Documentation for held Workshops on - Aquafima · Documentation for held Workshops on: a) ... Stock enhancement, restocking; marine fish (Josianne G. Støttrup, DTU Aqua, ... a stocking

Documentation for held Workshops on:

a) Stocking / re-stocking criteria and strategies

b) Aquaculture technologies and strategies

c) Methods to recognise released fish species

Workshop documentation 4.1 | Page 2

Outline

Introduction……………………………………………………………………………………………………. 2

Workshop a) stocking / re-stocking criteria and strategies................................................................. 4

Workshop b) aquaculture technologies and strategies....................................................................... 7

Workshop c) Methods to recognise released fish species.................................................................. 11

Conclusion.......................................................................................................................................... 14

Introduction

During the past decades fish consumption has risen dramatically and it is accepted that this trend will

continue. Coming from 9.9 kg per capita consumption the number reached 17 kg per person.

Figure 1: World Fish production and consumption (FAO, 2010; p.5)

With the ever growing demand the problem of exploiting the natural fish stock becomes predominant.

Therefore the overall status of fish stocks had not improved. About 32% are overexploited, depleted or

recovering

A possible strategy to counteract on the depletion of stock is to apply enhancement measures for the

specific fish stocks. There are three basic types of fisheries enhancement. The following table will give

an overview about these methods.


So the enhancement measures can be distinguished according to their production goal: Measures for:

- commercial production of fish for human consumption,

- production of fish in order to maintain the species diversity in the area and

- production of fish for recreational fisheries.

With view to analyse the situation for certain fish stocks within the Baltic Sea the AQUAFIMA project

partners compared the used measures and methods in each country aiming to come up with the best

and most useful practices for stocking in this region.

During three thematic workshops the consortium tried to contrast the different strategies concerning the

subsequent topics:

a) Stocking/re-stocking criteria / strategies,

b) Aquaculture technologies and strategies,

c) Methods to recognise released fish species.

The workshops were connected to partner meetings thus ensuring a broad participation and a lively

discussion. To some extent external experts were invited to give a detailed insight into best practice

examples.

Restocking Stock Enhancement Sea-Ranching

Definition (Bell et al.,

2008)

the release of

cultured juveniles

into wild

population(s) to

restore severely

depleted spawning

biomass to a level

where it can once

again provide

regular, substantial

yields

the release of

cultured juveniles

into wild

population(s) to

augment the natural

supply of juveniles

and optimize

harvests by

overcoming

recruitment limitation

the release of

cultured juveniles

into unenclosed

marine and estuarine

environments for

harvest at a larger

size in ‘put, grow,

and take’ operations

Goals provide additional catch for commercial and recreational

fishermen

rebuild spawning stock biomass for the promotion or

acceleration of recovery

ensure the survival of stocks threatened by extinction

mitigate losses due to anthropogenic effects


The workshops followed the timeline given in the project workplan:

Stocking/re-stocking criteria / strategies

Aquaculture technologies and strategies

Methods to recognise released fish

Date 23rd February 2012 14th May 2012 12th September 2012

Venue Copenhagen, Denmark

Gdansk, Poland Vilnius, Lithuania

Within the next pages the detailed minutes of the workshops are listed additionally the given

presentations are available upon request.

Workshop a) stocking / re-stocking criteria and strategies

1. Introduction

Prof. Harry Palm (University of Rostock) opened WP4 Workshop and introduced to the agenda. Prof.

Palm stated that the next workshop during the partner meeting in May 2012 will be dedicated to

aquaculture technologies and strategies.

2. Expert Inputs and presentations partner countries

Stock enhancement, restocking; marine fish (Josianne G. Støttrup, DTU Aqua, National Institute of

Aquatic Resources, Denmark)

Mrs. Stottrup presented an overview of stock enhancement and restocking activities, based on research

experiments with Eastern Baltic cod, stated the definition for “sea-ranching”, “restocking” and “stock

enhancement”, reported on criteria for restocking of Baltic Cod, the economic evaluation, rearing

requirements, cod production in “poll” systems in Norway; provided a lot of statistical data and

information as well as drawn the conclusion that there is a potential for restocking of the Eastern Baltic

cod stock, the unique Baltic Sea dynamics provide the potential for releasing first-feeding cod larvae

and it’s economic benefit.

