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NRS 534 Term Paper
BJC Fuller / Advances in seascape ecology: applying landscape metrics to marine systems
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NEWS & VIEWS
What is seascape ecology?
Landscape ecology is a relatively new, multidisciplinary field which studies the relationship
between ecological functions and spatial patterns
(Boström et al. 2012, Pittman et al. 2011, Wedding
et al. 2011), and was primarily developed to
inform management practices in terrestrial
systems (Pittman et al. 2011). Several important
tools, models, and methods of analysis have
emerged which advance our understanding of the
influence of geographic heterogeneity on the
health and sustainability of ecosystems on several
scales (Pittman et al. 2011, Wedding et al. 2011).
Generally, these metrics assess three fundamental
landscape properties: 1) composition, the diversity
of patch types; 2) configuration, the arrangement
of those patch types; 3) and fractal dimension, the
complexity of that arrangement (Wedding et al.
2011).
While these tools have been developed for
and applied in terrestrial systems for nearly 50
years (Pittman et al. 2011), their use in describing
spatial patterns in marine contexts has only
recently emerged, prompting the analogous term
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seascapes. This newest branch of landscape ecology
treats the physical characteristics of marine
environments, including geographic and chemical
properties, as fundamentally landscape-like
patterns which can be correlated with the ecology,
life-history, and biodiversity of species in those
ecosystems.
The complex geographic heterogeneity that
exists on land does not end at the water’s edge;
geophysical processes give rise to incredibly
diverse coastal environments which support rich
species assemblages in both familiar and unique
ways. We know that aquatic environments offer
special mechanisms for enhancing patch connectivity and maintaining community structure, and
these factors are crucial for sustaining the ecological integrity of these systems from multiple
perspectives. Some of the most commonly
recognized marine spatial patters include the
patch mosaics of mangroves, coral reefs, seagrass
beds, and tidal marshes, and the zonation of rocky
shore and salt marsh biota (Pittman et al. 2011,
Boström et al. 2012). Additionally, seascapes may
not necessarily refer to any particular physical
geography of the underwater landscape, but can
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NRS 534 Term Paper
BJC Fuller / Advances in seascape ecology: applying landscape metrics to marine systems
also be used to describe variation in chemical
composition throughout the water column. These
chemical ‘landscapes’ play hugely influential roles
in the ecology of pelagic organisms, some of
which never encounter benthic geography. For
example, Yu et al. (2011) studied the correlation
between the pH ‘landscape’, or what they refer to
as the “ocean acidification seascape”, of nearshore
waters off California and the calcification of
urchin larvae.
Most fascinating of all, though, is the application of landscape metrics which define pelagic
distributions of biota as seascapes themselves.
Mitchell et al. (2008) described complex spatial
arrangements of phytoplankton in the water
column this way. These biological ‘patches’
influence ecological functions, community
dynamics, and biodiversity in much the same way
as do geographic landscapes and seascapes, and
they are, in turn, influenced by physical parameters like turbulence. Phytoplankton patches don’t
last long, only on the order of 100 to 1000
seconds, but nonetheless they are distinctive
enough to allow conceptual modeling of their
distribution, which has implications for determining grazing efficiency and taxonomic diversity of
predatory species. It also emphasizes the concept
of scale in the context of time in addition to space;
these biological seascapes might not be obvious at
large timescales, but become readily apparent
when that scale is narrowed appropriately. This is
probably the case with other dynamic mosaics,
such as chemical seascapes. It should be noted,
though, that no landscape (terrestrial or marine) is
perfectly static; appreciating the lifespan of
mosaics is critical in recognizing spatial patterns
which might be masked by assuming inappropriate timescales.
Coral reef connectivity and management
From the plethora of studies concerning marine
ecology, we know that aquatic biota is indeed
responsive to pelagic and benthic seascapes; by
comparison, though, little has been done to assess
these relationships in the way that landscape
ecology has done for terrestrial systems (Boström
et al. 2012). However, several studies have used
these metrics to analyze aspects of coral reef ecospatial relationships (Mumby 2006, Olds et al.
