DOI: 10.5061/dryad.vdncjsz3b
title: Mussels, algae and climate change

description: The effects of climate change on coastal biodiversity are a major concern
 because altered community compositions may change associated rates of
 ecosystem functioning and services. While responses of single species or
 taxa have been studied extensively, it remains challenging to estimate
 responses to climate change across different levels of biological
 organisation. Studies that consider the effects of moderate realistic
 near-future levels of ocean warming and acidification are needed to
 identify scope for adaptation and evolution. Also, studies including
 different levels of biological complexity may reveal opportunities for
 amelioration or facilitation under changing environmental conditions. To
 test experimentally for independent and combined effects of predicted
 near-future warming and acidification on key benthic species, we
 manipulated three levels of temperature (ambient, +0.8 °C, +2 °C) and two
 levels of pCO2 (ambient at 450 ppm, elevated at 645 ppm) and quantified
 their effects on mussels and algae growing separately or together (to also
 test for inter-specific interactions). Warming increased mussel clearance
 and mortality rates simultaneously, which meant that total biomass peaked
 at + 0.8 °C. Surprisingly, however, no effects of elevated pCO2 were
 identified on mussels or algae. Moreover, when kept together, mussels and
 algae had mutually positive effects on each other’s performance (i.e.
 mussel survival and condition index, mussel and algal biomass, and proxies
 for algal productivity including relative maximum electron transport rate
 [rETRmax], saturating light intensity [Ik], and maximum quantum yield
 [Fv/Fm]), independent of warming and acidification. Our results show that
 even moderate warming affected the functioning of key benthic species, and
 we identified a level of resistance to predicted ocean acidification.
 Importantly, we show that the presence of a second functional group
 enhanced the functioning of both groups (mussels and algae), independent
 of changing environmental conditions, which highlights the ecological and
 potential economic benefits of conserving biodiversity in marine
 ecosystems.
description: Data collected during an experimental laboratory study presented
 in Schertenleib et al. (2024). Key benthic species are affected by
 predicted warming in winter but show resistance to ocean acidification.
 <em>Ecology and Evolution</em>, <em>14</em>(9),
 1–19. https://doi.org/10.1002/ece3.70308, and processed in R (https://github.com/katmarsci/MesocosmExperiment-Mussels-Algae_2020-10to12_pub/releases/tag/v1.0.0_datalink).
description: # Mussels, algae and climate change
 [https://doi.org/10.5061/dryad.vdncjsz3b](https://doi.org/10.5061/dryad.vdncjsz3b) Corresponding article: Schertenleib, K. S. H., Davey, T., Taylor, D., & O’Connor, N. E. (2024). Key benthic species are affected by predicted warming in winter but show resistance to ocean acidification. *Ecology and Evolution*, *14*(9), 1–19. [https://doi.org/10.1002/ece3.70308](https://doi.org/10.1002/ece3.70308) The dataset contains ecological data collected from mussels (placed on mesh tiles) and algae (grown on seeded strings that were wrapped around header ropes) during a marine mesocosm experiment in which water temperature and pCO2 were manipulated to simulate predicted ocean warming and acidification of climate change scenarios. Experimental factors: * Temperature: ambient (Ta), ambient +0.8 °C (T+), ambient +2 °C (T++) * pCO2: ambient at 450 ppm (Ca), elevated at 645 ppm (C+) * for mussels: mussels on their own (M), mussels in the presence of algae (KM) * for algae: algae on their own (K), algae in the presence of mussels (KM) This dataset includes a total of 12 .csv files. Please use the two "README" .csv files and the information provided below for interpreting the ten data files. Please refer to the corresponding paper for detailed descriptions of the response variables that can be obtained from this dataset. The link to the R code used to process this data is provided further down.     