Progress in Oceanography 87 (2010) 331–337

Contents lists available at ScienceDirect

Progress in Oceanography

journal homepage: www.elsevier .com/ locate /pocean

Global changes in marine systems: A social–ecological approach

R. Ian Perry a,⇑, Manuel Barange b, Rosemary E. Ommer c

a Fisheries & Oceans Canada, Pacific Biological Station, Nanaimo, BC, Canada V9T 6N7b GLOBEC International Project Office, Plymouth Marine Laboratory, Plymouth, PL1 3DH, UKc Adjunct Professor, Department of History, University of Victoria, PO Box 1700 STN CSC, Victoria BC, Canada V8W 2Y2

a r t i c l e i n f o

Article history:Available online 25 September 2010

0079-6611/$ - see front matter Crown Copyright � 2doi:10.1016/j.pocean.2010.09.010

⇑ Corresponding author. Tel.: +1 250 756 7137; faxE-mail address: Ian.Perry@dfo-mpo.gc.ca (R.I. Perr

a b s t r a c t

This paper presents the case for the adoption of a social–ecological approach to marine systems, whichrecognises the interdependence of biophysical and human social components. It discusses the manage-ment and governance challenges that arise when biophysical marine systems and fishing-dependenthuman communities, considered as interdependent marine social–ecological systems, are stressed byglobal changes. Drivers of change in marine biophysical systems include processes such as climate var-iability and change, human processes such as fishing, habitat degradation, and contaminants, and theirinteractions. Fishing makes marine populations, marine communities, and ecosystems more sensitiveto climate forcing. Human communities’ responses to marine ecosystem variability can ameliorate orexacerbate these changes. Drivers of change in fishing-dependent human communities include environ-mental and resource changes, human social changes relating to demographics, health issues, and shiftingsocietal values, and their interactions at local and global scales. This multi-faceted interdependencemeans that fisheries management needs to develop approaches which maintain the capacities of bothfish and fishing communities, acting as interactive social–ecological systems, to adapt to the impactsof globalization and environmental change. In general, a less-heavily fished marine system managedon an ecosystem basis is likely to provide more stable catches under normal conditions than would aheavily fished system. However, under climate change the whole ecosystem may alter in ways that can-not yet be predicted. Issues of scale are crucial, and fisheries governance needs a concerted effort to con-trast and compare multiple local management ‘experiments’, since the exposure, susceptibility, andadaptive capacities of biophysical and human social marine systems varies immensely. These ‘experi-ments’ should be conducted in developed and developing nations so as to understand the range of policyissues which support marine social–ecological systems in an era of global change.

Crown Copyright � 2010 Published by Elsevier Ltd. All rights reserved.

1. Introduction

As understanding of the responses of marine ecosystems to cli-mate variability and change expanded during the 1990s, so didunderstanding of the human impacts of fishing, contaminants,and habitat change on marine ecosystems (e.g. Pauly et al., 2002;Kaiser et al., 2003; Jennings et al., 2005; Lotze et al., 2006). This in-creased understanding led to the realisation that marine ecosysteminteractions with humans and the impacts of climate change arenot additive, but multiplicative: it is both climate and fishing, ta-ken together, that affect marine ecosystems (Perry et al., 2010a).Also during this time the concept of social–ecological systems be-gan to emerge (Berkes and Folke, 1998) and to be proposed formarine ecosystems (Ommer and Team, 2007; Berkes, in press).Such systems can be thought of as comprising two interactingsub-systems: the biophysical (including climate), and the human

010 Published by Elsevier Ltd. All r

: +1 250 756 7053.y).

(including cultural, management, economic, socio-political, andethical aspects) (Fig. 1; Perry et al., 2010b).

When the Global Ocean Ecosystem Dynamics (GLOBEC) pro-gram began in the late 1980s and early 1990s, it was seen as a nat-ural science program focused on examining marine ecosystemresponses to climate variability and change. This was encapsulatedin the program goal statement of GLOBEC: ‘‘To advance our under-standing of the structure and functioning of the global ocean eco-system, its major sub-systems, and its response to physical forcingso that a capability can be developed to forecast the responses ofthe marine ecosystem to global change” (GLOBEC, 1999). However,emerging conceptual developments such as social–ecologicalthinking considerably broadened the scope of GLOBEC and thetypes of problems and issues that GLOBEC would need to consider,and to which it could contribute, as it worked to understand thecauses and consequences of marine ecosystem changes. This papertherefore contributes to the discourse on the human dimensions ofmarine ecosystem change within the broader context of studies oninteractive social–ecological systems. It presents the case foradopting a social–ecological approach to marine systems, which

ights reserved.

Water properties, circulation patterns,

enrichment processes

Global forcing and responses

Regional and local responses

Kin relationships; occupational

pluralism

Demographic, cultural features;

institutional, economic bases

Socio-economic development;

legislative regime

Biophysical sub-system Human sub-system

Marine social-

ecological system

Plankton production, food-web dynamics

Fish production

and distribution

Atmospheric pressure

systems; global atmosphere

tele-connections

Global and national markets; capital and labour

flows; legal instruments

Fishing vessels, gears; target

species

Fig. 1. Schematic illustrating characteristics and processes within the biophysicaland human sub-systems of marine social–ecological systems, and how they areinterconnected. Predominant connections between the natural (non-human) sub-system and the human sub-system occur at large-scales (regional to global) and atthe local scales (local to regional) at which fish production and distributionsinteract with fishing. Solid arrows represent stronger interactions; dashed arrowsrepresent weaker effects. Reprinted with permission from Perry et al. (2010b).

Table 1Examples of stressors of biophysical marine systems.

