De bijvangst bij het vissen met de ringzegen op FAD’s blijkt aanzienlijk groter dan bij het uitzetten van de netten op vrij zwemmende scholen tonijn. De ISSF probeert de bijvangstcijfers te verlagen door ten eerste een goed wetenschappelijk inzicht in de bijvangst te verkrijgen, en die kennis vervolgens te gebruiken voor aanpassing van het vistuig en de methoden en zodoende de bijvangst te verminderen.

De ISSF werkt momenteel aan een belangrijk #BycatchProject dat een tocht van 6 weken in de Indische Oceaan omvat. De wetenschappers aan boord verrichten een ‘volkstelling’ onder water om de samenstelling en abondantie van de soorten onder FAD’s te bepalen, bestuderen het natuurlijk gedrag van vissen rondom FAD’s en testen methoden om haaien en andere bijvangst van FAD’s weg te lokken.

Klik hier voor meer informatie over alle ISSF-projecten voor bijvangstreductie.

Zuinig brandstofverbruik

Ook efficiëntie en brandstofverbruik zijn factoren. De ringzegenvisserij vangt het merendeel van de tonijn die wereldwijd wordt ingeblikt, en is met kop en schouders de efficiëntste vismethode. Die efficiëntie vertaalt zichzelf in lagere kosten (zowel financieel als milieutechnisch) voor de vangst van tonijn. De financiële besparingen kunnen gemakkelijk worden gemeten en zijn een voordeel, maar de milieutechnische besparingen (voornamelijk minder verbruik van fossiele brandstoffen) moeten worden afgewogen tegen de prijs die het ecosysteem betaalt.

Ringzegenschepen zijn het efficiëntst bevonden, met een ‘fuel use intensity’ (FUI) getal van 368, vergeleken met een FUI van 1490 voor de hengelvisserij en een FUI van 1070 voor de beuglijnvisserij. Deze getallen zijn gebaseerd op het aan wal gebrachte gewicht, en werden onlangs gepubliceerd in “Fuel Consumption and Greenhouse Gas Emissions from Global Tuna Fisheries: A preliminary assessment” door Peter Tyedmers en Robert Parker.

Klik hier voor het volledige paper.

Wereldvisserijcongres

Van 7 tot 11 mei houdt de World Council of Fisheries Societies het zesde Wereldvisserijcongres in Edinburgh (Schotland). De World Council of Fisheries Societies is een niet-gouvernementele non-profitorganisatie van 12 wetenschappelijke en professionele visserijverenigingen en aanverwante organisaties over de gehele wereld. De Council bevordert de internationale samenwerking bij het bestuderen, in stand houden en beheren van visgronden door methoden voor duurzaam beheer, uitmuntendheid in visserijonderzoek en het verstandig gebruik van visbronnen aan te moedigen en te bevorderen.

De voorzitter van de Scientific Advisory Committee van de ISSF, Victor Restrepo, neemt als gastspreker deel aan de conferentie, in de sessie Resilience, Adaptive Management & Governance: Alternative Approaches. Dr. Restrepo zal een overzicht geven van de missie van de ISSF als mondiaal samenwerkingsverband voor het werkelijk duurzaam maken van de tonijnvisserij over de gehele wereld.

Klik hier voor meer informatie over het congres

Congresblog: Dr. Restrepo

Dr. Restrepo blogt over het congres, zijn deelname en de ideeën van de andere sprekers over een duurzame tonijnvisserij.

Klik hier voor de blog van dr. Restrepo.

Il a été démontré que les sennes coulissantes mises à l’eau autour de DRP (dispositifs de regroupement du poisson) produisent un taux de prises accessoires plus élevé que lorsqu’elles sont jetées à la mer autour de bancs de thons nageant librement. L’ISSF s’efforce d’améliorer ces résultats tout d’abord en étudiant à fond la problématique des prises accessoires, en vue d’ensuite appliquer les connaissances ainsi acquises aux équipements et aux méthodes de pêche afin de réduire les prises accessoires.