Stocking policy in Poland (Henryk Kuzminski, Inland Fisheries Institute Olsztyn, Poland)

Mr. Kuzminski gave a report on Polish Marine area overview, stocking policy, and stocking areas;

discussed stocking criteria for salmon, see trout, white-fish, vimba bream, and Baltic sturgeon as well

as fish tagging systems and catch and stocking statistical data by species.


Stock enhancement studies of Turbot, Black Sea Salmon and Sturgeon in Black Sea Region (Ozen

Ozcan, Canakkale Onsekiz Mart University, Faculty of Fisheries, Yilmaz Emre, Mediterranean Fisheries

Research Production and Training Institute, Turkey)

Mr. Ozcan stated his presentation with the objective of the studies - that is to compensate the depletion

of natural stocks in the Black Sea Region of Turbot, Black Sea salmon, Danube sturgeon and Starry

sturgeon. Mr. Ozcan gave an overview of statistical information on tagging activities, recapture

locations and rates, releasing sites. With regards to other stocking studies Mr. Ozcan stated that about

25 million juvenile common carp are released into reservoirs and in the past, pike-perch, wels catfish

and brown trout had been released into rivers and reservoirs.

Sea trout reproduction and stocking (Norbert Schulz, Association Fish & Environment, Germany)

Mr. Schulz presented the report on sea trout reproduction and stocking activities, stated that since 2009

videotape recordings are used to count upstream and downstream of sea trout, presented the

illustrations of RFID devices, video devices, tagging, as well as stocking activities statistical data;

recapture locations and migration of tagged sea trout.

Mr. Schulz continued with the report on establishment of brood stock reproduction and on-growing of

Acipenser oxyrinchus results 2010 – 2011 (G.-M. Arndt, J. Geßner, C. Kühn). The report contained

important statistical information as well outlook of present problems and future work that needs to be

done. He also informed about stocking measures with Baltic whitefish (Coregonus maraena).

Mussel cultivation in the Baltic Sea – a stocking or sea-ranching method? (Gerald Schernewski, Leibniz

Institute for Baltic Sea Research (IOW), EUCC – The Coastal Union Germany)

Mr. Schernewski started his presentation from the overview of statistical data of aquaculture in Europe

and according to Eurostat 83/2009 – Agriculture and fisheries source: 48% of the total aquaculture

production was of fish and 52% of mollusks and the major species at EU-27 level are the blue mussels

(Mytilus edulis). Mr. Schernewski continued with mussel cultivation diagram and showed an examples

of mussels farming: long-line mussel farming, smartfarm system, mussel farming near Kiel, Szczecin

Lagoon; pointed that there is interest of farming blue mussels for human consumption, but no interest in

zebra mussels, because of the size and the consumer habits. Mr. Schernewski stated that mussel

farming in the Baltic requires a new perspective and new thinking and questioned whether the mussel

farming in the Baltic is profitable business. Mussels improve the water quality; can be used for human

consumption, as pet food. Mr. Schernewski stated that zebra mussel farming will require additional

funding (subsidies) and the development of strategies to provide funding for the mussel farming as a

nutrient removal measure could be important in water quality improvement.

Fish stocking/restocking in Estonia (Tiit Paaver, Estonian University of Life Sciences, Department of

Aquaculture, Estonia)

Mr. Paaver gave a report on fish stocking and restocking activities in Estonia. There are eight major

species which are reproduced and stocked: salmon, trout, eel, whitefish, pike, pikeperch, tench and

freshwater crayfish. Mainly Atlantic salmon is stocked. Salmon and sea trout share the spawning and

nursery areas, therefore hybrids are common. Mr. Paaver presented statistical data on stocking

activities.


Latvian aquaculture (Dilara Shabayeva, Dr. biol. Andis Mitans, Environmental Development

Association, Latvia)

Ms. Shabayeva presented an overview of aquaculture activities in Latvia: historical benchmarks as well

as current activities, statistical data for stocking in inland waters, migratory fish stocking in Latvian rivers

as well as tagging activities and list of cultivated species. Ms. Shabayeva admitted that in general,

Latvian aquaculture production is quite small and there is a need for aquaculture development in Latvia.

