Managing Fisheries to Conserve Groundfish and Benthic Invertebrate Species Diversity (MAFCONS): An introduction to the project

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Managing Fisheries to Conserve Groundfish and
Benthic Invertebrate Species Diversity(MAFCONS)
An introduction to the project
Jo King

• Simon Greenstreet

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MAFCONS Project Objective

• The goal of the MAFCONS project is
• To provide Fisheries Managers with the capability
  to adopt an ecosystem approach to management
  which enables them to set and achieve species
  diversity goals, with respect to fish and benthic
  communities, alongside their more traditional
  single species objectives for commercial fish
  stocks

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Introduction

• What is this project all about?
• What is the rational behind it?
• Why are we doing it?
• What do we hope to achieve?
• What exactly are we going to do?

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Introduction

• Lets start with a bit of scientific
  background...

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Effects of Fishing on Fish Communities?

• Fishing mortality is not directed evenly across
  all fish in the community individuals of a
  limited size range belonging to selected species
  are removed preferentially.
• Changes relative population sizes.
• Alters balance between numbers of predators and
  prey.
• Alters balance between competing species.
• Alters size frequency distributions of particular
  populations.
• Changes in the relative abundance of species can
  lead to changes in community structure and
  ecosystem function.

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Long-term trends in the groundfish assemblage

• Partitioned the North Sea into zones based
  broadly on hydrographic and topographic
  characteristics.
• Analysed groundfish survey data for three areas
  in NW North Sea where reasonably long-term
  records of fishing effort were available.

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Areas with increasing effort
species diversity has shown a long-term decline.
In two areas where demersal fishing effort has
steadily increased
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Area with decreasing effort
In a third area, where fishing effort has
declined in recent years,
Groundfish species diversity has also decreased
here!
So we observe both positive and negative
relationships between fishing effort and species
diversity!
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Problems with this correlative approach

• No hypotheses relating fishing disturbance to
  species diversity have been tested.
• This correlative approach does not even prove
  that fishing caused the observed changes in
  groundfish species diversity.
• Even if cause and effect can be demonstrated,
  these results cannot be used to predict the
  future consequences of changes in fisheries
  management practice on species diversity.
• Both positive and negative relationships between
  species diversity and fishing effort were found.
• No insight was provided which could allow us to
  predict the direction of the relationship under
  certain circumstances.

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Addressing these problems

• Is there any other evidence which might help to
  confirm a causative relationship?
• That fishing really has caused the observed
  changes in diversity?
• That there really is a potential management issue?

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Does Fishing affect Fish Species Diversity?

• where effort has increased over recent decades

• and species diversity has declined,

• In areas 1 and 2

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Does Fishing affect Fish Species Diversity

• these changes in groundfish assemblage structure
  have been associated with marked changes in
  species composition.

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Some Theory
There is a growing body of theory which
suggests that particular life history traits
render a species more or less vulnerable to
fishing mortality.

• More vulnerable
• large ultimate size
• slow growth rates
• large size at maturity
• older age at maturity
• low fecundity

• Less vulnerable
• small ultimate size
• fast growth rates
• small size at maturity
• younger age at maturity
• high fecundity

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A Hypothesis

• If increasing fishing pressure were the cause of
  these changes in species composition, then
  species whose life history traits render them
  more vulnerable to fishing mortality should have
  decreased in abundance relative to species with
  the opposite characteristics.
• Over time the groundfish assemblage should have
  become more dominated by fish with small ultimate
  size, fast growth rates, and an early age and
  small size at maturity.

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The Test

• The average ultimate length of fish in the
  groundfish assemblage has decreased,
• and the average growth rate has increased.

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The Test (continued)

• And average age and length at maturity have both
  declined.

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Conclusions

• Trends in life history traits averaged across the
  whole groundfish assemblage provide much stronger
  evidence that the changes in species composition,
  and the coinciding decline in species diversity
  (in this area), have occurred as a consequence of
  increased fishing mortality.
• So what!!
• Is the impact of fishing on the species diversity
  of Fish (and Benthic) Communities an issue that
  fisheries management needs to take into account?

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Political Backgound

• To answer this question we need to review (very
  briefly) the political developments over the last
  two decades...

