Presentation on theme: "Jo King: Managing Fisheries to Conserve Groundfish and Benthic Invertebrate Species Diversity (MAFCONS): An introduction to the project Simon Greenstreet."— Presentation transcript:
1 Jo King:Managing Fisheries to Conserve Groundfish and Benthic Invertebrate Species Diversity (MAFCONS): An introduction to the projectSimon Greenstreet
2 “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
3 What is this project all about? What is the rational behind it? IntroductionWhat 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?
4 Lets start with a bit of scientific background………... IntroductionLets start with a bit of scientific background………...
5 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.
6 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.
7 Areas with increasing effort … species diversity has shown a long-term decline.In two areas where demersal fishing effort has steadily increased…
8 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!
9 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.
10 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?
11 Does Fishing affect Fish Species Diversity? where effort has increased over recent decades…and species diversity has declined,In areas 1 and 2…
12 Does Fishing affect Fish Species Diversity these changes in groundfish assemblage structure have been associated with marked changes in species composition.
13 There is a growing body of theory which suggests Some TheoryThere is a growing body of theory which suggeststhat particular life history traits render a speciesmore or less vulnerable to fishing mortality.More vulnerablelarge ultimate sizeslow growth rateslarge size at maturityolder age at maturitylow fecundityLess vulnerablesmall ultimate sizefast growth ratessmall size at maturityyounger age at maturityhigh fecundity
14 A HypothesisIf 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.
15 The TestThe average ultimate length of fish in the groundfish assemblage has decreased,and the average growth rate has increased.
16 And average age and length at maturity have both declined. The Test (continued)And average age and length at maturity have both declined.
17 ConclusionsTrends 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?
18 Political BackgoundTo answer this question we need to review (very briefly) the political developments over the last two decades………...
19 Overview of some major Global Conventions The first step in the legislative process involved international agreements on a global scale where essential, universally applicable, principles and objectives have been established.
20 North Sea Ministerial Conferences Five “full-blown” North Sea Ministerial Conferences to dateBremen in 1984London in 1987The Hague in 1990Esbjerg in 1995Bergen in 2002Plus two “Intermediate Ministerial Meetings”Copenhagen in 1993Bergen in 1997These are political eventsThe decisions of the Ministers are recorded in Ministerial DeclarationsThese are political commitments
21 North Sea Ministerial Conferences Bremen 1984, London 1987:dealt mainly with pollution issues through Oslo/Paris CommissionsHague 1990: (just prior to Rio Summit, CBD Agenda 21)pollution mainly addressedturned attention to protection of species and habitatsimpact of other human activities (fishing) on the ecosystemCopenhagen 1993, Esbjerg 1995: (following Rio, coinciding with FAO Code of conduct)fisheries management to safeguard NS ecosystem as a wholeintroduction of concept of ecosystem objectivesintegration of fisheries and environmental policiesadoption of precautionary approachall marine environment matters addressed through OSPARBergen 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 approachinvited competent authorities to develop this approach
22 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 1998need 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 1999Here the basic “template” for a proposed “ecosystem approach to management” was effectively confirmed
23 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 developmentthey 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 healththey agreed to use the EcoQOs already developed for the North Sea and invited OSPAR to review progress by 2005
24 EcoQ IssuesTen issues for setting EcoQOs for the North Sea have been proposedThis is the basisfor an ecosystemapproach to man-agement acceptedat the Bergen 2002NSMCWhat EcoQOshave been setcurrently forFish and BenthicCommunities?
25 EcoQOs for Fish and Benthic Communities Tables A and B, Annex 3 Bergen DeclarationIssue 5: Fish CommunitiesEcological Quality ElementsChanges in the proportion of large fish and hence the average weight and average maximum length of the fish communityEcoQOsnone set as yet!Issue 6: Benthic CommunitiesChanges/kills in zoobenthos in relation to eutrophicationInposex in dog whelk (Nucella lapillus)Density of sensitive (e.g. fragile) speciesDensity of opportunistic speciesThere should be no kills in benthic animal species as a result of oxygen deficiency and/or toxic phytoplankton speciesA low(<2) level of imposex in female dog whelks as measured by the Vas Deferens Sequence Index
26 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 Seaacknowledged in the Esbjerg 1995 Ministerial Declarationconfirmed in Article 4 of Annex V of the OSPAR conventionEuropean Union policy impinges directly on the exploitation and management of the North Sea in several waysOnly the European Commission and Norway have the authority to determine legally binding legislation for the non-territorial waters of the North Sea.European Union policy impinges directly on the exploitation and management of the biological resources of the North Sea in several areas.