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2012, Berkström et al. 2012, Moberg & Rönnbäck
2003). These habitats provide a wonderful
opportunity to assess correlations between flora,
fauna, and the physical structure of the reef.
Because of their incredible biodiversity, it seems
fundamental that we understand how abiotic
patterns influence species distribution throughout
reefs, which could allow us to break down the
ecological complexity of these systems and have
enormous implications for the management of
reefs worldwide.
Mumby (2006) attempted to accomplish some
of these goals by correlating the availability of
mangrove nursery habitats with the health of adult
reef fish, and then translating these results into
algorithms that inform management practices.
The algorithms are fundamentally landscapeecology-derived metrics, and assess the spatial
distribution of Caribbean mangroves that provide
high-quality habitat for juvenile fish, the connectivity between nursery sites and adult reef habitat,
the relative importance of mangroves in providing
nursery habitats for key reefs, and those mangroves which are of highest priority for restoration. These algorithms are all important in
understanding the affect of mangrove-reef spatial
relationships on reef community structure and
biological sustainability, and operate in much the
same way as similar metrics (like connectivity) do
in terrestrial systems.
Most recently, Olds et al. (2012) looked specifically at the correlation between mangrove-reef
connectivity and reef complexity. They describe
coral reefs as “mosaics of seemingly disjointed
[habitats] that are functionally connected by the
movement and dispersal of organisms”, heightening the ecological parallels that exist between
terrestrial and marine systems, and thus justifying
the application of traditional landscape metrics in
aquatic environments. Using a combination of
field surveys and satellite imagery, benthic habitat
classifications (including coral reefs, mangroves,
seagrass beds) were identified, and five spatial
pattern metrics were used to quantify connectivity
between patches. They specifically highlight the
importance of scaling so that results are meaningful and appropriate to the particular species of
interest. These methods and concerns exactly
mirror the approach of traditional landscape
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NRS 534 Term Paper
BJC Fuller / Advances in seascape ecology: applying landscape metrics to marine systems
ecology, reinforcing the universality of basic
ecological norms across all ecosystems.
In broader terms, Berkström et al (2012) describe coral reefs as part of a more comprehensive
network of patches, including mangroves and
seagrass beds, which they call “the tropical
seascape”. In their extensive review of ecological
connectivity in tropical seascapes, they find that
the role of migrating fish in providing this
connectivity is not well-understood through any
particular study. However, through their assessment of what little has been learned on the topic,
it is clear that these fish probably perform a
number of ecologically important functions and
should be studied more heavily in the future.
They also draw conclusions about the importance
of understanding connectivity throughout the
tropical seascape in the context of reserve design
and placement; while coral reefs are often the
highest priority in determining the location of
marine protected areas (MPAs), interlinked
patches like mangrove and seagrass beds are rarely
included. By appreciating the role of connectivity
between these patches in collectively maintaining
them, MPAs might be expanded to include
habitats which support reefs via these important
biotic and abiotic pathways; if the entire network
is not protected, MPAs will have little chance of
effectively maintaining high-priority patches.
These metrics can also answer a number of
important non-MPA-related questions pertaining
to human interaction with the tropical seascape.
Moberg & Rönnbäck (2003) investigated coastal
anthropogenic pressures on the tropical seascape
in order to address the limits of technological
substitutes for ecosystem services (which they
exemplify as artificial reefs, artificial seawalls,
aquaculture in mangroves, etc.) and ways in which
ecosystem restoration can not only rejuvenate
these services but simultaneously result in a more
resilient ecosystem. Some patch types, such as
mangroves and seagrass beds, are more successfully restored than complex habitats like coral
reefs. By understanding the interaction between
geographic heterogeneity (some of which we
create ourselves) and the health of the biotic
communities which are supported by it, we can
begin to predict the impact various management
techniques will have in a given ecosystem, which
may subsequently help us determine the most
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appropriate patch types in which to apply those
techniques. Patch connectivity, of course, is an
integral part of the tropical seascape which must
be considered for these techniques to be successful, especially when replacing ecosystem services
with technological substitutes. The Moberg &
Rönnbäck (2003) study emphasizes the importance of recognizing seascapes in developing
management frameworks which foster ecofriendly technology and promote the resilience of
both ecological communities and the societies that
depend on them.
