EIFAAC International Symposium - Recreational fishing in an era of change Lillehammer, Norway 14 - 17 June 2015 - DAFV

 
EIFAAC International Symposium - Recreational fishing in an era of change Lillehammer, Norway 14 - 17 June 2015 - DAFV
REPORT

M-369 | 2015

EIFAAC International Symposium
Recreational fishing in an era of change
Lillehammer, Norway 14 – 17 June 2015
COLOPHON
Executive institution

 Norwegian Environment Agency

Project manager for the contractor             Contact person in the Norwegian Environment Agency

 Øystein Aas                                    Arne Eggereide

M-no                    Year                 Pages                 Contract number

 369                     2015                 70

Publisher                                              The project is funded by
                                                        Norwegian Environment Agency, NINA, NASCO,
 Norwegian Environment Agency
                                                        EIFAAC Registration Fees

Author(s)

 Øystein Aas (editor)

Title – Norwegian and English

 EIFAAC International Symposium - Recreational fishing in an era of change. Symposium Program and
 Abstracts.

Summary – sammendrag

 Norway host an international symposium on recreational fisheries initiated and organised through the
 European Inland Fisheries and Aquaculture Advisory Commission (EIFAAC), in Lillehammer, 14 – 17
 June 2015. Nearly 200 participants from around 20 countries have registered for the meeting. This
 report presents the full program of the Symposium, including abstracts for the more than 100
 presentations given at the meeting.

4 emneord                                              4 subject words

 Konferanse, fritidsfiske, EIFAAC, program              Conference, programme, EIFAAC, angling

Front page photo

 Øystein Aas

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EIFAAC International Symposium | M-369 | 2015

Content
1. Preface ....................................................................................................... 4
2. Symposium organisation ................................................................................... 5
3. Supporters and sponsors ................................................................................... 6
4. Main Programme ............................................................................................ 7
5. EIFAAC Symposium Abstracts .......................................................................... 10
   5.1 Keynote presentations ............................................................................. 10
   5.2 Technical Parallel Sessions ....................................................................... 14
         A1: Integrative Management of Esox Lucius Considering Ecological, Evolutionary and
         Socio-economic Perspectives. Chairs: Skov & Arlinghaus ................................. 14
         B1a: Crayfish Recreational Fisheries Management: Challenges and Opportunities.
         Chairs: Johnson & Skurdal ........................................................................ 18
         B1b & B2: Use of Data Collected from Anglers for Management of Recreational
         Fisheries. Chairs: Pope, Wilde, Aarts & Sawynok ............................................. 19
         C1: Participation and Monitoring of Recreational Fisheries, Recruitment and Outreach.
         Chairs: Fjeldseth & Evensen ...................................................................... 26
         D1: Social Dynamics in C&R Fisheries. Chairs: Stensland & Kagervall ................... 31
         A2a: Challenges and Opportunities in Using Reference Points for the Management of
         Recreational Fisheries for Atlantic Salmon. Chairs: Vehanen & Hutchinson ............. 36
         B2: See above on B1b .............................................................................. 39
         C2: Trans-disciplinary Approaches to Sustainable Fish Stocking and the Besatzfisch
         Project. Chair: Arlinghaus ........................................................................ 40
         D2: C&R Fisheries – New Insights from Fish Biology Research.
         Chairs: Uglem & Kraabøl .......................................................................... 44
         A3: The Right Angle – Balancing Biological, Social and Economic Goals in the
         Management of Recreational Fisheries. (NB. Starts with Intro 1230 after Session A2)
         Chairs: Hyder & Strehlow ......................................................................... 49
         B3: Trait-based Vulnerability of Fish to Angling Gear. Chairs: Köck & Arlinghaus ...... 54
         C3: Sustainable Fishing Tourism in Freshwater Environments Chair: Liberg ............. 58
         D3: Stocking for Conservation – the Cases of Salmon, Eel and Sturgeon. The IMPRESS
         Project. Chairs: Weltzien & Mayer ............................................................ 61
6. Graduate student’s grant for best presentations sponsored by NASCO ......................... 65
7. List of Participants ....................................................................................... 66

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EIFAAC International Symposium | M-369 | 2015

1. Preface
EIFAAC, the European Inland Fisheries and Aquaculture Advisory Commission, has for decades
promoted and encouraged informed, sustainable and science-based use, management and
conservation of freshwater fish resources. An important milestone event took place in 1996
with the EIFAC Symposium on Social, Economic and Management aspects of recreational
fisheries in Dublin chaired by Phil Hickley and Helena Tompkins. This symposium established a
platform for the development of European recreational fisheries including the promotion of
applied and multidisciplinary “recreational fisheries sciences”. These themes were later
addressed in EIFAC recreational fisheries symposia, annual meetings, by several working
groups and specific activities with the aim to professionalize and improve recreational
fisheries management and development in Europe. Outputs include for instance the Code of
practice for recreational fishing (2008) and the Guidelines for assessing social and economic
benefits of recreational fisheries (2010).

Europe is seeing a rapid transformation in social issues, e.g. there has been a shift in values
caused by globalization and urbanization, as well as by more recent and very different
challenges such as climate change and the economic crisis in several countries. All this
influences freshwater fisheries and recreational fishing in many ways. It might affect behavior
and preferred outcomes of recreational fisheries, recruitment of anglers and the general
standing of recreational fisheries and freshwater resources in society as well as how we
manage and utilize freshwater resources in a wider sense. While we have seen improvements
in the ecological status of some aquatic environments, e.g. reduction in nutrient loading in
lakes and reduction in acid deposition, there are new pressures e.g. the demand for carbon
neutral electricity through hydropower. At the same time, rural areas are constantly seeking
to capitalize on their natural resources through tourism, including fishing tourism as a means
to create jobs and income.

In order to address many of these and other issues the 2015 EIFAAC Symposium “Managing
recreational freshwater fisheries in an era of change” bring together stakeholders, managers,
scientists and users to focus on the multidisciplinary challenges of sustainable recreational
fisheries management. The Symposium endeavors to provide a forum for exchange of novel
research, practical experiences and management approaches that foster and support
sustainable recreational fisheries. Nearly 200 participants and contributors have signed up for
the meeting, which will have more than 100 presentations from scientists, managers, NGOs
and business representatives from approximately 20 countries. We look forward to the
symposium and will use the opportunity to thank all participants and contributors for their
eager and friendly responses so far!

