World squid fisheries

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The future of cephalopod populations, fisheries, culture, and research in Europe

International audienc

Cephalopod biology and fisheries in Europe

Over the past two decades, cephalopod molluscs have attracted increased attention from marine biologists and fishery scientists. Several species are important for European fisheries, as targets of small‐scale coastal fisheries and/or as bycatch in multispecies fisheries for demersal fish. The present report draws on a series of reviews prepared in 2005 for the CEPHSTOCK project (see Section 1). The taxonomy of the main resource species is reviewed (Section 2), and brief descriptions of each species are provided, along with information from studies of population genetics, habitat requirements of paralarvae and adults, and health and ecotoxicology (Section 3). The main fisheries are described, including illustration of gears used in specialized small‐scale fisheries and a discussion of the socio‐economic importance of the fisheries. The current status of cephalopod aquaculture is reviewed, highlighting notable advances in commercial culture of octopus and cuttlefish (Section 4). Current fishery data collection and fishery management are described, noting that there is no setting of landings quotas and no routine assessment of stock status. Options for stock assessment are discussed, drawing on one‐off assessments made during specific projects and current practice elsewhere in the world. The “live fast, die young” lifehistory strategies of cephalopods present particular challenges, but parallels can be drawn with short‐lived fish (Section 5). Finally, the report looks to the future, reviewing possible effects of climate change on cephalopods. It discusses the future development of aquaculture and fisheries for cephalopods, including prospects for fishery forecasting and fishery management – especially in relation to the small‐scale directed fisheries. Various knowledge gaps are identified, and ideas for research to fill these gaps are presented

Working group on cephalopod fisheries and life history (WGCEPH; outputs from 2019 meeting)

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Life-history, ecology and fisheries of cephalopods in the western Mediterranean

