Download Causes of these pressures

4.0
DRIVERS OF BIODIVERSITY
4.1 Environmental drivers of biodiversity: A working framework
[GRC/SJ/JB/GB]
A suggested framework for examining the primary environmental drivers is to consider two
time-scales- evolutionary and ecological- (Figure X) with some consideration of how these
differ.
4.1.1 Evolutionary time-scales – (GRC + ??? ) (slow trajectory of increase punctuated by mass
extinctions) - e.g. climate, tectonic/geological, global patterns,
A variety of drivers shape the extent, patterns and dynamics of biodiversity, which are essentially
the end result of speciation, dispersal and extinction- including:
 Historical events across a geological time-scale- major changes in distribution of land
masses, sea level and major oceanographic features such as currents and oceanographic
fronts;
 Global variation in environmental parameters and diversity of habitats, such as latitudinal
and longitudinal variation in temperature and habitat diversity;
 Ecological processes such as dispersal capacity, competition, predation and herbivory,
disease and parasitism, disturbance and facilitation (the conditioning of the environment
by one species, allowing another species to invade)
Figure X. General trends in marine biodiversity over evolutionary and ecological times (After
Sala & Knowlton, 2006). A. General increase over geological timescales, punctuated by declines
caused by mass extinctions. Abbreviation: M, million. B. Olid line: typical trend of marine
biodiversity (e.g. species richness, ecodiversity, evenness, functional diversity) over ecological
timescales in the absence of human disturbance. Arrows indicate pulse disturbances that reset
succession. Dashed line represents decrease in ecodiversity during late successional stages in
communities with competitively dominant species. C. Marine biodiversity trends under chronic
human disturbance.
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4.1.2 Ecological time-scales (Simon) SIMON TO ADD DETAILS
(SJ has agreed to coordinate this) human threats (plus natural? variation) – rapid decline – e.g.
overfishing, global warming, biological introductions, pollution, etc- here a brief consideration
of the ecological ongoing factors such as competition, predation, pathogens, disease, physical
factors such as oceanographic and oceanographic features (local, regional and global processes) changes in environment/communities might shift dynamics of ecological factors, resulting in
shifts in various levels of biodiversity (e.g. impacts of disturbance on the approx. non linear
increase during successional change over time in species richness, evenness and functional) .
[There is a lot of potential overlap between this section and the comments on the Jackson papers
etc in Section 2 and on impacts as already added to Section 3, since on ecological timescales the
effects of human impacts will be especially strong. As such, have focused on biogeographic
patterns and links to the local species pool]
On ecological time scales, local diversity is influenced by the number of individuals in the
community, diversity and abundance in the regional species pool and the rate of dispersal
between the local and regional pools. To understand patterns of diversity at local scales, and the
effects of human impacts, it is almost always necessary to interpret these patterns and impacts in
the regional context. Conversely, to understand the regional effects of human impacts on
biodiversity, it is necessary to upscale, since it is the cumulative effects of local impacts that lead
to regional changes e.g. local extinctions leading to regional or global extinction.
The bounds of regional species pools are often determined by the physical environment and
regional pools have characteristic communities that reflect their isolation on evolutionary time
scales. For example, many extant teleost fishes evolved after the K-T mass extinction that
marked the end of the Mesozoic Era (Scotese 1997). At this time, South America, North
America, Eurasia and Africa all had continuous eastern and western coastlines running from low
to high latitudes; although the Indian and Atlantic Oceans were still connected by the Tethys Sea
(Scotese 1997). Polar climates had also cooled before the K-T mass extinction event (Spicer &
Parrish 1986) and thus global latitudinal temperature gradients were well established thereafter
(Frakes et al. 1994). During cooling events, the tropics were restricted to these low-medium
latitudes, but the overall latitudinal gradients in temperature persisted and faunas could likely
relocate given north-south continuity of the shallow seas to the east and west of the main
continents. Thus, at the regional scale, relative differences in temperature have likely been
maintained on the eastern and western boundaries of the main continents. However, other
ecosystems changed substantially or were not in existence in their present form until the last 10
Ma. Thus the Mediterranean dried and flooded, the Indian and Atlantic Oceans divided (10 Ma)
and Panama closed to separate the Atlantic and Pacific (3-4 Ma). As faunas were isolated there
was additional speciation and extinction over the period 1-2 Ma, but contemporary faunas in
these regions also reflect substantial immigration. These constraints that have been imposed by
movements of the land masses, thermal gradients lead to isolation of regional pools. Today,
therefore, even for many taxa with relatively high dispersal capacity, regional species pools are
broadly split between the main ocean basins in the northern and southern hemispheres with the
warm equatorial waters forming a natural barrier to the movement of temperate and cold water
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species from northern to southern hemispheres and land masses limiting dispersal to the east and
west.