On behalf of the organizing committee,

Øystein Aas, Symposium Project Leader

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EIFAAC International Symposium | M-369 | 2015

2. Symposium organisation
Organising committee

Petri Heinimaa, Finland

Miran Aprahamian, United Kingdom

Cathal Gallagher, Ireland

Arne Eggereide, Norway

Robert Arlinghaus, Germany

Tomislav Treer, Croatia

Håkan Carlstrand, Sweden

Carl Burger, USA

Brian Graeb, USA

Ian Winfield, UK

Øyvind Fjeldseth, Norwegian Hunters and Anglers Association

Torfinn Evensen, Norwegian Salmon Rivers

Ola Hegge, County Administration Oppland, Norway

Berit Torsbakken, County Administration Oppland, Norway

Øystein Aas, Norwegian Institute for Nature Research, Norway (Symposium project leader)
Oystein.aas@nina.no ; phone + 47 934 66 710

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3. Supporters and sponsors
American Fisheries Society – AFS
www.fisheries.org

European Angling Alliance - EAA
www.eaa-europe.org

European Fishing Tackle and Trade Association - EFTTA
www.eftta.com

Fisheries Society of the British Isles - FSBI
www.fsbi.org.uk

Institute of Fisheries Management - IFM
www.ifm.org.uk

North Atlantic Salmon Conservation Organisation - NASCO
www.nasco.int

Norwegian Hunters’ and Anglers’ Alliance
www.njff.no

Norwegian Salmon Rivers
www.lakseelver.no

Lillehammer Museum, Maihaugen (http://www.maihaugen.no/en/Maihaugen/)

Oppland County Council (http://oppland.org/Oppland-English/)

County Governor Administration Oppland
http://www.fylkesmannen.no/en/Oppland/

Norwegian Institute for Nature Research
http://www.nina.no/ninaenglish/Start.aspx

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4. Main Programme
Sunday 14th June 2015

From 1400: Registration

1900 - 2100: “Get together” barbeque in the Lillehammer Radisson Hotel Garden

Monday 15th June 2015

From 0700: Breakfast

0800 - 1000: Registration

1000 – 1230: Plenary Opening of Symposium. Recreational fisheries in an era of change –
       an international perspective. Chair: Head of Department, Mr Raoul Bierach,
       Norwegian Environment Agency

1000 – 1015: Opening. Welcome to Lillehammer and Oppland. County Governor of Oppland,
Ms Christl Kvam

1015 – 1030: Aim and goal of Symposium. Symposium project leader Professor, Dr. Øystein
Aas, NINA, Norway

1030 – 1105: Demographic, economic and social change in sustainable recreational fisheries –
an international perspective. Professor, Dr. Robert Arlinghaus, IGB, Germany

1105 – 1120: Break

1120 – 1155: More people fishing more often – England’s national angling strategy. CEO Mark
Lloyd, Angling Trust, UK

1155 – 1230: Migratory freshwater and diadromous fish resources: Challenges and
opportunities for recreational fisheries management. Professor, Dr. Eva Thorstad, NINA,
Norway

1230 – 1330: Lunch

1330 – 1800: Technical parallel sessions. (See separate program below for details)

A1:    Integrative management of Esox lucius considering ecological, evolutionary and socio-
       economic perspectives. (7 presentations). Chairs: Christian Skov and Robert
       Arlinghaus.

B1a:   Crayfish recreational fisheries management: Challenges and opportunities (4
       presentations). Chairs: Stein Johnsen and Jostein Skurdal.

B1b:   Use of Data Collected from Anglers for Management of Recreational Fisheries (Intro
       and 4 presentations). Chairs: Kevin Pope, Gene Wilde, Toine Aarts and Bill Sawynok.
       OBS Starts 16:30

C1:    Participation and monitoring of recreational fisheries, recruitment and outreach (9
       presentations). Chairs: Øyvind Fjeldseth and Torfinn Evensen.

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D1:    Social dynamics in Catch & release recreational fisheries (10 presentations). Chairs:
       Stian Stensland and Anders Kagervall.

1830: Opening reception at Maihaugen Outdoor Museum

2030: Buffet Dinner at Symposium Hotel

Tuesday 16th June

From 0700: Breakfast

0900 – 1300: Technical parallel sessions. (See separate program below for details)

A2a:   Challenges and opportunities in using reference points for the management of
       recreational fisheries for Atlantic salmon (7 presentations). Chairs: Teppo Vehanen
       and Peter Hutchinson.

A3:    The right angle - balancing biological, social and economic goals in the management
       of recreational fisheries (Intro and 1 presentation). Chairs: Kieran Hyder and Harry
       Strehlow - OBS Session starts 12:30.

B2:    Continued from B1b: Use of Data Collected from Anglers for Management of
       Recreational Fisheries (10 presentations). Chairs: Kevin Pope, Gene Wilde, Toine Aarts
       and Bill Sawynok – OBS Session starts 0830.

C2:    Trans-disciplinary approaches to sustainable fish stocking and the Besatzfisch project
       (7 presentations). Chair: Robert Arlinghaus.

D2:    C&R fisheries – new insights from fish biology research (8 presentations). Chairs:
       Ingebrigt Uglem and Morten Kraabøl.

1300 – 1400: Lunch

1400 – 1820: Technical parallel sessions. (See separate below program for details)

A3:    The right angle - balancing biological, social and economic goals in the management
       of recreational fisheries- continued (9 presentations). Chairs: Kieran Hyder and Harry
       Strehlow.

B3:    Trait-based vulnerability of fish to angling gear (8 presentations). Chairs: Barbara
       Köck and Robert Arlinghaus.

C3:    Sustainable fishing tourism in freshwater environments (8 presentations). Chair: Egil
       Liberg.

D3:    Stocking for conservation – the cases of salmon, eel and sturgeon. The IMPRESS
       project (6 presentations). Chairs: Finn A. Weltzien and Ian Mayer.

1830 - 1930 (voluntary): Film from “Besatzfisch”-project. Short introduction by Robert
Arlinghaus.

