Restoration Project

University of Tasmania - Maria Island

Restoration Objective:

This study aimed to explore how the resilience and stability of E. radiata habitats is influenced by habitat degradation Specifically it looked at how patch size and kelp density influence the habitat-forming role of kelps.

Site Selection Criteria:

The experimental site was a semi-exposed, sandy embayment off Maria Island on the east coast of Tasmania, Australia. This area was selected for its uniform depth (6.5m) and isolation from natural rocky reefs (>1.5 km)

Cause Of Decline:

Ecklonia radiata is the most widespread and abundant habitat-forming kelp in Australasia, and supports high levels of biodiversity and endemism. Like many kelp globally, E. radiata is under threat from rising ocean temperatures, overgrazing from invasive and range-expanding species, and urbanisation and pollution. As a result, this species is becoming increasingly sparse and patchy in many locations across its range.

Key Reasons For Decline:

Multiple

Scientific Paper

Resilience and stability of kelp forests: The importance of patch dynamics and environment-engineer feedbacks

C. Layton, V. Shelamoff, M.J. Cameron, M. Tatsumi, J.T. Wright, C.R. Johnson, , PloS one, Vol. 14, p.210220.https://doi.org/10.1371/journal.pone.0210220

Organisation:

University of Tasmania

Site Observations:

Observation Date

15th Jan 2015 – 15th Apr 2015

Action Summary:

An array of reefs patches of various sizes were created, supporting adult Ecklonia radiata kelp transplanted at four different densities. The treatment levels were no kelp, half-natural, natural, and double-natural kelp density. Artificial reefs had a length-width ratio of 4:3 and consisted of a steel frame and concrete Turfstone pavers. The reef frames were elevated 30 cm above the substratum on legs to eliminate sand inundation and allow drift algae to pass underneath. Adult sporophytes were collected at depths of 4–8 m from the closest extensive population of E. radiata and transplanted onto the reefs.

Lessons Learned:

This study indicates ecosystem engineering by adult E. radiata facilitates the development of juvenile conspecifics.

Project Outcomes:

The presence of E. radiata reduced sub-canopy water flow, sedimentation, and irradiance. However, this was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

7.7

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

97.22953216
%
100
%
Costings:
Cost Currency:USD

Observation Date

15th Jan 2015 – 15th Apr 2015

Action Summary:

An array of reefs patches of various sizes were created, supporting adult Ecklonia radiata kelp transplanted at four different densities. The treatment levels were no kelp, half-natural, natural, and double-natural kelp density. Artificial reefs had a length-width ratio of 4:3 and consisted of a steel frame and concrete Turfstone pavers. The reef frames were elevated 30 cm above the substratum on legs to eliminate sand inundation and allow drift algae to pass underneath. Adult sporophytes were collected at depths of 4–8 m from the closest extensive population of E. radiata and transplanted onto the reefs.

Lessons Learned:

This study indicates ecosystem engineering by adult E. radiata facilitates the development of juvenile conspecifics.

Project Outcomes:

The presence of E. radiata reduced sub-canopy water flow, sedimentation, and irradiance. However, this was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

4.3

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

77.70833333
%
100
%
Costings:
Cost Currency:USD

Observation Date

15th Jan 2015 – 15th Apr 2015

Action Summary:

An array of reefs patches of various sizes were created, supporting adult Ecklonia radiata kelp transplanted at four different densities. The treatment levels were no kelp, half-natural, natural, and double-natural kelp density. Artificial reefs had a length-width ratio of 4:3 and consisted of a steel frame and concrete Turfstone pavers. The reef frames were elevated 30 cm above the substratum on legs to eliminate sand inundation and allow drift algae to pass underneath. Adult sporophytes were collected at depths of 4–8 m from the closest extensive population of E. radiata and transplanted onto the reefs.

Lessons Learned:

This study indicates ecosystem engineering by adult E. radiata facilitates the development of juvenile conspecifics.

