**6. Preliminary data on seaweed resources of the Russian sector of North Pacific**

The largest and most productive algal communities in the Russian sector of North Pacific (western continental part of Bering Sea and Commander Islands) are formed by seaweeds of the order Laminariales. These algae are main objects of commercial harvest. Unfortunately there are no exact present-day quantitative data on seaweed resources in the studied area. The only information available is just preliminary, fragmentary and rather old, dated to the first dacades of the last century (Kongisser, 1933; Gail, 1936). Naturally we need more updated information concerning this matter but practical estimation works require considareble expeditionary expenses, equipment and efforts of many specialists. At present it is unreal to expect that these works will be carried out. So the only way out is to make calculations using so called expert method. It is a theoretical estimation based on remote sensing data on the bottom area suitable for the growth of seaweeds and their projective cover in communities. In accordance with this expert estimation general stock of seaweeds resources in the Russian sector of North Pacific comes to 10 million tons.

In spite of such rich stock there is a risk of overharvest in case of poor organization of catch. Exceeding press on commercial algae may cause abrupt decrease of their number and futher replacement by competitive species, for example, by crustose coralline algae. This may cause irreversible changes in the structure of plant benthic communities and as a result total loss of commercial species. That is why scientific recommendations on permissible level of harvest are very important.

Peninsula and adjacent water area of Lavrov Bay (Olyutorskii Gulf) (Fig. 1 (3). The protected water area totals to 83000 hectares. The purpose of creation of the "Koryakskii" Reserve was to provide protection of the whole ecosystem complex of the northern Kamchatka including

Nature park "Beringia", founded in 1992, is located in Chukchi Autunomous District and

In addition there are five **Nature Monuments of regional significance** that have protected marine area within their borders: «**Verkhoturov Island**», «**Witgenstein Cape**», «**Witgenstein Rock**», «**Yuzhnaya Glubokaya Bay**» and «**Anastasia Bay**». It is planned to crerate some new marine nature parks and state nature reserves of federal significance. However all already existing SPNA-s with the exception of Commander State Biosphere Reserve are just nominal organizations without real system of nature protection service. As far as the level of knowledge on their biodiversity is concerned it is extremely low and

However it should not preclude the possibility of seaweed harvest on the territory of SPNAs even with high nature protective rank. For instance, Commander Reserve is thought to be perspective for plant resources exploitation in the areas with permitted economic activity (Selivanova, 2008b). It is necessary to elaborate well-grounded recommendations on permissible level of harvest that in its turn should be based on reliable estimate of algal resources. Correct estimation of resources is important for proper decisions on biodiversity conservation not destroying ecosystem integrity and providing restoration of natural

**6. Preliminary data on seaweed resources of the Russian sector of North** 

resources in the Russian sector of North Pacific comes to 10 million tons.

The largest and most productive algal communities in the Russian sector of North Pacific (western continental part of Bering Sea and Commander Islands) are formed by seaweeds of the order Laminariales. These algae are main objects of commercial harvest. Unfortunately there are no exact present-day quantitative data on seaweed resources in the studied area. The only information available is just preliminary, fragmentary and rather old, dated to the first dacades of the last century (Kongisser, 1933; Gail, 1936). Naturally we need more updated information concerning this matter but practical estimation works require considareble expeditionary expenses, equipment and efforts of many specialists. At present it is unreal to expect that these works will be carried out. So the only way out is to make calculations using so called expert method. It is a theoretical estimation based on remote sensing data on the bottom area suitable for the growth of seaweeds and their projective cover in communities. In accordance with this expert estimation general stock of seaweeds

In spite of such rich stock there is a risk of overharvest in case of poor organization of catch. Exceeding press on commercial algae may cause abrupt decrease of their number and futher replacement by competitive species, for example, by crustose coralline algae. This may cause irreversible changes in the structure of plant benthic communities and as a result total loss of commercial species. That is why scientific recommendations on permissible level of

marine and coastal ecosystems of Bering Sea with large colonies of sea birds.

**5.4 Nature park "Beringia"** 

seaweed resources.

harvest are very important.

**Pacific** 

includes a part of Bering Sea water area (Fig. 1 (4).

scientific studies seem to us to be the major task for future.

In my opinion the most prespective region for sustainable use of seaweed resources is a shallow water area of Commander Islands in spite of the fact that their major part is included in the state biosphere reserve. The reasons for such statement are as follows: 1) this region is one of the most pristine in the Far Eastern seas of Russia, seaweeds growing there are suitable for food and pharmaceutical use not only by the local population but also for export; 2) analysis of the benthic communities of the Islands reveal that their state is good enough and the number of laminarian algae is actually excessive; 3) it will be expedient and even necessary to organize harvesting of commercial algae in the zones of permitted economic activity; 4) in the latest few years the scheme of initial zonation of the Reserve was reconsidered and the limits of economic zones were appreciably extended.