Ms. Shabayeva stated main objects of aquaculture development in Latvia: to increase and diversify

aquaculture production and develop multipurpose aquaculture enterprises, to develop and introduce

resources-saving and modern breeding technologies and better management practices at farm level, to

ensure implementation and further development of fish stocking state programmes, to ensure the safety

and improve the quality of aquaculture products and to develop the education and information networks

in aquaculture.

Lithuanian stocking system (Arina Motova, University of Klaipeda, Lithuania)

Ms. Motova presented a summary of statistical data on stocking by species: salmon, sea trout, eel,

white-fish, sturgeon and turbot. Ms. Motova stated motives and criteria for stocking activities in

Lithuania as well as gave an overview of production capacities for species to be stocked. Ms. Motova

informed about legal regulations for stocking measures.

Analyzing stocking / restocking criteria and strategies (Grethe Adoff, Norwegian Seafood Centre,

Norway)

Mrs. Adoff underlined the main focus of assessment of current and future BSR region fisheries

management e.g. overfishing (Baltic cod, Baltic white-fish). The EU recent fisheries management policy

is not effective enough to maintain and rebuild stocks, alternative management schemes are needed,

stocking of young fish is suggested. Also an integrated fisheries and aquaculture management towards

a sustainable regional development in the BSR is needed. Mrs. Adoff introduced to legislation of

aquaculture in Norway, cold water aquaculture, stated potential species for aquaculture, stock

enhancement activities, species cultured in Norway. Norway – the “home” of the Atlantic salmon,

Atlantic salmon belongs to the Norwegian fauna, and Norway has some of the strongest wild salmon

stocks in the world. Mrs. Adoff listed the aquaculture species in Norway: cod, white halibut, turbot,

salmon, wolffish and sea bream as well as production statistics. Mrs. Adoff also introduced to research

institutions in fisheries and aquaculture.

3. Plenary Discussion

Prof. Palm stressed the importance of monitoring activities – how the success of sea-ranching activities

could be determined in terms of using methods of fisheries biology. Prof. Palm underlined that

according to information received today the result of discussion is that the sea ranching is not

economically useful.

The recapture rates of tagged young fish is not a criteria for successful stocking measures, depending

of low reporting by fishermen an angler. Main problematic here is how politicians justify in Lithuania, in

Russia, in Norway or another countries stocking activities, which are not beneficial for fishermen? Prof.

Palm stressed that this point is very important to all work packages.


Arina Motova gave an example of what is done in Lithuania: Government sell the licenses for regulation

of fisheries. How government justifies the money? In the previous years, state owned hatchery didn’t

have possibilities to sell their products to the market; they only produced stocking material for state

supported measures. Therefore Ms. Motova suggested that maybe private enterprise could be more

cost efficient?

Prof. Palm added that the criteria, whether the sea-ranching activities are successful could be

measured perhaps in the numbers of fishing licenses for commercial fishermen angling licences sold in

the member states or in the country. Prof. Palm asked partners whether the fishing licenses are sold in

other BSR countries.

Sergey Shibayev stated that in Russia there is no such type of licenses. Mr. Skor stated, if restocking

activities have less economic output, the production of fish for human consumption in recirculation

systems or net cages could reduce the fishing pressure on wild stocks.

Prof. Palm underlined that to fulfill this point of activity, there is a need to distinguish between

commercial production of fish for human consumption, production of fish in order to maintain the

species diversity in the area and the production of fish for recreational fisheries. All partners agreed.

Prof. Palm added that the EU water framework directive demands to maintain the species diversity in

the area – therefore for that purpose restocking activities must be used even if it consumes money. For

monitoring purposes there is need for fisheries biological measures and different tag systems could be

used for that; however the most essential point here is to harmonize the tagging system within the

Baltic member states.

Partners discussed, that in terms of recreational activities in the Baltic Sea, clear success criteria could

demonstrate that restocking measures have very positive effect on the economy and it is possible to

measure by for example sold fishing licenses or number of fishing tour operators etc. All partners

agreed.

