Reducing green turtle bycatch in small-scale fisheries using illuminated gillnets: the cost of saving a sea turtle

Ortiz, Natalia; Mangel, Jeffrey C.; Wang, John; Alfaro‐Shigueto, Joanna; Pingo, Sergio; Jiménez, Astrid; Suarez, Tania; Swimmer, Yonat; Carvalho, Felipe; Godley, Brendan J.

doi:10.3354/meps11610

Cited by 81 publications

(114 citation statements)

References 47 publications

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“…Bottom set gillnets were made of multifilament twine and were composed of multiple net panes that measured 56.4 m long by 2.8 m high, with a stretched mesh of approximately 24 cm (Alfaro-Shigueto et al, 2010b;Ortiz et al, 2016). Typical to this fishery, nets were deployed in the late afternoon, soaked overnight and retrieved the following morning.…”

Section: Study Area and Data Collectionmentioning

confidence: 99%

“…Typical to this fishery, nets were deployed in the late afternoon, soaked overnight and retrieved the following morning. The soak time ranged from 12 to 24 h (López-Barrera et al, 2012;Ortiz et al, 2016). The target species in this fishery are flounder Paralichthys spp., guitarfish Rhinobatos planiceps and other species of ray from the Batoidea superorder as common stingray Dasyatis spp.…”

Section: Study Area and Data Collectionmentioning

confidence: 99%

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Incidental capture of sea turtles in the artisanal gillnet fishery in Sechura Bay, northern Peru

Pingo¹,

Jiménez²,

Alfaro‐Shigueto³

et al. 2017

lajar

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ABSTRACT. Gillnets are recognized globally as one of the fishing gears with the highest levels of bycatch and mortality of sea turtles. Through onboard observer monitoring from July 2013 to June 2014 we assessed the bycatch of sea turtles by an artisanal gillnet fishery operating from Sechura Bay, Peru. One hundred and four sea turtles were incidentally caught in 53 observed fishing sets. The observed species composition of bycatch was green turtle Chelonia mydas (n = 100), hawksbill Eretmochelys imbricata (n = 3) and olive ridley Lepidochelys olivacea (n = 1). Bycatch occurred in 62.3% of monitored sets, with an average of 1.96 turtles caught per set. For all sea turtles combined, 28.8% of individuals were dead and 71.2% were alive at the time of retrieval. The majority of individuals caught were classified as juveniles and sub-adults, with an average carapace length (CCL) of 57.3 ± 0.9 cm for green turtles and 40.2 ± 2.4 cm for hawksbills. The mean annual catch per unit effort (CPUE) of sea turtles was 1.11 ± 0.31 turtles km -1 12 h -1), but varied by seasons. These results suggest that Sechura Bay is an important developmental habitat for juvenile and sub-adult green turtles and hawksbill turtles, but one subject to intense fishing interaction pressure. The development of monitoring programs, local awareness-raising activities, and enhanced management and protection of this critical foraging area and developmental habitat is recommended.

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Section: Study Area and Data Collectionmentioning

confidence: 99%

Section: Study Area and Data Collectionmentioning

confidence: 99%

Incidental capture of sea turtles in the artisanal gillnet fishery in Sechura Bay, northern Peru

Pingo¹,

Jiménez²,

Alfaro‐Shigueto³

et al. 2017

lajar

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“…Penggunaan alat bantu tersebut berdasarkan pada pengetahuan tentang kemampuan penglihatan dan tingkah laku penyu pada aktivitas penangkapan ikan (Southwood et al 2008;Bartol et al 2002;Swimmer et al 2005;Lohmann et al 2008;Schuyler et al 2014). Beberapa penelitan dalam upaya mengurangi bycatch penyu pada alat tangkap gillnet dengan memanfaatkan kemampuan penglihatan penyu telah banyak dilakukan, seperti penggunaan lampu tanda (marker light) cahaya putih (broader spectrum white) (Gilman et al 2010), penggunaan hiu buatan (shark shape) , penggunaan lightstick dan lampu 2013;Ortiz et al 2016), namun hanya teknik penggunaan lampu pada jaring (net illumination) yang dapat mengurangi bycatch penyu tanpa mengurangi hasil tangkapan ikan target catch (Gilman et al 2010). Uji coba penggunaan lampu LED hijau telah dilakukan di beberapa negara seperti, Meksiko, Peru, dan Chile yang menunjukkan bahwa terjadinya penurunan hasil tangkapan penyu sebesar 40 -64% tanpa menurunkan hasil tangkapan ikan target catch Ortiz et al 2016).…”

Section: Pendahuluanunclassified

“…Pengurangan bycatch penyu hijau (Chelonia mydas) dengan menggunakan lampu LED hijau juga ditunjukkan penelitian sebelumnya yaitu sebesar 40% (kontrol 117 ekor dan eksperimen 70 ekor) , serta pada penelitian Ortiz et al (2016), pengurangan tangkapan penyu hijau sebesar 50,4% (kontrol tertangkap 125 ekor dan eksperimen 62 ekor), namun pada penyu sisik (Eretmochelys imbricata) tidak mengalami pengurangan (kontrol tertangkap 3 ekor dan eksperimen 3 ekor). Penelitan Wahju et al (2014), menunjukkan pengurangan terhadap spesies penyu hijau sebesar 37,5% (kontrol tertangkap 8 ekor dan eksperimen tertangkap 5 ekor), spesies penyu lekang (Lepidochelys olivacea) sebesar 50% (kontrol tertangkap 2 ekor dan eksperimen tertangkap 1 ekor), serta penyu sisik (Eretmochelys imbricata) sebesar 75% (kontrol tertangkap 4 ekor dan eksperimen tertangkap 1 ekor).…”