The direct and indirect impacts of human activities, coupled with environmental variation, are
the main causes of changes in diversity on local and regional scales. The pressures and their
causes are diverse (Table)
Table 1.Pressures on biodiversity. Based on Table 2 EC (2008)
Physical loss: smothering and sealing
Physical damage: siltation, abrasion, extraction
Physical disturbance: underwater noise, marine litter
Interference with hydrological processes: changes in thermal and salinity regimes
Contamination by hazardous substances: synthetic compounds, non synthetic compounds,
radioactivity
Nutrient and organic matter enrichment
Biological disturbance: pathogens, introductions of non indigenous species, extraction
(repeated here for info but we likely want them in one place eventually)
Causes of these pressures
Fishing activity
Shipping
Power generation
Oil and gas extraction
chemical spills and discharges
nutrient release and discharge
climate variation and change
species introductions and invasions
The relative contribution of these pressures to changes in biodiversity will vary in space and time
and depends on their spatial extent and distribution in relation to habitat types, their duration and
magnitude and the environment in which they occur. For example, a given level of fishing
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disturbance has lower impacts on benthic species diversity on a highly mobile sand habitat than a
complex biogenic habitat in an area subject to low natural disturbance. Pressures that are patchy
(e.g. direct fishing impacts) rather than diffuse (e.g. chemical pollution) will create a mosaic of
local habitats that are impacted to different extents and may be in different stages of recovery.
The impacts they receive and their recovery times are not independent, but governed by rates of
immigration and emigration, seasonal production and reproduction cycles and their locations in
relation to currents, gyres and other oceanographic features.
Despite the ecological processes that influence diversity acting across multiple scales there are
relatively few studies of the relationships between diversity on local and regional scales. As a
generalisation, regional gradients in species diversity tend to be influenced by environmental
factors such as temperature and depth (Rees et al 1999; Callaway et al 2002) rather than the
human pressures that dominate at local scales. However, in areas subject to high pressures the
cumulative impacts of local pressures can lead to significant regional change (Bianchi et al 2000;
Greenstreet et al 1999).
References to add to Section 8
Bianchi G, Gislason H, Graham K, Hill L, Jin X, Koranteng K, Manickchand-Heileman S, Paya
I, Sainsbury K, Sanchez F, Zwanenburg K. 2000. Impact of fishing on size composition and
diversity of demersal fish communities. ICES Journal of Marine Science 57:558-571.
Callaway R, Alsvåg J, de Boois I, Cotter J, Ford A, Hinz H, Jennings S, Kröncke I, Lancaster J,
Piet G, Prince P. 2002. Diversity and community structure of epibenthic invertebrates and fish in
the North Sea. ICES Journal of Marine Science 59:1199-1214.
Frakes, L.A., Probst, J.L. & Ludwig, W. (1994). Latitudinal distribution of paleotemperatures on
land and sea from early Cretaceous to middle Miocene. Comptes Rendus de l’Academie des
Sciences Serie II, 318, 1209-1218
Greenstreet SPR, Spence FE, McMillan JA. 1998. Fishing effects in northeast Atlantic shelf
seas: patterns in fishing effort, diversity and community structure. V. Changes in the structure of
the North Sea groundfish species assemblage
between 1925 and 1996. Fisheries
Research(40):153-183.
