Sorry, you need to enable JavaScript to visit this website.

Long-term trend in substratum occupation by a clonal, carbonate bryozoan in a temperate rocky reef in times of thermal anomalies

TitoloLong-term trend in substratum occupation by a clonal, carbonate bryozoan in a temperate rocky reef in times of thermal anomalies
Tipo di pubblicazioneArticolo su Rivista peer-reviewed
Anno di Pubblicazione2014
AutoriCocito, Silvia, and Sgorbini S.
RivistaMARINE BIOLOGY
Volume161
Paginazione17-27
ISSN00253162
Parole chiaveBryozoa, bryozoan, Ligurian Sea, Mediterranean Sea, Pentapora fascialis, population decline, Population dynamics, reef, substrate, subtidal environment, temperate environment, temperature anomaly
Abstract

Studies over time provide opportunities to detect variations in the spatial and temporal patterns of clonal organisms and measure changes on their population dynamics related to extreme events. We assessed population dynamics for a bryozoan species dominating a subtidal rocky reef at Tino Island, in the eastern Ligurian Sea (NW Mediterranean). Using 9 years of annual photosurveys (1997-2005), rapid decline in Pentapora fascialis colony cover was shown at 11 and 22 m depths following the anomalous warming events in 1999 and 2003. An 86 % reduction in live colony portion was found after the 1999 warming event (2.3 A degrees C higher than normal), with larger colonies being most affected. Effects from the 2003 event were delayed, and gradual cover decline occurred during the following 2 years. At the ``Shallow'' photostations, none of the larger colonies (> 1,000 cm(2)) survived after the first cover decline. Availability of new substrate after the 1999 disturbance resulted in enhanced recovery through new colony production. At the ``Deep'' photostations, the population structure did not change over the duration of the monitoring period showing the same monomodal structure and same dominant size class (50-500 cmA(2)). In the 4 years following the first cover decline, the deeper population regained colony cover to levels similar to pre-disturbance level, showing a good resilience. This 9-year monitoring analysis provided the temporal resolution needed to detect changes occurring in the P. fascialis population and will contribute to the assessment of long-term changes on benthic populations suffering during recent decades from dramatic increases in extreme events.

DOI10.1007/s00227-013-2310-9
Citation Key ISI:000329792700003