L’ISSF travaille actuellement sur un important projet de réduction des prises accessoires comprenant une expédition en mer de 6 semaines sur l’océan Indien. Les scientifiques à bord auront pour mission de recenser les poissons sous l’eau afin d’analyser la composition et l’abondance des espèces sous les DRP. En outre, ils étudieront le comportement des poissons autour des DRP et feront l’essai de diverses techniques visant à éloigner des DRP les requins et d’autres prises accessoires.

Cliquez ici pour lire les projets de l’ISSF sur la réduction des prises accessoires.

Efficacité énergétique

Dans une évaluation environnementale, il faut également tenir compte de l’efficacité énergétique et de la consommation de carburant. La pêche à senne coulissante est utilisée pour capturer la majorité des thons mis en conserve, mais elle est aussi une méthode de pêche considérablement plus efficace que toutes les autres. Cette efficacité se manifeste par un moindre coût financier et environnemental (mesuré par l’empreinte carbone). Les réductions de coûts financiers sont faciles à calculer et constituent un avantage, mais les réductions de coûts environnementaux (principalement la réduction de l’utilisation des carburants fossiles) doivent tenir compte des coûts pour l’écosystème.

Les navires de pêche à senne coulissante sont considérés les plus efficaces avec un indice d’intensité d’utilisation de carburant (IUC) de 368, alors que les navires canneurs ont un indice IUC de 1490 et les navires à palangre un indice IUC de 1070. Ces résultats sont basés sur le poids à terre des prises et ont été récemment publiés dans un document intitulé « Fuel Consumption and Greenhouse Gas Emissions from Global Tuna Fisheries: A preliminary assessment », rédigé par le Dr Peter Tyedmers et Robert Parker.

Cliquer ici pour accéder au document complet.

Congrès mondial des pêches

Le Conseil mondial des sociétés de pêche tient son 6^e Congrès mondial des pêches à Édinbourg (Écosse) du 7 au 11 mai. Le Conseil mondial des sociétés de pêches est une organisation non gouvernementale sans but lucratif composée de 12 sociétés de pêche professionnelles et scientifiques, ainsi que de diverses organisations affiliées du monde entier. Le Conseil œuvre pour une coopération internationale renforcée en océanographie, en conservation et gestion des ressources, notamment en encourageant et soutenant les pratiques d’exploitation durable, l’excellence dans la recherche océanographique et l’utilisation judicieuse des ressources de pêche.

Le président du Comité consultatif scientifique de l’ISSF, le Dr Victor Restrepo, participera au congrès à titre d’orateur, durant la session intitulée Résilience, gestion et gouvernance; nouvelles approches. Le Dr Restrepo présentera la mission de l’ISSF, consistant à créer un grand partenariat mondial œuvrant pour une exploitation vraiment durable des ressources mondiales de thon.

Cliquez ici pour en savoir plus sur le congrès.

Blog du congrès : Dr Restrepo

Le Dr Restrepo propose un blog sur le congrès, sur sa participation et sur les idées d’exploitation durable des ressources en thon présentées par les autres orateurs.

Cliquez ici pour lire le blog du Dr Restrepo.

Es hat sich gezeigt, dass Ringwaden-Netze an FADs mit höheren Beifangraten verbunden sind als Netze auf frei schwimmenden Thunfischschwärmen. Die ISSF konzentriert ihre Bemühungen auf die Verbesserung dieser Zahlen, indem sie zunächst die Wissenschaft des Beifangproblems zu verstehen versucht, um dieses Wissen dann auf die Anpassung der Fanggeräte und Fangmethoden anzuwenden und den Beifang zu verringern.

Derzeit engagiert sich die ISSF in einem großen #BeifangProjekt, zu dem auch eine 6-wöchige Forschungsfahrt im Indischen Ozean gehört. Die Wissenschaftler an Bord werden eine Unterwasserzählung entwickeln, um die Artenzusammensetzung und Artenvielfalt unter FADs zu bestimmen, das natürliche Verhalten der Fische an FADs studieren und Techniken erproben, um Haie und andere Beifangarten von FADs wegzulocken.

Klicken Sie hier, um alles über die ISSF-Projekte zur Reduzierung von Beifang zu lesen.