Rees HL, Pendle MA, Waldock R, Limpenny DS, Boyd SE. 1999. A comparison of benthic
biodiversity in the North Sea, English Channel and Celtic Seas. ICES Journal of Marine Science
56:228-246.
Scotese, C.R. (1997). Continental Drift, 7th edition (PALEOMAP Project, Arlington), 79 pp.
Sherman, K., Alexander, L.M. & Gold, B.D. (1993). Large marine ecosystems: stress, mitigation
and sustainability. American Association for the Advancement of Science Press, Washington.
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Spicer, R.A. & Parrish, J.T. (1986). Paleobotanical evidence for cool north polar climates in
middle cretaceous (albian-cenomanian) time. Geology, 14, 703-706.
4.2 Importance of disturbance : Biodiversity, resilience and rustness of marine ecosystems
4.2.1 The challenge
Despite the increasing awareness of ecosystem-based approaches to the management of marine
ecosystems, the range and simultaneous nature of multiple stressors on natural ecosystems,
makes it necessary to assess quantitatively the probability of ecosystem collapse or recovery in
relation to projected environmental change (Boyer et al., 2009; Hendricks et al., 2009; Jones &
Schmitz, 2009; Ling et al., 2009; Thrush et al., 2009). For ecosystem services to be sustained
over time, the various ecological components and the intricate interdependence across many
levels must be able to continue functioning despite disruptions. Thus, there is a requirement for
them to be robust and resilient, that is, retain the capacity to continue functioning even when
exposed to stressors or gradual and rapid disturbance. The key challenge is that both natural and
socio-economic systems are complex, and characterised by multiple possible outcomes and by
the potential for rapid change and major regime shifts arising from slower and smaller changes in
exogenous and endogenous influences. The inherent nature of ecosystems means that the
dynamics of interactions at small scales may become manifest at macroscopic levels, which may
then feed back to influence the smaller scales. Understanding the linkages among the various
scales, and how to most effectively incorporate such knowledge into public awareness,
management actions and policy decisions, are priority needs in biodiversity research.
4.2.2 What we know
It is well established that the effects of such factors as climate change, coastal development,
overexploitation of marine resources, nutrient and chemical pollution from the land, and other
anthropogenic influences, can result in marked disruption of marine ecosystems (Levin &
Lubchenco, 2008). Such effects in turn can diminish ecosystem services, resulting for example in
a reduced fisheries yield , poorer water quality and increased incidence of pests and disease. The
rate at which a system returns to a single steady or cyclic state following a perturbation is known
as resilience. The two key components that are relevant here are: (1) resistance to change (as
well as flexibility, the amount a system can be perturbed from its reference state without that
change being essentially irreversible, and (2) the ability of a system to recover. As discussed in
Section XXX, there is a generally positive relationship between biodiversity and resilience and
recovery, though generating precise forecasts is in many cases inaccurate because of the inherent
complexity of linkages across different ecosystem components and their interactions. Such
effects can perhaps be predicted with some level of accuracy where single environmental or
human drivers are sufficiently strong to force an ecological system into an alternative state.
Increased temporal variability can provide a proxy for early-warning signals of an approaching
regime shift or disruption to ecosystem services (Carpenter & Brock, 2006). However, there is
increasing evidence that interactions between intrinsic ecological dynamics and chronic,
cumulative or multiple stressor effects can increase the uncertainty in any predictive framework,
leading to a loss in resilience and an increased risk of regime shift (drastic broad-scale changes in
species composition and function). Such factors are summarised below in Table XXX.
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Table XXX Community dynamics, feedbacks and thresholds in resilience of coastal marine
ecosystems (after Thrush et al., 2009).
4.2.3 What we do not know
Ecosystem shifts are typically impossible to predict (de Young et al., 2008), but the
consequences are clear- a general homogenisation of communities and ecosystems owing to a
reduction in foodweb complexity, diversity within functional groups and habitat structure.The
development of an enhanced forecasting ability to identify increased risk of a regime shift would
provide a valuable resource for environmental managers. A major obstacle to forecasting shifts
in resilience and recovery of ecosystems is the disparity between theory and our ability to
investigate empirically such effects in ecologically realistic conditions.