Abstract: Cephalopods constitute an important faunistic group in marine ecosystems, representing keystone elements in marine food webs. Additionally, they are an important fishing resource, and their contribution to worldwide fishery landings has been rising significantly over the last decades. In the Mediterranean Sea, several local short-term studies on cephalopod abundance and distribution exist, but few integrate longer time scales and larger areas. The present thesis work combines large-scale, long-term studies on cephalopods community composition, diversity and abundance (Part I) with small-scale, local case studies around the Balearic Islands (Part II). First, a community analysis was conducted at the whole Mediterranean scale in order to describe the present status and reveal possible differences between the western and the eastern Mediterranean sub-basins (Chapter 2). The aim was to compare assemblage structures between sub-basins together with the influence of large-scale environmental gradients on species composition. While basins did not differ significantly in cephalopod species composition, relative species contributions varied. Cephalopods are very sensitive to environmental changes, and adapt quickly due to their short life cycle and typically seasonal semelparity impeding generation buffering. Therefore sea surface temperature (SST) and chlorophyll a (Chl a) were hypothesised and documented as important drivers of cephalopod assemblages. While their importance differed between sub-basins, depth was confirmed as the most important factor structuring cephalopod communities. At the same spatial scale, cephalopod diversity was analysed during two decades (Chapter 3). Results revealed the absence of clear longitudinal or latitudinal gradients in cephalopod diversity, combined with no distinct temporal trends over the last twenty years. Besides, temporal changes in diversity varied between various Mediterranean sub-regions. Location, depth, SST and productivity regime resulted to influence diversity. To assess whether environmental variability impacts cephalopod populations at species level, the influence of SST and surface primary production on the spatial structuring and the population dynamics of two commercially important cephalopod species was investigated (Chapter 4). Although Octopus vulgaris and Illex coindetii exhibit contrasting life history traits and inhabit different habitats, long-term abundance trends and synchronic behaviour of their populations was similar, and population sub-structuring across the Mediterranean Sea were revealed. In consistency with former chapters, SST and Chl a regimes were shown to be significant drivers of distribution patterns and inter-annual abundance fluctuations. The motivation for the second part of the thesis was fuelled by the present situation in the Mediterranean Sea, where cephalopod stocks are presumably overexploited, but where their ad- hoc assessment and management is far from being implemented. To contribute to existing knowledge of the current situation in the Balearic Sea, a case study on cuttlefish fishery, life-history and population dynamics was conducted using short-term and intra-annual data (Chapter 5). Possible drivers of cuttlefish abundance fluctuations were analysed, revealing significant influences of SST and local climatic variability. While the study provided a complete view of the intrinsic and extrinsic drivers of cuttlefish population fluctuations in the Balearic Sea, the next step was applying stock assessment techniques to cuttlefish and squid fisheries of this area (Chapter 6). Being the first application of depletion methods to Mediterranean cephalopod stocks, the study combined information of those two fisheries with the evaluation of this stock assessment method for short life cycle species. Results uncovered existing problems and suggested that the current sampling scheme under the EU-Data Collection Framework is inadequate for cephalopods in view of the assessment´s data requirements. Consequently, a modification of the existing scheme was proposedResumen: Los cefalópodos constituyen un grupo faunístico importante en los ecosistemas marinos, representando elementos clave en la estructura y dinámica de las redes tróficas. Además, son un importante recurso pesquero y su contribución a los desembarcos pesqueros mundiales se ha incrementado significativamente en las últimas décadas. En el Mar Mediterráneo existen varios estudios locales sobre la abundancia y distribución de cefalópodos, pero pocos integran escalas temporales largas y áreas extensas. Esta tesis combina estudios sobre la estructura de la comunidad, la diversidad y la abundancia de cefalópodos a gran escala espacio-temporal (Parte I) con estudios a escala local alrededor de las Islas Baleares (Parte II). En primer lugar, se realizó un análisis de la comunidad de cefalópodos a escala de todo el Mediterráneo para describir el estado actual y determinar posibles diferencias entre las sub- cuencas occidental y oriental (Capítulo 2). El objetivo fue comparar la estructura de las comunidades faunísticas entre estas dos sub-cuencas y analizar la influencia de gradientes ambientales a gran escala sobre la composición específica. Aunque no se observaron diferencias significativas en la composición específica, las contribuciones relativas de las diferentes especies variaron entre ambas cuencas. Debido a su corto ciclo vital y estrategia reproductiva semélpara, los cefalópodos son muy sensibles a los cambios ambientales, adaptándose a ellos con relativa rapidez. Se esperaba, por tanto, que factores ambientales como la temperatura superficial del mar (SST) y el contenido de clorofila a (Chl a) fueran factores importantes en la estructuración de las comunidades de cefalópodos. Si bien su importancia difirió entre las dos sub-cuencas, se confirmó que la profundidad era el factor estructural más importante en dichas comunidades. Se analizaron también cambios en la diversidad específica de las comunidades de cefalópodos a escala de todo el Mediterráneo durante los últimos 20 años (Capítulo 3). Los resultados no mostraron ninguna tendencia temporal ni espacial (latitud, longitud) clara y homogénea en la diversidad. Las únicas tendencias temporales