HARVESTING OF SEAWEED RESOURCES IN PARTICULAR KELP FORESTS:

MCM seaweed harvesting workshop 2004

D. V. Robertson-Andersson

HARVESTING OF SEAWEED RESOURCES IN PARTICULAR KELP FORESTS:

MANAGEMENT

PROBLEMS

CONCLUSION

13 companies currently have seaweed concessions

A seaweed concession is a right to harvest a functional group (genus)

There are 23 Seaweed Concession Areas (SCA)

Applications for current concessions were awarded in 2002 and are valid for 4 years after which 10-year concessions will be awarded

HARVESTING

Laminaria predominates along the northern reaches of the West Coast.

Ecklonia beds found further south.

Harvesting

3 methods:

Diving

Hand harvesting including picking

Beach cast

Ecklonia is harvested by divers who cut plants greater than 50 cm high at the holdfast/stipe junction.

Plants then float to the surface where they are collected.

Holdfast rot off after 4 – 6 months

Done mainly at SCA 9 for Kelpak ®

Diver Harvesting

Ecklonia is harvested from boats where either:

just the fronds are removed 30 – 40 cm from the bladder or

the top of the bladder is cut off

If the bladder is cut then the plant will die

Boat Harvesting

Ecklonia and Gracilaria that has washed ashore is collected by harvesters and dried

For Ecklonia often fronds are removed and stipes are harvested once dried

Beach cast Harvesting

Gelidium is collected at low tide by mainly female harvesters and dried

It is then collected by the concessionaire

Picking

Regulations For each SCA a total biomass is determined

8 – 15 % of which are exclusion areas (rights holder can’t use)

10 % of what’s left can be harvested

If the harvest is fronds only then 5 % may be harvested

In SCA 6, which is a frond only harvest 10 % of frond biomass may be harvested

After 2004 SCA 7 maybe a frond only harvest

On west coast this method of harvesting wont work as granite cliffs with steep drop off

Potential Problems18 Abalone farms at present

With another 3 – 5 on the cards

2 Cultivate their own seaweeds in ponds (Ulva, Gracilaria)

5 Are experimenting with tank cultivation

Abalone require 10 % of body weight in fronds, which are supplied to farms by seaweed concessionaires close by

Farms also feed their abalone kelp chips (plain kelp or kelp & Gracilaria mix) or ABFEED ®

Potential Problems

Kelp: Abalone Feed

0.2 1 1.6 2.1 5.2 8.1 68 300

2784

5346

7000

0

1000

2000

3000

4000

5000

6000

7000

8000

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2003

Tons

wet

wt.

Seaweed Research Unit

Potential Problems

Largest farm 120 T expanding to 240 T

Smallest farm 35 T

Average 70 T

18 farms with 70 T of abalone

Feeding 10 % body mass

kelp demand has the potential to increase or exceed 35 280 T per year just for abalone feed

Farms are concentrated in certain areas

Managerial Problems

No central data base of aerial surveys, biomass estimates or growth rates

Evidence of kelp poaching in SCA 6 & 7

Accurate records of kelp frond harvest going to abalone farms not easily accessible

Long term management of SCA not possible with present permit system

Access for minority users not possible

Ecological constraints

SCA 6 & 7 High grazer densities compared to SCA 9

More juvenile sporophytes on holdfasts than on rocks when compa70

red to Soetwater

Levitt et al. 2000

To combat the problem of juvenile sporophytes being lost when the holdfasts rotted off,

harvest fronds only

Would obtain enough frond biomass from 40 ha by harvesting 30cm from the primary blade every 4 months instead of harvesting ⅓ of the kelp bed

Levitt et al. 2000

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

Control harvest

g e

pip

hyt

es/k

g o

f ke

lp

P = 0.002

Christie et al (1987) found that epiphytes required 9 years to return to pre-harvest densities, What about South Africa?

R. Anderson (pers. comm.)

Ecological constraints

Conclusion: Reserve areas essential

At what scale for management

Essentially 3 problem areas

Beach cast

Kelp

Other seaweed resources

Bed size + 12 km

Californian kelp beds and

managementMBNMS, 1999

Regulations

Kelp beds leased from Californian state government

Leased by individual or company with valid permit

Open beds harvested by anyone with a permit

Closed/reserve beds exist

Tenant can lease a bed on short to long term (5 – 25 years)

Donnelllan & Foster, 1999

Edwards & Foster

Managing RSA kelp beds

• There are gaps in our knowledge of the location and biomass of Laminaria and Ecklonia kelp beds along the west coast of South Africa.

• A Geographical Information System (GIS) digital archive of kelp information for sustainable management is being developed by the seaweed unit.