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Natural disturbance tends to be relatively short in duration, while anthropogenic
disturbance increasingly tend to be nearly permanent. Thus, our current understanding is
generally unbalanced toward shorter-terms disturbances, which may not necessarily apply to
more long-terms effects.
Dynamics- options with environmental change- tolerance, adaptation, migration or extinction.
Key factors influencing outcome include dispersal capacity and gene flow (esp. larval access),
generation time (in relation to pace of env, change), demography such as effective population
size and extent of fluctuations in population size, genetic diversity, phenotypic plasticity, rate
and magnitude of environmental change.
Figure X The interaction of rapid climate change and habitat fragmentation within populations
leading to a range-wide increase in extinction risk. This can occur in the absence of habitat
fragmentation if climate change occurs at a rate faster than the maximum rate of gene flow
between populations. (After Alistair S. Jump* and Josep Peñuelas, 2005)
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Response to disturbance – resilience – require experimental approach to assess
resilience (?)
Balanced between aquaculture & fishery activities (interactions) – Example of Penaeus
aquaculture in Greece due to introduction as well as Lessepsian species migration
Invasive species : Crepidula + macroalgae in Thau lagoon
Vectors of introduction (ballast waters, aquaculture….)
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4.2
Environmental Drivers
4.2.1. What we know
Biodiversity is closely linked to biogeography, being a consequence of physical and biological
constraints operating over a range of spatial and temporal scales. Parts of the world that currently
experience similar climates may have very different biotas as a result of contrasts in evolutionary
histories, the severity of previous extreme conditions (e.g. geologically-recent glacial events;
Graham et al, 2003), intervening geographical barriers, and dispersal capabilities. An
appreciation of past dynamic processes and stochastic events determining present distributions of
species is therefore critical for understanding observed genetic structures and ecological
interactions. Natural climate variability has previously encompassed both rapid warming (at end
of last ice age), and cooling (Younger Dryas). Predicted climate changes over the next 50-100
years are of similar rates and magnitude, with ecological responses of species and communities
depending on a complex mix of global and local forcing factors (Parmesan & Yohe, 2003). Thus
understanding of past events enables forecast of future scenarios.
Analysis of DNA genealogies in a geographical context has greatly improved our understanding
of climatic influences on terrestrial biodiversity (e.g. Avise, 2000; Hewitt, 2000). A multispecies, comparative phylogeographic approach is particularly powerful: it can identify the
boundaries of regional biotas, and elucidate the forces responsible for structuring genetic
diversity and promoting speciation. Relatively few studies (except those by our CORONA
partners - Cunningham & Collins, 1998, Wares & Cunningham 2001) have applied this approach
to marine distributions and diversity, despite the ecological importance and complexity of
Atlantic colonization patterns.
A major outcome of multi-species phylogeography is that intraspecific genetic breaks and areas
of high (or low) genetic diversity are detected in the same geographic location for groups with
diverse ecological requirements and taxonomic affinities (Avise, 2000). Such patterns indicate
that similar forces (probably linked to Pleistocene glacial cycles) were involved, identifying the
genetic background upon which local adaptation and competition act. The importance of specific
morphological or life-history characteristics may also be revealed, by identifying groups that
have responded differently to common environmental challenges.
Climate as a driver of evolutionary change
In future climate scenarios it is not only an increase in global mean temperatures that is
predicted, but also an increase in the frequency of extreme climatic events. Under such
conditions, marine species will require tolerance to an increase in frequency of extreme weather
events around a directionally changing norm (in this example, rising mean temperatures). Such
events require individuals to possess near 'perfect' plasticity – tolerating all changes in climate
with no apparent fitness costs (DeWitt et al. 1998). Ongoing distributional changes and reports of
climate-related species dieback demonstrate that such widespread plastic tolerance of the
changing climate is not typical (insert refs).
