Restoration Project

University of Barcelona - MIMBT Natural Park

Restoration Objective:

This study tested the success of active revegetation techniques as a tool to promote functional and productive Treptacantha elegans forests in sea urchin barren grounds under different restoration strategies (active, and combined active with passive strategies).

Site Selection Criteria:

Six urchin barrens were selected for restoration, three inside a no-take marine reserve and three outside the reserve. Two forested sites and two urchin barren sites were used as reference sites.

Cause Of Decline:

Canopy forming algae play a key role in temperate coastal ecosystems, where they sustain complex habitats that provide food and refuge for biodiverse communities. These macroalgae are in decline in many coastal areas, where overgrazing by herbivores. and in particular sea urchins, can lead to the loss of these highly structured and diverse habitats towards less complex sea urchin barren grounds.

Key Reasons For Decline:

Overgrazing

Scientific Paper

From marine deserts to algal beds: Treptacantha elegans revegetation to reverse stable degraded ecosystems inside and outside a No-take marine reserve

A. Medrano, B. Hereu, M. Cleminson, Rovira Pagès-Escolà, G. L., J. Solà, C. Linares, , Restoration Ecology.https://doi.org/10.1111/rec.13123

Organisation:

University of Barcelona

Site Observations:

Observation Date

15th Apr 2018 – 15th Apr 2019

Action Summary:

In 6 barren grounds (3 inside no-take marine reserve and 3 outside), researchers eradicated sea urchins, seeded Treptacantha elegans and enhanced recruitment. Restoration success was assessed after 1 year. Two forested and two barren sites were used as reference sites. Apical branches with fertile receptacles were collected from a healthy, fertile T. elegans donor population and placed in PVC mesh bags. Six bags were placed in each site.

Lessons Learned:

Found that reserves had a positive impact.

Project Outcomes:

1 year after revegetation, T. elegans cover increased in locations with complete sea urchin eradication. However, it did not reach the cover observed at the reference forests. We observed a higher T. elegans cover at equal densities of sea urchins in the locations where both active and passive restoration strategies were combined. T. elegans individuals in the no-take marine reserve reached similar heights to the reference forest ones, whereas mean height was about half of the wild canopy where active strategies alone were applied. Limited dispersal ability was observed, which was three times higher inside the NTZ, with a maximum distance of 3 to 10 m away from the seedling bags, and lower outside the NTZ, with a maximum of 1 to 3 m away.

Key Reasons For Decline:

Overgrazing

Area of Restoration (In Square Metres)

200

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Kelp Cover

6.790865385
%
0
%
Costings:
Cost Year:2019
Cost Currency:Euro
Total Cost:1,140

Observation Date

15th Apr 2018 – 15th Apr 2019

Action Summary:

In 6 barren grounds (3 inside no-take marine reserve and 3 outside), researchers eradicated sea urchins, seeded Treptacantha elegans and enhanced recruitment. Restoration success was assessed after 1 year. Two forested and two barren sites were used as reference sites. Apical branches with fertile receptacles were collected from a healthy, fertile T. elegans donor population and placed in PVC mesh bags. Six bags were placed in each site.

Lessons Learned:

Found that reserves had a positive impact.

Project Outcomes:

1 year after revegetation, T. elegans cover increased in locations with complete sea urchin eradication. However, it did not reach the cover observed at the reference forests. We observed a higher T. elegans cover at equal densities of sea urchins in the locations where both active and passive restoration strategies were combined. T. elegans individuals in the no-take marine reserve reached similar heights to the reference forest ones, whereas mean height was about half of the wild canopy where active strategies alone were applied. Limited dispersal ability was observed, which was three times higher inside the NTZ, with a maximum distance of 3 to 10 m away from the seedling bags, and lower outside the NTZ, with a maximum of 1 to 3 m away.

Key Reasons For Decline:

Overgrazing

Area of Restoration (In Square Metres)

200

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Kelp Cover

14.18269231
%
0
%
Costings:
Cost Year:2019
Cost Currency:Euro
Total Cost:1,140