However as it was already said, competent exploitation of seaweed resourses should be based on reliable research data on the algal species composition, number and distribution within the area. This information is obviously insufficient and additional studies are necessary.

We have at our disposal only relatively old data on the stock and distribution of the laminarian algae on Commander Islands obtained during expeditions of Kamchatka Branch of the Pacific Institute of Geography in 1986, 1989-1991. In accordance with these data *Saccharina bongardiana* forms relatively small areas (20-30 hectares) covered by kelp at the depths of 1-2 meters. In sheltered bays *S. bongardiana* is met up to the depth of 12 m, forming mixed communities with other brown algae. Mean biomass of *S. bongardiana* varied in different years. The area covered by the kelp with the dominance of this species did not exceed 10 km2, total stock came to а 1-1.5 thousand tons. In exposed habitats *S. bongardiana*  was replaced by a competitive species *S. dentigera.* 

*S. dentigera* formed a distinct belt aroung the coast of Bering Island at the depths from 3 to 10 m. Some patches are met from the depth of 0 (in exposed to waves places) to 25 m. Plants often settled on coralline alga *Clathromorphum nereostratum* and obtaining big size were cast ashore by storms together with coralline crusts on haptera. The portion of *S.dentigera* in cast ashore mass reached 70%. The biomass of *S. dentigera* varied in different years in 3-4 times. The area occupied by the kelp of this species came to 200 km2, and the stock averaged to 2 million tons.

At present only algae of the genera *Saccharina* and *Laminaria* are the objects of harvest in Kamchatka Region though other laminarian algae (*Alaria, Eu*a*laria*) are also suitable for food, forage and technological use. In particular a giant alga *Eualaria fistulosa* that forms dense population around Bering Island at the depths 5-15 m may be treated as a perspective commercial species. Sometimes it is met in deeper places (up to 25 m) and vice versa rises to 1-2 m in sheltered habitats. The density of populations of *E. fistulosa* varied up to 10 times from a year to year (from 0.6 to 7 kg/m2). Kelp formed by this alga occupied the area of about 100 km2. Floating plants of *E. fistulosa* and their parts formed rather thick fields with projective cover up to 60%. In autumn-winter period these floating fields of *E. fistulosa* were destroyed by storms but in April-May they appeared again and reached their maximal size (10-12 m) by June-July due to the fast growth of attached algae. The stock of this alga on Bering Island was estimated at its minimal amount in 1992 to be 82 thousand tons and at its maximal amount in 1990-1991 – up to 700 thousand tons. The total amount of *E. fistulosa* at both Bering and Medny Island in 1990-es averaged to 925 thousand tons.

As is well known abundance of brown algae is subjected to unpredictable changes as a result of harvesting, so their natural fluctuations should be taken into account because harvesting in unfavourable for seaweeds years may lead to abrupt decrease in their stock.

Marine Macrophytic Algae of the Western Sector of North Pacific (Russia) 207

Inventory of marine flora of the Russian sector of North Pacific is necessary not only for clarification of scientific problems of phycology but also for solving of some important practical problems. In particular, there is a threat of decrease of biodiversity of the region and loss of the still unknown species. Already known rare species included in the Red Data Book of Kamchatka (Selivanova, 2007) are also under the threat of loss. So I consider it very important to continue studies on biodiversity of marine coastal ecosystems of Bering Sea paying special attention to their plant components that form basic environments for valuable commercial objects (herring, rock trout, sea urchins etc.). In order to prevent their loss or decrease of number it is necessary to organize valid protection of resources of the shelf of the area. I am confident that sustainable harvest will make it possible to avoid destruction of marine ecosystem integrity and provide restoration of natural seaweed resources and their long-term exploitation. This will help to supply population of Kamchatka Region with this valuable food and technological natural raw material and

I am grateful to my colleague Galina G. Zhigadlova for participation in algal collection and

Belyakova, G.A.; Diakov, Yu. N. & Tarasov, K.L. (2006). *Botany in 4 volumes. V. 2. Algae and* 

Gabrielson, P.W.; Widdowson, T.B.; Lindstrom, S.C.; Hawkes, M.W. & Scagel, R.F. (2000).

Gabrielson, P.W.; Widdowson, T.B. & Lindstrom, S.C. (2006). *Keys to the seaweeds and* 

Guiry, M.D. & Guiry, G.M. (2011). *AlgaeBase*. World-wide electronic publication, National

Kafanov, A.I.; Borisovetz, Ye.E. & Volvenko, V.I. (2004). On application of cluster analysis in

Vol. 65, No 3, (May-June, 2004) pp. 255-270, ISSN 0044-4596 (In Russian). Kongisser, R.A. (1933). Hydrobiological studies in Bering Sea at the northeastern coasts of

Drude, O. (1890). *Handbuch der Pflanzengeographie*. Stuttgart, Germany, 487 S.