2000: Three-Course Dinner at Symposium Hotel

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Wednesday 17th June 1100 – 1300

From 0700: Breakfast

0830 - 1100: Plenary theme: Habitat restoration, biodiversity conservation and
recreational fisheries. Chair: Mr Thomas Moth Poulsen, EIFAAC/FAO

0835 – 0900: Citizen science and recreational fisheries: Monitoring and managing the Eel. Joe
Pecorelli, Zoological Society of London, UK

0900-0925: Watershed restoration – lessons from four decades and three continents. Dr Martin
O’Grady, Fisheries Ireland

0925 - 0950: Management of the Danish salmon stocks - What to do when your starting point is
a whole lot of nothing? Vice-director, Dr. Anders Koed, DTU Aqua, Denmark

0950 - 1010: Break

1010 – 1035: Restoring River Ecosystems and the Foundations of Recreational Fisheries. Dr
Luther Aadland, Minnesota Department of Natural Resources, USA

1035 - 1050: Reflections on restoration and conservation in European watersheds.
Environmentalist, angler and actor Jasper Pääkkönen, Finland (to be confirmed)

1050 – 1110: Break

1110 – 1300: Plenary closing theme: Integrative challenges of recreational fisheries
management. Chair: Mr Thomas Moth Poulsen, EIFAAC/FAO

1100 – 1125: The changing face of recreational fisheries in the Great Lakes and its ecological
and socio-economic consequences. Professor William Taylor, Michigan State University, USA.

1125 - 1150: Cross-disciplinary approaches to optimal, sustainable recreational fisheries
management. Dr Fiona Johnston, IGB, Germany.

1150 – 1250: The future of recreational fisheries in a globalized world. A roundtable summary
of the Symposium. Convened by Chairman of EIFAAC Dr Cathal Gallagher, with contributions
from cooperating organisations and supporters, keynote speakers, session chairs and other
Symposium attendees.

1250 – 1300: Closing of Symposium. Arne Eggereide, Norwegian Environment Agency.

1300 – 1400: Lunch

Excursions open for Symposium attendees according to pre-registration in the afternoon from
1645. A) Hydro Power Station and migratory inland brown trout - “Hunderfossen”. B) Small-
scale commercial fishery for whitefish – “Reinsvatnet”. Sandwich and softdrink served on
departure.

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5. EIFAAC Symposium Abstracts

5.1 Keynote presentations
Monday

Demographic, economic and social change in sustainable recreational fisheries –
an international perspective

Keynote Speaker: Professor, Dr Robert Arlinghaus (Leibniz-Institute of Freshwater Ecology
and Inland Fisheries), arlinghaus@igb-berlin.de

Recreational fisheries do not operate in isolation. Instead, they are tightly coupled to macro-
level changes in demography and the economy as well as changes in the contemporary
Zeitgeist. With increasing urbanization, societal-level values related to the environment and
animals shift, deemphasizing the extractive use of natural resources and increasing
importance placed on conservation of wildlife and of the well-being of individual fish. Some
of these changes challenge recreational fisheries in terms of affecting participation and
accepted management actions and fishing behaviour. Using examples mainly from Europe, I
will discuss how social value and demographic shifts affect recreational fisheries. It is
concluded that recreational fisheries development is strongly related to macro-level changes
and that fisheries managers and policy makers are well advised to develop a systems view on
recreational fisheries as social-ecological system.

More people fishing more often – England’s national angling strategy

Keynote Speaker: CEO Mark Lloyd (Angling Trust UK), mark.lloyd@anglingtrust.net

The Angling Trust is the new, united organisation for all anglers in England. It has used the
outputs of research into the economic, social and environmental benefits of angling to make
the political case for promoting angling participation. Working with the Environment Agency,
it carried out a survey of nearly 30,000 anglers to identify the barriers to them going fishing.
It has then developed a strategy (www.anglingtrust.net/nationalanglingstrategy) to
overcome these barriers and has begun implementation.
The strategy has four complementary objectives:
1. We want people to take up and continue fishing so it becomes a habit for life – getting the
fishing habit.
2. We want angling to be recognised for its role in improving the nation’s health and well
being, increasing educational attainment and reducing crime and anti social behaviour –
transforming and changing lives.
3. We want to improve people’s lives by using angling as a catalyst for bringing people and
society together – creating community waters.
4. We want people to recognise that fish and fishing are at the heart of a better environment
– hands up for the environment.
The presentation will describe some of the work that has been carried out to deliver these
objectives, describe the lessons learned and the work that still needs to be done.

Keywords: Participation, angling, development, outreach, recruitment.

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Diadromous fish: threatened and coveted

Keynote Speaker: Adjunct Professor, Dr Eva B. Thorstad (Norwegian Institute for Nature
Research), eva.thorstad@nina.no

Many migrating fishes are popular among recreational anglers, and valuable for commercial
fisheries - and sometimes threatened because they are attractive targets in the fisheries.
Some of these species have spectacular, long-distant and largely unknown migrations.
Individuals of migrating fishes perform regular migrations to take advantage of using the best-
suited habitat, for instance during different stages of the life cycle, or in different seasons, to
increase their individual fitness. Migrations may solely be within freshwater or the sea, or
between freshwater and the sea. Fishes performing migrations between freshwater and the
sea are referred to as diadromous fishes. Migrating species may be influenced by various
impacts in different habitats, and there are specific management challenges related to
migrating fishes compared to stationary populations. Many well-known migrating species
suffer population declines, but there are differences among species and geographic areas. In
this presentation, results and experiences from studies of Atlantic salmon, European eel and
sturgeons will be emphasised. What we can learn across species and regions related to
challenges and opportunities for recreational fisheries management will be discussed.

Keywords: Migratory species, management challenges, recreational fisheries

Wednesday:

Citizen science and recreational fisheries: Monitoring and managing the Eel (and
smelt and river water quality)

Keynote Speaker: Joe Pecorelli (Citizen Science Projects Manager, Zoological Society of
London), joe.pecorelli@zsl.org

Environmental citizen science encompasses a broad range of projects in which volunteers
partner with scientists to answer real-world questions at geographic scales too large for a
scientist to study alone. Anglers represent a fantastic resource that can be engaged in citizen
science projects in the aquatic realm. ZSL has been working with anglers and other volunteers
as part of their citizen science programme since 2011. Three case studies will be presented.
1)       Eels, Anguilla anguilla: ZSL field staff have been monitoring the upstream elver
migration in four of London’s rivers since 2005. In 2011, in order to expand the programme,
we started to engage the help of citizen scientists. Now with over 500 volunteers trained and
14 partnership organisations involved the project has become the largest and most wide-
ranging study on eel migration through a single catchment in the UK. The information from
the study not only allows us to refine eel pass prioritisation by highlighting barriers to
upstream eel migration, but it also provides a unique insight into eel recruitment into the
Thames area, that has value at a national scale.
2)       Smelt, Osmerus eperlanus: This study highlights innovative ways of engaging citizen
scientists in research on the reproductive biology of an estuarine fish that is a Feature of
Conservation Importance in the Thames estuary.
3)       Water quality: ZSL locally coordinates the national Anglers Riverfly Monitoring
Initiative. A scheme that trains and supports anglers in the use of a biotic assessment for
measuring the health of their local waterways.