Matti Skor thanked Marco Frederiksen (EUROFISH) for organization of the event and all partners for a

successful lively workshop. Mr. Skor thanked Turkish and Russian colleagues for their input to the

meeting.

Workshop b) aquaculture technologies and strategies

1. Introduction

Hauke Siemen (REM • Consult) opened the workshop and introduced to the agenda of the day.

Additionally, he gave a short overview of the structure of the AQUAFIMA project. The aim of the

workshop is to get an insight of different aquaculture technologies along the Baltic Sea Region, it shall

build the baseline for further analysis of aquaculture technologies and management models suitable for

the Baltic Sea eco-system (SWOT analysis) and establish contact with and hear about experience from

other projects dealing with aquaculture – AQUABEST and SUBMARINER.


2. Opportunities and Problems Using Reticulating Aquaculture Systems (Susanne Stoye,

University of Rostock)

Susanne Stoye started her presentation with the differences between open and closed aquaculture

systems. When using Recirculating Aquaculture Systems (RAS) different biological requirements need

to be considered such as: oxygen, metabolic products, temperature, pH, solids, feed and animal

welfare. All over the world different RAS are found. All of them are adapted to the needs of the farmed

species e.g. flatfish – space and round fish – volume. One important issue in RAS is also the

aquaculture feed which is adjusted to the nutrient needs of the farmed fish. At the moment the

development of optimized feed for new aquaculture candidates takes a long time and thus for now

natural feed is used.

3. Russian restocking activities in the Baltic Region (Sergey Shibaev, Kaliningrad State

Technical University)

At first Sergey Shibaev gave an overview of the different breeding plants in Russia. There are about 6

breeding plants rearing eel, sturgeon, vimba vimba, salmon, trout, pikeperch and turbot which are

released for restocking the Baltic Sea. Just one breeding plant is places in Kaliningrad. The water

supply of the breeding plants is provided by the ambient rivers or the fish is grown in recirculation

systems.

4. Hatchery technology of marine species in Norway (Grethe Adoff, Norwegian Seafood

Centre)

Grethe Adoff started her presentation with three production types of cod and halibut juveniles. The first

option to grow juveniles can be the extensive production using lagoons as source for zooplankton as

feed. Another type is the “semi-intensive” production by using bags and large tanks for start feeding the

larvae. The last type will be intensive production. Grethe Adoff highlighted that with the three production

types different costs go along with. There are also some challenged regarding the egg production e.g.

eggs are not always available when hatcheries want them, fertilization rate varies in farmed fish,

increasing prices NOK 10.000 / liter in 2005 to NOK 80.000 /liter in 2011, stripping of eggs more time

consuming than natural spawning, eggs of good quality not always available and farmed fish lower

fecundity than wild. The production volume of cod in 2010 was 20.000 tons and had a value of NOK

347 million. On the other hand the production of halibut in 2010 was 16.000 tons with a value of NOK

121 mill. Besides the rearing of cod and halibut also salmon is produced in 260 hatcheries in Norway.

After the rearing of the salmon the fish will be checked for smoltification and transferred to the sea.

Grethe Adoff summarized that cod and halibut are the marine species with a commercial potential. She

also pointed out that cod is produced in a high value as the prices are low and halibut on the other hand

is reared in low volumes with high prices. One of the bottlenecks in hatchery productions is especially

the availability of good quality eggs.


Discussion

During the discussion the questions were raised if there is also a technology transfer among the

different systems. It was stated that the technologies are not a secret and can be transferred to any

other species but which might lead to an increase in production costs. If the production is too low the

prices will increase and the fish will be too expensive for the market. Also several participants

recommend using domestic brood stock as the price for the fish is getting higher.

5. Integrated multi-trophic aquaculture in the Baltic Sea Region (Tim Staufenberger, Coastal

Research & Management)

First of all, Tim Staufenberger introduced to the Integrated Multi-Trophic Aquaculture (IMTA) approach

which is consists of different parts. 1. Fed aquaculture (finfish) and 2. Extractive aquaculture (shellfish

and seaweed). There are ecological and economical advantages of IMTA. Ecological: balanced

systems for environment remediation. Economical: improved output, lower cost, risk reduction and

product diversification. In the Kiel Fjord is a co-cultivation of blue mussels and seaweed taking place.

