Tuesday, July 26, 2011

New study confirms global warming increases marine fish biodiversity

In another blow to the biodiversity eco-scare movement, a paper published last week confirms that global warming results in a net increase in marine fish biodiversity, even in areas of "low connectivity" such as the Baltic Sea. 

What is the effect of climate change on marine fish biodiversity in an area of low connectivity, the Baltic Sea?

Jan Geert Hiddink, Chris Coleby

Aim  Climate change could result in an increase in species richness because large-scale biogeography suggests that more species could be gained from equatorial regions than may be lost pole-ward. However, the colonization of newly available habitat may lag behind the rate dictated by climatic warming if there exists of a lack of connectivity between ‘donor’ and receiving areas. The objective of this study was to compare how regional warming affected the biodiversity of marine fish in areas that differed in their connectivity in the Baltic Sea.

Location  North-east Atlantic, Kattegat and Baltic Sea.

Methods  The total species richness and the mean species richness from scientific surveys were related to changes in temperature and salinity. Changes in the extent of the distribution of individual fish species were related to the latitudinal distribution, salinity tolerance, maximum body size and exploitation status to assess to what extent climate change and fishing impacts could explain changes in species richness in the Baltic.

ResultsRising temperatures in the well-connected Kattegat correlated to an increase in the species richness of fish, due to an increase in low-latitude species. Unexpectedly, species richness in the poorly connected Baltic Sea also increased. However, the increase seems to be related to higher salinity rather than temperature and there was no influx of low-latitude species.

Main conclusions  These results do not support the hypothesis that low-connectivity areas are less likely to see increases in species richness in response to warming. This indicates that the effect of climate change on biodiversity may be more difficult to predict in areas of low connectivity than in well-connected areas.


  1. Interesting that the paper mentions higher salinity in the Baltic. I read recently that salinity there is projected to decrease with increased river runoff due to "climate change", which will "devastate its marine life"


  2. Well it's not really saying global warming increases marine fish biodiversity. They're saying the increase is due to increased salinity.

    This paper does suggest though that global warming cannot be described as a decisive influence on marine life as the warmists always do

  3. John Simpson,

    They are saying in well-connected areas (most areas) such as Kattegat they increase in biodiversity is due to warming. They are theorizing that in low-connected areas such as the Baltic Sea it is due to salinity.