MesocosmExperiment_README_DatasetOverview_Abbreviations.csv     MesocosmExperiment_README_DatasetOverview_Columns.csv     2020-12-17_Mussel-Survival.csv     2020-12-11to12_MesocosmExperiment_CLEARANCE.csv     2020-12-17to18_MesocosmExperiment_MusselsOUT.csv     2020-10-28_MesocosmExperiment_MusselsIN.csv     2021-05-24_MesocosmExperiment_MusselShellBreakingForce.csv     2020-12-21_MesocosmExperiment_MusselByssusBreaking.csv     MesocosmExperiment_MusselLENGTHS.csv     2020-10-30_MesocosmExperiment_KelpIN.csv     2020-12-18_MesocosmExperiment_KelpOUT.csv     2020-12-15_MesocosmExperiment_DivePAMSummary.csv Response variables (and their units of measure) that can be obtained or calculated from these files: * mussel mortality rates [%] - file "2020-12-17_Mussel-Survival" * mussel clearance rates [L/(mussel*h)] - file "2020-12-11to12_MesocosmExperiment_CLEARANCE" * mussel condition index [%] - file "2020-12-17to18_MesocosmExperiment_MusselsOUT" * mussel biomass [mg] - files "2020-10-28_MesocosmExperiment_MusselsIN" and "2020-12-17to18_MesocosmExperiment_MusselsOUT" * mussel shell breaking force [N/mm] - files "2021-05-24_MesocosmExperiment_MusselShellBreakingForce" and "2020-12-17to18_MesocosmExperiment_MusselsOUT" * mussel byssus tensile force [N] - file "2020-12-21_MesocosmExperiment_MusselByssusBreaking" * mussel shell lengths [mm] - file "MesocosmExperiment_MusselLENGTHS" * algal biomass [g] - files "2020-10-30_MesocosmExperiment_KelpIN" and "2020-12-18_MesocosmExperiment_KelpOUT" * algal relative maximum electron transport rate [rETRmax = = micromol electrons/((m^2)*s)], saturating light intensity [Ik = micromol/((m^2)*s)], maximum quantum yield [Fv/Fm; decimal fraction], and light-harvesting efficiency α - file "2020-12-15_MesocosmExperiment_DivePAMSummary" * total accumulated biomass [g] - files "2020-10-28_MesocosmExperiment_MusselsIN", "2020-12-17to18_MesocosmExperiment_MusselsOUT", "2020-10-30_MesocosmExperiment_KelpIN" and "2020-12-18_MesocosmExperiment_KelpOUT" ## Description of the data and file structure File names include the dates on which the respective data was taken and refer to the response variable(s) that was/were investigated during the study. The only exceptions to this naming structure are the file containing proxies of photosynthetic activity, which was named after the measuring instrument ("DivePAMSummary"), and the file referring to mussel lengths, which does not contain a date. File names containing the label "IN" refer to data of the start of the experiment, while those containing "OUT" contain data from the end of the experiment. Observations are listed in rows, variables in columns. The columns contain headers that describe the column content (IDs, treatments, data, notes, legend). Data not relevant to the manuscript corresponding with this Data Dryad submission has been removed from the files. The original columns of removed data are still included to ensure that the R code used to process the data (see link below) still works. When labelled columns contain empty rows this means that no data was taken for the corresponding mesocosms, which can be identified via the first few columns (e.g. racktank). The empty cells were not filled with 'n/a' to not interfere with the R code used to process the data (see link below). Each data .csv file (except mussel survival and mussel lengths) has the same initial columns that reflect the experimental setup and help to filter by treatment or position of a mesocosm: 'position' (referring to all mesocosms numbered 1-96), 'rack' (referring to the rack on which the mesocosms were placed (A-K)), 'tank' (referring to the position of a mesocosm within one rack (1-6 or 1-9)), racktank as a combination of rack and tank, and 'treatment' containing abbreviated labels for the applied treatments (see legend abbreviations above; for example, one treatment was KM_T+_Ca, i.e. kelp and mussels kept together at the medium temperature level and ambient pCO2. The 96 experimental units (mesocosms) were labelled A1-6, B1-9, C1-9, D1-9, E1-9, F1-9, G1-9, H1-9, I1-9, J1-9, K1-9. Each data .csv file contains a legend of used abbreviations and their unit of measure (if applicable) on the far right. All abbreviations of all data files are also listed in the file "MesocosmExperiment_README_DatasetOverview_Abbreviations". Detailed overviews of the variables (columns) included in the ten data files of this dataset are listed in the file "MesocosmExperiment_README_DatasetOverview_Columns". ## Code/Software The R code used to process this data can be found here: [https://github.com/katmarsci/MesocosmExperiment-Mussels-Algae_2020-10to12_pub/releases/tag/v1.0.0_datalink](https://github.com/katmarsci/MesocosmExperiment-Mussels-Algae_2020-10to12_pub/releases/tag/v1.0.0_datalink)