Fishing pattern and interactions of fleet components in the <I>Argyrops spinifer</I> (Actinopterygii: Perciformes: Sparidae) fisheries of the Arabian Sea, Oman

Abstract

FISHING PATTERN AND INTERACTIONS OF FLEET COMPONENTS IN THE ARGYROPS SPINIFERBackground. The influx of foreign fishing vessels in the Arabian Sea, during the mid 1990's, has sparked some conflicts between artisanal and industrial fleets and raised concerns related to the resource management implications of fish stocks in the region. To address the lack of management data on the basic biology and stock assessment for targeted species, the Ministry of Fisheries Wealth in Oman initiated this study with a view to contributing towards the development of a management plan for the sustainable exploitation of the living resources of the sea in this region. Materials and methods.A database including biological parameters, length-frequency distributions and catches of king soldier bream, Argyrops spinifer (Forsskål, 1775), in Oman according to fleet (gear/technique) and region was compiled by monthly sampling in 2001 to 2002. In this study, length cohort and yield per recruit analyses were examined after simulating changes in fishing effort, in length at first capture and introducing a closed season for trawlers.Results. The results showed that: (i) the status of the stock is healthy, the average fishing mortality rate is moderate (0.1) and acts in general on the adult fraction of the stock. The fishing pattern differs, however, among fleets with some fleet components fishing, in part, for immature king soldier bream. (ii) An increase in total fishing effort would not lead to any long-term substantial increase of the catch (according the uncertainty of M value); however, the spawning stock biomass would decrease significantly. This measure affects negatively fleets that target the larger specimens. (iii) A moderate (±20%) modification of minimum length limit in catches would not affect, substantially, the sustainable yield and the spawning stock biomass. (iv) Any regulation of trawler fishing by closed season (i.e. restricted trawler activities during some seasons) would not have a significant effect on the long-term yield. Conclusion. The current pattern of exploitation and fishing effort acting on the A. spinifer stock are optimal and no changes to global fishing or length at first capture are recommended. Also, with the actual fishing effort of trawlers, no closed season is suggested. However, fleet components whose catches include some juvenile fraction should adopt more selective gear as used by the hand line fishery in the Al-Wusta region.

Strengths and weaknesses in the long‐term sustainability of two sympatric seabreams (Argyrops spinifer and Rhabdosargus haffara, Sparidae)

“…Such a change was also observed in the spangled emperor Lethrinus nebulosus in the Gulf when comparing samples from 4600 to 4000 BC to present years (Lidour et al ., 2018). Relative lesser presence of large‐sized individuals in the landings could be attributed to multiple factors connected to fishery exploitation, such as variation and changes in major fishing gears (from hooks to traps and trawls; Al‐Mamry et al ., 2011), increase in fishing pressure leading to depletion of older cohorts (Bianchi et al ., 2000; Blanchard et al ., 2005) and regional differences in length frequency (Lin et al ., 2019a; Roa‐Ureta et al ., 2019b). Future studies are needed to elucidate the real causes of the changes in the length frequency distributions.…”

“…It is a generalist carnivore and feeds on molluscs, crustaceans and fish (Ghanbarzadeh et al ., 2014; Lin et al ., 2019c). It is a relatively large seabream attaining a maximum size of 700 mm in total length (Randall, 1995) and is caught mainly by bottom trawls, hand‐lines and traps in the Gulf and Arabian Sea (Al‐Mamry et al ., 2011). The haffara seabream R. haffara is found in the western Indian Ocean, mostly in the Red Sea and Gulf (Fischer & Bianchi, 1984; Froese & Pauly, 2019).…”

“…It is a generalist carnivore and feeds on molluscs, crustaceans and fish (Ghanbarzadeh et al, 2014;Lin et al, 2019c). It is a relatively large seabream attaining a maximum size of 700 mm in total length (Randall, 1995) and is caught mainly by bottom trawls, handlines and traps in the Gulf and Arabian Sea (Al-Mamry et al, 2011).…”

Feeding habits of the king soldier bream, Argyrops spinifer (Forsskål, 1775) (Perciformes: Sparidae), in the northern Persian Gulf

“…In spite of a wide distribution and commercial importance, published information on its food, feeding habits, and ecology is limited. Previous studies on this species focused mainly on age, growth and mortality in other regions (Edwards et al., ; El‐Sayed and Abdel‐Bary, ; Grandcourt et al., ; Al Mamry et al., ; Al‐Mamry et al., ). However, data on feeding habits of this species is rarely reported; the only published data is related to the Gulf of Carpentaria, Australia (Salini et al., ).…”