Key words: citizen science, eel, smelt and river monitoring

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Watershed restoration – lessons from four decades and three continents

Keynote Speaker: Dr Martin O’Grady (Fisheries Ireland), martinogrady@fisheriesireland.ie

Management of the Danish salmon stocks - What to do when your starting point is
a whole lot of nothing?

Keynote Speaker: Dr Anders Koed (Technical University of Denmark, National Institute of
Aquatic Resources), anders.koed@dtu-aqua.dk

In the beginning of the 1980’ies the eight indigenous Danish salmon populations were either
gone extinct or were close to extinction, primarily due to habitat degradation. However,
conservation efforts, in the form of river restoration, fisheries regulations and
implementation of a supportive breeding program based on native brood-stock led to a
resurge of the populations, allowing annual catches by anglers of up to around 2500 salmon
today. Population increases have stagnated in recent years, but the production potential of
the salmon populations is expected to be much higher than current levels. It is unknown
whether the stagnation observed across populations is a response to limiting local factors
(e.g. spawning habitat or predation) or it is a correlated response across population (e.g. to
climate change). In order to further increase the production of the salmon rivers and their
unique salmon populations, there is a need both locally and globally to gain understanding
about key factors limiting current populations. Management activities combining conservation
of Danish salmon populations with the development of a profitable, sustainable recreational
fishery have been facilitated by a high degree of stakeholder awareness-building and
engagement. If the productivity of Danish salmon populations is optimised the recreational
fishery and the related economical gain have the potential to increase correspondingly. An
increase in salmon population size will not only be highly beneficial to the local economy, but
also to the genetically unique salmon populations and hence the protective status of the
species in Europe.

Key words: Salmon, Self-sustainable, Profitable recreational fishery

Restoring River Ecosystems and the Foundations of Recreational Fisheries

Keynote Speaker: Dr Luther Aadland (Minnesota Department of Natural Resources, USA),
luther.aadland@state.mn.us

Abstract:
Recreational fisheries in the United States have been adversely affected by anthropogenic
changes to ecosystems that include land-use changes, dam construction, stream
channelization, and pollution. These changes have resulted in alteration of ecosystem
functions causing substantial losses of freshwater biodiversity that include important game
species as well as non-game keystone species. For example, native species richness upstream
of complete barriers on 28 Minnesota rivers was reduced by an average of 44% while tolerant
invasive species persist or dominate. Fisheries agencies have traditionally focused on the
culture and stocking game-fish and other management-dependent activities to compensate
for these losses. In contrast, the restoration of ecosystem processes is a self-sustaining
approach that is not dependent on management or maintenance. While harvest limitations
will always be a critical role of fish management, restoration and reconnection of critical

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habitats and the processes that create habitat can reduce or eliminate the need for artificial
propagation. Restoration of channelized streams has reestablished fisheries and increased
species richness for fish and invertebrates by restoring habitat forming processes,
reconnecting riparian zones and floodplains and nutrient uptake and processes. Dam removal
and nature-like fish passage in Minnesota have resulted in the return of extirpated fish and
mussel species, dramatically improved recreational fisheries, and improvements in
recreational opportunities and safety for canoeing and kayaking.

Keywords: Ecosystems, recreational fisheries, restoration, streams, fish passage, dam
removal

The changing face of recreational fisheries in the Great Lakes and its ecological
and socio-economic consequences.

Keynote Speaker: Professor William Taylor (Michigan State University, USA),
taylorw@anr.msu.edu

Cross‐disciplinary approaches to optimal, sustainable recreational fisheries
management

Keynote Speaker: Dr Fiona D. Johnston (Leibniz-Institute of Freshwater Ecology and Inland
Fisheries), johnston@igb-berlin.de

Recreational fisheries are complex social-ecological systems and their management involves
the management of people as well as fish populations. Recreational fisheries managers need
to balance the benefits of exploiting fisheries, angler satisfaction, with the conservation of
fish populations; objectives which often conflict. Yet, while it has long been recognized that
anglers are dynamic players in fisheries, the integration of angler dynamics into fisheries
projection models used to guide policy decisions has been slow to develop. Despite the
extensive study of angler preferences by human dimensions researchers, interdisciplinary
barriers have limited the cross-disciplinary approaches to fisheries management. Bioeconomic
models, such as ones developed recently, incorporate biological, social and management
components into a single modelling framework. These models have the potential to be very
useful tools for managers and policy makers. They make a paradigm shift away from biological
yield-based management objectives (e.g., MSY) towards optimum social yield (OSY), an
objective that includes biological and socioeconomic benefits associated with fisheries. By
making management objectives explicit and using mechanistic models to describe angler
preferences and dynamics, policy decisions are more transparent and defensible. Moreover,
these models could be used in an adaptive management context, allowing input from
stakeholders to guide decisions. However, potential pitfalls associated with interdisciplinary
research, and the complexity and tractability of the models for managers need to be
recognized. Ultimately, cross-disciplinary approaches have the potential to challenge some
ingrained assumptions about recreational fisheries, and can help us to develop sustainable
management policies for recreational fisheries.

Keywords – interdisciplinary research; bioeconomic model; angler dynamics; optimum social
yield; fisheries management

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5.2 Technical Parallel Sessions
Monday Afternoon Timetable

    Time          A1 Esox lucius           B1a Crayfish      C1 Participation &             D1 C&R Social
                   Management                                     Outreach                     dynamics
 13:30         Intro                   Intro                Intro                        Intro
 13:40         A1-1                    B1a-1                C1-1                         D1-1
 14:00         A1-2                    B1a-2                C1-2                         D1-2
 14:20         A1-3                    B1a-3                C1-3                         D1-3
 14:40         Break                   Break                Break                        Break
 15:00         A1-4                    B1a-4                C1-4                         D1-4
 15:20         A1-5                    B1a Discussion       C1-5                         D1-5
 15:40         A1-6                    B1a Discussion       C1-6                         D1-6
 16:00         Break                   Break + 10 min       Break                        Break
 16:20         A1-7                    16:30 Intro to:      C1-7                         D1-7
                                       B1b/B2 Angler data
 16:40         A1 Discussion           B1b-1                C1-8                         D1-8
 17:00         A1 Discussion           B1b-2                C1-9                         D1-9
 17:20         A1 Discussion           B1b-3                C1 Discussion                D1-10
 17:40                                 B1b-4                C1 Discussion                D1 Discussion
 18:00         END                     END                  END                          END

