Impacts of Water Quality, Fishing Mortality and Food Availability on the Striped Piggy Pomadasysstridens Production in Bitter Lakes, Egypt

Abstract

Pollution, fi shing effort and food availability are the main factors affecting the fi sh production from natural resources. Bitter lakes are one of the important lakes in Egypt that produce a number of commercial species with mean annual fi sh production of 5000 ton. Recently a dramatic decline in this production is recorded and we try to fi nd the main reasons for this. Water quality of the Bitter lakes and trace elements in the water and fi sh tissues were investigated during 2013. Five different sampling sites covering the whole course of the Bitter lakes were selected and pH, water temperature and salinity were measured. The cations Ca, Mg, Na, and K concentrations in sample water as well as the heavy metals Cu, Cr, Mn, Pb, and Cd in water and its residues in the tissues of Pomadasysstridens were determined. The crustacean communities as one of the main food items for P. stridens were studied in the chosen fi ve sites. Density and diversity of marine crustaceans depend not only on the state of pollution but also on the type of substrates and different predators. The distribution of the crustaceans in the Bitter lakes varied widely within the different stations and seasons. A production model was applied to estimate some target reference points for the rational exploitation of P. stridens in Bitter lakes. The obtained results revealed that, the production depleting of this species is due to the overfi shing and pollution that affect the food availability and the estimated precautionary target reference points advised the reduction of fi shing effort by about 40-55% as well as the treatment of pollution resources along the lakes.

Population dynamics of an emergent invasive fish, striped piggy, Pomadasys stridens (Actinopterygii, Perciformes, Haemulidae) in the Gulf of İskenderun, north-eastern Mediterranean

“…The striped piggy populations inhabit the Suez Canal seem to have better growth performance with 2.15 (El-Ganainy and Sabra 2008) and 2.44 (El-Azim et al 2017) Ø′ values than in the Mediterranean and the Gulf of Suez. As mentioned above, the populations are overfished here, and they are smaller in size.…”

“…Striped piggy, Pomadasys stridens (Forsskål, 1775), naturally distributed in the western Indian Ocean extending from the Pakistani coasts to the east African coasts including the Red Sea (Froese and Pauly 2018), the Gulf of Suez, and the Suez Canal (El-Azim et al 2017). It was introduced to the Mediterranean via the Suez Canal.…”

“…As a consequence, Lessepsian fishes form an important part of the commercial fishery (Yemisken et al 2014). Although striped piggy has economic importance in its native range (Osman et al 2019;El-Azim et al 2017), it is discarded in the Turkish fishery (unpublished data).…”

“…Its spawning period is in spring and summer in the Gulf of Iskenderun (Özbek 2017). Although the population dynamics of the striped piggy has been comprehensively studied in the Indo-Pacific region (Safi et al 2013(Safi et al , 2014aOsman et al 2019;El-Azim et al 2017), there is still insufficient information on its age, growth, mortality, and morphometry in the Eastern Mediterranean. Therefore, the aim of this study was to determine the population dynamical parameters in the Gulf of Iskenderun, five years after the establishment of the population.…”

Fishery biology of Terapon puta (Cuvier, 1829) from east Egyptian Mediterranean waters

“…Different aspects of biological parameters of Terapon puta, have been studied in different regions by different authors, sucj as those of Ben-Tuvia and Mckay (1984) in north-eastern Atlantic and Mediterranean;Fisher et al (1990) in Mozambique; Pauly et al (1998) in Philippineanes waters; Hashemi and Taghavimotlagh (2012) in northwest of Persian Gulf (Khuzestan Coastal Waters. Iran, Amtyaz;Safi et al (2014) in Karachi coast, Pakistan and Abd El Azim;Mehanna and Belal (2014) in Bitter lakes, Egypt.…”