Characterization of the northernmost spawning habitat of Dosidicus gigas with implications for its northwards range extension

Abstract

The jumbo squid Dosidicus gigas is an ecologically and commercially important species whose northernmost geographic limit is the Gulf of California. However, over the last decades this species has extended its geographic distribution polewards, with associated impacts on the ecosystem. The origin of range-shifting individuals is poorly understood; therefore, we aimed to identify and characterize the northernmost spawning habitat of this species. Implications of the location and oceanographic conditions of the spawning habitats, migration capacity and life history characteristics of D. gigas are also discussed to elucidate its migration pattern. The northernmost spawning area was located between the biological activity centres (BACs) around the Gulf of Ulloa at the west coast of southern Baja California Peninsula during winter, summer and autumn 2005. Generalized linear models indicated that the interaction of sea surface salinity and thermocline depth, and the effect of latitude and sea surface temperature explained most of the variability in paralarval presence, whereas chlorophyll a and latitude explained paralarval abundance. Simulations indicated that paralarvae were dispersed towards the southwest or temporarily remained between BACs. The northwards incursion of D. gigas may be favoured by BACs and upwelling events along the coast of the northeastern Pacific. In warm years, D. gigas is likely to spawn off the Baja California Peninsula, it may actively migrate as far north as Alaska (USA) tracking BACs and upwelling conditions in search of feeding grounds, and it may return from different areas along the northeastern Pacific to spawn off the Baja California Peninsula.

Ommastrephid squid paralarvae potential nursery habitat in the tropical-subtropical convergence off Mexico

“…About 98% of the paralarvae collected in the present study were identified as belonging to the SD complex. However, previous studies of SD complex paralarvae off northwest Mexico that used molecular identification confirmed predominance of D. gigas paralarvae in the region north of 18 °N (Fernandez-Alvarez et al , 2018;Gilly et al , 2006;Ramos et al , 2017;Sanchez-Velasco et al , 20 16) . In contrast, south of 18 °N under properly tropical conditions, molecular methods identified S. oualaniensis as the numerically dominant SD complex paralarvae species (Staaf et al , 2013).…”

“…Bibliographic research on SD complex paralarvae presence in the study area was made to compare the GAM output with historical data. Most of the bibliographic data correspond to areas outside the main sampled area, along the Pacific coast of Baja California Peninsula (Camarillo-Coop et al , 2010;Ramos et al, 2017;Palomares-Garcia et al , 2018;Garcia-Guillen et al , 2018;Molina-Arenas, 2018).…”

Spatial segregation of striped marlin (Kajikia audax) by size in the eastern Pacific Ocean

“…Environmental oscillations can affect the range distribution of marine mobile organisms (Lan, Evans, & Lee, ; Norton, ; Parmesan, ; Ramos et al., ; Stewart, Hazen, Foley, Bograd, & Gilly, ; Zeidberg & Robison, ). Given this fact, we expected spatial variation in the distribution of striped marlin EFL caused by a large‐scale phenomenon as ENSO.…”

Predicting the Fishery Ground of Jumbo Flying Squid (Dosidicus gigas) off Peru by Extracting Features of the Ocean Environment

“…Machine learning techniques such as neural networks, random forests, support vector machines and the maximum entropy model have shown promise in improving fishery forecasts [11][12][13]. However, most of the current models use the monthly average value of marine environmental factors in the fishing area [14,15]. These variables cannot reflect the monthly temporal and spatial dynamics and complexity of the marine environment and thus make it difficult to accurately analyze the temporal and spatial dynamic habitat of jumbo flying squid.…”