Future considerations
The application of landscape ecology to marine
ecosystems seems obvious, necessary, and
relatively seamless. For each terrestrial process
assessed by landscape ecology, there is likely an
analogous marine process which can be assessed
similarly. The future seems bright for this
emerging field, which lies arguably at the crossroads of landscape and marine ecology. Metrics
have already been applied to map ecosystem
processes like benthic production, turbidity, and
denitrification, which advance our understanding
of the functional value of coastal environments
across large areas (Eyre & Maher 2011). The
study of sedimentary seascapes and the role of
benthic invertebrates which modify those mosaics
(termed ‘ecosystem engineers’) is also emerging,
and is important in extending seascape ecology on
and into the seabed. New technology will allow
us to study these systems at greater and greater
depths. Mathematical modeling of subterranean
biological-geological interactions has already
begun, and may result in new modeling methods
that could eventually be applied to other seascapes
and terrestrial systems as well (Meadows et al.
2012).
Other studies have investigated the
influence of seascapes on predation in coastal
environments (Roliv & Schiel 2006), allowing us
to understand the dependency of these interactions on geographic spatial patterns. This might
cause us to revise previous models of predatorprey interactions to include metrics that consider
patch composition, configuration, and fractal
dimension.
Since many useful tools have already been
developed through the study of landscape ecolo-
© 2013 (REV 118) 20130429
NRS 534 Term Paper
BJC Fuller / Advances in seascape ecology: applying landscape metrics to marine systems
gy, and can be applied, without much modification, to marine environments, it is likely that
seascape ecology will advance to an equal or nearequal state with landscape ecology relatively
quickly. As is the case with most offshoots of
well-established fields, tools developed specifically
for seascape ecology will most likely help advance
landscape ecology as well. The studies examined
here point out a number of important considerations that apply to all eco-spatial analysis. The
potential of seascape ecology in complementing
biological oceanography and marine ecology, as
well as informing ecosystem-based management
practices, seems timely and powerful, and is
perhaps the missing link in solving many of the
marine ecological problems facing the scientific,
policy, and management communities today.
Berkström C, Gullström M, Lindborg R, Mwandya AW, Yahya SAS,
Kautsky N, Nyström M. 2012. Exploring ‘knowns’ and ‘unknowns’ in tropical seascape connectivity with insights from East
African coral reefs. Estuar Coast Shelf S 107:1-21
 This is a very comprehensive review of literature on the
connectivity between coral reefs and supporting habitats like
mangroves and seagrass beds, with a focus on ecosystems in East
Africa. They refer to the mosaic of these patches as “the tropical
seascape” and find that the connectivity between patches is
relatively poorly understood, especially with regard to the role of
migratory fish as biological linkers. The actual article itself is
relatively brief, but paper includes extremely comprehensive
tables summarizing the documentation of fish species around
Zanzibar Island off Tanzania, and studies on fish connectivity
between various habitats. They emphasize that it is important to
approach environmental management from the perspective of
seascapes, as opposed to habitats, since this approach takes into
account the connectivity and relative importance of each patch
within the ecosystem mosaic. There is a lot of information in this
article, but identification of main points was not difficult. It seems
that much of the detailed data would be useful in subsequent
papers focusing specifically on the ecology and biology of fishes in
the Zanzibar region, but not in drawing general conclusions about
connectivity and seascapes in a more global sense.
Boström C, Pittman SJ, Simenstad C, Kneib RT. 2011. Seascape
ecology of coastal benthic habitats: advances, gaps, and challenges. Mar Ecol Prog Ser 427:191-217
 This article appeared in a Marine Ecology Progress Series
theme section focusing on seascape ecology, a special edition
edited in part by the authors of Pittman et al. (2011). It is a highly
useful review article that highlights both areas of progress and of
need in the field, and evaluates the response of biota to fragmentation in various marine habitats. Along with Pittman et al. (2011)
and Wedding et al. (2011), this article provides some wonderful
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background to the emerging field of seascape ecology and was
critical in cross-referencing several key pieces of information. The
variety of topics covered (e.g. the importance of scale; effects of
patch size, edge, and fragmentation; geomorphology in salt
marshes; connectivity in coral reefs and mangroves) make it a
lengthy paper, but numerous tables, graphs, and maps help
illustrate the main points more quickly. However, a comprehensive read is a must if the actual methods and application of
landscape metrics used to generate the data are to be understood.