Kraftstoffeffizienz

Ein weiterer Faktor sind Effizienz und Kraftstoffverbrauch. Die Ringwaden-Fangmethode, die für die größte Thunfischmenge für die Konservenindustrie verantwortlich ist, stellt bei weitem die effizienteste Fangmethode dar. Vorteil dieses hohen Wirkungsgrads sind niedrigere Kosten in finanzieller und ökologischer Hinsicht (in Bezug auf die Kohlenstoffemission) zur Gewinnung von Thunfisch. Die finanziellen Einsparungen lassen sich leicht messen und werden als Plus angesehen, doch müssen die Umwelteinsparungen – in erster Linie weniger Verbrauch von fossilen Brennstoffen – gegen die Kosten für das Ökosystem aufgerechnet werden.

Ringwadenfänger wurden als effizienteste Form erkannt, mit einer Kraftstoff-Nutzungsintensitäts-Zahl (FUI-Zahl) von 368 im Vergleich zur Angelfischerei mit einer FUI-Zahl von 1490 und zum Langleinenfang mit einer FUI-Zahl von 1070. Diese Zahlen sind auf das angelandete Gewicht bezogen und wurden vor kurzem in „Fuel Consumption and Greenhouse Gas Emissions from Global Tuna Fisheries: A preliminary assessment“ von Dr. Peter Tyedmers und Mr. Robert Parker veröffentlicht.

Klicken Sie hier, um den vollständigen Bericht aufzurufen.

World Fisheries Kongress

Vom 7. bis 11. Mai veranstaltet der World Council of Fisheries Societies den 6. World Fisheries Kongress in Edinburgh, Schottland. Der World Council of Fisheries Societies ist eine gemeinnützige, nichtstaatliche Organisation, die derzeit 12 wissenschaftliche und berufliche Fischereigesellschaften und beigeordnete Organisationen weltweit umfasst. Der Council fördert die internationale Zusammenarbeit in der Fischereiwissenschaft, die Erhaltung und Bewirtschaftung durch Unterstützung und Förderung nachhaltiger Bewirtschaftungsmethoden, die Exzellenz in der Fischereiforschung und die sinnvolle Nutzung der Fischbestände.

Der Vorsitzende des ISSF-Wissenschaftsbeirats, Victor Restrepo, wird als Redner auf der Konferenz während der Sitzung Widerstandskraft, adaptive Bewirtschaftung und Kontrolle: alternative Ansätze teilnehmen. Dr. Restrepo wird die Mission der ISSF als globale Partnerschaft hervorheben, um den weltweiten Thunfischfang wirklich nachhaltig zu gestalten.

Klicken Sie hier, um mehr über den Kongress zu erfahren

Kongress-Blog: Dr. Restrepo

Dr. Restrepo berichtet in diesem Blog über den Kongress, seine Teilnahme und die Erkenntnisse zur Thunfisch-Nachhaltigkeit von anderen Referenten.

Klicken Sie hier für den Blog von Dr. Restrepo.

Le battute di pesca sui FAD hanno rivelato un tasso di catture accidentali molto maggiore rispetto alle battute di pesca effettuate su banchi di tonno in mare aperto. L’ISSF fa di tutto per invertire la tendenza studiando la scienza delle catture accidentali e applicando quanto appreso nell’adattamento delle attrezzature e dei metodi di pesca al fine di ridurle.

Al momento l’ISSF è impegnata nel #BycatchProject, che prevede una spedizione di 6 settimane nell’Oceano Indiano. Gli scienziati a bordo realizzeranno un censimento sottomarino per individuare la composizione e l’abbondanza degli esemplari sotto i FAD, studiando il comportamento naturale dei pesci intorno ai FAD e testando tecniche per allontanare dai FAD squali e altre catture accidentali.

Clicca qui per tutte le informazioni sui progetti dell’ISSF per la riduzione delle catture accidentali.

L’efficienza del carburante

Altro fattore è l’efficienza e l’uso del carburante. La pesca con reti a circuizione, la più utilizzata nella pesca di tonno destinato all’inscatolamento, finora si è rivelata essere il metodo più efficace. Il vantaggio è rappresentato dai costi minori, dal punto di vista finanziario e ambientale (per le quantità di carbonio), per pescare il tonno. I vantaggi finanziari possono essere facilmente misurati ed essere considerati un plus, ma quelli ambientali—inannzitutto il minor uso di carburante fossile, deve essere controbilanciato dal costo dell’ecosistema.