Both organisms are cultivated on long-lines and will used for the production of food and cosmetics.

6. Cage and mooring systems for offshore fish farming (Grethe Adoff, Norwegian Seafood

Centre in cooperation with aqualine)

On behalf of the aqualine company, Grethe Adoff introduced to the cage and mooring systems for

offshore wind farming. In Norway a Standard (NS9415) for marine fish farms is available which contains

information about requirements for site survey, risk analyses, design, dimensioning, production,

installation and operation. The aqualine cages have a diameter from 12m to 100m.

Discussion

Regarding the presentation of Tim Staufenberger, Grethe Adoff mentioned that a polyculture system is

not allowed yet in Norway in order to avoid the disturbance of salmon. Through the eutrophication

problems of the Baltic Sea the participants highlighted that polyculture has a great potential for the

Baltic Sea.

7. Short introduction to the AQUABEST project and main fish farming technologies Finland

(Jouni Vielma, Finnish Game and Fisheries Research Institute)

First of all Jouni Vielma introduced to the importance of the topic aquaculture especially for the Baltic

Sea Region. Therefore, he mentioned that the aquaculture industry is very young industry that has

specific needs to be growing. He also pointed the bottlenecks of aquaculture in the BSR out which are:

- Licensing system ate not coherent and are not adopted to eco-efficient technologies;

- Spatial planning knowledge has not been transferred throughout the BSR;

- Aquaculture contributes to the eutrophication of the Baltic Sea and

- The feasibility of recirculation farming has not been assessed


Therefore, the AQUABEST project focuses on:

- Self-evaluation of environmental legislation and licensing systems of aquaculture

- Spatial planning and technological requirements for sustainable aquaculture

- Innovative fish feeds to close the nutrient loop of Baltic Sea aquaculture

- Concepts for land-based farms

After the presentation of the AQUABEST project Jouni Vielma gave an overview of the different fish

farming technologies in Finland. The main species cultivated in Finland are: Rainbow trout, brown trout,

Arctic char and salmon. For all of the technologies and management parameters are summarized in a

common handbook. The intensive pikeperch cultivation is just beginning.

8. Short introduction to the SUBMARINER project and marcoalgae and mussel farming in

the Baltic Sea (Magdalena Matczak, Maritime Institute Gdansk)

First of all Magdalena Matczak highlighted the common challenges for the Baltic Sea which are growing

transport, new installations (wind farms), decline of traditional fishery, marine pollution, excessive

nutrient input, eutrophication and climate change. She pointed out that further developing activities can

increase the pressure on marine environment. Therefore, novel technologies and growing scientific

knowledge offer opportunities for new uses of the marine environment with commercial appeal and may

contribute to solving environmental problems. These new uses are: Micro- and macro-algae cultivation

(and collection) for biofuel production, eutrophication reduction; innovative aquaculture solutions;

mussel cultivation; blue biotechnology; wave energy; reed collection and combined uses of offshore

wind farms. The SUBMARINER project focuses on all this uses.

Afterwards, Magdalena Matczak introduced one of the specific uses of the project: macroalgae

harvesting and harvesting. The benefit of the cultivation and harvest of the macroalgae is the uptake of

nutrients in the water. Additionally, gas can be produced by pyrolysis. She also pointed out that the

cultivation of seaweed is still in its beginnings and presented a SWOT Analysis on macroalgae

cultivation. Another important use is the mussel farming which is cost-effective and a simple tool to

improve eutrophic coastal waters by removing nutrients.

9. Closure

Along the world different aquaculture technologies exists. But not all of them are suitable for the Baltic

Sea. Therefore, an assessment for the preconditions, species and technologies is necessary. During

the workshop it became also clear that the nitrogen removal is a basic requirement for a future

aquaculture development in the Baltic Sea. In the Baltic Sea Region are different project engaged in

aquaculture but all of them have another focus but still the cooperation shouldn’t be get lost.

On the 15th of May the participants had an excursion to the Inland Fisheries Institute – Department of

Breeding Trout in Rutki. The participants were introduced to the different aquaculture systems, rearing

methods and stages of development of sturgeon and sea trout.