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4.2.2 What we do not know
Priority areas in relation to scale and dynamics of marine biodiversity is to integrate aspects of
component (1) (population-level processes) within ecologically predictive frameworks : for
example, the prediction of extinction risks under climate change by coupling stochastic
population models with dynamic bioclimatic habitat models (e.g. Keith et al., 2008- Biol. Lett. 4,
560-563), and the Integration of GIS-based environmental data into evolutionary biology. Many
evolutionary processes are influenced by environmental variation over space and time, including
genetic divergence among populations, speciation and evolutionary change in morphology,
physiology and behaviour. Yet, evolutionary biologists have generally not taken advantage of the
extensive environmental data available from geographic information systems (GIS). For
example, studies of phylogeography, speciation and character evolution often ignore or use only
crude proxies for environmental variation (e.g. latitude and distance between populations). The
integration of GIS-based environmental data, along with new spatial tools, can transform
evolutionary studies and reveal new insights into the ecological causes of evolutionary patterns
of biodiversity (e.g. Kozak et al., 2008; .Trends in Ecol Evol.23, 141-148).
4.3
Human Drivers of Biodiversity
[SH, GC, SJ, OT, CB, JB, HL, JW]
People depend on marine and coastal ecosystems for important good and services. Human use
has altered these ecosystems and changes marine biodiversity in both direct and indirect ways. .
A broad range of factors lead to changes in ecosystems, ecosystem services, and human wellbeing. Some ecosystem changes are intended, but many are unintended consequences of human
decisions and ensuing actions. The drivers of those changes may be specific, such as population
growth, commodity prices or pollution , but they may also involve more complex and diffuse
interactions arising from institutional or cultural influences.
Drivers may be considered direct if they serve a primary role in influencing marine ecosystems,
or they can be indirect if they serve a secondary role in influencing marine ecosystems through
their effect on direct drivers. Drivers exist at a variety of scales and with diverse connections.
Variability, uncertainty and complexity are endemic both within and among drivers.
The Millenium Ecosystem Assessment looks at the key interactions among drivers and decision
makers (2005b). It differentiates cases of exogenous drivers that are outside the control of a
decision maker from those that are endogenous, or within the decision maker’s control.
As in the fields of genetics and biology, the expansion of global databases on human activities
and the combination with ecological data sets allows the generation of large-scale assessments.
Halpern et al. (2008) for instance produced a global map of human impact on marine
ecosystems. Science, 319, 948-952. They developed an ecosystem-specific, multi-scale spatial
model to synthesize 17 global data sets of anthropogenic drivers of ecological change for 20
marine ecosystems. The approach allowed a geographic analysis of the distribution of driversand identification of those heavily impacted, and those less so (e.g. close to poles). The intention
was to use such detail to provide flexible tools for regional and global efforts to (1) allocate
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conservation resources; (2) to implement ecosystem-based management; (3) to inform marine
spatial planning, education and basic research. An example of how these human drivers and
associated “threat scores” is shown in Fig. X, and allows a quantitative comparison of effects
across a range of spatial scales.
Fig. X. Total area affected (square km, grey bars) and summed threat scores (rescaled units,
black bars) for each anthropogenic driver. (A) globally and (B) for all coastal regions ,200 m in
depth. Value for each bar are reported in millions (After Halpern et al., 2008).
The ongoing escalation in size of human populations will increase the pressure upon coastal and
marine goods and services. The above approach provides a structured framework for quantifying
and comparing the various impacts and threats produced by the different human uses of these
services and possibly the identification of strategies to minimize negative impacts and promote
sustainability. Moreover, the approach incorporates various types of data such as species
distributions and diversity data so that hot spots of diversity and high cumulative human impacts
can be identified and monitored spatially, allowing the targeting of resources and investment. A
priority will be to accumulate regional and global databases of empirical data to further validate
and apply such a quantitative and comparative framework.
4.3.1 What We Know
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Five main categories of human drivers can be considered, after those identified in the
Millennium Ecosystem Assessment (2005b): institutional, demographic, economic, social, and
cultural.. The net outcomes of drivers, their interactions and the incentives they create may be
either positive, negative or have ambiguous and complex effects on marine biodiversity.
