DOI: 10.5061/dryad.hqbzkh1q8
title: Data from: Environmental and local habitat variables as predictors of trophic interactions in subtidal rocky reefs along the SE Pacific coast

description: Temperature generally drives latitudinal patterns in the strength of
 trophic interactions, including consumption rates. However, local
 community and other environmental conditions might also affect
 consumption, disrupting latitudinal gradients, which results in complex
 large-scale patterns. This study assessed the relative effect of
 environmental variables and local consumer communities on predation and
 herbivory along more than 22 degrees of latitude (⁓2,500 km) of the
 Chilean coast. Consumption assays with animal prey (porcellanid crabs and
 squidpops) and the kelp Lessonia spp. were used to assess predation (after
 2 h and 24 h) and herbivory (after 24 h) at 12 study sites where important
 environmental variables (seawater characteristics, habitat features and
 consumer community characteristics) were measured. For each prey type, we
 aimed to identify the variables that best explained variation in
 consumption. Predation rates were positively related to temperature, but
 also with dissolved oxygen and higher salinities, all variables that are
 thought to favour higher metabolic rates in consumers. Local habitat
 characteristics (i.e. higher bare rock cover) negatively affected
 predation rates on porcellanid crabs, likely because large predatory fish
 feeding on crabs (which also explain higher crab consumption) are less
 abundant in seaweed-free areas (kelp or understory algae). There was a
 decrease in herbivory with higher understorey algae cover, possibly due to
 the presence of alternative, more palatable seaweeds. The fact that
 offered kelp blades were not consumed at latitudes where phlorotannin
 contents were very high also suggests a relationship between consumption
 and seaweed palatability. Since many of the explanatory variables did not
 show a strict latitudinal trend, large-scale consumption patterns can vary
 with sources of local variation that affect the consumer metabolism,
 foraging efficiency and consumption pressure.
description: The dataset was collected during fieldwork occurred in
 austral-summer 2018-2019. Tethering assays were deployed in 12 sites along
 the Chilean coast, using three different prey items: porcellanid crabs,
 squidpops and seaweed. In each site, data was collected on the day and 24
 h after the deployment of the assay. Environmental and habitat data from
 the site was collected either on the day of the deployment or the day
 after. A multiparameter was used to obtain water quality measurements
 YSI-95. Habitat data was taken from photoquadrants. Species abundances
 were counted via visual transects.
description: # **Environmental and local habitat variables as predictors of trophic
 interactions in subtidal rocky reefs along the SE Pacific coast**
 [https://doi.org/10.5061/dryad.hqbzkh1q8](https://doi.org/10.5061/dryad.hqbzkh1q8) All datasets correspond to data obtained from tethering assays and in situ measurements along 12 sites on the SE Pacific coast and open-access datasets (see code for details). * Metadata_lat2018-2019.csv: Metadata (e.g., Latitude and longitude) corresponding to each study site. - Predation_latitudinal2018-2019.csv: Data from predation tethering assays using porcellanid crabs and squidpops. The Number of baits consumed in each experimental unit (rope) was counted after 1-2 h and 24 h after the assay deployment. Five baits were attached to each rope. * Herbivory_latitudinal2018-2019.csv: Data from herbivory tethering assays using *Lessonia* spp. The proportion of the blades consumed was measured 24 h after the assay deployment. Five blades were attached to each rope. - Environmental_variables.csv: Data obtained at each site during the day of the assay deployment (see methods for details on environmental variables collection). * Percent_cover.csv: Data obtained from photo quadrats taken in the sites on the day of the assay deployment. We calculated the percentage cover for nine substratum types using a grid of 7x7 points in the area limited by the structure using the software CPCe 4.1. - Transect2018-2019.csv: Data from 10 m transects that considered any benthic and benthic-pelagic species counted along 10 and 1 m on each side. * Phlorotannins.csv: Phlorotrannin analyses from *Lessonia* spp. collected from each study site on the day of the assay deployment. - Size_Estimations.csv: The size of potential fish consumers (relative body length in cm) was estimated using video recordings. Videos were from cameras attached to tethering assay ropes. The fish length was estimated using reference objects, such as a reference ruler (positioned in the first section of the video), the line with the food items, and other structures. Perspective was also considered for the estimations (some organisms were closer than others). * extracted_o2_data.csv: Daily average dissolved oxygen (DO) obtained from open-access datasets. DO data were extracted from E.U. Copernicus Marine Service Information (doi =10.48670/moi-00169) for the period 1 November 2021 and 28 February 2025. * extracted_temp_data.csv: Daily average sea surface temperature (SST) obtained from open-access datasets. SST data were extracted from E.U. Copernicus Marine Service Information (doi =10.48670/moi-00015) between 1 December 2018 and 31 March 2019, which matches the period of the study * extracted_sal_data.csv: Daily average salinity obtained from open-access datasets. Salinity data were extracted using the NASA Earth Data Search (doi = SMP20-4U7CS). Data were collected between 1 December 2018 and 31 March 2019, which matches the period of the study. ## Description of the data and file structure Details on the data structure can be found below: * Metadata_lat2018-2019.csv (some columns are only relevant for the general project but not the analyses in this study): * Site = Names of the study sites. * Latitude = Decimal latitude of the study site. * Longitude = Decimal longitude of the study site. * Date = Date of the assay deployment (dd/mm/yyyy). * Campaign = Number of the