Bycatch, in the fishing industry, i

Bycatch, in the fishing industry, is a fish or other marine species that is caught unintentionally while catching certain target species and target sizes of fish, crabs etc. Bycatch is either of a different species, the wrong sex, or is undersized or juvenile individuals of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting.

In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species".[1] Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch.[2]

The fisherman bycatch issue originated due to the “mortality of dolphins in tuna nets in the 1960s” [3]

There are at least four different ways the word "bycatch" is used in fisheries:[4]

Catch which is retained and sold but which is not the target species for the fishery
Species/sizes/sexes of fish which fishermen discard[5]
Non-target fish, whether retained and sold or discarded[6]
Unwanted invertebrate species, such as echinoderms and non-commercial crustaceans, and various vulnerable species groups, including seabirds, sea turtles, marine mammals and elasmobranchs (sharks and their relatives).

Contents

1 Examples
1.1 Recreational fishing
1.2 Shrimp trawling
1.3 Cetacean
1.4 Albatross
1.5 Sea turtles
2 Mitigation
3 Alternative to release
4 Non-fisheries bycatch
5 See also
6 References
7 Further reading
8 External links

Examples
Recreational fishing

Given the popularity of recreational fishing throughout the world, a small local study in the USA in 2013 suggested that discards may be an important unmonitored source of fish mortality.[7]
Shrimp trawling
Photo of boat moving forward at sea. On each side, the boat has one pole pointing away from boat with nets attached
Double-rigged shrimp trawler hauling in the nets
Photo of hundreds of dead fish lying on ship deck
Shrimp bycatch

The highest rates of incidental catch of non-target species are associated with tropical shrimp trawling. In 1997, the Food and Agriculture Organization of the United Nations (FAO) documented the estimated bycatch and discard levels from shrimp fisheries around the world. They found discard rates (bycatch to catch ratios) as high as 20:1 with a world average of 5.7:1.[8]

Shrimp trawl fisheries catch 2% of the world total catch of all fish by weight, but produce more than one-third of the world total bycatch. American shrimp trawlers produce bycatch ratios between 3:1 (3 bycatch:1 shrimp) and 15:1(15 bycatch:1 shrimp).[9]

Trawl nets in general, and shrimp trawls in particular, have been identified as sources of mortality for cetacean and finfish species.[10] When bycatch is discarded (returned to the sea), it is often dead or dying.[11]

Tropical shrimp trawlers often make trips of several months without coming to port. A typical haul may last 4 hours after which the net is pulled in. Just before it is pulled on board the net is washed by zigzagging at full speed. The contents are then dumped on deck and are sorted. An average of 5.7:1 means that for every kilogram of shrimp there are 5.7 kg of bycatch. In tropical inshore waters the bycatch usually consists of small fish. The shrimps are frozen and stored on-board; the bycatch is discarded.[12]

Recent sampling in the South Atlantic rock shrimp fishery found 166 species of finfish, 37 crustacean species, and 29 other species of invertebrate among the bycatch in the trawls.[10] Another sampling of the same fishery over a two-year period found that rock shrimp amounted to only 10% of total catch weight. Iridescent swimming crab, dusky flounder, inshore lizardfish, spot, brown shrimp, longspine swimming crabs, and other bycatch made up the rest.[10]

Despite the use of bycatch reduction devices, the shrimp fishery in the Gulf of Mexico removes about 25–45 million red snapper annually as bycatch, nearly one half the amount taken in directed recreational and commercial snapper fisheries.[13][14]
Cetacean
Main article: Cetacean bycatch
Group of Fraser's dolphins.

Cetaceans, such as dolphins, porpoises, and whales, can be seriously affected by entanglement in fishing nets and lines, or direct capture by hooks or in trawl nets. Cetacean bycatch is increasing in intensity and frequency.[15] In some fisheries, cetaceans are captured as bycatch but then retained because of their value as food or bait.[16] In this fashion, cetaceans can become a target of fisheries.
A Dall's porpoise caught in a fishing net

One example of bycatch is dolphins caught in tuna nets. As dolphins are mammals and do not have gills they may drown while stuck in nets underwater. This bycatch issue has been one of the reasons of the growing ecolabelling industry, where fish producers mark their packagings with disclaimers such as "dolphin friendly" to reassure buyers. However, "dolphin friendly" does not mean that dolphins were not killed in the production of a particular tin of tuna, but that the fleet which caught the tuna did not specifically target a feeding pod of dolphins, but relied on other methods to spot tuna schools.[citation needed]
Albatross
See also: Longline fishing
Photo of bird struggling to fly away
This black-browed albatross has been hooked on a long-line.