• Which will provide a predictive/modeling system for biomass estimation of kelp.

(Rob Tarr 1993)

CONCLUSIONS

Present management of harvesting strategies of all species is good

Splitting up of the seaweed resources should not occur to the detriment of present harvesters.

Seaweed and in particular kelp needs to be treated as a separate fisheries, which its own management structure, as at present it is considered low priority given its size in relation to fisheries. However given the secondary conversion from fodder to abalone feed and the increase in demand it has the possibility of becoming a larger fishery.

CONCLUSIONS

Most companies have restricted access to the resource in their concession areas. Access is restricted by a number of factors:

• Poor infrastructure • Privately owned land (farmland) bordering the

coastline• Permits for beach going vehicles• Public opposition• Restricted access due to marine reserves and

restricted access through nature reserves in many concession areas

• Bad weather creating rough seas• Crime

ESSSI, 2001

Industry Perceptions

Little has been achieved by concessionaires towards stabilizing the kelp, Gracilaria and Gelidium industry via the development of value added end products.

R&D is lacking. South Africa still competes as a raw material supplier

with all the other main seaweed producing countries, limiting volume stability and price.

Consequences: Gracilaria, Gelidium and alginate markets are unstabile due to cheaper

international suppliers.

ESSSI, 2001

Industry Perceptions

Seaweed harvesting for the alginate industry requires large volumes This particular market is extremely volatile.

Present problems with applications and access once SCA has been awarded

Any product arising out of new technology requires extensive research to enable product registration and sale.

Markets need to be developed for new products and product niching is difficult.

ESSSI, 2001

Industry Expansion Points raised by concessionaires and abalone farmers regarding ways

in which the industry could be successfully expanded

Awarding long-term rights allocations with preference shown to companies that

• Develop technologies which value add end products

• High percentage resource allocation utilization

• Sustainable resource exploitation.

Developing domestic and international markets

Creating a central selling agent for concessionairesESSSI, 2001

AFASA 2004

Industry Expansion Managing the fresh kelp and beach cast resource

separately from other seaweed resourcesi.e. 3 new categories

beachcastintertidalsubtidal

Change the size of the SCA, which were originally chosen

as the minimum size needed to make beach cast harvesting economically viable to + 1000 tones which will also allow smaller entrants into the resource

Investigate paper quotas

Involve abalone farmers in the decision making process

Allow open areas to promote product development and R&D

AFASA 2004

THE END

Thank you

References

Abalone Farmers Association of Southern Africa. Kelp supply Review meeting. 2004Christie, H.; Fredriksen, S.; Rinde, E. 1988. Regrowth of kelp and colonization of epiphyte and fauna

community after kelp trawling at the coast of Norway. Hydrobiologia. Vol. 375/376. Pg 49 – 58. Critchley, A. T. & Rotmann, K. W. G. 1992. Industrial processing of seaweeds in Africa: The South

African experience. Proceedings of the first international workshop on sustainable seaweed resource development in sub-Saharan Africa, Windhoek, Namibia. K. E. Mshigeni (ed.) Pg. 85 – 95.

Donnellan, M. D. & Foster, M. S. 1999. The effects of small scale harvesting on the giant kelp surface canopy dynamics in the Ed Ricketts underwater park region. Final report to the MBNMS and the cities of Monterey and Pacific Grove. http://bonita.mbnms.nos.noaa.gov/research/techreports/kelp…/kelpcover.htm

Edwards, M.; Foster, M. Kelp forest and rocky subtidal habitats. http://bonita.mbnms.nos.noaa.gov/sitechar/kelp1.html4.

Economic Sectoral Study of the Seaweed Industry, 2001Levitt, G. J.; Anderson, R. J.; Simons, R. H. & Jarman, N. G. 1992. Past, present and future

utilization of South African Laminariales. Proceedings of the first international workshop on sustainable seaweed resource development in sub-Saharan Africa, Windhoek, Namibia. K. E. Mshigeni (ed.) Pg. 171 – 179.

Levitt, G. J.; Anderson, R. J.; Boothroyd, C. J. T. & Kemp, F. A. 2000. The effects of kelp harvesting on kelp regrowth and the understorey benthic community at Danger Point (Gansbaai) South Africa, and a method of harvesting kelp fronds. South African Journal of Marine Science.

Monterey Bay National Marine Sanctuary Draft Kelp Management Report, Media Advisory, executive summary. http://www.mbnms.nos.noaa.gov/into/press_releases/0602kpexec.html

Van Wagenen, R. F. 1999. California coastal kelp resources. MBNMS. http://bonita.mbnms.nos.noaa.gov/research/techreports/cak…cakelpintro.htm