survey carried out (all this dataset corresponds to campaign 13). * Season = Season of the assay development (all in summer in this case). * Temperature = Temperature (°C) measured by diver computer in the site. * Latitudinal_survey = Refer to the classification within the general project (these data were all part of the latitudinal survey). * Seasonal_survey = Refer to the classification within the general project (only three sites were part of the seasonal survey). - Predation_latitudinal2018-2019.csv: * Site = Names of the study sites. * Date = Date of the assay deployment (dd/mm/yyyy). * Campaign = Number of the survey carried out (all this dataset corresponds to campaign 13). * Season = Season of the assay development (all in summer in this case). * Bait = Refers to the bait type (porcellanid crab species or squidpops). * Rope = Refers to the number of the rope established for the tethering assay. * Camera = Number of the camera attached (no camera if empty). * Assay \_time = Time when the remaining baits were counted. * Initial_individuals = Number of individuals attached in the beginning of the assay deployment. * Remaining individuals = Number of individuals counted after the corresponding time (Assay_time) * Survival_proportion = Proportion of remaining individuals over the initial number. * Herbivory_latitudinal2018-2019.csv (each row corresponds to a blade): * Site = Names of the study sites. * Date = Date of the assay deployment (dd/mm/yyyy). * Campaign = Number of the survey carried out (all this dataset corresponds to campaign 13). * Season = Season of the assay development (all in summer in this case). * Bait = Refers to the bait type (*Lessonia **spicata or Lessonia** berteroana*). * Rope = Refers to the number of the rope established for the tethering assay. * Camera = Number of the camera attached (no camera if empty). * Hours = Time when the remaining blade was measured. * Initial_length = Length of the blade before deployment. * Final_length = Length of the blade after 24 h. * Scraped = 'Yes' if it had signs of scraping herbivory and 'No' where no signs were observed. * Survival_proportion = Proportion of remaining blade over the initial length. - Environmental_variables.csv:            Cells filled with null when values were not meadured. * Site = Names of the study sites. * Latitude = Decimal latitude of the study site. * Date = Date of the assay deployment (dd/mm/yyyy). * Campaign = Number of the survey carried out (all this dataset corresponds to campaign 13). * Temperature = Temperature (°C) on the day of the assay deployment. * D_oxygen = Dissolved oxygen (mg/L) on the day of the assay deployment. * Salinity_ppt = Salinity (ppt) on the day of the assay deployment. * V_Visibility = Visibility (m) measured as the visible distance (Secchi disk) from the surface to the bottom. *The following columns were eliminated from the dataset before analyses* * H_Visibility = Visibility (m) measured as the visible distance (Secchi disk) horizontally underwater * Conductivity_Ms = Conductivity (Siemens per meter) * C_i = Initial current flow * C_f = Final current flow * RPM = Revolutions per minute. * Percent_cover.csv: * Site = Names of the study sites. * Date = Date of the assay deployment (dd/mm/yyyy). * Type = The type of substrate categories (see method for classification) * Image = the image number (replicate) * Coverage = Percentage of cover of each substrate type. - Transect2018-2019.csv: * Site = Names of the study sites. * Date = Date of the assay deployment (dd/mm/yyyy). * Campaign = Number of the survey carried out (all this dataset corresponds to campaign 13). * Method = The method used to count benthic and bentho-pelagic organisms (visual census (VC) was not considered for the analyses carried out in this work, see code below). * Census = Replicate measurement with the same method in the same site. * Side = the side in case of transects (Left, Right or none for VC). * Number = For transects, it refers to transect number (same as census). For CV there are 2 numbers for each census. * Species = Name of the species observed. * Type = General taxonomic group of each species. * Group = Functional group of each species (description in the methods). * Individuals = Number of individuals counted. * Phlorotannins.csv: * Site = Names of the study sites. * Latitude = Decimal latitude of the study site. * Date = Date of the assay deployment (dd/mm/yyyy). * Replicate = Individual seaweed replicate number. * Species from the *Lessonia* spp. complex. * Phlorotannins = Phlorotannin content (mg/g DW). - Size_Estimations.csv: * Site = Names of the study sites. * Date = Date of the assay deployment (dd/mm/yyyy). * Campaign = Number of the survey carried out (all this dataset corresponds to campaign 13). * Camera = Number of the camera attached to the rope. * Bait = Type of prey attached to the rope that the camera recorded. * Video = Number of video where the individual was observed. * Species = Species name of the individual observed. * Time = Minute of the video in which the individual was measured. * Size_cm = Estimated relative length in cm of the individual, perspective was considered. * Individuals_in_same_frame = Number of individuals of the same species present in the same video frame. - extracted_o2_data.csv: * Latitude = Decimal latitude of the study site. * Longitude = Decimal longitude of the study site. * time = Date (yyyy-mm-dd) and time of the measurement. * o2 = Dissolved oxygen (mmol/L). - extracted_temp_data.csv: * Latitude = Decimal latitude of the study site. * Longitude = Decimal longitude of the study site. * time = Date (yyyy-mm-dd) and time of the measurement. * analysed_sst = Sea surface temperature (°C). - extracted_sal_data.csv: * Latitude = Decimal latitude of the study site. * Longitude = Decimal longitude of the study site. * time = Date (yyyy-mm-dd) and time of the measurement. * Salinity = Salinity (ppt). ## Sharing/Access information * Code required for the data analyses (also uploaded to Zenodo): [https://camusrri.github.io/ECOG-07338_Analyses_and_Figures_Musrrietal2025.html](https://camusrri.github.io/ECOG-07338_Analyses_and_Figures_Musrrietal2024.html)