Biophysical stressors Human stressors

Climate variability FishingClimate trends (change) Habitat degradationAcidification ContaminantsChanges in oxygen concentrations Introductions of exotic

speciesInternal ecosystem dynamics (predator – prey

interactions; disease)Mineral extraction

332 R.I. Perry et al. / Progress in Oceanography 87 (2010) 331–337

recognises the interdependence of biophysical and human socialcomponents. Specifically, it illustrates how separating the stressorson marine ecosystems into climate (often referred to as bottom-upforcing) and fishing (often referred to as top-down forcing), with-out considering the broader human social processes that influencepeople’s relationships with the sea, will fail to correctly recogniseand address changes in these social–ecological systems. The paperalso discusses the governance, management and policy challengesthat arise when marine ecosystems and fishing-dependent humancommunities are considered as interdependent marine social–ecological systems.

2. Marine social–ecological systems and change

Biophysical marine systems (what typically are called ‘‘naturalmarine ecosystems”) are affected by environmental and humanstresses (Table 1). These include (inter alia) climate variabilityand change, physical processes controlling water properties andcirculation, and biological processes related to population dynam-ics, food webs, and ecosystem processes (Moloney et al., 2010). Onthe human side, stressors of these biophysical marine systems in-clude fishing, habitat alterations, contaminants, species introduc-tions, and changes in freshwater flows into marine systems, aswell as other impacts (Brander et al., 2010). In a (additive) studyof direct human forcing of marine systems, Halpern et al. (2008)concluded that no area in the global ocean is unaffected by humaninfluence and that 41% is strongly affected by multiple stressors,but that large areas with relatively light human impacts still re-main. They also concluded that fishing impacts in particular arewidespread and important in both coastal and offshore areas.

Stressors of human social systems that are dependent on mar-ine ecosystems include (inter alia) obvious local events such asenvironmental and resource changes; as well as human demo-graphic and related changes such as age structure, leisure time(greater or lesser), and gender roles; and legal and policy changes(Table 2). At larger, often global scales, stressors on human socialsystems which can impact marine ecosystems include economicchanges (which can also be local stressors), and several of the im-pacts of globalization such as trade, technological advances withfish finding, catching, and processing, and changing societal goals,such as the UN Code of Conduct for Responsible Fisheries (Garcia,2000) and the enthusiasm for marine products certification (Thra-ne et al., 2009). Global stressors also include infectious diseases,which have been shown by Allison and Seeley (2004) to be a poten-tially significant threat to the food security of many developing na-tions. The overarching reality of these stressors in both Tables 1and 2, however, is that they will interact in a multitude of unex-pected ways to produce poorly anticipated or un-predictableoutcomes.

Several studies have examined the interactions among thestressors of biophysical marine systems (Table 1), particularly fish-ing impacts that can alter the capacities of biophysical marine sys-tems to adapt to global (especially climate) changes. The potentialimpacts of climate variability and change on marine systems,therefore, cannot be fully understood by taking a bottom-up ap-proach alone. Climate affects marine biophysical systems througha variety of processes (Drinkwater et al., 2010), of which tempera-ture is perhaps the most crucial (Cheung et al., 2010) as it has di-rect influence on the growth, swimming speed and activity rates,reproduction and recruitment, and distributions and timing of lifehistory events of marine organisms. Other climate-determined fea-tures include vertical stratification, sea ice, turbulence, and circula-tion (Barange and Perry, 2009); climate also has indirect effects onfoodwebs and trophic interactions (Drinkwater et al., 2010). Fish-ing impacts marine populations directly and indirectly since itcan modify the characteristics of marine biophysical systems sothat they no longer respond, or have the same capacity to adapt,to climate forcing as they did in their un-fished state (Planqueet al., 2010). Ottersen et al. (2006), for example, describe how thecorrelation of the abundance of age three Atlantic cod (Gadus mor-hua) and temperature has become increasingly stronger and moresignificant over the second half of the last century as fishing has re-moved the big old fish and reduced the median age from greaterthan 10 years to 7 years. Consequently, this Atlantic cod populationnow responds more rapidly to environmental variability than it did40 years ago because of the loss of the buffering capacity providedby long-lived individuals. Moreover, Anderson et al. (2008) demon-strate that age-truncated or juvenescent populations of fishes inthe California Current system have increasingly unstable popula-tion dynamics as a result of changes in such demographic charac-teristics as growth rates. Hilborn et al. (2003) describe how theproductivity of sockeye salmon (Oncorhynchus nerka) in a part ofBristol Bay, Alaska, has been sustained through different climateregimes over the past 100 years. This was because of a mixture

Table 2Examples of stressors of fishing-dependent human societies.

Local stressors Global stressors

Environmental changes Economic changesResource changes Market/trade changesEconomic changes Technological improvementsDemographic changes Infectious diseasesGender/ethnic relationships Shifting societal and international goalsLaw and property relationsPolicy changes

100

10

1 Fishing tow

Fishing trip

price fluctuations and economic cycles

human working lifespan

Fishing

Spat

ial s

cale

(km

)

Hr Day Wk Mo Season Yr Decade Century

10000

1000

100

10

1

inter-decadal

oscillations

currentsfronts

stratification

water mass exchanges

tideturbulence Physical

10000

1000

100

10

1

stock abundancemigration

spawning

bottom fidelity

schooling

vertical migration

feeding

Biological

10000

1000

100

10

1 Fishing tow

Fishing trip

price fluctuations and economic cycles

human working lifespan

Fishing10000

1000

100

10

1 Fishing tow

Fishing trip

price fluctuations and economic cycles

human working lifespan

Fishing

Hr Day Wk Mo Season Yr Decade Century

Temporal scale

10000

1000

100

10

1

Management Regulation

Employment

Investment

PoliticalBusiness

Human

Fishing Communities

Hr Day Wk Mo Season Yr Decade Century

Temporal scale

10000

1000

100

10

1

Management Regulation

Employment

Investment

PoliticalBusiness

Human

Fishing Communities

a

b

c

d

100

10

1 Fishing tow

Fishing trip

price fluctuations and economic cycles

human working lifespan

Fishing

Spat

ial s

cale

(km

)