Eyre BD, Maher D. 2011. Mapping ecosystem processes and
function across shallow seascapes. Cont Shelf Res 31:S162-S172
 This paper exemplified the power of using landscape metrics
to map coastal ecosystem functions over various scales in various
habitats. This information can then be used to identify conservation ‘hotspots’ and determine areas of high and low value to the
overall health of the ecosystem. This particular study focused on
mapping lagoons and river estuaries in Australia. In addition to
maps, the data can be summarized using innovative diagrams,
which provide a visual way to quickly compare the value of
functions across different habitat classifications. The paper is not
a difficult read, and any text which might need clarification can
usually be understood by studying the figures.
Meadows PS, Meadows A, Murray JMH. 2012. Biological modifiers
of marine benthic seascapes: their role as ecosystem engineers.
Geomorphology 157-158:31-48
 This article reviews research on the role of marine benthic
organisms in modifying the seabed seascape. The study introduces the idea of advanced mathematical modeling of this system, a
concept which could be applied to other seascape/landscape
systems. It also discusses the importance of looking at the fossil
record in determining the interaction of biological and geological
processes that contributed to the formation of present seabed
seascapes and sediment composition. Key points in the paper are
summarized in flow charts and diagrams, which are incredibly
useful in generalizing conclusions drawn from analysis conducted
on the species level. Their review is long and in-depth, and given
the density of the paper their conclusions did not seem as comprehensive as it could have been.
Mitchell JG, Yamazaki H, Seuront L, Wolk F, Li H. 2008. Phytoplankton patch patterns: Seascape anatomy in a turbulent ocean. J
Marine Syst 69:247-253
 This is a fascinating study which applied seascape ecology
metrics to describe patterns of phytoplankton patches. These
patches arise partly in response to turbulence and eddy currents,
and form distinctive asymmetric patches with regular distribution.
The study was most interesting for its recognition of biological
distributions as seascapes in and of themselves, which seems to be
a relatively new concept. It also emphasizes the importance of
appreciating timescales when applying landscape metrics and
recognizing seascapes; otherwise certain mosaics might not be
recognized as seascapes if inappropriate timescales are used. The
study used in situ fluorescence to identify plankton patches and
correlated these with measures of physical oceanographic
parameters such as salinity and temperature. Some graphs were
difficult to comprehend; however the conceptual 2D distributions
were very fascinating.
Moberg F, Rönnbäck P. 2003. Ecosystem services of the tropical
seascape: interactions, substitutions and restoration. Ocean
Coast Manage 46:27-46
 This is a rather elegant article which assesses the tropical
seascape in attempt to answer two fundamental management
questions: to what extent can technological substitutes for
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BJC Fuller / Advances in seascape ecology: applying landscape metrics to marine systems
ecosystem services be effective, and how can ecosystem restoration result in both the return of those services and the resilience of
the system to future disturbances. It is an important article for
understanding the potential of seascape ecology in a management context, and does a good job of providing background
information about each patch type as well as examples of management projects that have been successful because of their
integration within the tropical seascape patch mosaic.
Mumby, PJ. 2006. Connectivity of reef fish between mangroves and
coral reefs: Algorithms for the design of marine reserves at
seascape scales. Biol Conserv 128:215-222
 This study synthesized data on mangrove nurseries and the
health of adult reef fish to develop four algorithms which inform
management efforts in mangrove habitats. The study was fairly
comprehensive, using landscape metrics to assess connectivity and
patch importance throughout the Carribean. Information was
well-organized and summarized in both tabular and graphic
formats, which made it easier to identify the overall results and
implications of the study. This article was crucial for highlighting
the application of seascape ecology in directing management
practices, since this area of seascape ecology is as of yet underdeveloped.