observadas variaron entre diferentes sub-regiones, siendo la posición geográfica, profundidad, SST y productividad los principales factores determinantes de estas tendencias. Para confirmar la importancia de la variabilidad ambiental a nivel específico, se analizó la influencia de la SST y la producción primaria en la estructura espacial y la dinámica poblacional de dos especies de cefalópodos de importancia comercial (Capítulo 4). Aunque Octopus vulgaris e Illex coindetii exhiben diferentes estrategias vitales y viven en diferentes hábitats, las tendencias temporales a largo plazo en su abundancia y el comportamiento sincrónico de sus poblaciones fueron similares, observándose sub-poblaciones temporalmente persistentes a lo largo de todo el Mediterráneo. En consonancia con los capítulos anteriores, la SST y Chla resultaron ser factores significativos en la definición de patrones de distribución y fluctuaciones interanuales de la abundancia. La segunda parte de la tesis estaba motivada por la situación actual de los cefalópodos en el Mar Mediterráneo, donde no existen medidas de evaluación y gestión específica para este grupo y algunas de sus poblaciones se encuentran sobreexplotadas. Para contribuir al conocimiento de la situación actual en el Mar Balear, se analizó la pesquería, ciclo vital y dinámica poblacional de la sepia utilizando series temporales intra-anuales (Capítulo 5). El análisis de diferentes factores ambientales reveló que la SST y la variabilidad climática local influían significativamente en las fluctuaciones de abundancia de la especie. En un trabajo posterior (Capítulo 6) se aplicaron técnicas de evaluación de stocks a las pesquerías de sepia y calamar de las Islas Baleares utilizando datos procedentes de la EU Data Collection Framework (DCF). Hasta donde sabemos, este trabajo constituye la primera aplicación de los Lesly-Delury Depletion Methods a stocks de cefalópodos del Mediterráneo. Los resultados demostraron que el esquema actual de muestreo de la DCF es inadecuado para la evaluación de cefalópodos y se proponen posibles modificacionesResum: Els cefalòpodes constitueixen un grup faunístic important als ecosistemes marins, essent elements clau a les xarxes tròfiques. A més, són importants recursos pesquers i la seva contribució als desembarcs pesquers mundials s’ha incrementat en les últimes dècades. representant al voltant del 30% de la captura desembarcada a nivell mundial. Al Mar Mediterrani existeixen varis estudis locals sobre l’abundància i distribució de cefalòpodes, però pocs integren escales temporals llargues i àrees extenses. Aquesta tesi combina estudis sobre la composició de la comunitat, la diversitat i l’abundància de cefalòpodes a gran escala espaciotemporal (Part I) amb estudis a escala local al voltant de les Illes Balears (Part II). En primer lloc, es va realitzar un anàlisi de les comunitats de cefalòpodes a escala de tot el Mediterrani per descriure l’estat actual i determinar possibles diferències entre les sub-conques occidental i oriental (Capítol 2). L’objectiu fou comparar l’estructura de les comunitats faunístiques entre sub-conques i analitzar la influència de gradients ambientals a gran escala sobre la composició específica. Tot i que no s’observaren diferències significatives en la composició específica, les contribucions relatives de les diferents espècies variaren entre sub-conques. Degut al seu cicle vital curt i estratègia reproductiva semèlpara els cefalòpodes són molt sensibles als canvis ambientals, adaptant-se a ells amb relativa rapidesa. S’esperava, per tant, que factors ambientals com la temperatura superficial del mar (SST) i el contingut de clorofil•la a (Chla) fossin factors importants en l’estructuració de les comunitats de cefalòpodes. Si bé la seva importància va diferir entres les dues sub-conques, es va confirmar que la profunditat era el factor estructural més important en aquestes comunitats. S’analitzaren també canvies en la diversitat específica de les comunitats de cefalòpodes a escala de tot el Mediterrani durant els últims 20 anys (Capítol 3). Els resultats no mostraren cap tendència temporal ni espacial (latitud, longitud) clara i homogènia en la diversitat. Les úniques tendències temporals observades variaren entre diferents sub-regions, essent la posició geogràfica, profunditat, SST i productivitat els principals factors determinants d’aquestes tendències. Per tal de confirmar la importància de la variabilitat ambiental a nivell específic, es va investigar la influència de la SST i la producció primària en l’estructuració espacial i la dinàmica poblacional de dues espècies de cefalòpodes d’importància comercial (Capítol 4). Tot i que Octopus vulgaris i Illex coindetii tenen característiques vitals diferents i viuen en hàbitats diferents, les tendències temporals a llarg plaç en la seva l’abundància i el comportament sincrònic de les seves poblacions va ser similar, observant-se sub-poblacions temporalment persistents al llarg del Mediterrani. En consonància amb els capítols anteriors, la SST i Chla resultaren ser factors significatius en la definició de patrons de distribució i fluctuacions interanuals de l’abundància. La segona part de la tesi estava motivada per la situació actual dels cefalòpodes al Mar Mediterrani, on no existeixen mesures d’avaluació i gestió específica per aquest grup i algunes de les seves poblacions es troben sobre-explotades. Per contribuir al coneixement de la situació actual al Mar Balear, es va analitzar la pesqueria, cicle vital i dinàmica poblacional de la sípia utilitzant sèries temporals intra-anuals (Capítol 5). L’anàlisi de diferents factors ambientals va revelar que la SST i la variabilitat climàtica local influïen significativament en les fluctuacions d’abundància de l’espècie. En un treball posterior (Capítol 6) s’aplicaren tècniques d’avaluació d’stocks a les pesqueries de sípia i calamar de les Illes Balears utilitzant dades procedents de la EU Data Collection Framework (DCF). Fins on sabem, aquest treball constitueix la primera aplicació dels Lesly-Delury Depletion Methods a stocks de cefalòpodes del Mediterrani. Els resultats demostraren que l’esquema actual de mostratge de la DCF és inadequat per a l’avaluació de cefalòpodes i es proposen posibles modificacion

