University of Bologna - Due Sorelle

Restoration Project

University of Bologna - Due Sorelle

Restoration Objective:

This study aimed to determine the loss and scale of degradation of Cytoseira using historical data. It also used clearing experiments to test whether greater substratum stability would be sufficient to reverse the loss, or whether removal of opportunistic species including turf algae and mussels would also be required. They used transplantation experiments to identify the conditions that could facilitate natural recovery and guide possible restoration efforts of canopy-forming algae.

Site Selection Criteria:

A site was selected with relatively minimal human impacts, and a remnant Cytoseira forest nearby.

Cause Of Decline:

In the north Adriatic sea, as well as in the whole Mediterranean Sea, Cystoseira forests have suffered widespread and persistent loss. Along the Albéres coasts, only 5 out of 14 species of Fucales (Cystoseira and Sargassum spp.) documented as abundant in 1912 were still present in 2003, with the genus Sargassum being entirely lost. Similar trends are occurring along other coasts, and remaining fragments of algal forests are under continued threat. This study posits that recent loss of forests along the urbanized coasts of the north Adriatic Sea were triggered by increasing cumulative impacts of natural- and human-induced habitat instability and severe recruitment failure.

Key Reasons For Decline:

Multiple

Scientific Paper

Loss and Recovery Potential of Marine Habitats: An Experimental Study of Factors Maintaining Resilience in Subtidal Algal Forests at the Adriatic Sea

S. Perkol-Finkel, L. Airoldi
Plos One, Vol. 5.
https://doi.org/10.1371/journal.pone.0010791

Site Observations:

Observation Date

1st Jul 2008 – 1st Feb 2009

Action Summary:

At each site, small sized boulders covered with C. barbata recruits were collected from zones of low survival probability (i.e., small, shallow boulders ~0.161m3), broken into small fragments holding 1–2 individuals, and transplanted in plots of 5 individuals onto more stable bedrocks (boulders .10 m3) using epoxy putty. Recruits were set: 1) horizontally with adults, 2) horizontally without adults, or 3) vertically. Controls comprised of recruits that were manipulated and transplanted back to their original location. Transplantations were carried out during July 2008, when juveniles had reached a manageable size of ca. 5 cm. Four replicated plots of each treatment were prepared at each site.

Lessons Learned:

All transplants were lost due to a storm.

Project Outcomes:

C. barbata transplanted onto more stable habitats had higher survival rates than controls, but the final survival rates varied between study sites and treatments. By October 2008, controls supported the least surviving juveniles at both sites. At Due Sorelle, no juveniles survived the storm of December 2008. Survival in the other treatments differed between the two study sites, without any clear or consistent trend, e.g., at La Vela survival was greatest on vertical substrata, while at Due Sorelle survival was greatest on horizontal substrata. There were no differences in relation to presence or absence of an adult canopy at either site.

Nature of Disturbance:

At Due Sorelle, all plants were destroyed by a storm in December 2008.

Key Reasons For Decline:

Multiple

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

0.0000
%
100.0000
%

Observation Date

1st Jul 2008 – 1st Feb 2009

Action Summary:

At each site, small sized boulders covered with C. barbata recruits were collected from zones of low survival probability (i.e., small, shallow boulders ~0.161m3), broken into small fragments holding 1–2 individuals, and transplanted in plots of 5 individuals onto more stable bedrocks (boulders .10 m3) using epoxy putty. Recruits were set: 1) horizontally with adults, 2) horizontally without adults, or 3) vertically. Controls comprised of recruits that were manipulated and transplanted back to their original location. Transplantations were carried out during July 2008, when juveniles had reached a manageable size of ca. 5 cm. Four replicated plots of each treatment were prepared at each site.

Lessons Learned:

All transplants were lost due to a storm.

Project Outcomes:

C. barbata transplanted onto more stable habitats had higher survival rates than controls, but the final survival rates varied between study sites and treatments. By October 2008, controls supported the least surviving juveniles at both sites. At Due Sorelle, no juveniles survived the storm of December 2008. Survival in the other treatments differed between the two study sites, without any clear or consistent trend, e.g., at La Vela survival was greatest on vertical substrata, while at Due Sorelle survival was greatest on horizontal substrata. There were no differences in relation to presence or absence of an adult canopy at either site.

Nature of Disturbance:

At Due Sorelle, all plants were destroyed by a storm in December 2008.

Key Reasons For Decline:

Multiple

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

58.6207
%
100.0000
%