I pescherecci sono risultati essere i più efficienti, con un’intensità di consumo di carburante (FUI, Fuel Use Intensity) pari a 368, rispetto al FUI della pesca a canna e correntina (1490) e del palamito (1070). Le cifre si riferiscono al peso sbarcato e sono state pubblicate in “Fuel Consumption and Greenhouse Gas Emissions from Global Tuna Fisheries: A preliminary assessment” del Dott. Peter Tyedmers e Robert Parker.

Clicca qui per consultare il documento completo.

Il World Fisheries Congress

Dal 7 all’11 maggio a Edimburgo, Scozia, si terrà il 6° World Fisheries Congress organizzato dal World Council of Fisheries Societies. Il World Council of Fisheries Societies è un’organizzazione no-profit e non governativa che al momento include 12 associazioni professionali e altre organizzazioni dedite alla pesca in tutto il mondo. La sua missione è la promozione della cooperazione internazionale per lo studio, la conservazione e la gestione della pesca, incoraggiando e promuovendo tecniche di gestione sostenibili, l’eccellenza nella ricerca e l’uso attento delle risorse di pesca.

Il presidente del comitato scientifico dell’ISSF, Victor Restrepo, parteciperà al convegno come relatore nel corso della sessione Resilience, Adaptive Management & Governance: Alternative Approaches. Il Dott. Restrepo illustrerà la missione dell’ISSF come partnership globale per rendere davvero sostenibile l’industria del tonno in tutto il mondo.

Clicca qui per ulteriori informazioni sul convegno

Blog del convegno: Dott. Restrepo

Nel suo blog, il Dott. Restrepo parla del convegno, della sua partecipazione e delle considerazioni di altri relatori sulla sostenibilità del tonno.

Clicca qui per consultare il blog del Dott. Restrepo.

Se ha comprobado que la pesca con redes cerqueras asistida por dispositivos FAD tiene un mayor índice de capturas incidentales que la pesca de bancos de atún que nadan en libertad. La ISSF centra sus esfuerzos en la mejora de esta condición, entendiendo, en primer lugar, los principios científicos del problema de las capturas incidentales, y aplicando después estos conocimientos para la adaptación de los aparejos y métodos de pesca a fin de reducir las capturas incidentales.

En la actualidad, la ISSF participa en un #BycatchProject de gran envergadura que incluye un crucero de 6 semanas por el océano Índico. El científico a bordo del buque creará un censo submarino para determinar la composición y abundancia de las especies debajo de los dispositivos FAD, estudiando el comportamiento natural de los peces alrededor de dichos dispositivos y poniendo a prueba técnicas para procurar alejar de los dispositivos FAD a los tiburones y otras especies que caen presas de modo incidental.

Pulse aquí para leer acerca de todos los proyectos de ISSF relativos a la reducción de las capturas incidentales.

Eficacia de combustible

Otro factor es la eficacia y consumo de combustible. La pesca con buques cerqueros, responsable de la mayoría del atún que se pesca para la industria conservera, es, con mucho, el método de pesca más eficaz. El beneficio de esta eficacia es el menor coste, tanto económica como ecológicamente, (desde la perspectiva de la huella de carbono), de la pesca del atún. El ahorro económico se puede calcular fácilmente y considerarse una ventaja adicional, pero el ahorro medioambiental, principalmente el menor uso de combustible fósil, tiene que equilibrarse en relación con el coste al ecosistema.

Los buques cerqueros obtuvieron los índices de mayor eficacia, con un número de intensidad de consumo de combustible (FUI) de 368, comparado con 1490 para la pesca con caña y sedal, y 1070 para los buques palangreros. Estos números se basan en peso de capturas y fueron publicados recientemente en el estudio titulado “El consumo de combustible y las emisiones de gas invernadero de las pesquerías de atún a nivel global: Una evaluación preliminar”, del Dr. Peter Tyedmers y Mr. Robert Parker.

Pulse aquí para acceder al documento completo.

