Disturbance and subsequent recovery of mid-shore assemblages on seasonal, tropical, rocky shores

Abstract

Hong Kong experiences a strongly seasonal climate, with distinct hot, wet summers and cool, dry winters, which has a great influence on intertidal assemblages. The impacts and relative importance of disturbance events on assemblage structure and subsequent recovery in this environment were examined on semi-exposed rocky shores. In August 1997, Typhoon Victor affected Hong Kong coastal waters bringing high seas and strong winds. Effects on mid-shore assemblage structure were patchy, with an increase in free space and a decrease in the abundance of the dominant molluscan grazer Monodonta labio occurring on one 10 m site on a shore, but not at other areas 10s of m away. The long-term impacts of this pulse disturbance were, however, negligible, as at this time of year there is little algal cover and grazer abundances are low, due to predictable annual disturbance caused by an increase in temperature with the onset of summer. Monitoring of plots artificially disturbed at different times of the year showed that recovery to undisturbed conditions was rapid following pulse disturbance events such as typhoons. Such disturbances had no lasting (> 6 mo) effect, as the die-off of species in the summer caused assemblages on shores to dissipate, and any long-term impacts of these disturbances were not obvious after one summer. It appears that the short-term effects of pulse disturbances on Hong Kong shores are rapidly eclipsed by annual, summer die-off events.

Effects of Hurricane Katrina on Freshwater Fish Assemblages in a Small Coastal Tributary of Lake Pontchartrain, Louisiana

“…More common and generalist species in both areas, however, exhibited rapid recovery and some species even increased in abundance. While initial mortality is high from storm surges, due to turbulence and low dissolved oxygen, estuarine fishes are mostly resilient to saltwater storm surges and recover to preimpact conditions within 4-6 weeks (Hutchinson and Williams 2003;Paperno et al 2006;Stevens et al 2006). Freshwater fishes in the downstream reaches (e.g., centrarchids) also exhibited an ability to withstand storm surge impacts.…”

Ecological indicators performance during a re-colonisation field experiment and its compliance with ecosystem theories

“…Connell and Slatyer, 1977;Sousa, 1979;Paine and Levin, 1981;Van Tamelen, 1996;Chapman and Underwood, 1998) and there is a rich literature describing such successional changes in detail in a wide variety of coastal marine ecosystems (e.g. rocky shores: Kim and DeWreede, 1996;Benedetti-Cecchi and Cinelli, 1996;Dye, 1998;Williams et al, 2000;Hutchinson and Williams, 2003;coral reefs: Connell et al, 1997;Diaz-Pulido and McCook, 2002; soft sediments: Levin and DiBacco, 1995;Rosenberg et al, 2002;estuaries: Nogueira et al, 2000;salt-marshes: Valiela, 1995;Levin et al, 1996;Craft and Sacco, 2003) from all over the world. These studies have demonstrated that succession is likely the composite result of several processes (depletion, tolerance, facilitation, inhibition, removal, allelopathy, etc.) that determine if replacement takes place (Connell and Slatyer, 1977) and at what rates it is accomplished (Valiela, 1995).…”

A Framework to Advance the Understanding of the Ecological Effects of Extreme Climate Events

“…To go one step further, the long-term effects of extreme events could be studied. Since rocky shores are highly dynamic systems, recoveries are expected to occur relatively fast, within months or few years [71,72]. Therefore, the temporal scale to monitor in rocky shores should be adapted to this temporal scale, and several samplings should be done within the year to embrace seasonal variation of this ecosystem.…”