A1: Integrative Management of Esox Lucius Considering Ecological,
      Evolutionary and Socio-economic Perspectives.
      Chairs: Skov & Arlinghaus

A1-1. Transition of Pike Fisheries in Denmark; Regulations, Stocking Activities, Animal
Welfare and Habitat Improvement

Authors:
Christian Skov (Danish Technical University, DTU Aqua), ck@aqua.dtu.dk
Søren Berg (Danish Technical University)

Abstract:
In recent years, political awareness in Denmark that rod and reel caught pike represents
important socioeconomically values has emerged. Trophy and C&R fisheries are growing in
popularity and an increasing number of private fishing clubs practice voluntarily inverse slot
regulations as a regulation measure to facilitate this. Moreover, in 2014 legal minimum
harvest size of pike was increased from 40 cm to 60 cm to increase the number of pre-harvest
spawning events of smaller fish. Also in 2014, the Danish minister of Food, Agriculture and
Fisheries published a vision for growth within the recreational fisheries sector. One of the
focus areas of the vision is pike angling including possible increased angler tourism. This
includes several regulation actions. For example in some of the popular pike fishing areas in
brackish waters on the Danish Baltic coast mandatory C&R angling, a ban of commercial
landings and certain commercial fishing gears are envisioned. Final decisions about this will
be taken in spring 2015. Animal welfare aspects in relation to angling were evaluated in 2013
by the Danish animal welfare committee (appointed by the Ministry of Food, Agriculture and
Fisheries). The evaluation questioned two aspects of pike angling: C&R fishery and the use of
living fish bait. As a consequence the latter will be banned, whereas no official action will be

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EIFAAC International Symposium | M-369 | 2015

taken in relation to C&R fishing. From being common practise in both fresh and brackish
waters, stocking activities has declined during the last decade and today very few pike are
stocked. It is concluded that the management of Danish pike fisheries is in transition
especially with regards to regulation and stocking activities whereas habitat improvement
measures, such as water level regulations in spring and creation of artificial spawning
grounds, are still rare. The presentation will be supplied with examples of scientific work that
relates to the management issues presented.

Keywords: C&R fisheries; Recreational fisheries; Angler tourism; Regulations; Pike angling;
Animal welfare

A1-2. Status of Pike and Pike Management in France

Authors:
Nicolas Guillerault (Centre National de la Recherche Scientifique; Université de Toulouse),
nicolas.guillerault@univ-tlse3.fr
Julien Cucherousset (CNRS; Université de Toulouse), Frédéric Santoul (CNRS; Université de Toulouse),
Géraldine Loot (CNRS; Université de Toulouse)

Abstract:
Pike is one of the most targeted species by recreational anglers in France that represents the
southwestern limit of the native distribution of the species in Europe. The species is currently
classified as vulnerable in France and important management programs have been
implemented in the last decades. After briefly introducing the general characteristics of the
recreational fishery and the management practices in France, we will synthesize the current
knowledge about pike biology and ecology in the country. We will then present current
research and preliminary results about the efficiency of pike stocking to sustain pike
populations. At the national level, and using a national fish distribution database, we
investigate whether stocking affects the spatial distribution of the species. At the local level,
using molecular tool, we aim at quantifying the contribution to recruitment of stocked
individuals in a pike population located in an urbanized stretch of a large river. Overall, this
work aims to better appreciate whether stocking, which is among the most popular measure
used to sustain recreational fisheries in France, is efficient for pike conservation.

Keywords: Angling in France; Stocking; Molecular biology; Country-scale database

A1-3. Sustainably Managing Pike (Esox Lucius) using Harvest Slots – Theoretical
Considerations and Practical Implementation Issues in Germany

Authors:
Robert Arlinghaus (Leibniz-Institute of Freshwater Ecology and Inland Fisheries; Humboldt-
Universität zu Berlin), arlinghaus@igb-berlin.de
Shuichi Matsumura (University of Gifu), Daniel Gwinn (University of Florida), Micheal S. Allen (University
of Florida)

Abstract:
Pike (Esox lucius) populations in Germany are generally managed based on one-size-fits-all
policies based on state-wide minimum-length limits. Such regulations can lead to strong
juvenation of pike stocks, which according to new theoretical and empirical results can
destabilize stock dynamics. As an alternative tool the use of harvest slots that also save large
fish from harvest have been proposed. Several simulation models that we constructed reveal
the substantial superiority in performance over minimum-length limits both in terms of the
conservation of a more natural age structure and numerical yield. Moreover, fisheries-induced
selection on slower growth was not present when pike stocks were exploited based on harvest
slots, and many fewer fish died due to cryptic mortality compared to the management by
minimum-length limits. Importantly, the probability of maintaining the catch of desired
trophy fish was much higher in management scenarios with harvest slots compared to

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EIFAAC International Symposium | M-369 | 2015

minimum-length limits. Despite all these benefits, managers and anglers are very reluctant to
implement harvest windows in Germany, inter alia, because they are perceived as illegal
catch-and-release of harvestable fish sizes. The story shows how pervasive the influence of
animal welfare is in Germany because it prevents a superior management strategy to reach
practical reality as anglers and manager fear the Sword of Damocles of being accused of
illegal play with large fish through catch and release.

Keywords: Animal welfare; Perception; Age structured simulation model

A1-4. Capability of Slot-length Limit Regulation in Conserving Large Pike

Authors:
J. Tiainen (University of Helsinki), joni.tiainen@helsinki.fi
M. Olin (University of Helsinki), H. Lehtonen (University of Helsinki), K. Nyberg (University of Helsinki),
J. Ruuhijärvi (Natural Resources Institute Finland)

Abstract:
In this study of size-selective fishing, we compared the effects of minimum length limit (MLL)
of 40 cm and harvestable slot-length limit (HSL) of 40-65 cm on pike (Esox lucius) population
density, biomass and size structure in years 2008-2013. The study was conducted in four 2.1-
13.8 ha pristine forest lakes located in southern Finland, in which the dominant fish species
are perch (Perca fluviatilis), roach (Rutilus rutilus) and pike. According to our results,
intensive size selective fishing can rapidly alter the size structure of pike populations, as in
MLL-lakes large pike (>65 cm) were extinct in just four years. Small pike were resilient to
fishing, since only 1 of 4 lakes showed signs of decrease of population density or biomass by
pike removal. HSL-treatment managed to retain large pike in the lake, which is considered an
essential feature of sustainable fishing. However, the results suggest that the number of large
pike can decrease even under HSL-regulation if the growth rate is slow and fishing is
intensive, due to the high possibility to get caught before reaching the upper length limit.
Thus adequate survival of pike of harvestable size has to be assured in order to maintain large
pike in the lake in the long term.

