Universidad Austral de Chile - Bahia Chasco

Restoration Project

Universidad Austral de Chile - Bahia Chasco

Restoration Objective:

Studies on Macrocystis population dynamics, management, and restoration techniques are not only important for ecological aspects, but also crucial for future legal and administrative actions. This report aimed to test techniques for repopulation of Macrocystis integrifolia via explantation of laboratory-grown juvenile seedlings and spore seeding by sporophylls from nearby kelp stands.

Site Selection Criteria:

This experiment was conducted in Bahia Chasco, an area with one of the most important M. integrifolia populations of northern Chile that supports a number of local fishermen.

Cause Of Decline:

The Chilean kelp fishery produces more than 300,000 t yearly, and it is carried out mainly by local fishermen. The incapacity to reproduce high-energy tolerant culture systems for Lessonia nigrescens and economically feasible installations for Macrocystis pyrifera led to 100 % of kelp biomass being collected only from natural beds in Chile, despite already having developed several aquaculture alternatives for them.

Key Reasons For Decline:

Harvest

Scientific Paper

Holdfast fragmentation of Macrocystis pyrifera (integrifolia morph) and Lessonia berteroana in Atacama (Chile): a novel approach for kelp bed restoration

R. Westermeier, P. Murua, D.J. Patino, L. Munoz, D.G. Muller
Journal of Applied Phycology, Vol. 28.
https://doi.org/10.1007/s10811-016-0827-2

Organisation:

Universidad Austral de Chile

Site Observations:

Observation Date

1st Jun 2011 – 1st Oct 2012

Action Summary:

Mature Macrocystis pyrifera sporophylls were placed at 8 m depth on the sea bottom, supported by cotton gauze sleeves attached to boulders of different origin.

Lessons Learned:

Laboratory-produced spores or small recruits often die off when translocated to the sea, since they cannot tolerate new environmental and biotic conditions. Attachment of mature sporophylls to medium sized boulders has the potential to overcome this problem, as; sufficient space is guaranteed for fixation of freshly released spores; the developing recruits have ample chances to acclimate to their habitat; and this method could be initiated any time.

Project Outcomes:

Explanted sporophytes on substate reached 150–200 cm in length within 5 months (relative growth rate≈1.3–1.7 % day−1), and reproductive maturity in 5–7 months. For spores seeded on boulders, 60% of clean boulders collected on the beach produced up to 7 recruits per boulder. In contrast, 20% of the boulders from the sea bottom, colonized by epibionts, showed up to two recruits. Relative growth rates, however, were similar (≈2.4–2.6 % day−1).
Macrocystis integrifolia, commonly known as giant kelp, is an important natural resource in northern Chile that is intensely harvested for abalone feed and alginate manufacture in the Atacama region. Macrocystis has also been suggested as marine biomass for ethanol production, promoting expectations for kelp fisheries and mariculture along the coast of Chile. Consequently, M. integrifolia in northern Chile is likely to face unfavourable prospects.

Key Reasons For Decline:

Harvest

Scientific Paper:

R. Westermeier, P. Murua, D.J. Patino, L. Munoz, C. Atero, D. Muller
Journal of Applied Phycology, Vol. 26.
https://doi.org/10.1007/s10811-013-0069-5

Area of Restoration (Ha)

0

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Adult Kelp Density

0.4986
/ m2
0.0000
/ m2

Observation Date

1st Jul 2012 – 1st Nov 2012

Action Summary:

Holdfast portions were excised from parental specimens of Macrocystis pyrifera and Lessonia berteroana including parts of stipes and phylloids. Untreated adult thalli and unmanipulated specimens served as controls. Fragments of both species were attached to boulders or rock platforms with elastic bands or cyanoacrylate glue.

Lessons Learned:

In future studies, it is recommended that researchers incorporate fragments from multiple parent individuals and even from different populations in order to enlarge the genetic diversity of a desired restored population, avoid consanguinity problems, and promote a sustainable natural recruitment.

Project Outcomes:

Transplanted fragments quickly formed new haptera, colonised new substrata, and reached reproductive maturity. At 4 months, maximum growth was seen on the rocky platform with fronds reaching over 200 cm and holdfasts over 30 cm in size. Fragments attached to boulders also showed good growth irrespective of fixation methods. In Lessonia, tissue of non-injured zones took over new holdfast growth. There were no differences in total growth on different substrata and thalli grew up to 25–80 cm in 8 months. Holdfast growth was significantly higher in rocky platform plants and lowest boulders and the unmanipulated controls. Both species proceeded to complete regeneration of holdfasts. However, holdfasts of older Macrocystis thalli partly decomposed, resulting in two apparently identical individuals.
Macrocystis integrifolia, commonly known as giant kelp, is an important natural resource in northern Chile that is intensely harvested for abalone feed and alginate manufacture in the Atacama region. Macrocystis has also been suggested as marine biomass for ethanol production, promoting expectations for kelp fisheries and mariculture along the coast of Chile. Consequently, M. integrifolia in northern Chile is likely to face unfavourable prospects.

Key Reasons For Decline:

Harvest

Scientific Paper:

R. Westermeier, P. Murua, D.J. Patino, L. Munoz, C. Atero, D. Muller
Journal of Applied Phycology, Vol. 26.
https://doi.org/10.1007/s10811-013-0069-5

Area of Restoration (Ha)

0

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

79.7436
%
100.0000
%

Observation Date

1st Jun 2011 – 1st Oct 2012

Action Summary:

Laboratory-grown juvenile Macrocystis pyrifera sporophytes were fixed to different substrata (plastic grids, ceramic plates, or boulders) by elastic bands or fast-drying glue (cyanoacrylate).

Lessons Learned:

Laboratory-produced spores or small recruits often die off when translocated to the sea, since they cannot tolerate new environmental and biotic conditions. Attachment of mature sporophylls to medium sized boulders has the potential to overcome this problem, as; sufficient space is guaranteed for fixation of freshly released spores; the developing recruits have ample chances to acclimate to their habitat; and this method could be initiated any time.

Project Outcomes:

Explanted sporophytes on substate reached 150–200 cm in length within 5 months (relative growth rate≈1.3–1.7 % day−1), and reproductive maturity in 5–7 months. For spores seeded on boulders, 60% of clean boulders collected on the beach produced up to 7 recruits per boulder. In contrast, 20% of the boulders from the sea bottom, colonized by epibionts, showed up to two recruits. Relative growth rates, however, were similar (≈2.4–2.6 % day−1).

Key Reasons For Decline:

Harvest

Area of Restoration (Ha)

0

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Length

0.1342
m
1.2691
m
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