Hr Day Wk Mo Season Yr Decade Century

10000

1000

100

10

1

inter-decadal

oscillations

currentsfronts

stratification

water mass exchanges

tideturbulence Physical

10000

1000

100

10

1

stock abundancemigration

spawning

bottom fidelity

schooling

vertical migration

feeding

Biological

10000

1000

100

10

1 Fishing tow

Fishing trip

price fluctuations and economic cycles

human working lifespan

Fishing10000

1000

100

10

1 Fishing tow

Fishing trip

price fluctuations and economic cycles

human working lifespan

Fishing

Hr Day Wk Mo Season Yr Decade Century

Temporal scale

10000

1000

100

10

1

Management Regulation

Employment

Investment

PoliticalBusiness

Human

Fishing Communities

Hr Day Wk Mo Season Yr Decade Century

Temporal scale

10000

1000

100

10

1

Management Regulation

Employment

Investment

PoliticalBusiness

Human

a

b

c

d

Fig. 2. Space/time-scale diagram of characteristic processes from the biophysicalsciences: (a) physical; (b) biological and from the human social sciences; (c) fishing;(d) fishing communities. Reprinted with permission from Perry and Ommer (2003).

R.I. Perry et al. / Progress in Oceanography 87 (2010) 331–337 333

of three stocks in different locations, each of which had compen-sating responses to shifting climate conditions; Schindler et al.(2010) have termed this the within-species portfolio effect. Thestudy of Hilborn et al. (2003) is an example of why it is necessaryto maintain different stocks of the same species but with diversespatial distributions as a buffer against climate variability andchange (Planque et al., 2010).

In synthesising the manner in which direct human forcing ofmarine biophysical systems interacts with climate forcing, Perryet al. (2010a) concluded that fishing tends to remove individualfish with particular characteristics that, in aggregate, can impactthe structure and function of higher levels of organisation. Removalof older fish (by changing life-history characteristics such as age-of-first-spawning) and/or depletion of spatially distinct sub-populations can collectively make populations of fish more sensi-tive to climate variability. Reduction of the mean size of fish anda corresponding increase in their turn-over rates can alter the com-position of communities of fish and cause them to track environ-mental variability more closely (Jennings and Brander, 2010).Finally, fishing causes entire marine biophysical systems to be-come more sensitive to climate forcing by evolving towards stron-ger bottom-up control (e.g. Frank et al., 2007). Thus there arestrong interactions among the environmental and human stressors(Table 1) of marine biophysical systems, to the extent that anincomplete (at best) or possibly incorrect (at worst) understandingof what is driving changes in these systems may occur if only oneclass of stressor is examined.

Interactions among biophysical and human stressors acting atlocal and global scales in turn drive changes in fishing-dependenthuman societies – the social side of the interdependent social–eco-logical marine system. The scale of analysis is crucial here (Perryet al., 2010b). Time–space scale maps are commonly used to por-tray the range of scales over which physical and biological pro-cesses overlap (e.g. Haury et al., 1978). Human processes such asfishing trips, employment, investment and business cycles can use-fully be added to such scale maps (Fig. 2), thereby enabling directcomparisons across all scales and processes, and identifying thedifferent scales at which different processes apply. This is crucialfor good fisheries management, since it is immediately apparentthat the scaling of fishing activities requires several categoriesranging from the high-technology and wide-ranging deep-seafleets of some nations, through intermediate-size industrial fleets,to small-boat owner-operator enterprises and individual subsis-tence-based local fisheries. Each of these categories has differentscales of impacts on fish and fish communities (e.g. Ommer andTeam, 2007). These fishing activities also are driven by differentmotivations: local subsistence fisheries are primarily concernedwith family food security, for example, while at national and globalscales the concern of the industrial large-scale fleets is the deriva-tion of profit from fish products possessed of high export value.These larger enterprises are increasingly driven by the processesof globalization (e.g. Taylor et al., 2007; Table 2).

Human social systems have developed the capacity to adjust tomarine ecosystem changes, at least those changes within the rangeof variability that they have encountered in the past. Such strate-

gies include exploiting marine resources more intensively, initiallyat local scales but expanding to larger scales as the crisis persists;deployment into activities other than fishing thereby building mul-tiple and diverse income sources; increasing use of familial andcommunity support networks, as well as state support systems;undertaking seasonal or permanent migrations; and importing fishat the national level to deal with shortages and to supplement foodsupplies (Perry and Sumaila, 2007). Kalikoski et al. (2010) describehow the lack of institutional support for small-scale fishing com-munities combined with an erosion of traditional resource systemsand declining fish stocks led to increasing vulnerability of fishingcommunities in southern Brazil. They concluded that fishing com-munities which diversified and had a higher degree of self-organi-sation were better able to reduce their vulnerability during adverseconditions. Diversification strategies included other species, indus-

334 R.I. Perry et al. / Progress in Oceanography 87 (2010) 331–337

tries other than fishing, and to jobs in local cities. In other loca-tions, diversification to other species can include a move awayfrom marine species and an increase in the harvesting of terrestrialspecies, legal or otherwise (e.g. Brashares et al., 2004).

Migration is another response used by human societies to ad-just to marine ecosystem changes. Migration can take many forms,such as temporary movements by fishers to follow the fish withtheir families remaining at home, to seasonal and more permanentmigrations with families to exploit new fishing opportunities else-where or jobs outside of fishing. Njock and Westlund (2010) pro-vide a case study of fisheries-related migrations in West Africa,including who migrates, why they migrate, and how they are re-ceived by the recipient communities. They conclude that it isimportant to recognise and to include migrant fishers into fisheriesmanagement policies, in particular with impending climatechange. Another aspect of migration is the movement of youngpeople out of fishing communities (and therefore usually out offishing), in particular to larger urban centres, with one conse-quence being the ageing of traditional fishing communities (Om-mer and Team, 2007; Murray, in press). Taken together, thesefishing family responses to multiple stressors both reflect and as-sist in the restructuring of human social systems in ways that ben-efit some sectors while others are disadvantaged, includingdeclines in the importance of fishing in the community and a shiftin the control of fishing away from individuals to corporations andmore urban centres (Hamilton, 2007; Murray, in press).