Project Outcomes:

The presence of E. radiata reduced sub-canopy water flow, sedimentation, and irradiance. However, this was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

2

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

100
%
100
%
Costings:
Cost Currency:USD

Observation Date

15th Jan 2015 – 15th Apr 2015

Action Summary:

An array of reefs patches of various sizes were created, supporting adult Ecklonia radiata kelp transplanted at four different densities. The treatment levels were no kelp, half-natural, natural, and double-natural kelp density. Artificial reefs had a length-width ratio of 4:3 and consisted of a steel frame and concrete Turfstone pavers. The reef frames were elevated 30 cm above the substratum on legs to eliminate sand inundation and allow drift algae to pass underneath. Adult sporophytes were collected at depths of 4–8 m from the closest extensive population of E. radiata and transplanted onto the reefs.

Lessons Learned:

This study indicates ecosystem engineering by adult E. radiata facilitates the development of juvenile conspecifics.

Project Outcomes:

The presence of E. radiata reduced sub-canopy water flow, sedimentation, and irradiance. However, this was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

1.1

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

77.708
%
100
%
Costings:
Cost Currency:USD

Observation Date

15th Jan 2015 – 15th Apr 2015

Action Summary:

An array of reefs patches of various sizes were created, supporting adult Ecklonia radiata kelp transplanted at four different densities. The treatment levels were no kelp, half-natural, natural, and double-natural kelp density. Artificial reefs had a length-width ratio of 4:3 and consisted of a steel frame and concrete Turfstone pavers. The reef frames were elevated 30 cm above the substratum on legs to eliminate sand inundation and allow drift algae to pass underneath. Adult sporophytes were collected at depths of 4–8 m from the closest extensive population of E. radiata and transplanted onto the reefs.

Lessons Learned:

This study indicates ecosystem engineering by adult E. radiata facilitates the development of juvenile conspecifics.

Project Outcomes:

The presence of E. radiata reduced sub-canopy water flow, sedimentation, and irradiance. However, this was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

0.5

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

74.90131579
%
100
%
Costings:
Cost Currency:USD

Observation Date

15th Jan 2015 – 15th Apr 2015

Action Summary:

An array of reefs patches of various sizes were created, supporting adult Ecklonia radiata kelp transplanted at four different densities. The treatment levels were no kelp, half-natural, natural, and double-natural kelp density. Artificial reefs had a length-width ratio of 4:3 and consisted of a steel frame and concrete Turfstone pavers. The reef frames were elevated 30 cm above the substratum on legs to eliminate sand inundation and allow drift algae to pass underneath. Adult sporophytes were collected at depths of 4–8 m from the closest extensive population of E. radiata and transplanted onto the reefs.

Lessons Learned:

This study indicates ecosystem engineering by adult E. radiata facilitates the development of juvenile conspecifics.

Project Outcomes:

The presence of E. radiata reduced sub-canopy water flow, sedimentation, and irradiance. However, this was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

0.2

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

1.052631579
%
100
%
Costings:
Cost Currency:USD

Observation Date

15th Jan 2015 – 15th Apr 2015

Action Summary:

An array of reefs patches of various sizes were created, supporting adult Ecklonia radiata kelp transplanted at four different densities. The treatment levels were no kelp, half-natural, natural, and double-natural kelp density. Artificial reefs had a length-width ratio of 4:3 and consisted of a steel frame and concrete Turfstone pavers. The reef frames were elevated 30 cm above the substratum on legs to eliminate sand inundation and allow drift algae to pass underneath. Adult sporophytes were collected at depths of 4–8 m from the closest extensive population of E. radiata and transplanted onto the reefs.

Lessons Learned:

This study indicates ecosystem engineering by adult E. radiata facilitates the development of juvenile conspecifics.

Project Outcomes:

The presence of E. radiata reduced sub-canopy water flow, sedimentation, and irradiance. However, this was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp.

Key Reasons For Decline:

Multiple

Area of Restoration (In Square Metres)

0.1

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

23.95833333
%
100
%
Costings:
Cost Currency:USD