A Drop in the Ocean: Future acidification and temperature change could affect benthic diversity.

<p>Oikos, 120 (5), 661-674.</p> <p>A mesocosm experiment was conducted to quantify the effects of reduced pH and elevated temperature on an intact marine invertebrate community. Standardised faunal communities, collected from the extreme low intertidal zone using artificial substrate units, were exposed to one of eight nominal treatments (four pH levels: 8.0, 7.7, 7.3 and 6.7, crossed with two temperature levels: 12 and 16°C). After 60 days exposure communities showed significant changes in structure and lower diversity in response to reduced pH. The response to temperature was more complex. At higher pH levels (8.0 and 7.7) elevated temperature treatments contained higher species abundances and diversity than the lower temperature treatments. In contrast, at lower pH levels (7.3 and 6.7), elevated temperature treatments had lower species abundances and diversity than lower temperature treatments. The species losses responsible for these changes in community structure and diversity were not randomly distributed across the different phyla examined. Molluscs showed the greatest reduction in abundance and diversity in response to low pH and elevated temperature, whilst annelid abundance and diversity was mostly unaffected by low pH and was higher at the elevated temperature. The arthropod response was between these two extremes with moderately reduced abundance and diversity at low pH and elevated temperature. Nematode abundance increased in response to low pH and elevated temperature, probably due to the reduction of ecological constraints, such as predation and competition, caused by a decrease in macrofaunal abundance. This community-based mesocosm study supports previous suggestions, based on observations of direct physiological impacts, that ocean acidification induced changes in marine biodiversity will be driven by differential vulnerability within and between different taxonomical groups. This study also illustrates the importance of considering indirect effects that occur within multispecies assemblages when attempting to predict the consequences of ocean acidification and global warming on marine communities.</p

Appendix B. Recovering spectral exponents from simulated data using repeated hierarchical analysis of variance over a range of nested spatial scales.

Recovering spectral exponents from simulated data using repeated hierarchical analysis of variance over a range of nested spatial scales

Supplement 1. The R code for simulating 2-D data with known spectral exponents, sampling, and ANOVA estimation of β.

<h2>File List</h2><blockquote> <p><a href="SynthesiseSpectra2DBetaDetection1000.r">SynthesiseSpectra2DBetaDetection1000.r</a>  -- r code for generating 2D data and determining variance spectra repeatedly from subsamples (<i>n</i> = 1000)</p> </blockquote><h2>Description</h2><blockquote> <p>The SynthesiseSpectra2DBetaDetection1000.r program uses r code to recover spectral exponents from 2D simulated data using repeated hierarchical analysis of variance over a range of nested spatial scales. The method for generating the simulated data using inverse Fourier transforms of 1/<i>f^β</i> weighted random phases and numbers, and the returned <i>β</i>-values are given in <a href="appendix-B.htm">Appendix B</a>.</p> </blockquote

Appendix C. Modes of reproduction in intertidal species used in the analysis of spatial scales of variation as described by β values.

Modes of reproduction in intertidal species used in the analysis of spatial scales of variation as described by β values

Appendix A. Ordination of sampling sites using multidimensional scaling (MDS) based on distances between sites by sea and measurement of coastline fractal dimension.

Ordination of sampling sites using multidimensional scaling (MDS) based on distances between sites by sea and measurement of coastline fractal dimension

Robomussel data

Robomussel data: intertidal biomimic body temperature of mussels deployed at 6 different countries. 1913 .txt files in total. Files are categorized by location (country, region, site). In addition, metadata file show specific information for loggers at each site

iButton/Tidbit data

ibutton/Tidbit data: intertidal thermal sensors (aerial and water temperature) deployed at 5 different countries. 160 .txt files in total. Files are categorized by location (country, region, site). In addition, metadata file show specific information for loggers at each site