Congreso sobre caladeros mundiales

Del 7 al 11 de mayo, el World Council of Fisheries Societies (Consejo Mundial de Sociedades de Pesquerías) celebra el VI Congreso Mundial de Pesquerías en Edimburgo (Escocia). Se trata de una organización no gubernamental sin ánimo de lucro compuesta actualmente por 12 sociedades de pesquerías profesionales y científicas a nivel mundial. El Consejo promueve la cooperación internacional en la ciencia, conservación y gestión de caladeros, alentando y promoviendo prácticas de gestión sostenibles, excelencia en la investigación y un consumo apropiado de los recursos de los caladeros.

Víctor Restrepo, presidente del Consejo de Asesoramiento Científico de ISSF, participará en el congreso como ponente durante la sesión titulada Resiliencia, gestión adaptativa y gobernabilidad: enfoques alternativos. El Dr. Restrepo ofrecerá una descripción resumida de la misión de ISSF como asociación global en pro del logro de caladeros de atún sean verdaderamente sostenibles a nivel internacional.

Pulse aquí para más información sobre el congreso

Blog del congreso: Dr. Restrepo

El Dr. Restrepo escribe en su blog acerca del congreso, su participación y las ideas compartidas por los demás ponentes acerca de la sostenibilidad del atún.

Pulse aquí para acceder al blog del Dr. Restrepo.

University of Massachusetts Dartmouth graduate student Corey Eddy was recently onboard a purse seinefishing vessel in the eastern Pacific Ocean. He is studying sharks, specifically the physiological stress response, survival, and post-release behavior of sharks captured during purse seining operations. Corey explains the focus of his project in this video.

Hmm. Where to begin? I’m writing this from the airport in Guayaquil, Ecuador, headed back to Boston. The cruise came to an abrupt end when a crewmember tragically passed away. As I was writing a draft of this blog, there was a huge commotion outside my door, a lot of anxious voices, a lot of hurried footsteps. When the boat suddenly changed speed and direction, it became obvious something was seriously wrong. I won’t say much more than that. After speaking with the captain and ISSF, we decided to continue with the blog and to be honest with events, while remaining respectful. We all felt it was important to acknowledge what happened, as I am trying to describe life at sea in addition to the research.  I didn’t know the man well, but he always greeted me with a smile, a thumbs-up, and “todo bien (everything’s good)” when I’d see him out on deck or below. We didn’t talk much, unfortunately.  May he rest in peace.

There are a lot of stories that I wanted to share so in tribute to the entire crew for hosting me on this trip, I’ll share a few.

A couple weeks ago, March 14^th actually, we came across a whale carcass as we were en route between FADs. There wasn’t much left and I don’t know much about whales, so I can’t tell you what species. I did hear that it was possibly a pilot whale. Check out the photo. Anyway, not to get too gory, but the last three feet were chewed to the bone by sharks.

Several crew members turn a whale carcass into a FAD.

Most of the flesh of the head was gone too. It was really interesting to see the very clear bite marks, but what was even more interesting was that the crew turned it into a FAD. Three of the guys jumped in to wrap the carcass with netting, before tying that to a man-made raft and one of our buoys. Keep in mind the fresh bite marks and the fact that it was still bleeding.

Now I’m going to jump ahead in time, back to April 25^th, the day I actually began writing this entry. We’d been busy for over a week, having fished every day between the 17^th and 25^th, twice one day and three times another.  After a slow and discouraging start, we had put a good amount of fish on the boat, almost 400 tons. Our best set was 95 tons. With that came a few sharks; 20 actually. I put out PSATs on five silkies and three scalloped hammerheads. I wasn’t expecting to tag hammers on this cruise, but it was an unforeseen and fortunate opportunity that I couldn’t pass up. After all, I’m studying the sharks regularly taken as bycatch in the purse seine industry; silkies are just the most common species, but hammers are encountered quite often in the area we were fishing. What made it an especially good opportunity was that we caught five in one set and the physical condition (although subjective) of these three ranged from excellent to fair. They were also just about the same size and all male, so we may have a good look into how length of the capture event affects their survival and behavior. In about 45 days, when the tags pop-up and transmit data, we shall see.