4.3.1.1 Institutional
Institutional arrangements –broadly defined as the complex of laws, customs, markets, norms
and associated organisations that channel human activities toward societal objectives- provide a
structure for human behavior in relation to the use and conservation of marine ecosystems. Those
interact and overlap at international, national, regional and local levels. International agreements
and conventions –such as the United Nations Convention on the Law of the Sea- affect
environmental protection, guide responsible practice and influence trade. At the national level,
legislation is usually designed to provide protections and controls over ecosystem goods and
services and to define policies providing incentives for resource development and use. For
instance the ... These national legislation can be reinforced (or weakened) by regional policies
that provide positive (or negative) incentives for capital investment, technology development,
population growth and guidelines for labor management and trade. For example, the Common
Fisheries Policy provides the overall framework within which fishing activities in the European
Union’s Exclusive Economic Zone are implemented. It sets catch quotas for member states and
includes various market interventions affecting the fishing industry. Public and private sectors
and non-profit organizations all work within these institutional opportunities and constraints,
implementing activities and initiatives that influence or affect ecosystem uses and have varying
effectiveness in protecting marine biodiversity.
A central institutional driver relates to the fact that most components of marine biodiversity, e.g.
from phytoplankton in shellfish farms to bluefin tunas or sharks in the open ocean, are under
appropriation regimes which produce incentives to develop excessive usage and degradation of
the resource base. This has been well established in the fisheries domain, where excess
harvesting derives from the common pool nature of marine fish resources, leading to what
economists have termed reciprocal negative externalities between fishers, and to the
development of “race for fish” phenomena. Understanding such drivers of ecosystem uses has
thus proved a key in the exploration of future scenarios for sustainable fisheries.
Accounting for the multiple uses of marine biotic resources leads to the extension of this analysis
to a larger set of potentially more complex processes. Many human activities directly or
indirectly impact marine ecosystems, leading to interactions between these different uses of
ecosystem services via their impacts on ecological processes. These interactions entail collective
costs and benefits which economic agents are not incited to take into account in their decisions
regarding the use of ecosystem services.
XXXXXXXX Common pool resources and public goods
4.3.1.2 Demographic
Human populations can be both direct and indirect drivers of biodiversity change. Two billion of
the global population lives within 100 kilometres of the coast. At present, half of the world’s
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major cities (those with more than 500,000 people) are found within 50 kilometres of a coast
(Fig.X). Coastal population densities are nearly three times those of inland areas (Kay and Alder
2005).
This increasing number of people moving into coastal zones exerts a direct pressure on coastal
marine resources. Population size, composition, distribution density and rate of growth can also
indirectly affect biodiversity through changes in demand for marine products, human and
industrial waste, pollution and alteration of coastal habitats. Today approximately 9.3 x 107
people (37%) of the total U.S. population reside in coastal areas and discharge about 3.78 x 1010
liters of treated wastewater per day (NRC 1993). In 2000, there were over 11,000 beach closings
or advisories (freshwater and marine beaches) in the United States, a number that had almost
doubled from the previous year, and a majority of these closings were due to wastewater
pollution (NRCD 2001). On a global scale, coastal development is twice that of inland sites, with
90% of the generated wastewater being released untreated into marine waters (Henrickson et al.
2001).
The growth of urban centres and rise in incomes worldwide is also expected to increase the
global demand for fish products (Delgado et al., 2003), as well as the demand for recreational
uses of marine biodiversity, both extractive and non-extractive.
Fig.X shows the global distribution of top 400 "urban areas" with at least 1,000,000 inhabitants
in 2006. Half of the world’s major cities are located on the coasts. Data were extracted on 27th
June 2007 from http://www.citymayors.com/statistics/urban_2006_1.html
Other demographic factors such as age, gender, and education can indirectly affect the patterns
of resource consumption and use. While the individual trajectories of most of these demographic
factors are relatively well known (UN 2004 ), what is less well understood is how the effect of
these different factors (size, age) combined with economic factors and in particular increase in
wealth (see below) will affect the ability of future societies to control their impacts on marine
biodiversity.
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4.3.1.3 Economic
Economic activities at international, regional, national, and local levels are critical drivers of the
societal impact on marine ecosystems. Economic growth in particular, with its material
composition and geographical distribution, affects demand for ecosystem goods and services.
