3.1 The Léon Region
3.2 Seaweed resources
3.3 Means of production
Figure 1. The Léon, a province of Brittany
The Léon is a small province of Brittany which includes the arrondissements of Brest and Morlaix. Geographically, the area corresponds to the northwest point of the Breton peninsula. It is a rather low plateau, deeply carved by tides which have created the deep estuaries so characteristic of this region. The plateau is a shale-covered platform, 1 to 5 km wide, which extends under the sea to the isobath-40. Strong currents and gale force winds are typical of the sea off these coasts.
The Léon is densely populated (100 inhabitants per km2). The inhabitants are peasants, fishermen, and seamen in the navy and merchant marine. The same socio-professional division is found in the littoral communes situated where the Arvor, a narrow land stretching along the coast, meets the Menez, an inland region.
The conditions present along the Breton coast are favourable to the development of all varieties of seaweed. The rocky bottom essential to seaweed growth is found on the ocean floor and also in intertidal areas. Because the various seaweed species have different ecological needs, their populations grow in successive layers or bands:
1) The Pelvetia caniculata and Fucus spiralis band is at high-sea, spring-tide level and is wave-beaten.
2) The Ascophyllum band. Ascophyllum nodosum is found in sheltered areas at mid-high, spring-tide level.
3) The Fucus vesiculosis band. Fucus vesiculosis lives at the same level as Ascophyllum nodosum but in a more open, wave-beaten location.
4) The Fucus serratus band. This seaweed is found below the preceding seaweeds, reaching as far as the low neap-tide level. It tends to prefer calmer areas.
5) The Himanthalia elongata band is found in both rough and sheltered areas, beginning at the low neap-tide level. Chondrus crispus and Gigartina stellata, two valuable red seaweeds, occur together here.
6) The Laminaria band. Laminaria digitata occurs beginning at the low-tide level, coefficient 90. It prefers calm zones and is replaced by Laminaria hyperborea in more open areas. Laminaria ochroleuca can be found below these two seaweeds, to a depth of 10 metres above the sea floor. The following diagrams by J. Y. Floch (1964) illustrate this zonation (Figure 2).
Figure 2. Zonation of seaweed populations. J.Y. Floch (1964)
A quantitative inventory of littoral flora can be obtained through research of the kind done in 1967 in the Molène Archipelago by J. Y. Floch, U.B.O., and now being conducted on the coasts of Brittany by Perez, et al., of the Scientific and Technical Institute of Maritime Fisheries.
3.3.1 Harvesting methods
3.3.2 Labour force
3.3.4 Fleet transformation
Large quantities of seaweed torn from the bottom by winter winds are left on shore by the tides. A considerable amount of beached driftweed, or cast, is also seen in the spring when Laminaria hyperborea fronds are shed and regenerated. Professional harvesters and also farmers seeking inexpensive fertilizer are mobilized for the collection of this seaweed. The professionals prefer drying these seaweeds to be burned later to make "soda".
184.108.40.206 Shore seaweed
a) Black seaweed. Throughout history, black seaweed has been the most sought after seaweed variety. Since the 19th century, it has been reserved for agricultural use. During open harvest season, virtually every member of the community is involved, some using sickles to cut the seaweed and others carrying it to the cart tracks to be taken away. The very poor transport their harvest in baskets.
b) Lichen. Harvesting lichen is a recent activity in Brittany, begun in the 1890s on the initiative of German industrialists. It began in the Côtes-du-Nord, eventually spread to the Finistère region, and reached from Picardie to Oléron by 1920. The only materials required for this totally manual harvest are sacks and baskets in which to collect the clumps of lichen torn from the rocks. Later the harvest is spread on the dunes to dry and bleach.
220.127.116.11 Bottom seaweed
Boats are usually used to harvest bottomweed. The tool used, called a guillotine, is a sickle-like blade mounted on a handle 3 to 4 metres long. The sloop-type boats used are about 6 metres long. Their rigging consists of a staysail and a topsail, lowered during the harvest to make less work. Dry-cutting is possible at times of very low tide. The crew leaves the boat moored at some distance from the coast and then proceeds to cut the seaweed with sickles. When the tide turns, the harvest is loaded into the tender and transferred to the boat.
18.104.22.168 Yield estimates
a) Driftweed. It is difficult to estimate driftweed yield because the abundance of the cast, or drift, varies. During an average morning's work, however, one team can remove 8 to 10 cartloads, or approximately 5 to 6 tons of wet seaweed.
b) Rockweeds. During the first days of the season, a family of five or six can usually collect 12 to 15 cartloads of black seaweed per day. This is the equivalent of 7 to 9 tons of fresh seaweed.
For lichen, the estimate is only approximately 100 to 150 kg per person per day, because these seaweeds are small and must be gathered by hand.
c) Bottom or Oarweeds. Yield obviously varies from one region to another, but on the mainland, a single harvester with a boat is able to produce at least three cardloads of Laminaria per day, or about 2 tons. Yield is greater in the islands. By the end of the season, an industrious professional will have produced 100 tons of fresh seaweed on the continent or 250 tons of fresh seaweed from the islands.
It is usually a simple matter to quantify the manpower and fleet involved in a fishery. In the case of the seaweed industry, this task is complicated by the occasional addition to the professional labour force of farmers, fishermen and also women, children and retired persons. Resource abundance determines the numbers involved. A rough estimate places the number of professional seaweed harvesters in the Léon during the year between World Wars I and II at about 2,500. Since 1950, their number has been recorded and can be found in the Appendix.
Production statistics are often inaccurate. Product classification, category grouping and units of measure (ton or m3) are not standardized. Dry and fresh weights are cited indiscriminately and allowance is rarely made for seaweed processing.
Yield statistics, if available, might not be truly representative as it is unlikely that the tonnage of shore seaweed taken directly for use as fertilizer would be included. The annual Fucus harvest in the Léon before World War II is estimated at 30 to 40,000 tons of fresh seaweed. The annual production of 60 to 70 tons of iodine required about 200,000 tons of fresh Laminaria. Post-war production is better known (Appendix) and most originates in the Léon region, whose contribution has risen from 50 percent of the total in 1920 to 90 percent today.
Post-war modernization of the seaweed industry began with the motorization of the fleet. The next step, in 1960, was the adoption of a new hand tool. The "scoubidou", which pulls seaweed out rather than cutting it, increased yield considerably.
In their effort to eliminate manual labour, seaweed fishermen first tried in 1960 to vacuum from the bottom seaweed which had first been cut by a diver using a sickle. When this failed a new method was sought. A second experiment, begun in 1967, used a steel hull fitted with a hydraulic crane. The crane had a strong metal arm ending in a hook which rotated under water to pull out seaweed. As the crane moved in the opposite direction above the ship's hold, the seaweed dropped and was stacked. Seventy-five of these units have been built since 1971. The present fleet is limited to this number for commercial reasons (see 7.2.3 Bottomweed).