Università Politecnica delle Marche - La Vela Portonovo

Restoration Project

Università Politecnica delle Marche - La Vela Portonovo

Restoration Objective:

Here, for the first time, we tested the effect of transplanting depth as a potential factor that could protect the new juveniles transplanted from the high hydrodynamic impact or, at least, guarantee the highest survival and growth rates.

Site Selection Criteria:

Identification of historic G. barbata presence at the site as well as previous restoration project at the site.

In accordance with Bianchelli et al. (2023), we selected La Vela, Portonovo, as receiving site, even if characterised by a high hydrodynamism, testing the effect of water depth to counteract the hydrodinamism effect.

Cause Of Decline:

In the last decades, the Conero Riviera (Northern Adriatic Sea, Mediterranean Sea) experienced a severe decline (up to 70%) of the macroalgal forests formed by canopy forming species Gongolaria barbata (Munda 1993; Perkol-Finkel and Airoldi 2010). At local level, this regression has been related to high hydrodynamic forces (seasonal storms, currents, waves) and human-induced chemical and physical modification of the habitat, which hampered the natural recovery of algal forests (Perkol-Finkel and Airoldi 2010).

Key Reasons For Decline:

Multiple

Physical Disturbance

Water Pollution

Scientific Paper

The Effect of Transplantation Depth on the Restoration Success of Gongolaria barbata (Fucales) in the Mediterranean Sea

https://onlinelibrary.wiley.com/doi/full/10.1002/aqc.70151

Site Observations:

Observation Date

25th Jul 2023 – 25th Dec 2023

Action Summary:

Kelp receptacles were collected from a nearby donor site and cultivated on clay tiles in mesocosms for five months. The tiles and kelp were then transplanted to the restoration site at different depths and monitored for a further five months.

Lessons Learned:

Select deeper transplanting depths within the species’ depth range to reduce wave exposure and storm-driven detachment, particularly at hydrodynamically exposed sites.

Extended mesocosm cultivation, though more costly, increases transplant survival by producing larger, more resilient individuals capable of tolerating wave exposure, sedimentation, and grazing.

Project Outcomes:

The highest success in terms of survival and growth rates increased with increasing transplanting depth. This study confirmed that, even within a narrow bathymetric range, transplantation at deeper depths of the upper infralittoral zone can reduce the impact of wave energy enhancing the success of restoration interventions.

Nature of Disturbance:

In the present study, during the monitoring of the tiles in the field, as expected, two strong storms occurred: one on the 30 October and one on the 25 November, both with waves of 3 m in height.

Area of Restoration (Ha)

0.00005

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Juvenile Kelp Density

89133.3300
/ m2
224000.0000
/ m2
Transplant Info:
Life Stage:Juveniles
Source:Culture