Workshop c) Methods to recognise released fish species

1. Introduction

Mr. Palm (University of Rostock) opened the workshop and introduced to the agenda of the day.

Additionally, he highlighted that the marking of fish allows to collect a wide-variety of information

(movement and migration pattern, fish growth and survival estimates etc.). Therefore, it is important to

get an overview of used tagging methods recapture data in the Baltic Sea Region.

2. Presentations by the partner countries

Marking and recapturing in Germany (Norbert Schulz, Association Fish and Environment)

Norbert Schulz opened his presentation with Germany’s wide range of experiences in the application of

fish tags. Different tagging methods are used within Germany .

Biological (natural) marks:

Parasitic marks

Morphological marks (e.g. meristic counts, age marks of otoliths, pigmentation etc.)

Genetic marks

Chemical marks: (immersion, injection, tattooing, feeding)

e.g. staining with Alizarin Red Complex (ALC), Oxytetracycline (OTC)

Physical marks:

Coded wire tags

Passive Integrated Transponder (PIT)

Thermal tags

Sonar tags

Data storage tags (DST) GPS Tags

Carlin tags

Fin clipping

Floy tags

Most information on marking and recapturing is available on the following fish species: sea trout, Baltic

sturgeon, eel and cod. The research has been focused on a method to estimate migration pattern. Data

about recapturing is made by reports of fishermen and own surveys.

Marking and recapturing of fish in Latvia (Ilze Rutkovska, Institute of Food Safety, Animal Health and

Environment “BIOR”)

Ms. Ilze Rutkovska stated that anthropogenous influences and hdyropower stations have a negative

influence on fish poulations. Therefore, fish restocking is funded by governmental programmes. In


Latvia there are just two fish species which are tagged: atlantic salmon and sea trout the funding is

provided by the Ministry of Agriculture. Until 2011 adipose fin clipping was used, until 2006 Carlin tags

were used and from 2008 t-bar anchor are used in the tagging programmes.

The recapturing data in Latvia are quite low as the there wasn’t much money for tagging purposes

available and also the fishermen do not get any incentives to send the tags back to the responsible

authority.

Marking and recapturing of fish in Lithuania (Antanas Kontautas, University of Klaipeda)

There is no programme on marking of fish species in Lithuania available. Fish species are just tagged

for scientifically research. The following fish species have been tagged: sturgeon, sea trout, salmon and

eel. Adipose fin clipping was used for research purposes only from 1991 until 2006. Carlin tags are

used for salmon smolt and sea trout. From 1998 until 2012 around 6000 fishes were tagged. Also the

recapturing of this fish is quite low.

Marking and recapturing of fish in Estonia (Tiit Paaver, Estonian University of Life Science Tartu)

In Estonia stocking is based on governmental program of Ministry of Environment. Marking is an

essential part of the stocking plan in order to research on migration pattern. The main stocked fish

species are salmon, sea trout and eel. For salmon the following methods of marking are applied: Carlin

tags, adipose fin clipping and Telemetry tags. Eels and bream have been tagged with Carlin tags.

Recapture data about Carlin tags are presented by both commercial and sport fishermen. The return

rates for salmon are very low (under 1%). Tiit Paaver highlighted several reasons for the low recapture

rates of salmon: decreasing fishing effort in the sea, poor survival of post smolts, decline in quality of

smolts and sea and bird predation.

Marking and recapturing of fish in Denmark (Marco Frederiksen, EUROFISH)

Marco Frederiksen introduced to the A variety of tagging systems (T-bar, Carlin label, Acoustic label,

Radio tags, satellite transmitter, PIT labels) are mainly used in Denmark for marking turbot, flounder,

cod, trout, salmon, pike, pike perch, eel and brace. In Denmark the certain fish species got tagged to

identify migration patterns and disclose stocking activities. Incentives are given for fishermen to send

back founded tags.

Marking and recapturing of fish in Russia (Sergey Shibaev, Kaliningrad Technical State University)

Sergey Shibaev gave the participants an overview of restocking activities in Kaliningrad region and

clarified that no marking and tagging measures are taking place at the moment.


