Effects of human trampling on tidalflat infauna

Abstract

1. Human trampling has been shown to be detrimental to the survival of fauna of terrestrial habitats and on rocky coastal areas. However, its effects on saltmarsh benthic infauna were not known. 2. The abundance of macro‐benthic fauna at five locations on a transect across a footpath on the emergent marsh and on the tidalflat at Lindisfarne NNR were sampled during the summer 1994 and winter 1995. 3. The abundances of dominant taxa increased in summer in the intensely trampled path on the unvegetated tidalflat leading to a change in the community structure. These changes were not apparent when the trampling intensity was lower in winter. 4. The abundances of dominant taxa at a less intensively trampled site in the vegetated emergent marsh did not change in either season. 5. The susceptibility of the saltmarsh infauna to human trampling depends on the intensity of trampling disturbance and on the nature of the habitat. The possible effects of human trampling on the macrofauna in these intertidal habitats are discussed with reference to coastal management. © 1996 by John Wiley & Sons, Ltd.

Lactate accumulation in the intertidal hermit crab, <i>Pagurus samuelis</i>, in response to burial-induced hypoxia

“…While this was not within the scope of the current study, it nevertheless provides another potential area of exploration into hermit crab physiology. Duration strongly influenced survival of a shallow burial event, with death positively correlated with burial duration, consistent with other burial studies (Chandrasekara & Frid, 1997;Schiel et al, 2006).…”

“…Freshwater inflow due to flooding is a common threat to animals living near the sediment-water interface and can include with it a significant amount of sediment (Maurer et al, 1981;McCall, 1978;Niedoroda et al, 1989). Organisms can also become buried by sediment from river deposits (McKnight, 1969), tides (Grant, 1983), bioturbation (Thayer, 1983), terrestrial runoff (Edgar & Barrett, 2000) dredging (Messieh et al, 1991), fishing (Hall et al, 1990;Jackson & James, 1979), wind erosion, or trampling (Chandrasekara & Frid, 1997).…”

Crab-tiling reduces the diversity of estuarine infauna

“…This suggests that trampling was the mechanism that contributed most to the decrease in infaunal abundance rather than the insertion of the tiles. This association could be due to the mortality of individuals from the direct effect of trampling, or indirectly through burial (Chandrasekara & Frid 1996, Rossi et al 2007). Species may also have avoided trampled sediment, decreasing immigration to the area, and/or may have increased the number of organisms leaving the area (emigration) (Negrello Filho et al 2006).…”

“…Species may also have avoided trampled sediment, decreasing immigration to the area, and/or may have increased the number of organisms leaving the area (emigration) (Negrello Filho et al 2006). Increased trampling intensity has been directly related to the damage of flora in terrestrial assemblages (Bayfield 1979, Cole 1995, the extent of disturbance of salt marsh infauna in vegetated and unvegetated areas (Chandrasekara & Frid 1996), the densities and diversities of algae and sessile organisms on rocky shores (Keough & Quinn 1998) and the amount of direct breakages to coral reefs and/or mortality of coral colonies (Hawkins & Roberts 1993).…”

“…Both can cause the soft-bodied fauna which live close to the sediment surface to suffer direct mortality, or indirect mortality through burial (Chandrasekara & Frid 1996). When trampling causes compaction of the sediment, available oxygen is decreased, leading to infaunal mortality through burial, burrow collapse, or asphyxiation (Wynberg & Branch 1994, Chandrasekara & Frid 1996.…”