The structure and performance of international commodity markets such as seafood influences
the type and level of ecosystem use (in particular in relation to fisheries activities) at both global
and local scales. Price fluctuations of inputs (e.g. fuel -Abernethy et al. 2010) and outputs (e.g.
food commodities) underlie changes in economic activities and in resource use. Technological
innovation also influence demand for ecosystem goods and services by lowering costs and
improving effectiveness of technologies that lead to shift in production and eventually changes in
ecosystem use. Labor markets determine the attractiveness of employment in marine ecosystem
related occupations. Ultimately the level of wealth at both individual and society levels drives
consumer demand for commodities upward (Hoyer and Macinnis 2010), which increases directly
demand for ecosystem goods and services, generally leadings to increased pressures on
biodiversity. At the same time, change in wealth has also been documented as one of the main
factors affecting change in consumption patterns and consumer choice, with an overall (although
not systematic) positive correlation between societal wealth and willingness to pay for
biodiversity conservation (Horton et al. 2003; Chukwuone and Okorji 2008). Finally
globalization of markets and commodities trade leads to increasing integration of producers and
consumers over large geographic scales (Gereffi 1999; Phillips 2006), but with still poorly
understood and documented effects on biodiversity (Heal 2002, Toly 2004; Zimmerer 2006).
Add Berkes case of sea urchin fishery
4.3.1.4. Social
Governance reforms
The globalization of market and trade has been accompanied by a shift of governance away from
national-level institutions toward the international arena, expressed in international bodies,
conventions and treaties. Simultaneously, decentralization reforms and the associated
subsidiarity principle have been forcefully promoted and implemented both in developed and
developing countries, especially with regard to the governance of natural resources (Ribot 2002).
Market-based governance, including ‘fair-trade’, corporate responsibilities and public-private
partnerships, is also increasingly presented as another potential for addressing issues related to
the conservation of natural resources and biodiversity (Barrientos 2000; Raynolds 2004;
Wilenius 2005). The devolution of resource management responsibilities closer to end-users or
conversely toward international level has often been presented as a positive shift to create a more
supportive policy environment for resource management and biodiversity conservation
(Pinkerton 1989, Colchester 1994; OCDE 2003). Current decentralization experiences are
however mixed and the effects on biodiversity conservation ambiguous (Dupar and Badenoch
2002; Lind and Cappon 2001; Béné et al. 2009). As for international treaties, Kyoto and
Copenhagen are vivid evidence that global governance does not ensure effective interventions.
Market-based management approaches, while offering the promise of positive incentives for
biodiversity conservation, are as yet too new to provide definitive evidence of performance.
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Poverty levels and food security
The poverty-environment nexus is one of the most heated debates in the current literature, with
proponents and opponents of the equation “poverty = environmental threat” still unable to find
consensus (Duraiappah 1998; Adams et al. 2004; Dasgupta et al 2005). Certainly, poverty does
not have a positive effect on resource/biodiversity conservation but the negative relationship
between poverty and the environment seems to be context-specific and not a universal rule
(Cavendish 2000). One should in particular be reminded, especially in the fisheries context, that
the high levels of capitalization and wealth of larger-scale fleets in developed countries does not
necessarily create a more effective context to sustain marine biodiversity, as confirmed by the
European EEZ situation. Even more complex is the link between food security and biodiversity.
While a food insecure population may engage in exploitive harvest of aquatic resources to levels
that appear unsustainable in the short-term, the root causes of this food insecurity relates
generally to structural issues beyond the local management scale, highlighting the complex and
multi-dimensional nature of the problem (Béné and Friend 2010).
4.3.1.5 Cultural
Culture is the expression of shared knowledge, values, beliefs, and norms. Culture shapes
worldviews, influences social priorities, and determines bounds of acceptable behavior in
relation to many values, including biodiversity (Yamin 1995). Culture may be shared within
communities of various types, including national, regional, ethnic, occupational or
organizational. Scientific knowledge – its investment, distribution, absorption and application –
is also an expression of culture.
4.3.2 What We Do Not Know
The net outcomes of drivers, their interactions and the incentives they create may be either
positive, negative or have ambiguous and complex effects on marine biodiversity.