Of the 21 albatross species recognised by IUCN on their Red List, 19 are threatened, and the other two are near threatened.[17] Two species are considered critically endangered: the Amsterdam albatross and the Chatham albatross. One of the main threats is commercial long-line fishing,[18] because the albatrosses and other seabirds which readily feed on offal are attracted to the set bait, become hooked on the lines and drown. An estimated 100,000 albatross per year are killed in this fashion. Unregulated pirate fisheries exacerbate the problem.
Sea turtles
Photo of sea turtle swimming near a diverse group of fish.
Loggerhead sea turtle

Sea turtles, already critically endangered, have been killed in large numbers in shrimp trawl nets. Estimates indicate that thousands of Kemp's ridley, loggerhead, green and leatherback sea turtles are caught in shrimp trawl fisheries in the Gulf of Mexico and the US Atlantic annually[19] The speed and length of the trawl method is significant because, “for a tow duration of less than 10 minutes, the mortality rate for sea turtles is less than one percent, whereas for tows greater than sixty minutes the mortality rate rapidly increases to fifty to one hundred percent”[20]

Sea turtles can sometimes escape from the trawls. In the Gulf of Mexico, the Kemp’s ridley turtles recorded most interactions, followed in order by loggerhead, green, and leatherback sea turtles. In the US Atlantic, the interactions were greatest for loggerheads, followed in order by Kemp’s ridley, leatherback, and green sea turtles.[19]
Mitigation
A turtle excluder device

Concern about bycatch has led fishermen and scientists to seek ways of reducing unwanted catch.[21] There are two main approaches.

One approach is to ban fishing in areas where bycatch is unacceptably high. Such area closures can be permanent, seasonal, or for a specific period when a bycatch problem is registered. Temporary area closures are common in some bottom-trawl fisheries where under-sized fish or non-target species are caught unpredictably. In some cases fishermen are required to relocate when a bycatch problem occurs.

The other approach is alternative fishing gear. A technically simple solution is to use nets with a larger mesh size, allowing smaller species and smaller individuals to escape. However, this usually requires replacing the existing gear. In other cases, it is possible to modify gear. The "Bycatch Reduction Device" (BRD) and the Nordmore grate are net modifications that help fish escape from shrimp nets.

BRDs allow many commercial finfish species to escape. The US government has approved BRDs that reduce finfish bycatch by 30%. Spanish mackerel and weakfish bycatch in the South Atlantic was reduced by 40%.[10] However, recent surveys suggest BRDs may be less effective than previously thought.[13] A rock shrimp fishery off Florida found the devices did not exclude 166 species of fish, 37 crustacean species, and 29 species of other invertebrates.[10]

In 1978, the National Marine Fisheries Service (NMFS) started to develop turtle excluder devices (TEDs). A TED uses a grid which deflects turtles and other big animals, so they exit from the trawl net through an opening above the grid. US shrimp trawlers and foreign fleets which market shrimp in the US are required to use TEDs. Not all nations enforce the use of TEDs.

For the most part, when they are used, TEDs have been successful reducing sea turtle bycatch.[10][22][23] However, they are not completely effective, and some turtles are still captured.[10][19] NMFS certifies TED designs if they are 97% effective. In heavily trawled areas, the same sea turtle may pass repeatedly through TEDs.[19] Recent studies indicate recapture rates of twenty percent or more, but it is not clear how many turtles survive the escape process.[19]

The size selectivity of trawl nets is controlled by the size of the net openings, especially in the "cod end". The larger the openings, the more easily small fish can escape. The development and testing of modifications to fishing gear to improve selectivity and decrease impact is called "conservation engineering."
Photo of hundreds of seabirds on water surface around boat
Seabirds with longline fishing vessel

Longline fishing is controversial in some areas because of by-catch. Mitigation methods have been successfully implemented in some fisheries. These include:

weights to sink the lines quickly
streamer lines to scare birds away from baited hooks while deploying the li

Hasil (Bahasa Indonesia) 1:

Bycatch, dalam industri perikanan, adalah ikan atau lain spesies laut yang tidak sengaja tertangkap saat penangkapan spesies target tertentu dan target ukuran ikan, kepiting dll. Bycatch adalah salah satu spesies yang berbeda, seks, atau berukuran atau remaja individu dari spesies target. Istilah "bycatch" juga kadang-kadang digunakan untuk menangkap yang ditargetkan dalam bentuk lain dari hewan panen atau mengumpulkan.Pada tahun 1997, organisasi untuk kerjasama ekonomi dan pembangunan (OECD) didefinisikan bycatch sebagai "total Memancing kematian, termasuk yang diperhitungkan secara langsung oleh menangkap dipertahankan spesies target". [1] Bycatch berkontribusi terhadap penurunan Perikanan dan mekanisme penangkapan ikan secara berlebihan untuk menangkap tidak disengaja. [2]Edisi bycatch nelayan berasal karena "kematian lumba-lumba di jaring ikan tuna di tahun 1960-an" [3]Ada setidaknya empat cara kata "bycatch" digunakan dalam perikanan: [4] Menangkap yang dipertahankan dan dijual tetapi yang tidak spesies target untuk perikanan Spesies/ukuran/jenis kelamin ikan nelayan yang membuang [5] Bebas-target ikan, Apakah dipertahankan dan dijual atau dibuang [6] Yang tidak diinginkan spesies invertebrata, seperti Echinodermata dan non-komersial krustasea, dan berbagai kelompok spesies rentan, termasuk burung laut, penyu, mamalia laut dan elasmobranchs (hiu dan kerabat mereka).Isi Contoh 1 1.1 rekreasi Memancing 1.2 udang trawl 1.3 cetacean 1.4 albatross 1.5 penyu 2 mitigasi 3 alternatif untuk melepaskan 4 bebas-Perikanan bycatch 5 Lihat juga 6 referensi 7 Bacaan selanjutnya 8 Pranala luarContohRekreasi MemancingMengingat popularitas rekreasi Memancing seluruh dunia, sebuah penelitian lokal kecil di Amerika Serikat pada tahun 2013 menyarankan bahwa membuang mungkin sumber tanpa sepengetahuan penting kematian ikan. [7]Udang trawlFoto dari perahu bergerak maju di laut. Pada setiap sisi, perahu memiliki satu kutub menunjukkan dari perahu dengan jaring terpasangDouble-kecurangan udang pukat pengangkutan dalam jaringFoto dari ratusan ikan mati tergeletak di dek kapalUdang bycatchTingkat tertinggi tak terduga menangkap spesies non binaan berhubungan dengan udang tropis trawl. Pada tahun 1997, organisasi pangan dan pertanian Perserikatan Bangsa-Bangsa (FAO) didokumentasikan perkiraan tingkat bycatch dan membuang dari udang Perikanan di seluruh dunia. Mereka menemukan TARIF membuang (bycatch untuk menangkap rasio) sebagai tinggi sebagai 20:1 dengan rata-rata dunia 5.7:1. [8]Udang pukat Perikanan menangkap 2% dari total dunia menangkap semua ikan dengan berat, tapi menghasilkan lebih dari sepertiga dari dunia total bycatch. Kapal pukat Amerika udang menghasilkan bycatch rasio antara 3:1 (3 bycatch:1 udang) dan 15:1(15 bycatch:1 shrimp). [9]Jelajahi jaring secara umum, dan udang trawls khususnya, telah diidentifikasi sebagai sumber dari kematian untuk spesies cetacean dan finfish. [10] saat bycatch dibuang (kembali ke laut), hal ini sering mati atau sekarat. [11]Tropical shrimp trawlers often make trips of several months without coming to port. A typical haul may last 4 hours after which the net is pulled in. Just before it is pulled on board the net is washed by zigzagging at full speed. The contents are then dumped on deck and are sorted. An average of 5.7:1 means that for every kilogram of shrimp there are 5.7 kg of bycatch. In tropical inshore waters the bycatch usually consists of small fish. The shrimps are frozen and stored on-board; the bycatch is discarded.[12]Recent sampling in the South Atlantic rock shrimp fishery found 166 species of finfish, 37 crustacean species, and 29 other species of invertebrate among the bycatch in the trawls.[10] Another sampling of the same fishery over a two-year period found that rock shrimp amounted to only 10% of total catch weight. Iridescent swimming crab, dusky flounder, inshore lizardfish, spot, brown shrimp, longspine swimming crabs, and other bycatch made up the rest.[10]Despite the use of bycatch reduction devices, the shrimp fishery in the Gulf of Mexico removes about 25–45 million red snapper annually as bycatch, nearly one half the amount taken in directed recreational and commercial snapper fisheries.[13][14]CetaceanMain article: Cetacean bycatchGroup of Fraser's dolphins.Cetaceans, such as dolphins, porpoises, and whales, can be seriously affected by entanglement in fishing nets and lines, or direct capture by hooks or in trawl nets. Cetacean bycatch is increasing in intensity and frequency.[15] In some fisheries, cetaceans are captured as bycatch but then retained because of their value as food or bait.[16] In this fashion, cetaceans can become a target of fisheries.A Dall's porpoise caught in a fishing netOne example of bycatch is dolphins caught in tuna nets. As dolphins are mammals and do not have gills they may drown while stuck in nets underwater. This bycatch issue has been one of the reasons of the growing ecolabelling industry, where fish producers mark their packagings with disclaimers such as "dolphin friendly" to reassure buyers. However, "dolphin friendly" does not mean that dolphins were not killed in the production of a particular tin of tuna, but that the fleet which caught the tuna did not specifically target a feeding pod of dolphins, but relied on other methods to spot tuna schools.