In that time, I’d also been able to take blood samples from two silky sharks. One was actually gilled (meaning he got his head stuck in the net, trying to get out), but survived and actually swam away with a surprising amount of energy. I didn’t tag him with a PSAT however, as he didn’t go through the entire capture process and, again, I’m trying to minimize the stress of those we do. The second blood sample came from another male, but this one went came up in the brail, several minutes after the hammers. Although he was moving his jaws, eyes, and whole body while on deck, I didn’t see him swim away after release, but they don’t always do that. That one also didn’t get a PSAT.

I suppose this is my chance to talk a little about why I’m taking blood samples. I’m studying the physiological stress response that silkies exhibit following capture. I may be repeating myself, but it has been generally assumed that bycatch survives when returned to the sea. Unfortunately, we now recognize this may not be true and the animals (sharks, turtles, tuna, whatever you’ve got), may actually succumb to stress or injury and die after days or even weeks. For that reason, I am studying their physiological response, to see what goes on inside their bodies that may ultimately kill them.  Sharks typically undergo short periods of physical exercise when capturing prey or evading other predators. They are built for that and have species-specific limitations on how much activity they can manage. However, they are not designed for extreme bouts of physical exercise characteristic of capture by fishing gear. In these circumstances of prolonged duress, they may actually exercise themselves to death.  Therefore, I am looking at key indicators of the stress response to see how physiological, biochemical, and molecular changes may alter the function of the cardiovascular system. If the system cannot sufficiently deliver oxygen and nutrients throughout the body, while also removing wastes, the shark’s behavior and chances of survival may ultimately be compromised. Using the relative physical condition of sharks, we can compare the physiological response of those that donate blood with the behavior and survival rate of those that are tagged. With that, we can see how the sharks react physiologically to the capture event and how this stress response may indicate the extent to which their behavior and survival may be affected.  An understanding of how these sharks respond to capture in purse seines may allow resource managers and the fishing industry to modify fishing techniques to minimize the occurrence of post-release delayed mortality.

Although the journey came to a tragic end, I was able to collect some valuable data and I had a memorable time doing it. While I already mentioned seeing my first hammerheads and mako sharks, I also saw my first whale shark, a 2 meter juvenile that was alongside the boat as we passed a FAD. I saw a lot of longliners while we were at sea too, and I had hoped to talk about the extreme amounts of bycatch frequently taken in that industry and the role it plays in shark finning. Aside from the work aspects, I also enjoyed a few great meals on the Via Simoun and several great conversations with the captain and crew. I might even have inspired the captain to buy a new boat and start catching invasive lionfish in the Atlantic before they become the ocean’s greatest man-made disaster. Well, that’s a topic of conversation for another blog…

The helicopter onboard the Simoun.

Photo of a longliner taken from the helicopter.

I’m in Edinburgh, Scotland this week for the 6^th World Fisheries Congress held by the World Council of Fisheries Societies. The council’s mission is a lot like ISSF’s—we both aim to promote international cooperation in fisheries science, further sustainable management practices, encourage excellence in research and improve the use of fishery resources.

The themes of this year’s conference are especially relevant: meeting the increasing food and nutrition needs; resilience and adaptive management governance; biodiversity, food security and the need for Ecosystem management; and the science underpinning sustainable fisheries. The Congress’ speakers are a diverse group, including students, researchers, fishers, NGOs, politicians, etc., all of whom are interested in ensuring healthier and more productive fisheries; they also hail from all over the world, countries like Chile, Denmark, South Africa, Zambia and Japan.

Yesterday, there were great opening addresses. Ray Hilborn gave an excellent and provocative presentation comparing the impacts, measured at different levels, of various types of protein production. It evident from the available data that capture fisheries tend to have much lower impacts than other forms of food production. So he raised a very interesting question: If we just about stopped fishing as many groups are asking for so that oceans become pristine again, that protein that is foregone (over 80 million tons) must be replaced from increased land production; what would the environmental cost be? His answer: Huge!

Another great opening address was given by Mike Mitchell of Young’s Seafood in the UK. He spoke in general about responsible seafood sourcing and had a great message: No one group alone holds the key to sustainability. Not fishers, not scientists, not politicians. The work to achieve sustainability needs to be a collective effort.