Working group on cephalopod fisheries and life history (Wgceph; outputs from 2022 meeting)

Rapports Scientifiques du CIEM. Volume 5, nº 1WGCEPH worked on six Terms of Reference. These involved reporting on the status of stocks; reviewing advances in stock identification, assessment for fisheries management and for the Ma- rine Strategy Framework Directive (MSFD), including some exploratory stock assessments; re- viewing impacts of human activities on cephalopods; developing identification guides and rec- ommendations for fishery data collection; describing the value chain and evaluating market driv- ers; and reviewing advances in research on environmental tolerance of cephalopods. ToR A is supported by an annual data call for fishery and survey data. During 2019–2021, com- pared to 1990–2020, cuttlefish remained the most important cephalopod group in terms of weight landed along the European North Atlantic coast, while loliginid squid overtook octopus as the second most important group. Short-finned squid remained the least important group in land- ings although their relative importance was almost double in 2019–2022 compared to 1992–2020. Total cephalopod landings have been fairly stable since 1992. Cuttlefish landings are towards the low end of the recent range, part of a general downward trend since 2004. Loliginid squid landings in 2019 were close to the maximum seen during the last 20 years but totals for 2020 and 2021 were lower. Annual ommastrephid squid landings are more variable than those of the other two groups and close to the maximum seen during 1992– 2021. Octopod landings have generally declined since 2002 but the amount landed in 2021 was higher than in the previous four years. Under ToR B we illustrate that the combination of genetic analysis and statolith shape analysis is a promising method to provide some stock structure information for L. forbsii. With the sum- mary of cephalopod assessments, we could illustrate that many cephalopod species could al- ready be included into the MSFD. We further provide material from two reviews in preparation, covering stock assessment methods and challenges faced for cephalopod fisheries management. Finally, we summarise trends in abundance indices, noting evidence of recent declines in cuttle- fish and some octopuses of the genus Eledone. Under ToR C, we describe progress on the reviews of (i) anthropogenic impacts on cephalopods and (ii) life history and ecology. In relation to life history, new information on Eledone cirrhosa from Portugal is included. Under ToR D we provide an update on identification guides, discuss best practice in fishery data collection in relation to maturity determination and sampling intensity for fishery monitoring. Among others, we recommend i) to include the sampling of cephalopods in any fishery that (a) targets cephalopods, (b) targets both cephalopods and demersal fishes or (c) takes cephalopods as an important bycatch, ii) Size-distribution sampling, iii) the use of standardized sampling pro- tocols, iv) an increased sampling effort in cephalopod. Work under ToR E on value chains and market drivers, in conjunction with the Cephs & Chefs INTERREG project, has resulted in two papers being submitted. Abstracts of these are in the report. Finally, progress under ToR F on environmental tolerance limits of cephalopods and climate en- velope models is discussed, noting the need to continue this work during the next cycle.info:eu-repo/semantics/publishedVersio

Large-Scale Spatio-Temporal Patterns of Mediterranean Cephalopod Diversity

Species diversity is widely recognized as an important trait of ecosystems’ functioning and resilience. Understanding the causes of diversity patterns and their interaction with the environmental conditions is essential in order to effectively assess and preserve existing diversity. While diversity patterns of most recurrent groups such as fish are commonly studied, other important taxa such as cephalopods have received less attention. In this work we present spatio-temporal trends of cephalopod diversity across the entire Mediterranean Sea during the last 19 years, analysing data from the annual bottom trawl survey MEDITS conducted by 5 different Mediterranean countries using standardized gears and sampling protocols. The influence of local and regional environmental variability in different Mediterranean regions is analysed applying generalized additive models, using species richness and the Shannon Wiener index as diversity descriptors. While the western basin showed a high diversity, our analyses do not support a steady eastward decrease of diversity as proposed in some previous studies. Instead, high Shannon diversity was also found in the Adriatic and Aegean Seas, and high species richness in the eastern Ionian Sea. Overall diversity did not show any consistent trend over the last two decades. Except in the Adriatic Sea, diversity showed a hump-shaped trend with depth in all regions, being highest between 200–400 m depth. Our results indicate that high Chlorophyll a concentrations and warmer temperatures seem to enhance species diversity, and the influence of these parameters is stronger for richness than for Shannon diversityVersión del editor4,411

Reports of the Scientific, Technical and Economic Committee for Fisheries Management plan for boat seines in Greece & derogation for boat seines targeting transparent goby (Aphia minuta) in Murcia, Spain (STECF-16-15) - Study

Commission Decision of 25 February 2016 setting up a Scientific, Technical and Economic Committee for Fisheries, C(2016) 1084, OJ C 74, 26.2.2016, p. 4–10. The Commission may consult the group on any matter relating to marine and fisheries biology, fishing gear technology, fisheries economics, fisheries governance, ecosystem effects of fisheries, aquaculture or similar disciplines In this report the STECF advises on a management plan for boat seines in Greece & Derogation for boat seines targeting transparent goby (Aphia minuta) in Murcia, Spain

Addressing cetacean–fishery interactions to inform a deep-sea ecosystem-based management in the Gulf of Taranto (Northern Ionian Sea, Central Mediterranean Sea)

Understanding of cetaceans’ trophic role and the quantification of their impacts on the food web is a critical task, especially when data on their prey are linked to deep-sea ecosystems, which are often exposed to excessive exploitation of fishery resources due to poor management. This aspect represents one of the major issues in marine resource management, and trade-offs are needed to simultaneously support the conservation of cetaceans and their irreplaceable ecological role, together with sustainable fishing yield. In that regard, food web models can represent useful tools to support decision-making processes according to an ecosystem-based management (EBM) approach. This study provides a focus on the feeding activity occurrence and the trophic interactions between odontocetes and the fishery in the marine food web of the Gulf of Taranto (Northern Ionian Sea, Central Mediterranean Sea), by zooming in on cetaceans’ prey of commercial interest. In particular, the quantification of trophic impacts is estimated using a food web mass-balance model that integrates information on the bathymetric displacement of both cetaceans’ prey and fishing activity. The results are discussed from a management perspective to guide future research and knowledge enhancement activities as well as support the implementation of an EBM approach