Universidad Católica del Norte - Punta Lagunillas

Restoration Project

Universidad Católica del Norte - Punta Lagunillas

Restoration Objective:

This study aimed to repopulate areas of the intertidal with Lessonia in order to increase production for commercial harvests and to improve restoration techniques.

Site Selection Criteria:

Punta Lagunillas is an exposed site with the rocky intertidal dominated by L. nigrescens.

Cause Of Decline:

Chilean brown seaweeds (particularly species of Lessonia and Macrocystis) are regularly harvested and exported. In addition to harvesting pressure, production of subtidal and intertidal populations of Lessonia were adversely affected by the El Niño of 1982-83.

Key Reasons For Decline:

Harvest

Scientific Paper

Repopulation of intertidal areas with Lessonia nigrescens in northern Chile

J.A. Vásquez, F. Tala
Journal of Applied Phycology, Vol. 7.
https://doi.org/10.1007/BF00003791

Organisation:

Universidad Católica del Norte

United States of America

Site Observations:

Observation Date

1st Jun 1993 – 1st Sep 1993

Action Summary:

In February, Lessonia nigrescens plants were transplanted to Punta Lagunillas and La Herradura Bay. Juveniles (20-60 cm length, n = 20) were attached to natural substrate using non-toxic epoxy cement. Adult reproductive plants were tied to boulders with rubber bands and anchored to the bottom with cement nails. Individual plants were tagged, and holdfast diameters, number of stipes and maximal length of the plants were measured monthly.

Lessons Learned:

All juveniles and 50% of adult plants died during the first two weeks in the field. Surviving plants did not produce recruits.

Project Outcomes:

Juvenile plants transferred to natural substrata did not survive beyond 15 days. There was a 50% mortality of transplanted adult plants during the first two weeks in the field. The surviving plants reattached to the substrate by their holdfasts and produced additional fronds. Three months after transplantation, 38% of the remaining plants were reproductive, although no recruits were found in adjoining areas during the following month.

Key Reasons For Decline:

Harvest

Area of Restoration (Ha)

0

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Percent Survival

38.0000
%
0.0000
%

Observation Date

1st Dec 1992 – 1st Dec 1994

Action Summary:

At Punta Lagunillas, 17 bundles of 5 desiccated Lessonia nigrescens reproductive fronds were fixed to hard substrata (1m2 , n = 3) with concrete nails and plastic cable ties. These fronds were left in the field for one week for spore release. Three similar areas were established as control plots, and in both control and experimental plots sea urchins were nominally absent.

Lessons Learned:

Some plants survived, but there were no recruits observed.

Project Outcomes:

Following frond seeding, four sporophytes were observed in the experimental plots after the second month. There was an apparent early decline in all measurements, followed by increased growth which peaked in the late fall-early winter. Within 6 months, 30% of the plants had sori and this increased to 60% in the subsequent 6-month period. Plants in the natural population showed a similar pattern of growth and reproduction. No recruits were observed in the control plots throughout the 12-months of observations.

Key Reasons For Decline:

Harvest

Area of Restoration (Ha)

0

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Adult Kelp Count

22.05410.0000

Observation Date

1st Mar 1993 – 1st Mar 1994

Action Summary:

100 reproductive Lessonia nigrescens fronds were dried and transported to Punta Lagunillas and rehydrated in 40 L seawater for 2 h. The resulting spore suspension (8 x 106 spores) was introduced into the water at low tide over three 10 m2 sites lacking L. nigrescens and sea urchins. Three control sites of comparable area without spore seeding were established 15m from the experimental area.

Lessons Learned:

Five plants were recruited.

Project Outcomes:

Five plants were recruited during the one-year observation period, although none were observed in the control plots.

Key Reasons For Decline:

Harvest

Area of Restoration (Ha)

0

Indicator Data:

Indicator:

Ending Value:

Starting Value:

Adult Kelp Count

5.00000.0000
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