A third address was given by HRH the Prince of Wales who gave an overview of work that his International Sustainability Unit Marine Program plans to undertake. The ISU is keen to facilitate new initiatives to improve the collection and reporting of data that are needed for science-based management, especially in developing countries. It is great to see that a Charity with such huge convening power is interested in such a basic, yet hugely important, problem.

Yesterday, I gave an overview of ISSF as a partnership that aims to facilitate improvements in tuna fisheries worldwide. It was well received, as were many other presentations in my session that highlighted the positive changes that can occur when the fishing industry, the processing and retail sectors, scientists and decision-makers work together to achieve sustainability. While ISSF focuses on tuna, there are many other species with sustainability challenges.  There is great potential for all of us to learn from what’s working in fisheries that we may not be as familiar with.

You can read more about this week’s program and the Council online, just click here.

As part of our ongoing efforts to address concerns about the future of tuna fisheries, the International Seafood Sustainability Foundation (ISSF) has put considerable effort into understanding the impact of industrial fisheries, elevating best practices, and improving conditions around the globe.

Although much attention has been paid to the bycatch associated with purse seine nets, gillnets are the dominant gear in the Indian Ocean used in artisanal and semi-industrial fisheries from developing coastal countries, and are worthy of further study. Between 2006 and 2010, gillnets contributed between 30 to 40 percent of catches recorded in the Indian Ocean Tuna Commission (IOTC) nominal catch database, with a gradual increase in proportion over the five years.   Purse seine nets were responsible for only 25 to 30 percent of catches there, in contrast to other oceans where they are generally responsible for the majority of catches.

Although efforts to collect and analyze data on Indian Ocean artisanal and semi-industrial fisheries targeting tuna have proved difficult, a recent study sponsored by ISSF on the contribution of gillnet fisheries in the Indian Ocean to bycatch of non-targeted species found that catches of bycatch species from gillnet fishing were high across all species groups.  This was especially true for sharks, with gillnets accounting for 64 percent of shark catches recorded by the IOTC.

Read the Technical Report on gillnet bycatch in the Indian Ocean

Because of the nature of artisanal and semi-industrial fisheries, which are scattered and conduct fishing and landing operations at multiple locations, data collection is complex and subject to a high degree of uncertainty.  For example, very little reported data was available about the impact of gillnets on turtles, cetaceans, and seabirds, although information available in current literature indicates that turtles face a high risk of mortality because of gillnets operating in the Indian Ocean.

Of the 21 coastal countries on the Indian Ocean that fish with gill nets for tuna and tuna like species, seven were identified as the major contributors to gillnet catch: India; Indonesia; Islamic Republic of Iran; Oman; Pakistan; Sri Lanka and Yemen. The gillnet fisheries targeting tuna and the fisheries institutions in these countries warrant further study and engagement.

Just this year, the IOTC passed a resolution on minimum reporting requirements for gillnet vessels with an aim of producing more accurate statistics. Additionally, there is a need to build capacity within the developing coastal countries of the Indian Ocean to improve national reporting. The design and implementation of an improved system to track Indian Ocean fisheries will require the construction of significant infrastructure and robust international support; it won’t be easy, but these measures are integral to the long-term understanding and health of the world’s tuna populations and the impact of their fisheries on the ecosystem.

Our exciting work aboard the Torre Giulia continues. In my last blog post, I told you how we were receiving daily information on our tagged fish around the FADs. We continue to collect interesting information. We tagged 24 fish back in the middle of April, and are still monitoring the behavior of 16 of those fish including yellowfin tuna, silky sharks, triggerfish and rainbow runners. Of the 17 fish we tagged on the second FAD during the last week of April, we’re receiving data on 12.

For both rounds of tagging, we’re observing how much time fish are spending at the FADs, their schedules for leaving and returning, and their vertical behavior. We’ve also given some fish activity tags, which will give us a sense of how they’re behaving at the FADs.

We’ve also tagged over 300 fish from several different bycatch species with regular spaghetti tags. In one case, we found a triggerfish and a rainbow runner that were tagged between two and three miles away the day before. Considering how small these fish are, we were surprised to see how far they traveled.