DOI: 10.5061/dryad.9pt97sj
title: Data from: The global geography of fish diadromy modes

description: Aim: Geographical gradients in resource production are likely to translate
 into macro-ecological patterns in the biodiversity of migratory organisms
 but few studies have addressed this question at a global scale. Here we
 tested a hypothesis based on uncoupled latitudinal gradients in marine and
 freshwater primary productivities aimed at explaining where (e. g. at
 which latitude) and at which stage of the life cycle (larvae: amphidromy,
 juvenile: catadromy, adult: anadromy) migration from ocean to freshwater
 occurs (diadromy). Location: Global. Time period: Current. Major taxa
 studied: Fishes. Methods: We modelled, using multinomial regressions, the
 proportion of catadromous, anadromous, and amphidromous species in 994
 river basins as a function of freshwater and marine net primary
 productivities (NPP, mgC/m²/day) and additional biotic and abiotic
 variables. Using data extracted from GBIF we tested whether diadromous,
 catadromous and amphidromous species differed with respect to the NPP of
 their marine and freshwater occurrences. Results: Among diadromous
 species, anadromous species are present in higher proportion when
 conditions for growth are more favourable in the sea (higher productivity,
 higher temperature, lower number of competitors) than in freshwaters. The
 model reconstructs the latitudinal pattern observed in the proportion of
 anadromous species, including an asymmetry between the northern and
 southern hemispheres. According to GBIF occurrences, the ratio of marine
 over freshwater productivity is higher for anadromous species compared to
 catadromous and amphidromous species. Main conclusions: Our results
 support the hypothesis stating that migration between ocean and freshwater
 occurs by choosing the biome that optimizes pre-reproductive growth and is
 one more example of the importance of primary productivity in shaping
 large scale community patterns. This result suggests that some diadromous
 fish populations and species may suffer from anticipated climate change if
 inter-biome productivity gradients are affected.
description: Presence-absence
 tablePresence-absence of 350
 diadromous fish species (columns) in 994 river basins (rows). See also the
 method section in the accompanying paper.PA.csvBiotic and abiotic features of river basinsBiotic and abiotic features of 994 river basins. SR stands for Species richness, T° for temperature (°C), SST for sea surface temperature (°C), NPP for net primary productivity (mgC/m²/day). Land surface area is in arbitrary units. %Ice is the percentage of the river basin under ice at the last glacial maximum. See also the method section in the accompanying paper for further information about the variables.Rivers.csvSpecies statusTaxonomic status and diadromy type for 350 diadromous species. See also the method section in the accompanying paper.Species.csvSpecies occurrencesData for 161 diadromous species with more than 4 occurrences per biome (terrestrial, marine) in the GBIF database. NPP stands for net primary productivity (mgC/m²/day). The column “phylogeny” indicates whether (Y) or not (N) the species belongs to the phylogeny provided by Rabosky et al. (2013). Citations are available in the associated file 'SpeciesGBIF_README.txt'. See also the method section in the accompanying paper for further information about the variables.SpeciesGBIF.csvSpeciesGBIF_README.txt