Columbia, ISBN 0-88865-466-9, Vancouver, BC, Canada. 189 pp.

*fungi,* Center 'Academia" Press, ISBN 5-7695-2750-1, Moscow, Russia, 320 pp. (In

*Keys to the benthic marine algae and seagrasses of British Columbia, Southeast Alaska, Washigton and Oregon.* Phycological Contributions N 5. University of British

*seagrasses of Southeast Alaska, British Columbia, Washington and Oregon.* Phycological Contributions N 7. University of British Columbia, ISBN 0-9763817-1-0, BC,

University of Ireland, Galway. http://www.algaebase.org [searched on February,

the biogeographic classifications. *Zhurnal obshchei biologii [Journal of general biology*],

Kamchatka (Preliminary information). *Issledovaniya dal'nevostochnykh morei SSSR [Investigations of the Far Eastern seas of the USSR].* Issue 2, pp. 115–124 (In Russian). Kussakin, O.G. & Ivanova, M.B. (1978). Intertidal zone of Chukotka part of Bering Sea, In:

*Litoral' Beringova morya i yugo-vostochnoi Kamchatki [Intertidal zone of Bering Sea and* 

organize its export to other areas of Russia and abroad.

**7. Conclusion** 

**8. Acknowledgment** 

Russian)

Canada. 209 pp.

24, 2011].

identification.

**9. References** 

Three species we discuss (*S. bongardiana, S. dentigera* and *E. fistulosa*) have different growth peculiarities, reproduction and demographic structure of the populations, so the strategy of their harvest should be different.

For instance, *S. bongardiana* may be harvested in the volumes of 50 % of its stock in each area (for Bering Island 0.5-0.75 thousand tons). The most expedient way of this species harvesting is cutting of algae in the intertidal zone during low tides using special knife (pruner) in 20 cm above the meristem zone at basal part of the blade. This provides fast re-growth of the blade and makes it possible to get aftercrop in 1.5-2 months, i.e. to carry out multiple harvesting during a vegetation period.

On the other hand the total harvest volume of *S. dentigera* should not exceed 30 % of the total stock because algae of this species grow much slower than *S. bongardiana* but have longer lifetime (presumably, 4-5 years of *S. dentigera* versus 2-3 years of *S. bongardiana*). Inasmuch as *S. dentigera* grows at considerable depths and constitutes a major part in cast ashore algae, collection of fresh samples of *S. dentigera* from the stormy beached seaweed mass seems to be the most rational method of its harvesting.

Harvesting of *E. fistulosa* is possible from the boat by wrapping floating parts of the plants round long hook (kanza). For the sake of fast restoration of the stock it is expedient to cut them at the depth less than 1 m from water surface. Owing to high growth rate of the fronds of *E. fistulosa* it is possible to harvest phytomass several times during one vegetation season. Plants are able to reproduct successfully because the lower parts with sporophylles are not damaged. Annual estimated yield of *E. fistulosa* for Bering Island comes to 120 thousand tons.

It should be accentuated that the use of dragrope is inadmissible in seaweed harvest as it causes considerable loss of raw material, damage of substratum, death of juvenile plants and as a result – elimination of thickets of algae. Moreover torn off plants sink and form dead bottom sediments, in the process of decay they reduce hydrogene contents in the nearbottom water layers.

Recommended by us methods of brown algae harvesting at the coasts of Commander Islands satisfy the international requirements of exploitation of seaweed resources and do not conflict with the nature protection regime in the region. They are ecologically justified because produce no negative effects on the benthic marine ecosystems and populations of marine mammals. It is necessary to take into account the depths of algal vegetation and water temperature in order to fix optimal period of harvest in each specific area. According to our data the most favourable time of seaweed harvest on Bering Island is May-June. Plants growing in shallow water areas develop more rapidly and start reproduction earlier owing to faster water warming-up than algae growing in deeper areas. That is why first of all seaweeds from shallow water zones should be harvested. According to my calculations in the intertidal zone of Commander Islands it is possible to get 3-5 kg from m2 and in the upper sublittotal zone – up to 10-12 kg of raw seaweeds.

As far as the continental part of Bering Sea is concerned the present-day information on its seaweed resources is practically absent. That is why I would like to withhold recommendations on organization of harvest in this area. Commercial catch of seaweeds without scientific grounds at contemporary technological approach may cause irreplaceable losses of seaweeds and even destruction of the benthic communities. I think that studies on biodiversity of the western part of Bering Sea and ensuring of effective work of SPNA-s should precede organization of seaweed harvesting in the area.
