DOI: 10.5061/dryad.9p8cz8wtr
title: Data from: Ecological effects of habitat complexity vary with intertidal elevation: Implications for seawall eco-engineering

description: Coastal urbanisation is replacing natural shoreline habitats with built
 structures, such as seawalls. Built structures often lack complex habitat
 features that provide protective and cool microhabitats for biodiversity.
 We conducted field experiments to assess whether the addition (or
 eco-engineering) of complex habitat panels to seawalls influenced benthic
 community assemblages across the intertidal range, at panel and site
 scales. We expected: (i) effects of habitat complexity to vary with tidal
 elevation, reflecting spatial variation in the identity and magnitude of
 stressors from which habitat complexity provides protection; (ii) positive
 effects of complexity on functional groups of organisms with exposed soft
 tissues that make them prone to desiccation and predation, and especially
 on the high shore where temperature and desiccation is greatest, and (iii)
 increases in the upper vertical limit of key taxa inhabiting
 eco-engineered seawalls to match reference reefs, and exceed control
 seawalls, depending on the type of habitat complexity provided. Effects of
 habitat complexity increased with tidal emersion and varied by functional
 group. In the mid- and high-intertidal, across which temperatures
 increased, complex panels supported over two times the abundance of key
 taxa than flat control panels. In the low-intertidal, brown algae were
 more abundant on flat than complex panels, whereas mobile invertebrates
 with exoskeletons responded positively to complexity in the
 high-intertidal, and mobile soft-bodied invertebrates were only found in
 complex habitats of the mid-intertidal. Cool microhabitats (pools, shaded
 depressions) of complex habitat panels were important in supporting key
 taxa and functional groups at higher intertidal elevations than on flat
 surfaces, and that, often, matched natural rocky shores. Synthesis and
 applications: Our results demonstrate that the addition of habitat
 complexity through eco-engineering can promote key functional groups of
 algae and invertebrates on seawalls, but effects vary across tidal
 elevation gradients and with the type of complexity provided.
 Consequently, to achieve desired outcomes, eco-engineering interventions
 must be applied with knowledge of key limiting factors to target taxa, and
 of spatial variation in these limiting factors across small-scale
 gradients such as intertidal elevation, as well as sites.
description: # Data from: Ecological effects of habitat complexity vary with intertidal
 elevation: Implications for seawall eco-engineering Dataset DOI:
 [10.5061/dryad.9p8cz8wtr](10.5061/dryad.9p8cz8wtr) ## Description of the
 data and file structure Biodiversity surveys of intertidal seawalls with
 eco-engineered habitat panels, control (unmodified seawalls) and reference
 rocky reefs.  ### Files and variables #### File:
 Vozzo\_et\_al.\_Vertical\_Zonation\_Data.xlsx **Description:** File
 containing 3 tabs of different surveys. Surveys at the Site level, Panel
 level, and assessing the maximum vertical extent of taxa.  "." =
 n/a or no data on all spreadsheets.  ##### Variables * Site level *
 Location: location of site. Balls head = BH (RS1); Cremorne Point = CP
 (RS2); Milsons Point = MP (CON1, CON2 and FULL).  * Int = intervention
 type. reference reef = reef; control seawall = con; eco-engineered seawall
 = eco * Sites: Reference Reefs (RS1 and RS2): Natural rocky shores of
 similar aspect to seawalls; Control Seawalls (CON1 and CON2): unmodified
 seawalls of similar aspect to eco-engineered seawall; Eco-engineered
 seawall (FULL): seawall with habitat-enhancing panels affixed to it. (2
 levels reference reef RS1or control seawalls, 1 eco-engineered site).  *
 time: before or after installation of habitat panels  * month = month of
 survey. -1 = before installation of panels and 6, 12, 18, 24, or 36 months
 = after installation of panels.  * Intertidal height (low-, mid- or high-)
 = stratified height within intertial zone in which panels/seawall/rocky
 shore was sampled. * Rep = quadrat rep 1-5 (before) or 1-10 sampled. *
 total % cover and bare % cover included in columns H & I.  * The list
 cover for individual taxa are provided in columns J-FQ.  * Functional
 group cover is provided in columns FS-GQ.  * Richness is provided in
 column FR.  * Panel level: * All surveys were conducted at Eco-engineered
 site 1 at Milsons Point (same eco-engineered site in Site Level
 Biodiversity surveys). * Month = month surveyed after installation. 6, 12,
 18, 24 or 36. * panel_type = flat control panel or complex mangrove panel
 surveyed * panel_no = individual panel ID that was sampled. Control panels
 were sampled repeatedly. * height = intertidal height at which the panels
 were located. low- mid- or high-intertidal. * rep = replicate panel type
 surveyed within each intertidal height.  * total % cover and bare % cover
 included in columns H & I.  * The list cover for individual taxa are
 provided in columns J-FQ.  * Functional group cover is provided in columns
 FS-GQ.  * Richness is provided in column FR.  * Vertical Extent:  * int =
 intervention type. reference reef = reef; control seawall = con;
 eco-engineered seawall = eco * site = rockyshore 1 (rs1); rockyshore 2
 (rs2); eco-engineered (full); control seawall 1 (cs1) or control seawall 2
 (cs2)  * column = 1-3 on control and reference sites or 1-12 on
 eco-engineered site. "columns" were used to delineate areas to
 survey on control and refenrece sites or the individual columns of
 different panels on the eco-engineered site.  * panel = panel type on the
 eco-engineered site.  * rep = replicate column of each type surveyed. n =
 3 for control and reference seawalls and for each type of column on the
 eco-engineered seawall.  * species = one of 9 key taxa surveyed: four
 macro-algae (the fine red interlacing algae *Capreola implexa*, the red
 branching algae *Gracillaria secundata*, the sea lettuce *Ulva australis*,
 coralline algae *Corallina officinalis*), two sessile invertebrates (the
 Sydney rock oyster, *Saccostrea glomerata*, the rose barnacle,
 *Tesseropora rosea)* and three mobile invertebrates (the blue mussel
 *Mytilus* sp., the oyster limpet *Patelloida mimula*, the false limpet,
 *Siphonaria denticulata)*. * lowest_relative0m = lowest position of taxa
 relative to water height 0m * highest_relative0m = highest position of
 taxa relative to water height 0m * range = height range (m) observed for
 each taxa calculated as difference from lowest and heighest position  *
 highest_micro = type of microhabitat in which taxa were observed at their
 highest point.  ## Code/software Data were analysed using R and R Studio. 
 ## Access information Other publicly accessible locations of the data: *
 Additional information can be found in supplemental material of the online
 version of the published manuscript.