FISHERIES MANAGEMENT OF THE THINLIP GREY MULLET LIZA RAM AD A AND GOLDEN GREY MULLET LIZA AURATA FROM LAKE BARDAWIL, EGYPT | ||
| Egyptian Journal of Aquatic Biology and Fisheries | ||
| Article 3, Volume 10, Issue 2, April 2006, Pages 33-53 PDF (1.78 M) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/ejabf.2006.1847 | ||
| Author | ||
| Sahar Mehanna | ||
| National Institute of Oceanography and Fisheries, Suez. | ||
| Abstract | ||
| Monthly samples of Liza ramada and L. aurata were collected from Lake Bardawil during the period from April to December 2004. to study their population dynamics and to assess the fishery status of their stocks. The total length of L. ramada and L. aurata ranged from 16.9 to 42 cm and 16 to 30.5 cm respectively. Otoliths were used to estimate their ages. The age distribution covered age groups I to V for L. ramada and I to III for L. aurata with age groups II and I being the most frequent for L. ramada and L. aurata, respectively. The von Bertalanffy growth equations were Lt= 44.14 (3-e*d5Ul*n-9) for L ramada and L,= 33.77 (I-e °* ltl"r-J*j4J) for L. aurata. The respective instantaneous annual rates of total. natural and fishing mortality were 1.22. 0.16 and 1.06 year"1 for L. ramada and 1.36, 0.22 and 1.14 year"1 for L. aurata. Exploitation rate was estimated as 0.87 and 0.84 year"1 for L ramada and L. aurata respectively. The estimated lengths at first capture were 18.45 and 16.92 cm. while the length at first sexual maturity was 28.71 and 23.11 cm for L. ramada and L. aurata respectively. The relative yield per recruit and relative biomass per recruit analysis indicated that the stocks of L. ramada and L. aurata at Lake Bardawil were over-exploited and their respective current exploitation rate should be reduced by about 54% and 52.4% and their respective length at first capture should be raised to 30 and 25 cm | ||
| Keywords | ||
| Lake Bardawil; Mugilidae. Liza ramada; Liza aurata; Population dynamics; Stock assessment; Management | ||
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