27 EC policy/legislation Common Fisheries Policyconservation of available and accessible living marine aquatic resourcessustainable useaccounting for marine environmental implicationsBirds Directivepart of EU Ramsar conventionprotects wild birds and their natural habitat within EU areaincludes seabirdsHabitats Directiveselection of areas to protect species and/or habitatsmember states required to designate Special Areas of Conservation (SACs)these SACs should create a network of protected areas (Natura 2000)includes many marine sitesThe Common Fisheries Policy was introduced to effect the management of the “common” fisheries resource. It was established in 1983, revised in 1992 and is due for further revision in The 1992 revision added to its overall objectives, including many of the buzz-words found in the articles and annexes of the CBD and OSPAR Comm., in that it now aimed to:conserve available and accessible living marine aquatic resources;exploit resources in a sustainable manner;take account of marine environmental implications.Other EC policy also impinges directly on the manner in which we utilise the marine biological resources of the North Sea. For example, the Birds Directive, part of the EU Ramsar Convention, aims to protect species of wild birds and their natural habitat within the EU area. This includes seabird species. The Habitats Directive provides substantial detail on the selection of areas to be listed because of threat to habitat or species. Member states are required to designate Special Areas of Conservation (SACs) under this directive. It is intended that these sites should create a network of protected areas, called Natura Numerous marine sites in the North Sea have been designated as part of this process.
29 Treaty/Convention/Declaration objectives Sustainable use of natural resourcesconservation of biodiversityprotection of species and habitatsreduction of pollutionminimisation of detrimental effects of anthropogenic activitiesrestoration of degraded systemsThese conventions and treaties are generally directed towards:Sustainable use of natural resources;conserving biodiversity;protecting species and habitats;reducing pollution;minimising detrimental effects of anthropogenic activities.
30 Treaty/Convention/Declaration principles Integrated managementAn “Ecosystem Approach” to managementThe “Precautionary Approach”Polluters should payAnd they draw on several underlying principles:Integrated management;An “Ecosystem Approach” to management;The “Precautionary Approach”;Polluters should pay.These objectives and principles tend to be rather “qualitative” in nature and this has given rise to some debate over precise definition, interpretation and implementation.
31 Current EcoQOs for fish and benthic communities Will the current ecosystem approach conserve species diversity and restore degraded systems?If it can’t, why is this the approach being adopted?
32 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.
33 “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 disturbanceAt present therefore we cannot advise managers how to achieve specific diversity objectivesTHIS IS WHAT “MAFCONS” SEEKS TO PROVIDEHow will the project achieve this goal?
34 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.
35 “MAFCONS” ObjectivesThus, 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 objectivesThis protocol will be soundly based in well-tested ecological theory
36 Huston’s 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.
37 Huston’s Model cont.Huston combined these two relationships to produce a three dimensional model relating species diversity simultaneously to both productivity and disturbance.
38 Huston’s 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.
39 Testing Huston’s model using spatial data Can we test Huston’s model using spatial data?Spatial distribution of effort?Done and do-able!
40 Testing Huston’s model using spatial data Spatial distribution of species diversity?Done and do-able!
41 Testing Huston’s 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 cruisessamples all analysed by size (length/weight) categorysize specific P/B ratios applied to estimate productivity
42 The Test of Huston’s 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?
43 “An Ecosystem Approach” If Huston’s 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.
44 “MAFCONS” ObjectivesBefore a species diversity protocol can be implemented within the current assessment/management process, one further step is requiredAny theoretical community model produced by “MAFCONS” will almost certainly deal in the currency of “ecological disturbance” based on fishing effortCurrently 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 WP6this will allow conversion between these two currenciesproduce an algorithm that converts specific TACs to the effort level (including spatial distribution of effort) required to attain them
45 “MAFCONS” Management Protocol WP1 product: a management protocol
46 “MAFCONS” Work Package Arrangement WP 7 covers all Co-ordination activities