4.3.2.1 Institutional
Although the need for consistency in institutional layering is well-established, not enough is
known about how to design and execute that consistency. Additional research is needed (i) to
document the decision-making processes which determine the day to day governance of marine
biodiversity uses, (ii) to examine the incentives created by alternative institutional designs, and
(iii) to design control policies at different levels that have the appropriate incentives for natural
resources and biodiversity protection (Yamin 1995; Ruddle 1998; Baland and Platteau 1999;
Blaikie 2006). Also needed are the development of indices with which to perform monitoring
and evaluation of institutional effectiveness. The example of community-based and comanagement in forestry and/or fisheries show however that the design and application of such
indicators is not necessarily straightforward (Thompson 1999; Borrini-Feyerabend et al. 2000).
4.3.2.2. Demographic
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Measures of population size and rates of increase in coastal zones are available worldwide. What
is less understood are the specific pathways of influence between human demographics, demand
for marine resources, and impact on marine biodiversity. More research is needed on the
influence of age, gender, education and other demographic factors on the patterns of marine
resource use, understanding of risks to marine biodiversity, and response to conservation
regulations. Also needed is an enhanced understanding of the interactions of demographic factors
with economic factors and their resulting impact on marine biodiversity.
4.3.2.3 Economic
The dynamics underlying economic drivers at different scales of time, space and economic
organisation are poorly understood. The effect of global integration of producers and consumers
on biodiversity at local scales is in need of documentation and analysis (O''Hara S. and Stagl S.,
2001; Zimmerer 2006). The potential for international markets and trade agreements to either
promote or erode biodiversity is poorly understood, as is the role of governments and intergovernmental organizations’ economic growth policies in doing the same (Lawn 2008; Czech
2008). The array of values society places on changes in the availability and quality of ecosystem
goods and services, many of which are not subject to market exchanges remains unquantified in
many cases. Although growing emphasis is being place on the need to understand changes in
marine ecosystems, models of marine resource use still often offer an aggregated and static
representation of human interactions with marine ecosystems. There is a need to develop more
dynamic representations, fully accounting for the diversity of agents and of their interactions
with marine ecosystems at different scales, from very short term and local scale decisions such as
allocation of fishing effort, choice of commercial navigation routes or compliance with
environmental regulations by individual skippers, to longer term and wider ranging actions, such
as investment/disinvestment choices by firms, taking into account the influence of economic,
social, institutional and ecological contexts on such decisions. How economic incentives of
fishery regulations and other extractive activities can be designed to promote biodiversity
conservation needs more research in specific contexts, as does the role of economic and
environmental variability in determining human behaviour and impact on the marine
environment. The impact of policies to control the negative external effects of economic
activities on biodiversity is another area of needed investigation. The relation of wealth levels to
a preference for the type and level of marine resource use is poorly understood in specific
contexts. Labor mobility and labor markets in marine settings need further investigation.
4.3.2.4 Social
The social and political elements of governance reform need to be better understood, including
the distributional impacts of new governance arrangements (Johnson 2001; Nijenhuis 2003). The
distribution of costs and benefits of decentralization are often not fully understood, nor is the link
of decentralization to incentives to conserve or destroy biodiversity (Ribot 2002). The role of
normative and social influences in compliance with regulations aimed at protecting biodiversity
also needs to be better studied (Hatcher et al., 2000).What are the impacts of subsidiarity in
developing and developed country settings? The social impacts of market-based governance in a
range of settings needs to be better understood. What are the factors that contribute to the success
or failure of decentralized approaches to resource management (Campbell et al. 2001; Béné et al.
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2009), and what are the accompanying biodiversity outcomes? The policy context of food
security and its link to marine biodiversity also needs further understanding. The relation
between poverty and environmental outcomes directly relates to marine biodiversity and is an
area of unsettled research.
4.3.2.5 Cultural
The role of culture in shaping values toward marine biodiversity needs to be better understood in
specific contexts. The influence of culture on behaviour is of direct relevance to the effective
design of biodiversity protections.
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