A review of recent studies on the life history and ecology of European cephalopods with emphasis on species with the greatest commercial fishery and culture potential

Abstract

With the depletion of many commercial fish stocks and an increasing demand for marine protein for human consumption, cephalopods have become more important as a fishery resource. In EU waters, cephalopod stocks are not routinely assessed and exploitation of these species by large-scale fisheries is largely unregulated. For sustainable exploitation, adequate assessment and scientifically-supported management strategies are needed. However, there is still a lack of data on stock status and inadequate knowledge of the life history and ecology of these species. The present review examined more than 200 scientific articles, on life history and ecology of European cephalopods, published since 2013. It describes recent contributions to knowledge in the context of previously identified research priorities, along with recent advances towards sustainable fishing and aquaculture. It also identifies outstanding knowledge gaps. While some priority areas, such as the development of the species identification guides and evaluation of climate change impacts on cephalopods, have seen significant advances, other challenges remain for the future. These include monitoring of the life history traits and fishery status for the main commercially exploited species in the area, implementation of improved species identification methods during scientific surveys and fisheries monitoring, development of tools to identify stock units, and the study of the environmental and anthropogenic impacts on the stocks of cephalopods inhabiting European waters.

Conservation-Status Gaps for Marine Top-Fished Commercial Species

“…However, we acknowledge that many of the problems detected for fishes can be present in other groups. For instance, cephalopods have increased in commercial importance in the last decades [39] and yet face several threats from unregulated fisheries, bycatch, and poor life-history knowledge [40].…”

Molecular and Biological Analysis on Ommastrephes caroli Findings in the Central Western Mediterranean Sea (Sardinian Waters) Including First Age Investigation Using Eye Lenses and Beaks

“…Similarity to O. bartramii (Roper et al, 2010), our specimens confirm that asynchronous oocytes development, a relatively small oocytes (0.05-1.10 mm) and a protracted intermittent spawning with active feeding, are features of the species O. caroli. Considering that the biological knowledge on O. caroli is limited (e.g., Pinchukov, 1975;Nigmatullin, 1989;Jereb et al, 2015;Lishchenko et al, 2021), the value on potential fecundity here estimated (840061 oocytes), as well as the oviductal load (about 90000 ripe oocytes), at the moment represent the only information available for this species. Potential fecundity is decidedly lower when compared to O. bartramii for which between 3 to 8 million of oocytes were found in mature females of a size comparable with our sample (Roper et al, 2010;Vijai et al, 2014).…”

“…However, the scarcity of records contrasts with its frequency of occurrence in the stomach contents of apex predators (Bello, 1991;Romeo et al, 2012) suggesting that the species could be not so rare. Lishchenko et al (2021), stated that more than 90% of the studies on Ommastrephes specimens have been focused on Pacific populations, the remainder refer to what in the Atlantic and Mediterranean was considered to belong to O. bartramii and now instead has been designated as O. caroli (Fernández-Álvarez et al, 2020). Jereb et al (2015) noted that general information of the basic biology of O. caroli in the North Atlantic was still needed and that a translation of the published Russian studies into English would help make the available knowledge more accessible (Lishchenko et al, 2021).…”

“…Lishchenko et al (2021), stated that more than 90% of the studies on Ommastrephes specimens have been focused on Pacific populations, the remainder refer to what in the Atlantic and Mediterranean was considered to belong to O. bartramii and now instead has been designated as O. caroli (Fernández-Álvarez et al, 2020). Jereb et al (2015) noted that general information of the basic biology of O. caroli in the North Atlantic was still needed and that a translation of the published Russian studies into English would help make the available knowledge more accessible (Lishchenko et al, 2021). As regards the Mediterranean findings, biological information addressing reproductive and life cycle data is too fragmentary and lacking.…”

Assessing Cephalopods Fisheries in the Strait of Sicily by Using Poor Data Modeling

“…Cephalopods, both as predators and prey, are key components of marine ecosystems (Boyle and Rodhouse, 2005). Furthermore, commercially important cephalopods are relatively few in number but they support several fisheries, both inshore and offshore, in many oceanic regions (Pierce and Portela, 2014;Rodhouse et al, 2014;Lishchenko et al, 2021). Most cephalopods important to fisheries are semelparous, fast-growing, short-lived, and early maturing species with several cohorts overlapping in the year and their life cycle phenologies are strongly affected by environmental factors (Jackson and O'Dor, 2001;Rodhouse et al, 2014;Jereb et al, 2015;Lishchenko et al, 2021).…”