Section: Pembahasanunclassified

“…Menurut Wang et al (2010); (2013); Gilman et al (2010); Ortiz et al (2016), penggunaan lampu atau cahaya pada alat tangkap merupakan upaya mitigasi untuk mengurangi bycatch penyu, dimana memberikan seperti sinyal peringatan untuk menghindari alat tangkap. Lampu LED hijau dipasang pada tali ris atas gillnet (bagian atas jaring gillnet), sedangkan profil cahayanya diketahui cenderung memancar ke arah horizontal yang membuat bagian atas jaring lebih terlihat, tetapi bagian tengah atau bawah jaring gillnet relatif tidak terlihat, sehingga penyu yang mengetahui keberadaan cahaya tersebut memberikan respons menghindar.…”

Section: Pembahasanunclassified

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LIGHT EMITTING DIODE (LED) HIJAU DAN PENGARUHNYA TERHADAP PENGURANGAN BYCATCH PENYU PADA PERIKANAN GILLNET DI PERAIRAN PALOH (Green Light Emitting Diode (LED) and its Effect on Sea Turtle Bycatch Reduction of Gillnet Fisheries in Paloh Waters)

Prasetyo¹,

Wahju²,

Yusfiandayani³

et al. 2017

Jurnal Marfis

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Bycatch problem is a global issue and can be a driver of marine megafauna declines in the world, such as sea turtle, where is the animal's status as endangered species. Green Light Emitting ABSTRAKPermasalahan terkait bycatch merupakan isu utama global yang dapat mengancam penurunan populasi megafauna laut seperti penyu yang telah berstatus endangerd species. Lampu LED merupakan inovasi teknologi untuk mengurangi bycatch penyu tanpa mengurangi hasil tangkapan ikan utama secara efektif. Penggunaan lampu Light Emmitting Diode (LED) hijau untuk mengurangi bycatch penyu pada perikanan jaring insang (gillnet) dilakukan di perairan Paloh, Kalimantan Barat selama bulan Agustus hingga Oktober 2015. Uji coba dilakukan dengan menggunakan 2 unit kapal gillnet yang dioperasikan di setiap stasiun pengamatan secara bersamaan dengan jumlah ulangan sebanyak 20 kali, diantaranya gillnet kontrol (tanpa lampu LED) dan gillnet eksperimen (dengan lampu LED). Penyu yang tertangkap cenderung didominasi oleh fase juvenile sebesar 57,14% dan lokasi potensi tertangkapnya bycatch penyu pada stasiun 2 (1˚52' -1˚56' LU dan 109˚14' -109˚18' BT). Hasil penelitian menunjukkan bahwa penyu yang tertangkap merupakan penyu hijau (Chelonia mydas) berjumlah 7 ekor, terdiri dari 6 ekor tertangkap pada gillnet kontrol dengan CPUE 0,29 ± 0,03 ekor/E, dan 1 ekor pada gillnet

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Sea turtles bycatch in the Adriatic Sea set net fisheries and possible hot‐spot identification

Lucchetti

Vasapollo

Virgili

2017

Aquatic Conservation

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Bycatch resulting from fishing activities is the main threat for the conservation of sea turtles in the Mediterranean Sea. Fixed nets are a matter of concern for sea turtles mainly in coastal areas during the neritic stage when both juvenile and adult life stages are affected. Mortality caused by entanglement in set nets is related to forced apnoea due to the high soak time of the nets and consequent drowning. This study investigated the loggerhead turtle bycatch in set net coastal fisheries in the northern Adriatic Sea (General Fisheries Commission for the Mediterranean Geographical Sub‐Area 17, [GSA 17]) through an interview‐based approach, to understand the potential contribution of these fisheries to the general decline of the sea turtle population. A second goal was to identify a possible hot‐spot turtle bycatch area through on‐board observations. The study estimates that more than 5400 turtles are caught in the west GSA 17 each year with the largest number in the summer. A hot‐spot for entanglement was also identified in an area located south of the River Po delta (41.5–69 m depth) during the summer. Sixty‐four turtles were caught over a period of 30 fishing days by either trammel nets and gillnets (0.7 and 0.5 turtle per km of net respectively) and was the greatest number that has been observed anywhere in the Mediterranean. Possible management strategies to reduce bycatch include technical modification to gear setting (such as reducing netting slack and using small meshes), bycatch reducer devices (such as LED UV), and area and seasonal gear restrictions to small‐scale fisheries in areas of greatest concern in the northern Adriatic Sea.

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Reducing green turtle bycatch in small-scale fisheries using illuminated gillnets: the cost of saving a sea turtle

Abstract: In press. Reducing green sea turtle bycatch in small-scale fisheries using illuminated gillnets: the cost of saving a sea turtle. Marine Ecology Progress Series.

Cited by 81 publications

References 47 publications

Incidental capture of sea turtles in the artisanal gillnet fishery in Sechura Bay, northern Peru

Incidental capture of sea turtles in the artisanal gillnet fishery in Sechura Bay, northern Peru

LIGHT EMITTING DIODE (LED) HIJAU DAN PENGARUHNYA TERHADAP PENGURANGAN BYCATCH PENYU PADA PERIKANAN GILLNET DI PERAIRAN PALOH (Green Light Emitting Diode (LED) and its Effect on Sea Turtle Bycatch Reduction of Gillnet Fisheries in Paloh Waters)

Sea turtles bycatch in the Adriatic Sea set net fisheries and possible hot‐spot identification

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