Keywords: Pike; Esox lucius; Large individuals; Size-selective fishing

A1-5. A Review of the Effects of Northern Pike Regulations

Authors:
Gene R. Wilde (Texas Tech University), gene.wilde@ttu.edu
Robert Arlinghaus (Leibniz-Institute of Freshwater Ecology and Inland Fisheries; Humboldt-Universität zu
Berlin)

Abstract:
We review the literature on effects of regulations on northern pike Esox lucius regulations
and perform a meta-analysis to assess which regulations have been most effective. We use
these results, and those from other studies, to develop a simulation model for the general
management of northern pike, which considers regulations and other management actions,
such as stocking. Model results are discussed and then considered in light of what is known of
angler support and acceptance of regulations and management actions.

Keywords: Regulation; Esox lucius; Meta-analysis; Simulation model; Management actions

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EIFAAC International Symposium | M-369 | 2015

A1-6. Evaluating the Relative Fitness Importance of Early Life Conditions and Maternal
Size Effects in Windermere Pike - an Integral Projection Model Approach

Authors:
Yngvild Vindenes (University of Oslo), yngvild.vindenes@ibv.uio.no
Øystein Langangen (University of Oslo), Ian J. Winfield (Lake Ecosystems Group, Centre for Ecology &
Hydrology, UK), Asbjørn Vøllestad (University of Oslo)

Abstract:
Conditions experienced in early life stages can have long-term impacts on individual
phenotypes and life histories. The importance of temperature to early growth and
recruitment in fish is well known, but recent studies have also emphasized maternal effects
of body size or age. However, the relative importance of these early life effects to fitness
remains largely unexplored. Using a female based integral projection model (a demographic
length-structured population model) with long-term data from Windermere, U.K., we
evaluated the relative fitness importance of temperature, female length, and female recruit
length (at age 1), through different vital rates across the life history. The model included four
state variables (female current length, female recruit length, current and previous
temperature) determining seven vital rate functions. Overall, fitness (long-term population
growth rate) was more sensitive to parameters affecting survival and growth than
reproduction, in line with general life history theory for a relative long-lived species. Egg
weight increased with female length (leveling off for large lengths), but this effect had only
minor impacts on fitness, even when egg weight was assumed to have a strong effect on early
survival. In contrast, fitness was sensitive to early temperature effects on growth, and
potentially on early survival.

Keywords: Early life conditions; Impacts; Maternal effects; Fitness; Projection model;

A1-7. Reproductive Characteristics of Pikeperch (Sander Lucioperca) in Relation to Size-
selective Recreational Fishing in South Finnish Lakes

Authors:
M. Olin (University of Helsinki), mikko.olin@helsinki.fi
J. Ruuhijärvi (Natural Resources Institute Finland), T. Roikonen (University of Helsinki), J. Tiainen
(University of Helsinki), H. Lehtonen (University of Helsinki)

Abstract:
We studied the maternal effect, size-related fecundity, and size and age at maturation in
pikeperch, and contrasted the results to the prevailing recreational fishing pressure in three
lakes in southern Finland. Both fecundity and egg dry weight increased significantly with
female size and age, emphasizing the importance of large individuals for reproduction. Size
and age at maturation (50% probability) were 42-44 cm and 5-7 yr., respectively. The
estimated maturation length was considerably higher than the national minimum length limit
(MLL 37 cm). Also the local higher MLL recommendations (42-45 cm) are too low in lakes
where pikeperch growth is good. According to fisheries inquiries conducted, the most
fishermen obey the local recommendations of MLL and gillnet mesh size, and are also fairly
sympathetic to release large, reproductively important individuals. It seems that at least in
southern Finland, the potential for conservation of fish stocks by local voluntary agreement is
quite good.

Keywords: Pikeperch; Sander lucioperca; Maternal effect; Fecundity; Maturation;
Recreational fishing; Regulation; Sustainability

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EIFAAC International Symposium | M-369 | 2015

B1a: Crayfish Recreational Fisheries Management: Challenges and
     Opportunities.
     Chairs: Johnson & Skurdal

B1a-1. Catch them if you can – Management Dilemmas after Exclusion of Native Noble
Crayfish by Alien Signal Crayfish

Authors:
Jostein Skurdal (Lillehammer Museum), jostein.skurdal@lillehammermuseum.no
Stein I. Johnsen (Norwegian Institute for Nature Research), Trond Taugbøl (Glommens and Laagens
Water Management Association)

Abstract:
In Norway, exploitation of freshwater crayfish is almost without exception for recreational
purposes. Until 2006, the only freshwater crayfish species in Norway was the noble crayfish
(Astacus astacus), but a few populations of signal crayfish (Pasifastacus leniusculus) has
established recently. All the discovered populations of signal crayfish have been carriers of
the crayfish plague agent, Aphanomyces astaci, a disease lethal to all freshwater crayfish not
of North American origin. Locals have a strong desire to exploit signal crayfish, but the strict
legal framework of Norway ban fishing in fear of motivating further illegal introductions. To
illustrate the antagonism between authorities´ skepticism and the public desire to open for
recreational fishing we use the case of Lake Øymarksjøen. Here, introduced plague carrying
signal crayfish wiped out and substituted a healthy and productive population of noble
crayfish. We compare historical catch per unit effort (CPUE) data on noble crayfish with
present data on signal crayfish and discuss pros and cons of the strict legislative line of the
Norwegian authorities.

Keywords: Recreational fishing; Alien crayfish; Disease; Native crayfish; Conservation

B1a-2. How to Save the Native Noble Crayfish and the Crayfish Fishery at the Same Time -
the Importance of Culture, Consumption and Economy

Author:
Lennart Edsman (Swedish University of Agricultural Sciences), lennart.edsman@slu.se

Abstract:
Exploitation is one of the main threats to preserving biodiversity. In Sweden the endangered
native noble crayfish has steadily declined, due to the lethal fungal disease crayfish plague.
North American signal crayfish, introduced to substitute the fishery lost, was thought to be
immune to the disease but turned out to be both a chronic carrier and vulnerable to the
plague. The initial idea that it would give a better fishery, also turned out to be false.
Crayfisheries have strong traditions, playing a cultural, social, and recreational role, resulting
in a high economic value. For fishing right owners the main interest is catching crayfish for
the crayfish parties, regardless of species. With alien species readily available, the largest
threat is illegal introductions of plague-carrying signal crayfish by man, not over-fishing.
People that are allowed to catch and benefit from noble crayfish are the best protection
against illegal stocking of signal crayfish. Recreational and subsistence fishery is thus of major
importance locally for the will to protect. Exploitation, in the form of a sustainable fishery, is
the key to successful conservation of the noble crayfish. This is also the main point in the
Action plan for Conservation of the Noble crayfish in Sweden.