Fisheries management thus faces a cross-scale problem thatreaches from local to global in terms of activity, purpose and moti-vation, and includes stressors ranging from the ‘natural’ ecosystemto the human social system. It follows that to understand fish andfisheries, cross-scale analyses are needed. Such work will identifypathways to change, and the feedback processes involved therein,while place-based studies will provide the necessary understandingof human motivations, without which effective fisheries manage-ment cannot be secured (Perry and Ommer, 2003). Complex as thisis, an important further complication is the fact that the biophysicaland social (human) sub-systems are mutually interdependent: theyinteract, often iteratively. This means that global changes, that areoften difficult to predict, can combine and interact with the impactsof fishing, creating increased vulnerability for both fish and fishersthrough unexpected and undesirable changes in marine biophysicalsystems, such as fish stock collapses. Such crises damage both thebiophysical and human communities that depend on these marinesystems (Ommer and Team, 2007; Berkes, in press).

There is, therefore, an urgent need to move away from a uni-directional concept of humans as stressors of marine systems andtowards an appreciation of the interactive nature of marine so-cial–ecological stressors, including an awareness that these hu-man–biophysical systems possess interdependent adaptivecapacities and vulnerabilities. The interactions between the bio-physical and the human therefore need to be thought of less interms of managing the variability in the flow of biophysical re-sources and more in terms of maintaining the structure, function,biodiversity, and capacity of the marine social–ecological systemto adapt to stresses and to reduce vulnerabilities (Berkes, in press).Vulnerability is, of course, tightly tied to adaptive capacity, which isthe ability and capacity to cope with change in the human and bio-physical environment. If such capacity is poor, then vulnerability tochange is heightened (Tiessen et al., 2007; Allison et al., 2009).

3. Governance of marine social–ecological systems in an era ofglobal change

There are clear implications for the management and gover-nance of marine social–ecological systems under conditions of glo-

bal change in what has been discussed above. Changes to theseinterdependent systems will be complex, and will probably exhibitsignificant non-linear, threshold, and feedback effects caused bythe interactions between environmental changes and the impactsof globalization (e.g. Leichenko and O‘Brien, 2008). Uncertainty willbe high, in particular with increasing climate changes and the cur-rently poor ability to downscale global climate models to localareas (Barange and Perry, 2009). What is needed, therefore, is a ro-bust and flexible governance system, involving both parts of mar-ine social–ecological systems in the face of such uncertainty.Recent thinking (e.g. IPCC, 2007) suggests that maintenance ofadaptive capacity is essential.

What does building and maintaining the adaptive capacities ofmarine social–ecological systems mean in practice? For biophys-ical systems it means the adoption of policies and approacheswhich reduce overall intensive fishing pressure (e.g. McIlgormet al., 2010). A shift in fisheries management practices away fromsingle-species approaches and towards assemblages of specieswould reduce the pressure on those single species and permitflexibility of choice among target species by fishers (Jenningsand Brander, 2010). It is clear also from the discussion above ofhuman responses to stressors in the marine biophysical sub-systems, that biomass cannot be the sole consideration in man-agement (e.g. Ommer and Team, 2007; Planque et al., 2010). Itfollows that other characteristics of fish population health, suchas age at first spawning, will also have to be included in any anal-ysis that seeks to identify robust governance systems (e.g. Perryet al., 2010a). In addition to abundance and biomass targets, man-agement must strive for a ‘balanced portfolio’ of diverse ages offish (e.g. Ottersen et al., 2006) and diverse sub-populations (e.g.Schindler et al., 2010).

There is a related need to recognise the dangers and changesthat are likely to occur in ecosystems if the trophic level andturn-over times of marine fish communities are decreased, sincesuch altered systems will track environmental variability more clo-sely and in such a way that they appear to become more variableand less predictable (Perry et al., 2010a). Fish stock rebuildingplans need to consider current productivity conditions (Barangeet al., 2010) since major expenses directed at rebuilding depletedpopulations may be wasted if the productivity conditions, as deter-mined by climatic, environmental, and human factors, are unfa-vourable. In contrast, depleted fish stocks may begin to recoverunder favourable productivity conditions even without much man-agement intervention. It is clear that considerable research re-mains to be done before it will be possible to determine goodand poor conditions for individual fish populations.

Adopting a social–ecological approach to the governance ofthese biophysical–human systems requires recognising that areduction of overall fishing pressure would ease the stresses onthe biophysical sub-system but may shift the burden of impactsto the social (human) sub-system. For example, fish currently pro-vide almost 3 billion people with 15% of their per capita animalprotein intake; fish as a protein source is particularly importantin the developing world (FAO, 2009). The harvesting of marineproducts and its related multiplier effects provide activities thatare a source of work for hundreds of millions of people globally.Aquatic products contribute from 0.5% to 2.5% of the global grossdomestic product (FAO, 2009). The challenge, thus, is how to re-duce fishing pressure on a global basis. Part of the solution willbe to identify activities and employment opportunities that canprovide alternative sources of protein and employment, but therewill also have to be reductions in intensive industrial fishery quo-tas. Aquaculture, which is sometimes offered as an industry whichcould supply considerable amounts of alternative marine-derivedprotein (e.g. Naylor et al., 2000; De Silva and Soto, 2009), has itsown set of environmental and social issues.

1. Global climate model projections

2. High-resolution shelf seas physical-biological models for 20 Large Marine Ecosystems

3. Metabolic-based fish biomass estimation models

4. Bio-economic models of marine commodities

5. National vulnerability assessments

Fig. 3. Modeling the impacts of climate change on global fish production andestimating the consequences for national societies, as proposed by Barange et al. (inpress).