[citation needed]AlbatrossSee also: Longline fishingPhoto of bird struggling to fly awayThis black-browed albatross has been hooked on a long-line.Of the 21 albatross species recognised by IUCN on their Red List, 19 are threatened, and the other two are near threatened.[17] Two species are considered critically endangered: the Amsterdam albatross and the Chatham albatross. One of the main threats is commercial long-line fishing,[18] because the albatrosses and other seabirds which readily feed on offal are attracted to the set bait, become hooked on the lines and drown. An estimated 100,000 albatross per year are killed in this fashion. Unregulated pirate fisheries exacerbate the problem.Sea turtlesPhoto of sea turtle swimming near a diverse group of fish.Loggerhead sea turtleSea turtles, already critically endangered, have been killed in large numbers in shrimp trawl nets. Estimates indicate that thousands of Kemp's ridley, loggerhead, green and leatherback sea turtles are caught in shrimp trawl fisheries in the Gulf of Mexico and the US Atlantic annually[19] The speed and length of the trawl method is significant because, “for a tow duration of less than 10 minutes, the mortality rate for sea turtles is less than one percent, whereas for tows greater than sixty minutes the mortality rate rapidly increases to fifty to one hundred percent”[20]Sea turtles can sometimes escape from the trawls. In the Gulf of Mexico, the Kemp’s ridley turtles recorded most interactions, followed in order by loggerhead, green, and leatherback sea turtles. In the US Atlantic, the interactions were greatest for loggerheads, followed in order by Kemp’s ridley, leatherback, and green sea turtles.[19]MitigationA turtle excluder deviceConcern about bycatch has led fishermen and scientists to seek ways of reducing unwanted catch.[21] There are two main approaches.One approach is to ban fishing in areas where bycatch is unacceptably high. Such area closures can be permanent, seasonal, or for a specific period when a bycatch problem is registered. Temporary area closures are common in some bottom-trawl fisheries where under-sized fish or non-target species are caught unpredictably. In some cases fishermen are required to relocate when a bycatch problem occurs.The other approach is alternative fishing gear. A technically simple solution is to use nets with a larger mesh size, allowing smaller species and smaller individuals to escape. However, this usually requires replacing the existing gear. In other cases, it is possible to modify gear. The "Bycatch Reduction Device" (BRD) and the Nordmore grate are net modifications that help fish escape from shrimp nets.BRDs allow many commercial finfish species to escape. The US government has approved BRDs that reduce finfish bycatch by 30%. Spanish mackerel and weakfish bycatch in the South Atlantic was reduced by 40%.[10] However, recent surveys suggest BRDs may be less effective than previously thought.[13] A rock shrimp fishery off Florida found the devices did not exclude 166 species of fish, 37 crustacean species, and 29 species of other invertebrates.[10]In 1978, the National Marine Fisheries Service (NMFS) started to develop turtle excluder devices (TEDs). A TED uses a grid which deflects turtles and other big animals, so they exit from the trawl net through an opening above the grid. US shrimp trawlers and foreign fleets which market shrimp in the US are required to use TEDs. Not all nations enforce the use of TEDs.For the most part, when they are used, TEDs have been successful reducing sea turtle bycatch.[10][22][23] However, they are not completely effective, and some turtles are still captured.[10][19] NMFS certifies TED designs if they are 97% effective. In heavily trawled areas, the same sea turtle may pass repeatedly through TEDs.[19] Recent studies indicate recapture rates of twenty percent or more, but it is not clear how many turtles survive the escape process.[19]The size selectivity of trawl nets is controlled by the size of the net openings, especially in the "cod end". The larger the openings, the more easily small fish can escape. The development and testing of modifications to fishing gear to improve selectivity and decrease impact is called "conservation engineering."Photo of hundreds of seabirds on water surface around boatSeabirds with longline fishing vesselLongline fishing is controversial in some areas because of by-catch. Mitigation methods have been successfully implemented in some fisheries. These include: weights to sink the lines quickly streamer lines to scare birds away from baited hooks while deploying the li