Keywords: Noble crayfish; Conservation; Culture; Exploitation; Action plan

B1a-3. Fecundity and Female Size – Bigger is not Always Better

Authors:

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EIFAAC International Symposium | M-369 | 2015

Lennart Edsman (Swedish University of Agricultural Sciences), lennart.edsman@slu.se
Anders Asp (Swedish University of Agricultural Sciences), Patrick Bohman (Swedish University of
Agricultural Sciences), Fredrik Engdahl (Swedish University of Agricultural Sciences), Per Nyström (Ekoll
AB), Alfred Sandström (Swedish University of Agricultural Sciences), Marika Stenberg (Ekoll AB)

Abstract:
It is generally found that larger females have a higher reproductive output. This is also the
case for freshwater crayfish, where positive relationships between female size and number of
eggs have been found for many species. Large females are thus expected to be more
important for population growth rate compared to small females, by producing more
offspring. We investigated this in signal crayfish (Pacifastacus leniusculus) populations in two
lakes in eastern Sweden. Females were collected in autumn prior to mating and ovarian egg
number was counted. In late spring females were again collected and pleopodal egg number
was counted. As expected, and found earlier, there was a positive linear relationship between
ovarian egg count and female size in autumn. In contrast to expectations there was however
almost no relationship between female size and pleopodal egg number in the spring, just
prior to hatching. The largest signal crayfish females did not contribute more offspring to the
next generation. The usual management advice to save the larger females to promote
population growth was thus not applicable in this case.

Keywords: Signal crayfish; Female size; Fecundity; Population growth; Fisheries management

B1a-4. Active Spreading of an Invasive Species Challenges Ecosystem-based Management
of Crayfisheries

Authors:
Japo Jussila (University of Eastern Finland), japo.jussila@uef.fi
Anssi Vainikka (University of Eastern Finland), Raine Kortet (University of Eastern Finland), Harri Kokko
(University of Eastern Finland), Jenny Makkonen (University of Eastern Finland)

Abstract:
We describe the impact of the alien crayfish introduction on the Finnish inland fisheries. The
decision to introduce the alien signal crayfish was made to solve the problem of collapsing
native crayfish stocks and crayfisheries due to the crayfish plague epidemics. The original
idea was founded on overly optimistic expectations, partially by ignoring the available
warnings. The outcome of the massive stockings conducted during the last four decades now
shows that the alien crayfish has not performed as expected and might even end up as being
a failure. The alien crayfish is a permanent reservoir of the crayfish plague disease agent,
Aphanomyces astaci, spreads it efficiently and has been shown to experience elevated
mortality when infected. In spite of this, the official policy in Finland is still driving towards
spreading of the alien crayfish threatening original aquatic ecosystem functions and slowly
leading in the elimination of the native crayfish. The policy includes national alien species
strategy and national crayfisheries strategy, both contradicting EU alien species policy and
knowledge on the behavior of people who tend to illegally transfer signal crayfish. We will
focus on the loss of the native crayfish and its cumulative effects in ecosystems and society.

Keywords: Alien crayfish; Native crayfish; Conservation; Exploitation; Disease

B1b & B2: Use of Data Collected from Anglers for Management of
    Recreational Fisheries.
    Chairs: Pope, Wilde, Aarts & Sawynok

B1b-1. A Conceptual Model for Angler-supplied Data

Author:
Gene R. Wilde (Texas Tech University), gene.wilde@ttu.edu

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EIFAAC International Symposium | M-369 | 2015

Abstract:
A wide variety of data used to evaluate and manage fisheries are collected from anglers.
However, with few exceptions, these data are used as obtained, with little attention given to
data quality other than screening for obviously erroneous values. Here, I propose a general
model for angler-supplied data that attempts to identify and measure effects of angler bias,
error, and misreporting. I use published studies to parameterize a simulation model that
provides insight into which angler biases and errors have the greatest impact on catch, and
other estimates, obtained from these data.

Keywords: Angler-supplied data; Data quality; Effects; Bias; Error; Misreporting

B1b-2. Citizen Science in Norwegian Marine Recreational Fisheries

Author:
Alf Ring Kleiven (Institute of Marine Research, Norway), alf.ring.kleiven@imr.no

Abstract:
The Norwegian marine fishing authorities do not conduct fishing data sampling from marine
recreational fisheries, even though the participation rate is one of the highest in the world.
The last 10 years, the Institute of Marine Research (IMR) has increased its collaboration
directly with recreational fishers to collect knowledge about the activities and the target
stocks. In addition to traditional mark-recapture studies, IMR has developed standardized
report systems for specific recreational fisheries, including internet reporting and mobile
phone applications. The data is amongst other used for studies on management effects and
catch rate time series. Even though fishery dependent data has its limitations, voluntary
citizen data collection is cost-effective and has a great potential for research and
management in data-poor fisheries

Keywords: Citizen science; Data-poor fisheries; Recreational fishing

B1b-3. Using Angler Smartphones Applications for Data Collection and Fisheries
Management

Author:
Paul Venturelli (University of Minnesota), pventure@umn.edu

Abstract:
Fisheries assessment requires information about harvest and effort, and how these vary in
space and time. Conventional approaches to obtaining this information are costly, limited by
diminishing resources, and fairly restricted in time or space. Mobile smartphone applications
(apps) are a novel approach to collecting a wealth of angler behavior and fisheries data
cheaply, at high resolution, and over broad spatial scales. I present an analysis of three years
of angler data from a popular mobile fishing app in Alberta, Canada, that identifies province-
wide, seasonal patterns of i) lake popularity that were consistent with conventional data, and
ii) anthropogenic lake connectivity. I also present preliminary results from two ongoing
studies to determine if apps can complement or even replace conventional approaches (e.g.,
creel surveys). These studies, and similar work in other parts of North America and Europe,
show that mobile technologies can provide inexpensive, high-resolution, real-time harvest
data; and engage stakeholders through citizen science. The challenge before us is to
understand the benefits and limitations of this novel tool, and, where appropriate, tailor its
use to a diversity of recreational, commercial, and subsistence fisheries.