R.I. Perry et al. / Progress in Oceanography 87 (2010) 331–337 335

It must also be recognised that current marine managementand fisheries policies may not be appropriate under future climatechange conditions. For example, present fisheries management ref-erence points, with their assumptions of stock growth and produc-tivity, were developed during previous ocean productivityconditions and may not be appropriate under future conditions(e.g. Cheung et al., 2010). Increasing uncertainty, combined withan urgent need to adapt fisheries management and stock rebuild-ing plans to current conditions, indicate that a flexible manage-ment system is needed. Increased uncertainty requires increasedmonitoring and reporting of current conditions. This suggests thatnew methods and techniques for observing the ocean (e.g. Harriset al., 2010) along with increased collaboration with fishing peo-ples is in order. It is important that fisheries managers recognisethat it is fishers, who live daily with the complexity of ocean con-ditions, who are often the first to recognise change as they occur.Greater communication with, and involvement of, such stakehold-ers in marine observation programs would be beneficial (Ommerand Team, 2007; Vodden, 2009). Increased monitoring and report-ing of conditions on the human side are also needed, to be able toassess the state of the full interdependent social–ecological sys-tem. How stakeholders are involved in decision making, and howtheir information is combined with the information from govern-ment and academic scientists, is an important issue, and someexciting approaches using knowledge-based electronic decisionsupport tools are being developed (e.g. Paterson et al., 2010).

A full social–ecological systems approach to the management ofmarine resources would involve multiple-scale (from governmentto local fishing sectors) objective-setting, based on societal choices,including ecological, economic, cultural and social considerations.Operational objectives would then need to be established, requir-ing the identification of indicators and reference points for sectorimpacts (Barange et al., 2010). Ultimately, new institutions maybe needed for special problems. For example, progress is beingmade globally towards ecosystem-based marine management(Garcia and Cochrane, 2005; Barange et al., 2010). This still oper-ates from the narrow view of the marine ecosystem as being com-prised only of the biophysical system, however, in which humansare treated as external stressors. This is inadequate. The conceptu-alization of ecosystems, and the current approaches to ecosystem-based management, need to be expanded to fully embrace thesocial, economic, political, cultural, and ethical issues inherent inhuman interactions with the ocean, thus moving management to-wards a full marine social–ecological systems approach (e.g. DeYoung et al., 2008; Ommer et al., 2009).

In addition, ‘institutions’ need to be broadly defined. Marketsare a global institution, and market chains involve actors such asmiddlemen, for example. Institutions such as these need to beunderstood and acknowledged in management thinking. In EastAfrica, middlemen have played a positive role in the livelihoodstrategies of fishers by providing financial credit during periodsof resource scarcity. Historically, however, they have often playeda negative role in the stresses on marine ecosystems, particularlywhen they are key parts of financial loan systems that create incen-tives to continue fishing in order to ensure that those loans arethen paid back, even when fisheries resources are scarce (Cronaet al., 2010).

Migratory trans-boundary stocks represent a special problem.The shifting fish distribution and migration patterns that will re-sult from climate change are likely to disrupt traditional fish shar-ing and access agreements, thereby producing ‘‘winners” and‘‘losers”. The US – Canada treaty on the sharing of Pacific salmonduring their coastal ocean migrations (Miller and Munro, 2004) isan example of a legal instrument likely to be affected by the im-pacts of changing ocean conditions on salmon distributions. Milleret al. (in press) provide an example of skipjack tuna (Katsuwonus

pelamis) in the west-central Pacific and how their distributions,corresponding catch locations, and allocation of benefits amongfishing fleets and coastal nations change with El Niño conditions.What these changes in circumstances and conditions mean is thatmarine resource managers need to be aware of who benefits, wholoses, and how that can shift when environmental conditions andmanagement policies change. In the tropical Pacific tuna example,policies focussed on controlling the overall harvesting capacity of afleet will favour the distant-water fleet over the coastal nations,whereas policies focused on limiting harvesting opportunities, forexample, by limiting the number of harvesting days, will tend tofavour the coastal nations (Miller et al., in press).

4. Ways forward

Fisheries stock assessments have yet to fully integrate environ-mental, climate change, ecological, and human behavioural consid-erations into their models and management recommendations.This has to happen quickly: it is a crucial step in the implementa-tion of science-based social–ecological ecosystem approaches tofisheries management and should be made a priority. A next stepis the development of interdependent climate-ocean-fish-peoplemodels. Efforts to date have focused specifically on the potentialimpacts of climate change. For example, Barange et al. (in press)identified four key issues in predicting the biophysical impactsand socioeconomic consequences of climate change on fisheriessystems. These include: (i) the difficulties of downscaling globalclimate models to the scales of biological relevance, (ii) uncertain-ties over determining future net primary production and its trans-fer through the food chain, (iii) difficulties in separating themultiple stressors affecting fish production, and (iv) inadequatemethodologies to estimate human vulnerabilities to these changes.To these can be added the difficulty of incorporating cross-scaleinteractions.

The approach of Barange et al. (in press; Fig. 3) is to downscaleglobal climate predictions to estimate the plankton productivity oflarge marine ecosystems, to link primary production to fish pro-duction based on macro-ecological theory, and then to assess na-tional vulnerabilities to changes in fish production usingmethodologies similar to Allison et al. (2009). While such interde-pendent biophysical – human models are a good start, they ulti-mately need to go further and downscale in order to grapplewith methods that will incorporate understanding of the motiva-tions and capacities for adaptation of human societies. For fishingpeoples, life is lived locally and is embedded within their particularlocal environments. Awareness of scale issues is crucial (e.g. Perryand Ommer, 2003), since people experience the impacts of globalenvironmental changes and globalization at local scales. This

336 R.I. Perry et al. / Progress in Oceanography 87 (2010) 331–337

means that it can be difficult to correctly attribute cause and effectin marine social–ecological systems, and therefore to identify solu-tions that will be responsive to changes in both parts of the system.When studying such interdependent social–ecological systems atmultiple scales, it is therefore important to build inter-disciplinaryteams of natural and social scientists who can think outside thebox of their disciplinary expertise and work together creativelyto address these challenging problems (e.g. Ommer et al., 2008).It will also be necessary to take a long-term view as well as recogn-ising the short-term necessities. Such a view is needed becauseshort-term coping strategies such as fishing harder or in fish refugeareas may be mal-adaptive in the longer-term, leading to increas-ingly significant ecosystem damage. Similarly, management deci-sions that prioritise short-term economic and social objectivesover resource conservation goals may be detrimental to future pro-ductivity of both marine biophysical and human social systems(e.g. Leal et al., 2010). Fundamentally, it must be recognised thatone method of governance cannot fit all circumstances and scales.The exposure, susceptibility, and adaptive capacities of interdepen-dent marine biophysical – human social systems vary immensely,and one framework and policy response simply cannot apply in allsituations.