Hasil (Bahasa Indonesia) 2:

Bycatch, di industri perikanan, adalah ikan atau spesies laut lainnya yang tertangkap tidak sengaja saat penangkapan spesies tertentu target dan ukuran target ikan, kepiting dll bycatch adalah salah satu dari spesies yang berbeda, jenis kelamin yang salah, atau individu berukuran atau remaja spesies sasaran. Istilah "bycatch" juga kadang-kadang digunakan untuk menangkap ditargetkan dalam bentuk lain dari panen hewan atau mengumpulkan. Pada tahun 1997, Organisasi untuk Kerjasama Ekonomi dan Pembangunan (OECD) bycatch didefinisikan sebagai "kematian memancing total, diluar yang yang dicatat langsung oleh menangkap mempertahankan spesies target "[1] tangkapan berkontribusi. penurunan perikanan dan mekanisme penangkapan berlebih untuk menangkap disengaja. [2] Masalah nelayan bycatch berasal karena" kematian lumba-lumba di jaring ikan tuna di tahun 1960 "[3] Setidaknya ada empat cara yang berbeda kata "bycatch" digunakan dalam perikanan: [4] Tangkap yang dipertahankan dan dijual tetapi yang tidak spesies target perikanan Species / ukuran / jenis kelamin ikan yang nelayan membuang [5] Non ikan -target, apakah dipertahankan dan dijual atau dibuang [6] spesies invertebrata yang tidak diinginkan, seperti echinodermata dan krustasea non-komersial, dan berbagai kelompok spesies yang rentan, termasuk burung laut, kura-kura laut, mamalia laut dan elasmobranchs (hiu dan kerabat mereka). Isi 1 Contoh 1.1 memancing rekreasi 1,2 Shrimp trawl 1.3 Cetacean 1.4 Albatross 1,5 Penyu 2 Mitigasi 3 Alternatif untuk melepaskan 4 Non-perikanan bycatch 5 Lihat pula 6 Referensi 7 Bacaan lebih lanjut 8 Pranala luar Contoh memancing rekreasi Mengingat popularitas rekreasi memancing di seluruh dunia, studi lokal kecil di Amerika Serikat pada tahun 2013 menyarankan bahwa membuang mungkin menjadi sumber dimonitor penting dari kematian ikan. [7] Shrimp trawl Foto perahu bergerak maju di laut. Pada setiap sisi, perahu memiliki satu tiang menunjuk jauh dari perahu dengan jaring terpasang dua dicurangi udang pukat hauling di jaring Foto ratusan ikan mati tergeletak di kapal dek Udang bycatch Tingkat tertinggi menangkap insidental spesies non-target terkait dengan tropis udang trawl. Pada tahun 1997, Organisasi Pangan dan Pertanian Perserikatan Bangsa-Bangsa (FAO) didokumentasikan tingkat bycatch dan membuang yang diperkirakan dari perikanan udang di seluruh dunia. Mereka menemukan tingkat membuang (bycatch untuk menangkap rasio) setinggi 20: 1 dengan rata-rata dunia 5,7:. 1 [8] Udang Pukat perikanan menangkap 2% dari total tangkapan dunia semua ikan berat, tapi menghasilkan lebih dari satu sepertiga dari total bycatch dunia. Kapal pukat udang Amerika menghasilkan rasio bycatch antara 3: 1 (3 bycatch: 1 udang) dan 15: 1 (15 bycatch: 1 udang) [9]. Trawl jaring pada umumnya, dan pukat udang pada khususnya, telah diidentifikasi sebagai sumber kematian untuk cetacean dan finfish spesies [10] Ketika bycatch dibuang (kembali ke laut), itu. sering mati atau sekarat. [11] Tropical kapal pukat udang sering membuat perjalanan dari beberapa bulan tanpa datang ke pelabuhan. Sebuah jarak yang khas dapat berlangsung 4 jam setelah net ditarik di. Hanya sebelum ditarik di papan net dicuci oleh zig-zag dengan kecepatan penuh. Isi kemudian dibuang di geladak dan diurutkan. Rata-rata 5,7: 1 berarti bahwa untuk setiap kilogram udang ada 5,7 kg tangkapan sampingan. Di perairan pantai tropis bycatch biasanya terdiri