Restoration Project

Universitat de Girona - Menorca

Restoration Objective:

The main objective of this study was to experimentally test non-destructive restoration methods that can lead to the establishment of self-sustaining Cystoseira populations, and to describe the proper success indicators for the different restoration stages. Specifically, it described two techniques using in situ and ex situ recruitment enhancement aimed at restoring populations of C. barbata, and assessed the success and cost feasibility of each.

Site Selection Criteria:

A donor population was selected in an area with low human influence and healthy Cystoseira barbata forests. The area for restoration was selected as a location that historically harboured Cystoseira barbata forests, but these were lost due to low water quality and populations have not returned despite waste treatment.

Cause Of Decline:

In recent decades, the cumulative impacts of human pressures such as habitat destruction, pollution, overgrazing, invasive species and ocean warming, have largely disturbed canopy-forming macroalgae in many areas. Although some giant kelp populations have been shown to recover quickly from local-to large-scale disturbances this is not always the case. Despite not reaching the size of kelp or some other fucoids, Cystoseira species produce a dense canopy creating a “forest-like” assemblage, with unique species growing in the understory. Some Cystoseira forests have severely declined in recent decades. The low dispersal abilities of zygotes have been blamed for the lack of population recovery.

Key Reasons For Decline:

Multiple

Scientific Paper

Restoration of a Canopy-Forming Alga Based on Recruitment Enhancement: Methods and Long-Term Success Assessment

J. Verdura, M. Sales, E. Ballesteros, M.E. Cefali, E. Cebrian, , Frontiers in Plant Science, Vol. 9.https://doi.org/10.3389/fpls.2018.01832

Organisation:

Universitat de Girona

Site Observations:

Observation Date

1st Mar 2011 – 1st Aug 2017

Action Summary:

Bag dispersal using fertile branches of Cystoseira barbata from wild populations was used to perform in situ restoration, and lab-cultured zygotes attached to rocks were used to perform ex situ restoration. Feasibility and costs of the two techniques were compared and mid/long term monitoring of the restored and reference populations was conducted over 6 years.

Lessons Learned:

This study could have used survival rates for long term measurements of success.

Project Outcomes:

All four transplanted populations of Cystoseira barbata established self-maintaining populations of roughly 25 m2 (after 6 years) in areas from which they had completely disappeared. After 6 years, the densities and size structure distributions of the restored populations were comparable to those of the natural reference populations. However, the costs of the in situ recruitment technique were considerably lower than those of the ex situ technique.
In recent decades, the cumulative impacts of human pressures such as habitat destruction, pollution, overgrazing, invasive species and ocean warming, have largely disturbed canopy-forming macroalgae in many areas. Although some giant kelp populations have been shown to recover quickly from local-to large-scale disturbances this is not always the case. Despite not reaching the size of kelp or some other fucoids, Cystoseira species produce a dense canopy creating a “forest-like” assemblage, with unique species growing in the understory. Some Cystoseira forests have severely declined in recent decades. The low dispersal abilities of zygotes have been blamed for the lack of population recovery.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

26

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Adult Kelp Density

123.015873
/ m2
111.1111111
/ m2
Costings:
Cost Year:2011
Cost Currency:Euro
Total Cost:2,665
Capital Cost:505
Planning Cost:2,080
In-Kind Cost:80

Observation Date

1st Mar 2011 – 1st Aug 2017

Action Summary:

Bag dispersal using fertile branches of Cystoseira barbata from wild populations was used to perform in situ restoration, and lab-cultured zygotes attached to rocks were used to perform ex situ restoration. Feasibility and costs of the two techniques were compared and mid/long term monitoring of the restored and reference populations was conducted over 6 years.

Lessons Learned:

This study could have used survival rates for long term measurements of success.

Project Outcomes:

All four transplanted populations of Cystoseira barbata established self-maintaining populations of roughly 25 m2 (after 6 years) in areas from which they had completely disappeared. After 6 years, the densities and size structure distributions of the restored populations were comparable to those of the natural reference populations. However, the costs of the in situ recruitment technique were considerably lower than those of the ex situ technique.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

26

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Adult Kelp Density

126.984127
/ m2
111.1111111
/ m2
Costings:
Cost Year:2011
Cost Currency:Euro
Total Cost:1,092
Capital Cost:252
Planning Cost:120
In-Kind Cost:720