How then can policies be developed that are flexible enough tosupport a wide range of adaptive situations? Miller et al. (2010)recommend an integrative science approach which would examinepolicy options with respect to their robustness to uncertainty, andwould develop better assessments of the interdependent behav-ioural responses of fish, humans, and institutions. In a full social–ecological approach as proposed in the present study, policiesdeveloped for large spatial scales (e.g. global or ocean basin, highlymigratory populations) may be rather general, however, and localmanagement measures derived from these policies will need tobe modified to meet particular local biophysical and human socialcircumstances. These local approaches can then be considered as‘experiments’, each with their own mixture of local (possibly un-ique) and global (i.e. common amongst many locations) features.The challenge will be to maintain communication amongst thesemultiple local ‘experiments’, and to contrast and compare suc-cesses and failures in order to derive general lessons. Such ‘‘exper-iments” will need to be conducted in both developed anddeveloping nations. This approach would provide a basis for evi-dence-based policy development (e.g. Pullin et al., 2009). However,it must be recognised that the biggest losers in regard to the im-pacts of climate change in marine social–ecological systems arelikely to be in the developing world (Allison et al., 2009; Cheunget al., 2010: Badjeck et al., 2010), because of the potential impactsof climate change on their biophysical systems and the lack of ade-quate state social–support systems in many parts of the developingworld.

5. Conclusions

This paper proposes that adopting a interdependent social–ecological approach to marine systems which recognises the inter-active nature of the biophysical and human social systems, is nec-essary for understanding and developing effective managementand governance strategies in a world of increasing uncertainty. Ashift to a governance system that recognises and addresses the di-verse stressors and interacting impacts of globalization and envi-ronmental change is essential. Embracing the concept ofinterdependent marine social–ecological systems means going be-yond the traditional biophysical definition of marine ecosystemsand recognising that fisheries management must include humansboth as drivers and recipients of changes in these interdependentsystems. Said otherwise, the thinking that managers need to adopt

is not ‘‘climate-or-fishing”, ‘‘biophysical marine system-or-humansocial system”, but rather ‘‘climate-and-fishing”; ‘‘biophysical mar-ine system-and-human social system”. These are the importantinterdependent components of fisheries management that needto be recognised. To provide good future governance under a so-cial–ecological fisheries system model, research by integratedteams of natural and social scientists will be essential. This willlead to a fuller exploration of the concepts of vulnerability andadaptive capacity in both biophysical and human social compo-nents of these social–ecological systems. Ultimately, these issuesare critical for addressing the major challenges of sustainable mar-ine ecosystems, people’s livelihoods, and reducing poverty in anuncertain world.

Acknowledgements

We thank the Guest Editor, Dr. Geir Ottersen, and the anony-mous reviewers for their very helpful comments on this paper.

References

Allison, E.H., Seeley, J., 2004. HIV and AIDS among fisherfolk: a threat to ‘responsiblefisheries’? Fish and Fisheries 5, 215–234.

Allison, E.H., Perry, A.L., Badjeck, M.-C., Adger, W.N., Brown, K., Conway, D., Halls,A.S., Pilling, G.M., Reynolds, J.D., Andrew, N.L., Dulvy, N.K., 2009. Vulnerability ofnational economies to the impacts of climate change on fisheries. Fish andFisheries 10 (2), 173–196.

Anderson, C.N.K., Hsieh, C.-H., Sandin, S.A., et al., 2008. Why fishing magnifiesfluctuations in fish abundance. Nature 452, 835–839.

Badjeck, M.-C., Allison, E.H., Halls, A.S., Dulvey, N.K., 2010. Impacts of climatevariability and change on fishery-based livelihoods. Marine Policy 34, 375–383.

Barange, M., Perry, R.I., 2009. Physical and ecological impacts of climate changerelevant to marine and inland capture fisheries and aquaculture. In: Cochrane,K., De Young, C., Soto, D. and Bahri, T. (Eds). Climate Change Implications forFisheries and Aquaculture. Overview of Current Scientific Knowledge. FAOFisheries and Aquaculture Technical Paper. No. 530. Rome. FAO. pp. 7–106.

Barange, M., O’Boyle, R., Cochrane, K.L., et al., 2010. Marine resources managementin the face of change: from ecosystem science to ecosystem-basedmanagement. In: Barange, M., Field, J., Harris, R., Hofmann, E., Perry, R.I.,Werner, F. (Eds.), Marine Ecosystems and Global Change. Oxford UniversityPress, Oxford, pp. 253–284.

Barange, M., Allen, I., Allison, E., et al., in press. Predicting the impacts andsocioeconomic consequences of climate change on global marine ecosystemsand fisheries: the QUEST_Fish framework. In: Ommer, R.E., Perry, R.I., Cury, P.,Cochrane, K. (Eds.). World Fisheries: A Social–Ecological Analysis. Fish andAquatic Resources Series. Wiley-Blackwells, Oxford.

Berkes, F., in press. Marine social–ecological systems. In: Ommer, R.E., Perry, R.I.,Cochrane, K., Cury, P. (Eds.). World Fisheries: A Social–Ecological Analysis. Fishand Aquatic Resources Series. Wiley-Blackwells, Oxford.

Berkes, F., Folke, C. (Eds.), 1998. Linking Social and Ecological Systems: ManagementPractices and Social Mechanisms for Building Resilience. Cambridge UniversityPress, Cambridge, UK.

Brander, K.M., Botsford, L., Ciannelli, L., et al., 2010. Human impacts on marineecosystems. In: Barange, M., Field, J., Harris, R., Hofmann, E., Perry, R.I., Werner,F. (Eds.), Marine Ecosystems and Global Change. Oxford University Press,Oxford, pp. 41–71.