dari ikan kecil. Udang beku dan disimpan on-board; bycatch tersebut akan dibuang. [12] sampel Terbaru di Atlantik Selatan batu udang perikanan ditemukan 166 spesies ikan bersirip, 37 spesies Crustacea, dan 29 spesies lain dari invertebrata antara bycatch di trawl. [10] contoh lain dari perikanan yang sama lebih periode dua tahun menemukan bahwa batu udang hanya sebesar 10% dari total tangkapan berat. Iridescent kepiting renang, flounder kehitaman, perairan pantai lizardfish, tempat, udang coklat, kepiting longspine renang, dan bycatch lainnya terdiri sisanya. [10] Meskipun penggunaan perangkat pengurangan bycatch, perikanan udang di Teluk Meksiko menghilangkan sekitar 25- 45 juta kakap merah setiap tahun sebagai bycatch, hampir satu setengah jumlah diambil dalam diarahkan rekreasi dan komersial perikanan kakap [13] [14]. Cetacean Artikel utama: Cetacean bycatch. Kelompok lumba-lumba Fraser Cetacea, seperti lumba-lumba, lumba, dan paus, dapat serius dipengaruhi oleh keterikatan dalam jaring ikan dan garis, atau penangkapan langsung oleh kait atau jaring trawl. Bycatch Cetacean meningkat dalam intensitas dan frekuensi. [15] Dalam beberapa perikanan, Cetacea ditangkap sebagai bycatch tetapi kemudian dipertahankan karena nilai mereka sebagai makanan atau umpan. [16] Dengan cara ini, Cetacea bisa menjadi target perikanan. A Dall ini lumba-lumba tertangkap dalam jaring ikan Salah satu contoh bycatch adalah lumba-lumba tertangkap dalam jaring ikan tuna. Lumba-lumba adalah mamalia dan tidak memiliki insang mereka mungkin tenggelam sementara terjebak dalam jaring bawah air. Masalah bycatch ini telah menjadi salah satu alasan dari industri ekolabel berkembang, di mana produsen ikan menandai kemasan dengan penolakan seperti "dolphin ramah" untuk meyakinkan pembeli. Namun, "dolphin ramah" tidak berarti bahwa lumba-lumba tidak tewas dalam produksi timah tertentu tuna, tetapi bahwa armada yang menangkap ikan tuna tidak secara khusus menargetkan pod makan lumba-lumba, tapi mengandalkan metode lain untuk tempat tuna sekolah [rujukan?]. Albatross Lihat juga: Longline memancing Foto burung berjuang untuk terbang jauh. albatros hitam-beralis ini telah kecanduan a-garis panjang Dari 21 spesies elang laut diakui oleh IUCN pada Daftar Merah mereka, 19 terancam, dan dua lainnya di dekat terancam [17] Dua spesies dianggap terancam punah. albatros Amsterdam dan albatros Chatham. Salah satu ancaman utama adalah komersial memancing lama-line, [18] karena elang laut dan burung laut lainnya yang mudah memakan jeroan tertarik dengan umpan set, menjadi kecanduan garis dan tenggelam. Diperkirakan 100.000 albatros per tahun tewas dalam mode ini. Perikanan bajak laut yang tidak diatur memperburuk masalah. Sea penyu Foto penyu berenang dekat berbagai kelompok ikan. Loggerhead penyu Penyu, sudah terancam punah, telah tewas dalam jumlah besar di jaring pukat udang. Perkiraan menunjukkan bahwa ribuan ridley, tempayan, penyu hijau dan belimbing Kemp terjebak dalam pukat udang perikanan di Teluk Meksiko dan AS Atlantik tahun [19] Kecepatan dan panjang metode trawl adalah penting karena, "untuk derek durasi kurang dari 10 menit, tingkat kematian penyu kurang dari satu persen, sedangkan untuk TOWS lebih dari enam puluh menit angka kematian meningkat dengan cepat ke lima puluh sampai seratus persen "[20] Sea kura-kura kadang-kadang bisa lepas dari trawl. Di Teluk Meksiko, penyu belimbing Kemp tercatat paling interaksi, diikuti