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Overview of some major Global Conventions
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North Sea Ministerial Conferences

• Five full-blown North Sea Ministerial
  Conferences to date
• Bremen in 1984
• London in 1987
• The Hague in 1990
• Esbjerg in 1995
• Bergen in 2002
• Plus two Intermediate Ministerial Meetings
• Copenhagen in 1993
• Bergen in 1997
• These are political events
• The decisions of the Ministers are recorded in
  Ministerial Declarations
• These are political commitments

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North Sea Ministerial Conferences

• Bremen 1984, London 1987
• dealt mainly with pollution issues through
  Oslo/Paris Commissions
• Hague 1990 (just prior to Rio Summit, CBD Agenda
  21)
• pollution mainly addressed
• turned attention to protection of species and
  habitats
• impact of other human activities (fishing) on the
  ecosystem
• Copenhagen 1993, Esbjerg 1995 (following Rio,
  coinciding with FAO Code of conduct)
• fisheries management to safeguard NS ecosystem as
  a whole
• introduction of concept of ecosystem objectives
• integration of fisheries and environmental
  policies
• adoption of precautionary approach
• all marine environment matters addressed through
  OSPAR
• Bergen 1997 (attended by Fisheries and
  Environment Ministers, just prior to OSPAR Annex
  V)
• need to develop and apply and ecosystem approach
  to management
• laid down guiding principles for such an approach
• invited competent authorities to develop this
  approach

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Developing an Ecosystem Approach to Management

• Following the 1997 Intermediate Ministerial
  Meeting, a workshop on the Ecosystem Approach to
  Management and Protection of the North Sea was
  organised in Oslo in June 1998
• need for objectives at the general level
  obvious
• but also the requirement for specific
  objectives, as detailed operational goals, was
  recognised.
• Three further workshops set up to establish a
  methodology for describing Ecological Quality
  and setting Ecological Quality Objectives.
• The most important of these was the workshop on
  Ecological Quality Objectives (EcoQOs) for the
  North Sea held at Scheveningen, The Netherlands,
  in September 1999
• Here the basic template for a proposed
  ecosystem approach to management was
  effectively confirmed

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North Sea Ministerial Conferences

• Bergen 2002
• Ministers recognised the need to manage all human
  activities in the North Sea so as to conserve
  biological diversity and ensure sustainable
  development
• they agreed to implement an ecosystem approach
  based on the setting of EcoQOs as tools for
  setting clear operational environmental
  objectives and serving as indicators of ecosystem
  health
• they agreed to use the EcoQOs already developed
  for the North Sea and invited OSPAR to review
  progress by 2005

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EcoQ Issues

• Ten issues for setting EcoQOs for the North Sea
  have been proposed

This is the basis for an ecosystem approach to
man- agement accepted at the Bergen 2002 NSMC
What EcoQOs have been set currently for Fish and
Benthic Communities?
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EcoQOs for Fish and Benthic Communities

• Tables A and B, Annex 3 Bergen Declaration
• Issue 5 Fish Communities
• Ecological Quality Elements
• Changes in the proportion of large fish and hence
  the average weight and average maximum length of
  the fish community
• EcoQOs
• none set as yet!
• Issue 6 Benthic Communities
• Ecological Quality Elements
• Changes/kills in zoobenthos in relation to
  eutrophication
• Inposex in dog whelk (Nucella lapillus)
• Density of sensitive (e.g. fragile) species
• Density of opportunistic species
• EcoQOs
• There should be no kills in benthic animal
  species as a result of oxygen deficiency and/or
  toxic phytoplankton species
• A low(lt2) level of imposex in female dog whelks
  as measured by the Vas Deferens Sequence Index

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Authority over North Sea waters

• Only the European Commission and Norway have the
  authority to determine legally binding
  legislation with respect to the control of
  fishing activities in the non-territorial waters
  of the North Sea
• acknowledged in the Esbjerg 1995 Ministerial
  Declaration
• confirmed in Article 4 of Annex V of the OSPAR
  convention
• European Union policy impinges directly on the
  exploitation and management of the North Sea in
  several ways

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EC policy/legislation

• Common Fisheries Policy
• conservation of available and accessible living
  marine aquatic resources
• sustainable use
• accounting for marine environmental implications
• Birds Directive
• part of EU Ramsar convention
• protects wild birds and their natural habitat
  within EU area
• includes seabirds
• Habitats Directive
• selection of areas to protect species and/or
  habitats
• member states required to designate Special Areas
  of Conservation (SACs)
• these SACs should create a network of protected
  areas (Natura 2000)
• includes many marine sites

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WOW!!!

• And that is it - so far!!!

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Treaty/Convention/Declaration objectives

• Sustainable use of natural resources
• conservation of biodiversity
• protection of species and habitats
• reduction of pollution
• minimisation of detrimental effects of
  anthropogenic activities
• restoration of degraded systems

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Treaty/Convention/Declaration principles

• Integrated management
• An Ecosystem Approach to management
• The Precautionary Approach
• Polluters should pay

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Current EcoQOs for fish and benthic communities

• Will the current ecosystem approach conserve
  species diversity and restore degraded systems?
• If it cant, why is this the approach being
  adopted?

