Climate-related factors cause changes in the diversity of fish and invertebrates in subtropical coast of the Gulf of Mexico

Masami Fujiwara,Mariah C Livernois,Michaela Pawluk,Mark Fisher,Fernando Martinez-Andrade,R J David Wells

doi:10.1038/s42003-019-0650-9

Masami Fujiwara, Mariah C Livernois + Show 4 more

Open Access

https://doi.org/10.1038/s42003-019-0650-9

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Abstract

Climate change impacts physical and chemical properties of the oceans, and these changes affect the ecology of marine organisms. One important ecological consequence of climate change is the distribution shift of marine species toward higher latitudes. Here, the prevalence of nearly 150 species of fish and invertebrates were investigated to find changes in their distributions over 35 years along a subtropical coast within the Gulf of Mexico. Our results show that 90 species increased their occupancy probability, while 33 decreased (remaining species neither increase or decrease), and the ranges of many species expanded. Using rarefaction analysis, which allows for the estimation of species diversity, we show that species diversity has increased across the coast of Texas. Climate-mediated environmental variables are related to the changes in the occupancy probability, suggesting the expansion of tropical species into the region is increasing diversity.

Highlights

The ranges of fish have shifted northward in the North Sea[1], the assemblages of marine organisms have changed to include more warm-water species in the northeast United States[2,3] and the North Sea[4], the distribution of organisms has changed in the California Current[5], and warm-water fish have expanded their ranges in the Mediterranean Sea[6]
Coastal marine species are affected by other factors such as sea-level rise and salinity, both of which are affected by climate change
Our results show that species closer to the southern limit of their historical distribution tended to decline in prevalence and contract their range, and maximum temperature tolerance was an important factor in predicting changes in their spatiotemporal trends. These results are consistent with the idea that climate change is affecting the distributions of many fish species along the Texas coast

Summary

Results

Annual Shannon diversity index of fish and invertebrates. The Shannon diversity index was calculated in each major bay system. Compared with species that increased in occupancy probability, those species with declining occupancy probabilities had significantly lower-latitude southern range limits (single-tail Mann–Whitney U test, rank sum = 1176, n = [52, 24], Holm–Bonferroni adjusted p-value = 0.004), significantly lower maximum preferred/observed temperatures (single-tail Mann–Whitney U test, rank sum = 834, n = [55, 25], Holm–Bonferroni adjusted p-value = 0.062), and significantly narrower latitudinal distribution ranges (single-tail Mann–Whitney U test, rank sum = 1831, n = [54, 24], Holm–Bonferroni adjusted p-value = 0.084). Species that contracted their range had significantly higher-latitude southern range limits (single-tail Mann–Whitney U test, rank sum = 56.5, n = [14, 4], Holm–Bonferroni adjusted p-value = 0.088) and significantly lower maximum preferred/observed temperatures (single-tail Mann–Whitney U test, rank sum = 59, n = [4, 4], Holm–Bonferroni adjusted p-value = 0.069) compared with those that expanded their range. To investigate the effects of climate-related environmental variables on changes in occupancy probability, we fit sea level, temperature, salinity, and dissolved oxygen as covariates in the a b

Discussion

Methods

Code availability