37.57 cm; K= 0.2356year−1, t0 = -1.79 years for females and L∞ =30.96 cm; K= 0.49 year−1 and t0 = -0.68 years for males during fishing seasons (2019). The total, natural and fishing mortalities were 0.8356, 0.3201 and 0.5155 year−1 respectively for males, 0.8342, 0.2170 and 0.6172 year−1 respectively for females and 0.8342, 0.2768 and 0.5574year−1 respectively for sexes combined. Correspondingly, the exploitation ratio was E = 0.62, 0.74 and 0.67/y for males, females and sexes combined respectively. The estimated length at first capture Lc was 18.4, 20.3 and 19.8 cm for males, females, combined sexes, respectively while these results reflect the high level of the exploitation of S. solea, and The study recommends the need to expedite taking the necessary steps to preserve the catch of Common sole S. solea fish and urgent management regulations to conserve this fish.

Keywords:
Common sole S. solea, Bardawil lagoon, length – weight relationship, Mortality rates.