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Problems with this correlative approach

• No hypotheses relating fishing disturbance to
  species diversity have been tested.
• This correlative approach does not even prove
  that fishing caused the observed changes in
  groundfish species diversity.
• Even if cause and effect can be demonstrated,
  these results cannot be used to predict the
  future consequences of changes in fisheries
  management practice on species diversity.
• Both positive and negative relationships between
  species diversity and fishing effort were found.
• No insight was provided which could allow us to
  predict the direction of the relationship under
  certain circumstances.

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MAFCONS Purpose in Life

• We currently have no conceptual framework that
  links, through cause and effect mechanisms, the
  response of fish and benthic communities, in
  terms of changes in species diversity, to
  variation in fishing disturbance
• At present therefore we cannot advise managers
  how to achieve specific diversity objectives
• THIS IS WHAT MAFCONS SEEKS TO PROVIDE
• How will the project achieve this goal?

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The MAFCONS Approach

• MAFCONS seeks to develop the necessary theory
  upon which to base testable hypotheses relating
  fishing disturbance to ecosystem characteristics,
  such as species diversity.
• Such theory would enable the ecosystem
  consequences of fisheries management actions to
  be predicted and quantified.
• Application of such theory should therefore
  provide fisheries managers with the necessary
  tool to enable them to adopt a species
  diversity based ecosystem approach to fisheries
  management.

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MAFCONS Objectives

• Thus, the principal objective of MAFCONS is -
  To produce a Management Protocol which would
  allow managers to predict the consequences to
  fish and benthic community species diversity of
  setting specific TACs, thereby enabling them to
  achieve species diversity goals as well as fish
  stock size objectives
• This protocol will be soundly based in
  well-tested ecological theory

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Hustons Dynamic Equilibrium model

• Huston noted that two unimodal relationships
  concerning species diversity could be derived
  from the theoretical ecology literature, one
  related to disturbance and the second related to
  productivity.

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Hustons Model cont.

• Huston combined these two relationships to
  produce a three dimensional model relating
  species diversity simultaneously to both
  productivity and disturbance.

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Hustons Model cont.
It is quite clear from this model that the
relationship between disturbance and diversity
can differ markedly, depending on the level of
productivity.
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Testing Hustons model using spatial data

• Can we test Hustons model using spatial data?
• Spatial distribution of effort?
• Done and do-able!

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Testing Hustons model using spatial data

• Spatial distribution of species diversity?
• Done and do-able!

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Testing Hustons model using spatial data

• Spatial distribution of productivity?
• Difficult but, using recently published size
  spectra based methods, maybe not as hard as one
  would first imagine!
• MAFCONS will derive estimates of benthic
  secondary production by ICES rectangle throughout
  the North Sea.
• Sampling benthic invertebrate infauna and
  epibenthos on research vessel cruises
• samples all analysed by size (length/weight)
  category
• size specific P/B ratios applied to estimate
  productivity

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The Test of Hustons Dynamic Equilibrium model

• Group rectangles by productivity level.
• Within each productivity group, examine the
  relationship between effort and species
  diversity.
• Are the relationships predicted by the model for
  different productivity levels found in the field
  data?

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An Ecosystem Approach

• If Hustons model holds up to critical
  examination, then it could be used as the basis
  for a mathematical tool to enable fisheries
  managers to predict the ecosystem consequences
  (effects on species diversity) of their actions.
• Application of the tool could then become part
  of the annual assessment, advice, management
  round.
• If the project is successful and this becomes
  part of the assessment process, benthic sampling
  would become part of the standard GFS routine.

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MAFCONS Objectives

• Before a species diversity protocol can be
  implemented within the current assessment/manageme
  nt process, one further step is required
• Any theoretical community model produced by
  MAFCONS will almost certainly deal in the
  currency of ecological disturbance based on
  fishing effort
• Currently the EC CFP deals in the currency of
  Total Allowable Catches
• MAFCONS needs to determine the relationship
  between catch and effort. This is the role of WP6
• this will allow conversion between these two
  currencies
• produce an algorithm that converts specific TACs
  to the effort level (including spatial
  distribution of effort) required to attain them

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MAFCONS Management Protocol
WP1 product a management protocol
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MAFCONS Work Package Arrangement
WP 7 covers all Co-ordination activities
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No More!!!!
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