Brashares, J.S., Arcese, P., Sam, M.K., Coppolillo, P.B., Sinclair, A.R.E., Balmford, A.,2004. Bushmeat hunting, wildlife declines, and fish supply in West Africa.Science 306, 1180–1183.

Cheung, W.W.L., Lam, V.W.Y., Sarmiento, J.L., et al., 2010. Large-scale redistributionof maximum fisheries catch potential in the global ocean under climate change.Global Change Biology 16, 24–35.

Crona, B.I., Nyström, M., Folke, C., Jiddawi, N., 2010. Middlemen, a critical social–ecological link in coastal communities of Kenya and Zanzibar. Marine Policy 34,761–771.

De Silva, S.S., Soto, D., 2009. Climate change and aquaculture: potential impacts,adaptation and mitigation. In: Cochrane, K., De Young, C., Soto, D., Bahri, T.(Eds.), Climate Change Implications for Fisheries and Aquaculture. Overview ofCurrent Scientific Knowledge. FAO Fisheries and Aquaculture Technical Paper,No. 530. Rome, FAO, pp. 151–212.

De Young, C., Charles, A., Hjort, A., 2008. Human Dimensions of the EcosystemApproach to Fisheries: An Overview of Context, Concepts, Tools and Methods.FAO Fisheries Technical Paper, No. 489. Rome, FAO.152p.

Drinkwater, K.F., Beaugrand, G., Kaeriyama, M., Kim, S., Ottersen, G., Perry, R.I.,Pörtner, H.-O., Polovina, J., Takasuka, A., 2010. On the processes linking climateto ecosystem changes. Journal of Marine Systems 79, 374–388.

FAO, 2009. The State of World Fisheries and Aquaculture 2008. FAO Fisheries andAquaculture Department, Food and Agriculture Organization of the UnitedNations, Rome, 196 p.

R.I. Perry et al. / Progress in Oceanography 87 (2010) 331–337 337

Frank, K.T., Petrie, B., Shackell, N.L., 2007. The ups and downs of trophic control incontinental shelf ecosystems. Trends in Ecology and Evolution 22 (5), 236–242.

Garcia, S.M., 2000. The FAO definition of sustainable development and the code ofconduct for responsible fisheries: an analysis of the related principles, criteriaand indicators. Marine and Freshwater Research 51 (5), 535–541.

Garcia, S.M., Cochrane, K.L., 2005. Ecosystem approach to fisheries: a review ofimplementation guidelines. ICES Journal of Marine Science 62 (3), 311–318.

GLOBEC, <www.globec.org>, 1999. Global Ocean Ecosystem Dynamics (GLOBEC)Implementation Plan. GLOBEC Report 13/IGBP Report 47. GLOBEC InternationalProject Office, Plymouth, UK.

Halpern, B.S., Walbridge, S., Selkoe, K.A., et al., 2008. A global map of human impacton marine ecosystems. Science 319, 948–952.

Hamilton, L.C., 2007. Climate, fishery and society interactions: observations fromthe North Atlantic. Deep-Sea Research II 54, 2958–2969.

Harris, R.P., Buckley, L.J., Campbell, R., et al., 2010. Dynamics of marine ecosystems:observation and experimentation. In: Barange, M., Field, J., Harris, R., Hofmann,E., Perry, R.I., Werner, F. (Eds.), Marine Ecosystems and Global Change. OxfordUniversity Press, Oxford, pp. 129–178.

Haury, L.R., Mc Gowan, J.A., Wiebe, P.H., 1978. Patterns and processes in the time–space scales of plankton distributions. In: Steele, J.H. (Ed.), Spatial Pattern inPlankton Communities. Plenum, NY, pp. 277–327.

Hilborn, R., Quinn, T.P., Schindler, D.E., Rogers, D.E., 2003. Biocomplexity andfisheries sustainability. Proceedings of the National Academy of Sciences of theUnited States of America 100 (11), 6564–6568.

IPCC, 2007. Summary for policymakers. In: Parry, M.L., Canziani, O.F., Palutikof, J.P.,vanderLinden, P.J., Hanson, C.E. (Eds.), Climate Change 2007: Impacts,Adaptation and Vulnerability. Contribution of Working Group II to the FourthAssessment Report of the Intergovernmental Panel on Climate Change.Cambridge University Press, Cambridge, UK, pp. 7–22.

Jennings, S., Brander, K., 2010. Predicting the effects of climate change on marinecommunities and the consequences for fisheries. Journal of Marine Systems 79,418–426.

Jennings, S., Freeman, S., Parker, R., Duplisea, D.E., Dinmore, T.A., 2005. Ecosystemconsequences of bottom fishing disturbance. American Fisheries SocietySymposium 41, 73–90.

Kaiser, M.J., Collie, J.S., Hall, S.J., Jennings, S., Poiner, I.R., 2003. Impacts of fishinggear on marine benthic habitats. In: Sinclair, M., Valdimarsson, G. (Eds.),Responsible Fisheries in the Marine Ecosystem. CABI Publishing, Wallingford,pp. 197–217.

Kalikoski, D.C., Quevedo Neto, P., Almudi, T., 2010. Building adaptive capacity toclimate variability: the case of artisanal fisheries in the estuary of the PatosLagoon, Brazil. Marine Policy 34, 742–751.

Leal, C.P., Quiñones, R.A., Chávez, C., 2010. What factors affect the decision makingprocess when setting TACs? The case of Chilean fisheries. Marine Policy 34,1183–1195.

Leichenko, R.M., O‘Brien, K.L., 2008. Environmental Change and Globalization.Oxford University Press, Oxford.

Lotze, H.K., Lenihan, H.S., Bourque, B.J., et al., 2006. Depletion, degradation, andrecovery potential of estuaries and coastal seas. Science 312, 1806–1809.

McIlgorm, A., Hanna, S., Knapp, G., le Floc’H, P., Millerd, F., Pan, M., 2010. How willclimate change alter fishery governance? Insights from seven international casestudies. Marine Policy 34, 170–177.

