Climate change sensitivity of threatened, and largely unprotected, Amazonian fishes

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TwoTankAmin
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Climate change sensitivity of threatened, and largely unprotected, Amazonian fishes

Post by TwoTankAmin »

I was doing a search on Google Scholar for recent papers on Hypancistrus when I came across this:

Frederico, R. G., Olden, J. D., and Zuanon, J. (2016) Climate change sensitivity of threatened, and largely unprotected, Amazonian fishes. Aquatic Conserv: Mar. Freshw. Ecosyst., 26: 91–102. doi: http://dx.doi.org/10.1002/aqc.2658.

Abstract

1. Climate change is poised to have fundamental impacts on the freshwater environments of the Amazon River Basin, and protected areas are routinely proposed as a possible management strategy to conserve freshwater fishes. However, there remains a paucity of information regarding the sensitivity of threatened fish species to climate-induced changes in water quantity and quality.
2. An expert-based survey was used to address the following questions: (1) Are currently threatened fish species in Brazil also sensitive to projected effects of climate change? (2) Does the current conservation status of fish species also reflect their degree of sensitivity to climate change? and (3) What are the specific aspects of climate change that are likely to contribute the most to species sensitivity?
3. Survey respondents evaluated 35 species (11 families) representing 50% of the threatened species in the Brazilian Amazon. The results suggest that the majority of threatened Brazilian fish species are considered highly sensitive to climate change impacts.
4. Climate-induced changes in water quality were, on average, considered a greater threat to species persistence than potential changes in water quantity. Survey results also suggest that fishes exhibit high sensitivity to changes in temperature and dissolved oxygen, and moderate to high sensitivity to changes in high-flow (i.e. flood) and low-flow (i.e. drought) regimes.
5. A considerable mismatch was found between species conservation status and sensitivity to climate change, suggesting that perceptions of present-day extinction risk do not necessarily provide insight into future risks associated with climate change.
6. Species sensitivity to climate change showed no relationship to dispersal ability, indicating that protected areas may serve as important refugia for those species unable to keep pace with climate change. Despite this, the number and size of protected areas in Brazil have decreased over the past decade, largely to support the exploitation of hydropower and mining. Strategic conservation planning that involves existing and new protected areas for those species most at risk to climate change is warranted.

What I found most interesting was Table 2 and the introductory paragraph before it:
Fish species demonstrated considerable variability in their tolerances to climate change impacts (Figure 5). The overall sensitivity scores varied from 2.9 (Scobinancistrus pariolispos) to 4.8 (Sternarchorhynchus jaimei and Sternarchorhynchus kokraimoro) (Table 2). Sternarchorhynchus jaimei and S. kokraimoro are considered highly sensitive to changes in water quality and quantity parameters, whereas Sternarchorhynchus pariolispos showed the lowest overall sensitivity to climate change impacts, owing to moderate tolerance to changes in water quality and quantity (Table 2). Among the species with high overall sensitivity to climate change, five are categorized as critically endangered: Apteronotus lindalvae, Baryancistrus niveatus, Hypancistrus zebra, Microglanis robustus and Sternarchorhynchus higuchii. Another two species Leporinus pitingai and Crenicichla cyclostoma are highly sensitive to projected climate-induced changes in both water quality and quantity parameters, but demonstrate moderate to high dispersal ability thus reducing their overall sensitivity (Table 1). Survey experts reported considerable variability in fish dispersal ability, which was not associated with sensitivity to projected climate-induced changes in water quantity and quality (R = 0.04, F = 0.95, P = 0.33).
My point in all this is the paper would seem to indicate that H. zebra is indeed critically endangered and that this is exacerbated by climate change. The above papers are in Portuguese and I did not try translating them. However, if H. zebra and the other endangered species, are thought to be at great risk from climate change, I am pretty sure the effects of the Belo Monte dam on the Big bend of the Xingu would have similarities to those that climate change might create.

This paper only served to reinforce my belief that many of the fish in the Big Bend are doomed to extinction. Those which are only found there are likely going be lost in the wild.
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