Effect of type of bait on pelagic longline fishery-loggerhead turtle interactions in the Gulf of Gabes (Tunisia)

2010 ◽  
Vol 20 (5) ◽  
pp. 525-530 ◽  
Author(s):  
Khaled Echwikhi ◽  
Imed Jribi ◽  
Mohamed Nejmeddine Bradai ◽  
Abderrahmen Bouain
Keyword(s):  
Loggerhead Turtle ◽  
Longline Fishery ◽  
Gulf Of Gabes ◽  
Gulf Of Gabès ◽  
Pelagic Longline Fishery ◽  
Pelagic Longline

Are circle hooks effective management measures in the pelagic longline fishery for sharks in the Gulf of Gabès?

2020 ◽  
Vol 30 (6) ◽  
pp. 1172-1181
Author(s):  
Bechir Saidi ◽  
Khaled Echwikhi ◽  
Samira Enajjar ◽  
Sami Karaa ◽  
Imed Jribi ◽  
...  
Keyword(s):  
Longline Fishery ◽  
Effective Management ◽  
Gulf Of Gabes ◽  
Gulf Of Gabès ◽  
Management Measures ◽  
Pelagic Longline Fishery ◽  
Pelagic Longline

scholarly journals Shark pelagic longline fishery in the Gulf of Gabes: Inter-decadal inspection reveals management needs

2019 ◽  
Vol 20 (3) ◽  
pp. 532 ◽  
Author(s):  
BÉCHIR SAIDI ◽  
SAMIRA ENAJJAR ◽  
SAMI KARAA ◽  
KHALED ECHWIKHI ◽  
IMED JRIBI ◽  
...  
Keyword(s):  
Minor Component ◽  
Conservation Strategies ◽  
Longline Fishery ◽  
Life Stages ◽  
Sandbar Shark ◽  
Gulf Of Gabes ◽  
Additional Species ◽  
Gulf Of Gabès ◽  
Catch Rates ◽  
Pelagic Longline

This study explores the status of exploited shark populations in the Gulf of Gabes in relation to fishing pressure, based on data pertaining to shark longline fishery, collected during two periods. Catch data from 48 and 96 pelagic longline sets collected, respectively, during 2007/2008 and 2016/2017, were used to compare species composition and catch rates between periods. Four species were recorded during 2007/2008, while 11 additional species of pelagic and demersal elasmobranchs along with teleosts were fished during 2016/2017. Elasmobranch species dominated the catches with 94% and 99.3% in terms of specimens number, respectively, during 2016/2017 and 2007/2008. The sandbar shark, Carcharhinus plumbeus, was the predominant species in catch (>84% of all fishes) during both periods. Two other species of sharks, Carcharhinus brevipinna and Isurus oxyrinchus, were relatively common, while the other species were a minor component. Despite the increase in terms of diversity pertaining to species captured during 2016/2017, the nominal catch rates of elasmobranch and C. plumbeus decreased by 39.17% and 42.21%, respectively, suggesting populations’ declines. In addition, size distribution analyses revealed that this fishery may opportunistically operate on breeding and nursery areas, which affect main species over most of their life stages. The mortality and hooking location proportions were species-specific, with some species having significant percentages of live specimens at the time of haulback, providing an opportunity to release the sensitive life stages. Given the described state of shark exploitations in the Gulf of Gabes, urgent and efficient fishery regulation measures and conservation strategies, together with further investigations, are required to allow changing the unregulated shark longline fishery to a sustainable one.

Interactions of loggerhead turtle with bottom longline fishery in the Gulf of Gabès, Tunisia

2011 ◽  
Vol 92 (4) ◽  
pp. 853-858 ◽  
Author(s):  
Khaled Echwikhi ◽  
Imed Jribi ◽  
Mohamed Nejmeddine Bradai ◽  
Abderrahmen Bouain
Keyword(s):  
Loggerhead Turtle ◽  
Mitigation Measures ◽  
Longline Fishery ◽  
Target Species ◽  
Gulf Of Gabes ◽  
Awareness Campaign ◽  
Gulf Of Gabès ◽  
Gear Modification ◽  
By Catch ◽  
In The Beginning