Olds AD, Connolly RM, Pitt KA, Maxwell PS. 2012. Primacy of
seascape connectivity effects in structuring coral reef fish
assemblages. Mar Ecol Prog Ser 426:191-203
 This study focused specifically on using metrics to assess the
connectivity of mangroves and coral reefs, and the role of such
connectivity in maintaining healthy adult reef fish assemblages.
This was an important article in providing an in-depth look at how
these metrics can be applied to marine connectivity, and built
upon Mumby (2006). Reading was not terribly dense, but required
some special knowledge of reef fish assemblages and coral
reef/mangrove ecology in order to fully appreciate the results.
Pittman SJ, Kneib RT, Simenstad CA. 2011. Practicing coastal
seascape ecology. Mar Ecol Prog Ser 427: 187-190
 This is a highly useful review article that appeared as the lead
paper in a Marine Ecology Progress Series theme section focusing
on seascape ecology. The authors were also the editors of the
section, along with Ivan Nagelkerken, professor at The University
of Adelaide in Australia. It discusses the emergence of seascape
ecology as a subset of marine ecology, highlights various examples
of marine spatial patterns, and points to some important directions for the future study of seascape ecology. This was a perfect
article to provide some necessary background about the development of seascape ecology and the generally application of
landscape metrics to marine systems. Likewise, it seemed to serve
as an introduction to the remainder of the theme section, which
made it easier to relate subsequent articles to each other
throughout the research process.
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Rilov G, Schiel DR. 2006. Seascape-dependent subtital-intertidal
trophic linkages. Ecol 87:731-744
 This paper looked at settlement, predation, and trophic
linkages between fish, crab, and mussel species in coastal environments around New Zealand. The goal was to understand the
relationship between these predator-prey interactions and the
seascape itself, with considerations for scale. It was primarily
interesting for this reason, since the study of predator-prey
interactions often acknowledge the influence of geographic
heterogeneity, but only in the context of accounting for errors in
modeling. The application of seascape ecology in understanding
predator-prey interactions could have huge implications for
revising models and explaining and removing errors in the
analysis. The paper is heavy on statistics, which makes understanding the extent of the significance of interactions difficult
without a working knowledge of multivariate ANOVA. Trophic
webs help illustrate these interactions in the context of seascapes
when statistical specifics aren’t necessary for conveying overall
conclusions, which make the paper a bit more palatable.
Wedding LM, Lepczyk CA, Pittman SJ, Friedlander AM, Jorgensen S.
2011. Quantifying seascape structure: extending terrestrial
spatial pattern metrics to the marine realm. Mar Ecol Prog Ser
427:219-232
 This is a very comprehensive review article that appeared in a
Marine Ecology Progress Series theme section focusing on seascape ecology, which was edited in part by the authors of Pitmann
et al. (2011). It gives a general background about the origins of
seascape ecology, and covers advancements in some important
topics including 2D and 3D seascape applications, the influence of
scale, analytical techniques, and general problems encountered.
Diagrammatical representations of analytical problems and
factors that influence the accuracy of seascape metrics help
illustrate the main points made in what is otherwise a straightforward but fairly dense read. Along with Pittman et al. (2011)
and Boström et al. (2011), this article provides a nice overview of
the advancements in seascape ecology and gives suggestions for
future directions. Cross-referencing between these three articles
proved highly useful.
Yu PC, Matson PG, Martz TR, Hofmann GE. 2011. The ocean
acidification seascape and its relationship to the performance of
calcifying marine invertebrates: Laboratory experiments on the
development of urchin larvae framed by environmentallyrelevant pCO2/pH. J Exp Mar Biol Ecol 400:288-295
 This study looks at the relationship between pH ‘landscapes’,
or what they refer to as the “ocean acidification seascape”, and
the ability of urchin larvae to calcify their exoskeleton. This paper
was fascinating for its treatment of seascapes in a chemical, as
opposed to geographic, context, which was especially enlightening. This invites a much broader perspective on the application of
the term seascape, and perhaps ushers in a new vein of seascape
ecology that can be applied to wholly pelagic organisms that
never encounter any sort of physical landscape.
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