Cool barnacles: Do common biogenic structures enhance or retard rates of deterioration of intertidal rocks and concrete?

Abstract

Sedentary and mobile organisms grow profusely on hard substrates within the coastal zone and contribute to the deterioration of coastal engineering structures and the geomorphic evolution of rocky shores by both enhancing and retarding weathering and erosion. There is a lack of quantitative evidence for the direction and magnitude of these effects. This study assesses the influence of globally-abundant

Identifying mechanisms of shore platform erosion using Structure‐from‐Motion (SfM) photogrammetry

“…Significant insight has, however, been made at the micro‐scale where the following key mechanisms of erosion have been identified: (1) grain‐by‐grain abrasion (Kirk, ; Blanco‐Chao et al, ); (2) fragmentation of rock facilitated by wetting and drying (Robinson, ; Stephenson and Kirk, ), warming and cooling (Coombes, ; Mayaud et al, ), salt crystallization in rock lattices (Mottershead, ; Stephenson and Kirk, ) and biological activity (Andrews and Williams, ; Naylor et al, ), followed by removal of fragments via hydraulic drag‐and‐lift force, grain wedging (Kirk, ; Stephenson and Kirk, ; Blanco‐Chao et al, ) and impacts (Cullen and Bourke, ). The rate of platform down‐wearing has been shown to be controlled by: (1) rock type (Kirk, ; Stephenson and Kirk, ; Taylor, ; Dasgupta, ; Moura et al, ); (2) elevation with respect to tidal duration distribution (frequency of submergence/emergence transitions) which is observed to link erosion rate to direct wave action (Robinson, ; Foote et al, ), wetting and drying (Kirk, ; Robinson, ; Stephenson and Kirk, ) and biological activity (Torunski, ); (3) slope (Robinson, ); (4) rock structure (Swantesson et al, ); (5) the presence or absence of beach deposits (Robinson, ); (6) biological cover (Coombes et al, ). Erosion rates change through time, with higher rates observed either in summer when higher temperatures increase efficiency of thermal expansion of salt crystals, and wetting and drying (Robinson, ; Mottershead, ; Stephenson and Kirk, , ), or in winter as a result of increased storminess and wave energy delivery to the foreshore (Robinson, ; Foote et al, ; Moses and Robinson, ).…”

“…(1) rock type (Kirk, 1977;Stephenson and Kirk, 1998;Taylor, 2003;Dasgupta, 2010;Moura et al, 2011); (2) elevation with respect to tidal duration distribution (frequency of submergence/emergence transitions) which is observed to link erosion rate to direct wave action (Robinson, 1977;Foote et al, 2006), wetting and drying (Kirk, 1977;Robinson, 1977;Stephenson and Kirk, 1998) and biological activity (Torunski, 1979); (3) slope (Robinson, 1977); (4) rock structure (Swantesson et al, 2006); (5) the presence or absence of beach deposits (Robinson, 1977); (6) biological cover (Coombes et al, 2017). Erosion rates change through time, with higher rates observed either in summer when higher temperatures increase efficiency of thermal expansion of salt crystals, and wetting and drying (Robinson, 1977;Mottershead, 1989;Stephenson andKirk, 1998, 2001), or in winter as a result of increased storminess and wave energy delivery to the foreshore (Robinson, 1977;Foote et al, 2006;Moses and Robinson, 2011).…”

Testing A Methodology to Assess Fluctuations of Coastal Rocks Surface Temperature

“…Different hypotheses may be proposed to explain the thermal anomaly of line 5. Some papers suggest that barnacles [13] as well as seaweed canopies [26] reduce surface temperatures of rock and minimize their short-term fluctuations. This is contrary to experimental evidence of this work.…”

“…Geomorphological research in the field of thermoclastism widely relies on laboratory experiments [11]. Underrepresented are those experimental designs planned directly in the field, with few notable exceptions [12][13][14]. The instruments that are commonly employed are temperature sensors, frequently coupled with data loggers for recording temperature over time at defined intervals; sensors can be built in or external to the data logger.…”

Intertidal boulder-based wave hindcasting can underestimate wave size: Evidence from Yorkshire, UK

“…Intertidal ecological communities are an important additional contributor to platform surface roughness (Naylor and Viles, 2000) and they also act as bioprotectors reducing the intensity of other earth surface processes such as mechanical rock decay (Coombes et al, 2017). At…”