dalam rangka oleh tempayan, hijau, dan penyu belimbing. Di AS Atlantik, interaksi yang terbesar untuk berselisih, diikuti dalam rangka oleh Kemp Ridley, belimbing, dan penyu hijau. [19] Mitigasi A penyu excluder perangkat Kekhawatiran tentang bycatch telah menyebabkan nelayan dan ilmuwan untuk mencari cara-cara untuk mengurangi tangkapan yang tidak diinginkan. [21] Ada dua pendekatan utama. Satu pendekatan adalah untuk melarang penangkapan ikan di daerah di mana bycatch adalah sangat tinggi. Penutupan wilayah tersebut dapat menjadi permanen, musiman, atau untuk jangka waktu tertentu ketika masalah bycatch terdaftar. Penutupan wilayah sementara yang umum di beberapa perikanan bottom-trawl di mana di bawah berukuran ikan atau non-target spesies yang tertangkap tak terduga. Dalam beberapa kasus nelayan diminta untuk pindah ketika masalah bycatch terjadi. Pendekatan lain adalah alat tangkap alternatif. Sebuah solusi teknis yang sederhana adalah dengan menggunakan jaring dengan ukuran mesh yang lebih besar, yang memungkinkan spesies yang lebih kecil dan individu yang lebih kecil untuk melarikan diri. Namun, ini biasanya membutuhkan menggantikan gigi yang ada. Dalam kasus lain, adalah mungkin untuk memodifikasi gigi. The "Pengurangan tangkapan Device" (BRD) dan parut Nordmore modifikasi net yang membantu pelarian ikan dari jaring udang. BRDs memungkinkan banyak spesies ikan bersirip komersial untuk melarikan diri. Pemerintah AS telah menyetujui BRDs yang mengurangi bycatch finfish sebesar 30%. Mackerel Spanyol dan weakfish bycatch di Atlantik Selatan berkurang 40%. [10] Namun, survei terbaru menunjukkan BRDs mungkin kurang efektif daripada yang diperkirakan sebelumnya. [13] Sebuah batu udang perikanan off Florida menemukan perangkat tidak mengecualikan 166 spesies ikan, 37 spesies Crustacea, dan 29 jenis invertebrata lainnya. [10] Pada tahun 1978, National Marine Fisheries Service (NMFS) mulai mengembangkan perangkat penyu excluder (TED). Sebuah TED menggunakan grid yang mengalihkan penyu dan binatang besar lainnya, sehingga mereka keluar dari jaring trawl melalui sebuah lubang di atas grid. US udang kapal pukat dan armada asing yang memasarkan udang di AS diwajibkan untuk menggunakan TED. Tidak semua negara memberlakukan penggunaan TED. Untuk sebagian besar, ketika mereka digunakan, TED telah berhasil mengurangi penyu bycatch. [10] [22] [23] Namun, mereka tidak benar-benar efektif, dan beberapa kura-kura masih ditangkap. [10] [19] NMFS menyatakan TED desain jika mereka 97% efektif. Di daerah sangat trawled, penyu yang sama dapat lulus berulang kali melalui TED. [19] Studi terbaru menunjukkan tingkat merebut kembali dua puluh persen atau lebih, tetapi tidak jelas berapa banyak kura-kura bertahan proses melarikan diri. [19] Ukuran selektivitas trawl jaring dikendalikan oleh ukuran bukaan bersih, terutama di "akhir cod". Semakin besar bukaan, ikan lebih mudah kecil dapat melarikan diri. Pengembangan dan pengujian modifikasi alat tangkap untuk meningkatkan selektivitas dan mengurangi dampak disebut "rekayasa konservasi." Foto ratusan burung laut di permukaan air di sekitar perahu Burung laut dengan rawai memancing kapal Longline memancing kontroversi di beberapa daerah karena tangkapan. Metode mitigasi telah berhasil diterapkan di beberapa perikanan. Ini termasuk: bobot tenggelam garis cepat baris streamer untuk menakut-nakuti burung menjauh dari kait berumpan sementara penggelaran li