Marking and recapturing of fish in Norway (Jorgen Borthen, Norwegian Seafood Centre)

As Jorgen Borthen wasn’t able to participate in the meeting he provided the participants with an

exclusive summary of marking and recapturing in Norway. In Norway restocking activities of depleted

stocks took place. Furthermore, releases are tagged to monitor landings and for sea-ranching activities.

Efficient methods to tag and mark cod juveniles were developed, and include external tags (anchor

tag), chemical tags (alizarin complexone, oxytetracycline) and genetic markers. All juveniles released

for sea-ranching (harvesting) purposes were tagged. Research activities have been undertaken with

tagging for collecting data on migration family variations in growth, maturation and ocean survival and

simulating effects of stocking. These activities contribute to an improved management of our most

important fishery resources.

3. Discussion, summary and recommendations

The different presentations given by the participants showed a wide variety of used tagging systems

along the Baltic Sea Region. Nonetheless data and figures for the Bornholm basin can not be

considered, as the so far collected project data are not detailed enough due to rejection of the second

project proposal for stocking programs. The stocking programs for Baltic salmon and sea trout were

stopped on administrative level (e.g. ban on enhancement releases for salmon by EU management

plan).

Another important result is the differences of recapture rates within the different countries. Financial

problems in Latvia resulting in lower tag recovery rate. In Denmark on the other hand the tag recovery

rate is higher as the financial incentives for the fishermen are given. Therefore, without financial

incentive for the fishermen the recovery rates are low. In addition, the wide variety of applied tags along

the Baltic countries causes that not all are identifiable and probably will not be forwarded to the

respective country. This implicates that data on e.g. migration patterns of the species are getting lost if

a tagged fish got fished in another member country or even if the person doesn’t know where to send

the tag.

Additionally, a low recapture rate could also be caused due to other reasons e.g. methodological

problems, quality of smolt and predation (increased salmon activities in BSR in recent years). Beside

problems in returning tags to the official institutions there has also been a decrease in the recapture

rate in Finland possibly through methodological problems. The number of recovered finish tags along

the Estonian coastline has also been decreasing in the last years. Reasons are not known yet.

This does not only refer to methodological problems, but possibly also indicates increased salmon

activities in BSR in recent years.This shows that still a lot of research is needed.

Consequently, it is recommended that the responsible organisation for collecting tagging data in each

country should be published, e.g. in the form of a common website open to the public. Such a website

should include:

a. Tag system used


b. Tag labeling system

c. Organisation that await information

d. Data that can be made available to support fisheries management in the BSR

e. Information to fishermen and the public

There is also a need for international standards and/or common codes for future tagging experiments in

the BSR. This standard could include a country code, country number and a contact point on website.

In the case that financial possibilities in the BSR countries are not sufficient for direct payments for the

fishermen a lottery could be offered on the website. For that reason, the AQUAFIMA project will collect

available information on tag system used, tag labeling system and organisation where tags should be

send to.

Conclusion

During the three workshops and accompanying discussions the project consortium came to the

conclusion that stocking in the Baltic Sea from a commercial point of view is not efficient and feasible.

In general it can be stated that the different measures among the Baltic Sea Region states need to be

monitored on a larger scale in order to measure the success of stocking / re-stocking. If stocking / re-

stocking activities are successful, they could be measured in the numbers of fishing licenses for

commercial / fishermen angling licenses sold in the member states or in the country.

The importance of stocking activities could be determined in terms of using methods from fisheries

biology. And thus being a first step in order to measure success of stock enhancement activities.

In order to follow up with cultured fish stock it will be necessary to harmonize the tagging system within

the Baltic member states to ensure a constant system of monitoring. Even if recapture rates of tagged

young-fish are not a criteria for successful stocking measures.

As technologies are no secret and can easily be transferred with slight changes, best-practice

examples from other regions can be a first reference point to develop successful stocking strategies for

the Baltic Sea Region.

Within the next years it will be important to demonstrate that restocking measures have very positive

effect on the economy and regional development. This process may be measured for example by sold

fishing licenses or number of fishing tour operators etc.

Documentation for held Workshops on - Aquafima · Documentation for held Workshops on: a) ... Stock enhancement, restocking; marine fish (Josianne G. Støttrup, DTU Aqua, ... a stocking

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