Miller, K.A., Munro, G.R., 2004. Climate and cooperation: a new perspective on themanagement of shared fish stocks. Marine Resource Economics 19 (3), 367–393.

Miller, K.A., Golubtsov, P., McKelvey, R., in press. Fleets, sites and conservationgoals: game theoretic insights on management options for multinational tunafisheries. In: Ommer, R.E., Perry, R.I., Cochrane, K., Cury, P. (Eds.). WorldFisheries: A Social–Ecological Analysis. Fish and Aquatic Resources Series.Wiley-Blackwells, Oxford.

Miller, K., Charles, A., Barange, M., Brander, K., Gallucci, V.F., Gasalla, M., Khan, A.,Munro, G., Murtugudde, R., Ommer, R.E., Perry, R.I., 2010. Climate change,uncertainty, and resilient fisheries: institutional responses through integrativescience. Progress in Oceanography 87 (1–4), 338–346.

Moloney, C.L., Jarre, A., Kimura, S., et al., 2010. Dynamics of marine ecosystems:ecological processes. In: Barange, M., Field, J., Harris, R., Hofmann, E., Perry, R.I.,Werner, F. (Eds.), Marine Ecosystems and Global Change. Oxford UniversityPress, Oxford, pp. 179–218.

Murray, G., in press. Social–ecological restructuring and implications for socialvalues. In: Ommer, R.E., Perry, R.I., Cochrane, K. and Cury, P. (Eds), WorldFisheries: A Social–Ecological Analysis. Fisheries and Aquatic Resources Series,Wiley-Blackwells, Oxford.

Naylor, R.L., Goldburg, R.J., Primavera, J.H., et al., 2000. Effect of aquaculture onworld fish supplies. Nature 405, 1017–1024.

Njock, J.-C., Westlund, L., 2010. Migration, resource management and global change:experiences from fishing communities in West and Central Africa. Marine Policy34, 752–760.

Ommer, R.E., The Coasts Under Stress Research Project Team, 2007. Coasts UnderStress: Restructuring and Social–Ecological Health. McGill-Queen’s UniversityPress, Montreal, 574 p.

Ommer, R.E., Perry, R.I., Neis, B., 2008. Bridging the gap between social and naturalfisheries science: why is this necessary and how can it be done. AmericanFisheries Society Symposium 49, 177–185.

Ommer, R.E., Jarre, A.C., Perry, R.I., Barange, M., Cochrane, K., Moloney, C., 2009. Thehuman dimensions of small pelagic fisheries under global change. In: Checkely,D.M., Alheit, J., Oozeki, Y., Roy, C. (Eds.), Small Pelagic Fishes and Global Change.Cambridge University Press, Cambridge, pp. 275–284.

Ottersen, G., Hjermann, D.O., Stenseth, N.C., 2006. Changes in spawning stockstructure strengthen the link between climate and recruitment in a heavilyfished cod (Gadus morhua) stock. Fisheries Oceanography 15, 230–243.

Paterson, B., Isaacs, M., Hara, M., Jarre, A., Moloney, C.L., 2010. Transdisciplinary co-operation for an ecosystem approach to fisheries: a case study from the SouthAfrican sardine fishery. Marine Policy 34 (4), 782–794.

Pauly, D., Christensen, V., Guénette, S., Pitcher, T.J., Sumaila, U.R., Walters, C.J.,Watson, R., Zeller, D., 2002. Towards sustainability in world fisheries. Nature418, 689–695.

Perry, R.I., Ommer, R.E., 2003. Scale issues in marine ecosystems and humaninteractions. Fisheries Oceanography 12, 513–522.

Perry, R.I., Sumaila, U.R., 2007. Marine ecosystem variability and human communityresponses: the example of Ghana, West Africa. Marine Policy 31, 125–134.

Perry, R.I., Cury, P., Brander, K., Jennings, S., Möllmann, C., Planque, B., 2010a.Sensitivity of marine systems to climate and fishing: concepts, issues andmanagement responses. Journal of Marine Systems 79, 427–435.

Perry, R.I., Ommer, R.E., Allison, E., et al., 2010b. Interactions between changes inmarine ecosystems and human communities. In: Barange, M., Field, J., Harris, R.,Hofmann, E., Perry, R.I., Werner, F. (Eds.), Marine Ecosystems and GlobalChange. Oxford University Press, Oxford, pp. 221–252.

Planque, B., Fromentin, J.-M., Cury, P., Drinkwater, K., Jennings, Perry, R.I., Kifani, S.,2010. How does fishing alter marine populations and ecosystem sensitivity toclimate? Journal of Marine Systems 79, 403–417.

Pullin, A.S., Knight, T.M., Watkinson, A.R., 2009. Linking reductionist science andholistic policy using systematic reviews: unpacking environmental policyquestions to construct an evidence-based framework. Journal of AppliedEcology 46, 970–975.

Schindler, D.E., Hilborn, R., Chasco, B., Boatright, C.P., Quinn, T.P., Rogers, L.A.,Webster, M.S., 2010. Population diversity and the portfolio effect in an exploitedspecies. Nature 465, 609–612.

Taylor, W.W., Leonard, N.J., Kratzer, J.F., Goddard, C., Stewart, P., 2007.Globalization: implications for fish, fisheries, and their management. In:Taylor, W.W., Schechter, M.G., Wolfson, L.G. (Eds.), Globalization: Effects onFisheries Resources. Cambridge University Press, Cambridge, pp. 21–45.

Thrane, M., Ziegler, F., Sonesson, U., 2009. Eco-labelling of wild-caught seafoodproducts. Journal of Cleaner Production 17 (3), 416–423.

Tiessen, H., Brklacich, M., Breulmann, G., Menezes, R.S.C., 2007. CommunicatingGlobal Change Science to Society. SCOPE 68, Island Press, Washington.

Vodden, K., 2009. New Spaces, Ancient Places: Collaborative Governance andSustainable Development in Canada’s Coastal Regions, PhD thesis, Simon FraserUniversity, Burnaby, BC, Canada, unpublished.