Keywords: App; Behavior; Creel; iFish; Mobile; Smartphone application

B1b-4. Strategy for Recreational Fishing Data Collection in Sweden

Authors:
Martin Karlsson (Swedish University of Agricultural Sciences), martin.karlsson@slu.se

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EIFAAC International Symposium | M-369 | 2015

Henrik Ragnarsson Stabo (Swedish University of Agricultural Sciences), Erik Petersson ((Swedish
University of Agricultural Sciences), Håkan Carlstrand (The Swedish Agency for Marine and Water
Management), Stig Thörnqvist (The Swedish Agency for Marine and Water Management)

Abstract:
Recreational fishing has more than one million practitioners in Sweden and for many species
the catches are much larger than in the commercial fishery. Despite the high value of
recreational fishing and the potential impact on the fish stocks, most fisheries data collection
is focused on commercial fishing. However, data on recreational fishing is important for the
managers of common fisheries resources, monitoring of environmental status and evaluating
the goals set for recreational fishing development and performance. Here, we present how
we plan to collect the relevant data on recreational fishing in Sweden, and give an overview
of the strategies we used to decide what fish species we should focus on, what areas are
likely to receive a high fishing pressure, and what sampling methods to use. Our proposal is
based on combining several different survey methods. We believe that the strategies we
present are of general interest and can be applied in other countries.

Keywords: Recreational fishing, Data collection, Stock assessment, Management

B2-1. Gill-tags and Smartphones – Bringing Salmon Management into the 21st Century

Authors:
Dan Blomkvist (County Administrative Board of Norrbotten/Northern Lapland),
dan.blomkvist@lansstyrelsen.se
Glenn Douglas (Swedish National Sport Fishing Association)

Abstract:
The presentation covers results and experiences from the first year of applying an internet-
based management system for salmon fishing in state owned waters of the Lainio river,
Sweden. The system includes the use of gill-tags and mandatory catch reports as means of
controlling harvest and produce reliable catch statistics. Catch reports are made directly by
participating sport-fishermen via smartphone or computer. The system eases management
burden and provides opportunities for a number of statistical adaptations and also the
possibility to diversify regulations, license prices etc. for different user categories.

The Lainio river is the main salmon producing tributary of the Torne River which in turn is the
main wild salmon producing river system in the Baltic Sea. The upper parts of the Lainio river
is managed by the state through the County Administrative Board of Norrbotten/Northern
Lapland. The area is a true wilderness fishery with the main access being via helicopter and
with an environment similar to parts of the Kola peninsula in Russia and the Finnmark area in
Norway.

Keywords: Salmon management, Gill-tags, Internet, Catch reports, Statistics

B2-2. Cellphone Applications for Catch Reports and Swedish Anglers' Willingness to Report
their Catches

Author:
Peter Belin (Swedish Anglers’ Association), peter.belin@sportfiskarna.se

Abstract:
Swedish Anglers Association has been working with projects for catch reports among
recreational anglers since 2010. In a survey among 320 anglers in 2010, almost 90% said they
were willing to report their catches. In an investigation in some fishing areas there were 19%
of the anglers who reported their catches. (Swedish report available.) In the coastal region
and some of the big lakes in Sweden there is regulatory compulsion for license purchase or
registration for recreational anglers. This makes it difficult to value fishing effort and

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EIFAAC International Symposium | M-369 | 2015

catches. We have created applications for anglers to quickly and easily report their catches in
some specific recreational fisheries in Sweden. The application, Fångstdatabanken, for
android cellphones is available on Google Play from August 2014. iPhone application is under
development and will be released spring 2015. Android application for lake Vänern have more
than 170 users and more than 450 reported catches during August to December 2014. We have
been working with projects for catch reports in Lake Vänern 2012-14 and have data from
more than 6800 catches, mostly salmon and brown trout from boat fishing competitions.
Information, simplicity and continuity are key factors in the work to get anglers report their
catches.

Keywords: Catch; Reports; Cellphone; Application; Anglers

B2-3. Can Principles of Swarm Intelligence Help us Assess the Abundance of Freshwater
Fishes in Angling Waters? An Experimental Test in Pike (Esox Lucius)

Authors:
Robert Arlinghaus (Leibniz-Institute of Freshwater Ecology and Inland Fisheries; Humboldt-
Universität zu Berlin), arlinghaus@igb-berlin.de
Stefan Krause (University of Higher Education, Lübeck), Daniel Hühn (Leibniz-Institute of Freshwater
Ecology and Inland Fisheries), Thilo Pagel (Leibniz-Institute of Freshwater Ecology and Inland Fisheries),
Jens Krause (Leibniz-Institute of Freshwater Ecology and Inland Fisheries)

Abstract:
Swarm intelligence is generally the realisation that group living can facilitate solving
cognitive problems that go beyond the capacity of single individuals. In German freshwater
fishing clubs, the “swarm” of anglers organized in a club are not only users of local fisheries,
but also the collective managers using tools such as size-limits or stocking of fish. To manage
fisheries information about the state of fish stocks is needed. In the absence of scientific
stock assessments, one means by which an angler community can approximate the status of a
fishery is by asking each member of a club for his or her estimate of fish stock size and
average the result. In theory, this average estimate should closely match reality within
bounds of uncertainty. We tested this prediction by first assessing the size of northern pike
(Esox lucius) in 18 stillwaters managed angling clubs. We then surveyed a random sample of
anglers. In addition we conducted workshops with club heads. Workshop participants very
closely estimated the true stock size, while results for anglers were mixed. Swarm
intelligence may therefore be a suitable method to “assess” fish stocks in the absence of
scientific data, but results shall be interpreted with caution.

Keywords: Swarm intelligence; Mark and recapture; Averaging; Angler data

B2-4. Specialist Angler Data – a Resource in Recreational Fishing Management

Authors: Henrik Ragnarsson Stabo (Department of Aquatic Resources, Swedish University of
Agricultural Sciences) Henrik.ragnarsson-stabo@slu.se
Nicka Hellenberg (Swedish Anglers Association)

Abstract:
Data on fish species that are rare, not important for commercial fishing and/or hard to catch
using standard monitoring methods is often scarce. This applies to many of the species that
are targeted by recreational fisheries. The aim of this study was to evaluate if specialist
angling data could be used to improve management, evaluate the effect of fishing
regulations, and monitor rare species. In several countries detailed catch records are kept by
angler associations or fishing clubs/societies. We analyzed data from several sources, but
primarily a database that is maintained by the Swedish anglers association. The database was
started in 1971 and has more than 30000 detailed records of big fish. We found that if the
data meets certain criteria it can be very useful in management and conservation. We present

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