In the Gulf of Gabès (Tunisia), a fleet of bottom longliners operates in summer and in the beginning of autumn targeting groupers. This fleet interacts with loggerhead turtles. During twenty trips in which 48,020 hooks were deployed, a total of 16 loggerheads were captured, most of them were juveniles, and direct mortality was estimated to be 43.75%. During the fishing operation, the hauling of the gear started one to three hours after and sometimes occurred immediately after setting. Results obtained show that the soak time did not affect the capture of turtles and target species, whereas it influenced the mortality rate of turtles. Bottom longline should be studied more in depth throughout the Mediterranean Sea, as well as parameters related to the interaction with sea turtles. However, mitigation measures to reduce turtle by-catch are urgently needed. In this way, we propose: (i) reducing the fishing soak time; (ii) experimenting with gear modification such as the use of circle hooks; and (iii) conducting an awareness campaign aimed at fishermen to show them how to deal with turtle by-catch.

scholarly journals Tori lines mitigate seabird bycatch in a pelagic longline fishery

2021 ◽  
Author(s):  
Eric Gilman ◽  
Milani Chaloupka ◽  
Asuka Ishizaki ◽  
Mathew Carnes ◽  
Hollyann Naholowaa ◽  
...  
Keyword(s):  
Longline Fishery ◽  
Pelagic Longline Fishery ◽  
Pelagic Longline

scholarly journals Seasonal Abundance and Size Structure of Sharks Taken in the Pelagic Longline Fishery off Northwestern Cuba

2021 ◽  
Vol 13 (3) ◽  
pp. 289-305
Author(s):  
Alexei Ruiz‐Abierno ◽  
J. Fernando Márquez‐Farías ◽  
Ariadna Rojas‐Corzo ◽  
Valerie Miller ◽  
Jorge A. Angulo‐Valdés ◽  
...  
Keyword(s):  
Size Structure ◽  
Seasonal Abundance ◽  
Longline Fishery ◽  
Pelagic Longline Fishery ◽  
Pelagic Longline

Shark bycatch and depredation in the U.S. Atlantic pelagic longline fishery

2008 ◽  
Vol 18 (4) ◽  
pp. 427-442 ◽  
Author(s):  
John W. Mandelman ◽  
Peter W. Cooper ◽  
Timothy B. Werner ◽  
Kerry M. Lagueux
Keyword(s):  
Longline Fishery ◽  
Pelagic Longline Fishery ◽  
The U.S ◽  
Pelagic Longline

scholarly journals Analysis of marine mammal bycatch in the Uruguayan pelagic longline fishery operating in the Southwestern Atlantic Ocean

2015 ◽  
Vol 72 (5) ◽  
pp. 1637-1652 ◽  
Author(s):  
Cecilia Passadore ◽  
Andrés Domingo ◽  
Eduardo R. Secchi
Keyword(s):  
Atlantic Ocean ◽  
Marine Mammals ◽  
Population Decline ◽  
Additive Models ◽  
Longline Fishery ◽  
Southwestern Atlantic ◽  
Southwestern Atlantic Ocean ◽  
Pelagic Longline Fishery ◽  
The Impact ◽  
Pelagic Longline

Abstract Bycatch is one of the main causes of human-caused mortality and population decline of many marine mammals. Monitoring bycatch is the first step to understand the impact of the fisheries on the species affected. Understanding how the interaction between marine mammals and fishing operations varies in space and time, and how it is influenced by environmental variables, is essential for designing mitigation strategies to reduce bycatch mortality. In this paper, we use data gathered by scientific observers and a fishing skipper to analyse marine mammals bycatch by the Uruguayan pelagic longline fishery operating in the Southwestern Atlantic Ocean from 1996 to 2007. The total bycatch per unit effort (Bcpue) was 0.0150 marine mammals/1000 hooks and the highest values (∼0.2) were recorded between 37°–38°S and 49°–51°W. Total cetacean Bcpue during the study period was low (0.0051 cetacean/1000 hooks) and occurred between 32°–37°S and 46°–54°W. Generalized additive models showed that cetaceans' bycatch was mainly affected by the depth, sea surface temperature, and season. Although cetaceans were captured year-round, the highest values were registered in spring months, most bycatch events occurred over the continental slope (median = 619 m) and in waters with a median temperature of 19.7°C. The bycatch of pinnipeds was influenced by depth, location, and season. Pinniped bycatch occurred mainly in winter, in waters ranging from 80 to 5000 m of depth (median = 2366 m) between 34°–37°S (median = 35.9°S) and 54°–49°W (median = 51.8°W). The spatial analysis showed that most bycatch events occurred within the Brazil–Malvinas Confluence zone, an area of high productivity where the pelagic longline fleet concentrates its fishing effort and where marine mammals probably concentrate to feed.

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