DOI: 10.5061/dryad.9w0vt4bv2
title: Assessing synergistic habitat changes and interspecific relationships of small pelagic fish in the northwest Pacific Ocean

description: 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.
description: # Assessing Synergistic Habitat Changes and Interspecific Relationships of
 Small Pelagic Fish in the Northwest Pacific Ocean ## File Descriptions ###
 "model_code.txt" Data and commented code for the reproduction of
 modeling. The distribution data of the three species is not publicly
 available due to privacy or ethical restrictions. All environmental data
 and pseudo-absence data were provided in the ".xlsx" files.  ###
 variable definitions Sea Surface Temperature (SST): This variable
 indicates the temperature of the ocean’s surface water. It is an essential
 factor for studying species distribution and marine ecosystems.
 Chlorophyll-a Concentration (CHL): This variable represents the amount of
 chlorophyll-a pigment in the water, which is an indicator of phytoplankton
 biomass. Phytoplankton are microscopic plants that form the base of the
 marine food web, making this measurement crucial for understanding marine
 productivity and ecosystem health. Sea Surface Salinity (SSS): This
 variable indicates the salt concentration in seawater at the surface.
 Salinity affects water density and circulation patterns in the ocean,
 influencing marine species' life and distribution. Sea Level Anomaly
 (SLA): This variable represents variations from the average sea level in a
 given area. It can result from factors like ocean currents, temperature
 changes, and atmospheric pressure. Eddy Kinetic Energy (EKE): This
 variable quantifies the energy in ocean eddies, which are swirling water
 masses. EKE is important for studying ocean mixing processes, nutrient
 distributions, and the dynamics of marine ecosystems. Mixed Layer Depth
 (MLD): This variable refers to the depth of the upper layer of the ocean
 where water is well-mixed due to wind and wave action. The MLD influences
 the distribution of heat, nutrients, and marine organisms. Dissolved
 Molecular Oxygen (O2): This variable indicates the concentration of oxygen
 dissolved in seawater. Oxygen is vital for the survival of marine
 organisms, making its measurement important for marine species
 distribution and ecosystem health. Dissolved Molecular Nitrate (NO3): This
 variable represents the concentration of nitrate ions in seawater. Nitrate
 is a key nutrient for phytoplankton growth, and monitoring its levels
 helps understand primary production and nutrient cycling in marine
 ecosystems. Dissolved Molecular Phosphate (PO4): This variable indicates
 the concentration of phosphate ions in seawater. Similar to nitrate,
 phosphate is an essential nutrient for marine plants, and its levels
 influence primary productivity. Net Primary Production (NPP): This
 variable signifies the amount of organic matter produced by phytoplankton
 through photosynthesis minus the amount consumed through respiration. NPP
 is a critical measure of the productivity of marine ecosystems and overall
 ocean health. ### Units for all variables SST: Measured in degrees
 Celsius—°C CHL: Measured in milligrams per cubic meter —mg/m^3 SSS:
 Measured in practical salinity units—psu SLA: Measured in meters—m EKE:
 Measured in square meters per second squared—m^2/s^2 MLD: Measured in
 meters —m O2: Measured in millimoles per cubic meter—mmol/m^3 NO3:
 Measured in millimoles per cubic meter—mmol/m^3 PO4: Measured in
 millimoles per cubic meter—mmol/m^3 NPP: Measured in milligrams per cubic
 meter per day—mg/m^3day ### All files details **GLO_ENVI.xlsx** The data
 for the all environmental factors . **pseudo-absence.xlsx** The
 pseudo-absence data used to establish the model. ### Software versions for
 models Hierarchical Model of Species Communities: ‘Hmsc’ version 3.0-13
 ### Software version for R the script was created using R version 4.2.0.