Environmental effects on the jumbo squid fishery along Baja California’s west coast

Evidence of interactions between white sharks and large squids in Guadalupe Island, Mexico

“…In this study, most squid scars were observed in subadult male sharks throughout the season, suggesting that their arrival to Guadalupe Island could be related to the consumption of squids and tunas, while the Northern elephant seals Mirounga angustirostris arriving in December would complement the diet of adult sharks in a dietary shift related to their maturity 4 , 5 , 9 . This emphasizes the importance of habitat use for both white sharks and squids, where future conservation-related studies should include the potential impacts of both prey and predators distribution, mainly in terms of oceanographical changes related to temperature, productivity and minimum oxygen layers 6 , 9 , 14 – 16 , 26 . This type of research will also be able to elucidate evolutionary aspects of the interaction between sharks and cephalopods, since both lineages are ancient and their study could provide relevant information on the ecological importance of both taxa in the dynamic exchange of matter and energy in marine ecosystems 6 , 12 , 18 , 26 .…”

“…1a) allowed us to determine that the left side scar (≈ 20 cm long) had suction cups that measured 1-3 cm, while the length of the right side scar measured ≈ 60 cm long. Even though the cephalopod species could not be confirmed, observed marks from all analysed sharks could suggest an encounter with taxa such as the jumbo squid D. gigas, the neon flying squid O. bartramii, or the giant squid A. dux based on their potential distribution, arms and tentacles length, as well as the estimated size of the scars and suckers 12,[16][17][18] .…”

“…Within the distribution of white sharks in the eastern North Pacific Ocean, there are important areas for the occurrence of large squid species such as the neon flying squid Ommastrephes bartramii, purpleback squid Sthenoteuthis oualaniensis, sharpear enope squid Ancistrocheirus lesueurii, jumbo squid Dosidicus gigas, and probably the giant squid Architeuthis dux 3,10,12,15,16 . However, scientific research has focused mainly on fishing activities near the coast where a greater catch of D. gigas has been reported during the months of July-December, which coincides with the white shark sighting season in Guadalupe Island 8,9,16 . Nevertheless, the studies involving white sharks and squids are scarce, so there is a lack of information regarding these interactions in the eastern North Pacific.…”

Climate-related changes in seasonal habitat pattern of Sthenoteuthis oualaniensis in the South China Sea

“…Various anomalous climatic events occur will quickly induce the changes of local environments on the fishing and spawning grounds of squid species, leading to the spatial shifts of breeding and feeding habitats and abundance variability (Cao et al, 2009;Postuma and Gasalla, 2010). Consequently, squid abundance varies a lot and the locations of fishing ground undergo large movement with the changing environments, and annually squid catches for squid-jigging fisheries from different countries become fluctuant (Sakurai et al, 2002;Medellín-Ortiz et al, 2016;Igarashia et al, 2017). For example, in the western North Pacific Ocean, the neon flying squid Ommastrephes bartramii is dramatically affected by the El Niño-Southern Oscillation (ENSO) and critical environmental factors such as sea surface temperature (SST), sea surface height anomaly (SSHA) and net primary production (NPP).…”

Potential use of stable isotope and fatty acid analyses for traceability of geographic origins of jumbo squid (Dosidicus gigas)

“…With the continuous development of jumbo squid products, methods aimed to improve food quality and information, such as regional identity, are needed. Moreover, the market value of raw squid differs between fishing regions and it is significantly influenced by catches . In particular, diversification in the abundance of jumbo squid as a result of climate change has been observed …”