Assessing synergistic habitat changes and interspecific relationships of small pelagic fish in the northwest Pacific Ocean

Aim: Small pelagic species constitute a critical component of fishery
resources in the northwest Pacific Ocean. Understanding the interactions
among interspecific relationships, environmental niches, and resource
abundance is essential for developing science-based fisheries management.
This study aims to investigate the differential habitat responses of small
pelagic species in the Northwest Pacific to environmental factors,
specifically evaluating the ecological interpretation of interspecific
relationships through joint species distribution modeling. Location: The
northwest Pacific Ocean Taxon: Japanese sardine; Chub mackerel; neon
flying squid Methods: This study examined three economically important
small pelagic species from the northwest Pacific Ocean: Japanese sardine
(Sardinops melanostictus), chub mackerel (Scomber japonicus), and neon
flying squid (Ommastrephes bartramii). Using a joint species distribution
model (JSDM) and ecological niche theory, we integrated multiple
environmental variables to analyze interspecific associations and patterns
of synchronous habitat variation among these species. Results: The JSDM
accurately predicted suitable habitats for all three species, revealing
spatial synchrony in habitat suitability. Notably, a positive
interspecific (0.9) association is observed between S. melanostictus and
S. japonicus, while both exhibit negative associations (−0.84 and −0.95)
with O. bartramii. The breadth of suitable ecological niches for key
environmental factors and their corresponding response curves offers
ecological insights into these interspecific interactions, confirming the
dynamic variations in suitable habitat ranges for these species. Main
Conclusions: The interspecific relationships reflected similar species
responses to environmental factors and highlighted their occupation of
overlapping ecological niches. This consistency in environmental responses
may drive synchronized habitat shifts, potentially affecting fluctuations
in small pelagic fish abundance.