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SEASCAPE Seascape ecology: A new science for the spatial information age s society undergoes a spatial data revolution Afuelled by the rapid development of online maps, satellite navigation sys- tems and geo-portals, a transfor- mative shift is also underway in marine ecology. A new breed of marine ecologist, known as seascape ecologists, are bringing enhanced spatial awareness to ecological thinking, together with the tools to work with ‘big data’ and a desire to ask new types of applied research ques- tions. The latest generation of remote sensing data from water, Visually captivating seascape tors? How does human activity air- and space-based platforms patterns from the coastal zone to alter the structure and function reveal unimaginable and intrigu- of landscapes? ing structural complexity in our the open ocean are now being Several guiding principles oceans. Yet, despite our best revealed in ever more detail by the that exist at the core of land- efforts to acquire and make scape ecology have made major accessible vast datasets that cap- latest generation of remote sensing contributions to terrestrial land- ture in detail the multidimen- devices. Simon Pittman, a marine scape planning and conserva- sional patterning of the oceans, tion, but in marine systems our we still know surprisingly little spatial ecologist, explains the understanding is still in its infan- about the ecological conse- application of cy. For example: (1) environ- quences of spatial patterning. mental heterogeneity exists at concepts and tools to marine and multiple spatial scales to which What is seascape coastal data, which is providing vital organisms respond differently ecology? and at different scales; (2) con- Seascape ecology deals with information for marine management. nectivity is an important ecologi- the causes and ecological conse- cal pattern and process; (3) quences of spatial pattern in the patch boundaries/edges influ- marine environment, drawing their location relative to other ence ecological processes. heavily on conceptual and ana- things, influences how they func- lytical frameworks developed in tion. A landscape ecologist will Seascape patterns terrestrial landscape ecology. ask different questions focused Just like life on land, the sea Seascape ecologists are interest- at different scales than other sci- exhibits complex spatial pattern- ed in the spatially explicit geom- entists, such as: What are the ing that can be mapped and etry of patterns and the relation- ecological consequences of dif- quantified, such as gradients in ships between pattern, ecological ferent shaped patches, patch plant communities across tidal processes and environmental size, quality, edge geometry, spa- saltmarshes or the intricate change. A central tenet in land- tial arrangement and diversity of mosaics of patches typical of scape ecology is that patch con- patches across the landscape? At coral reefs. In the open ocean text matters, where local condi- what scale(s) is structure most too, dynamic spatial structure in tions are influenced by attributes influential? How do landscape the form of water currents, of the surroundings. For patterns influence the way that eddies, temperature fronts and instance, the physical arrange- animals find food, evade preda- patches can be meas- ment of objects in space, and tors and interact with competi- ured readily. Physical processes

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such as storms dramatically influence spatial patterning in the environment and human activity can also directly create patch structure, modify mosaic anchor the scale selection to a composition and even complete- known and functionally mean- ly remove elements of the ingful spatiotemporal scale that seascape. Furthermore, climate- can then form the focal scale in a change induced shifts in species hierarchical approach. related to water temperature The size of a seascape will change and sea level rise are thus be dependent on the driving a gradual reconfigura- research questions and the ecol- tion of the geography of species ogy of the organism or process of and habitats. interest. In landscape ecology, The patterns revealed by this approach to scaling is called remote sensing devices are most the ‘organism-based perspec- often mapped and represented tive’. For many marine species, using two types of model: (1) col- we do not have sufficient knowl- lections of discrete patches form- edge of movement patterns to ing mosaics e.g. as represented in that an amphipod perceives, select a meaningful focal scale two-dimensional benthic habitat experiences and responds to the and therefore an exploratory map, or (2) continuously varying surrounding seascape will be dif- multi-scale approach to meas- gradients in three-dimensional ferent than a shark. Further- urement of environmental pat- terrain models, e.g. in remotely more, this organism–seascape terning and analysis of organ- sensed bathymetric data. In land- relationship will change ism–seascape relationships is scape ecology, patches can be clas- throughout an organism’s life, appropriate. sified into a binary patch-matrix with juveniles responding differ- Nevertheless, whether the model based on island biogeogra- ently than adults. Individuals, seascape is a 1m2 patch of sea- phy theory where a focal habitat species and communities will grass or a 10km radius area patch type (e.g. seagrasses) is sur- respond to seascape patterning encompassing seagrass beds, rounded by an inhospitable across a hierarchy of spatial adjacent coral reefs and man- matrix (e.g. sand), or a patch- scales. groves, the analytical techniques mosaic of interconnected patches, So how do we select spatial and concepts applied can be the where the interactions of the scales for field investigations? same. The problem of scale is parts influence the ecological Movement behaviour is one not a new one for ecologists, but function of the whole mosaic. approach. In the Caribbean, we the challenge of ecologically Both patch and gradient models used acoustic telemetry to define meaningful scale selection is ever have provided important insights day and night activity spaces for present. into the spatial ecology of marine associated fish and species and biodiversity. then mapped that habitat at high Tools of the trade resolution to examine the influ- Typically, seascape ecologists Scale matters ence of seascape patterning on apply a suite of spatial pattern Seascape ecologists recognise the movement process, thereby metrics, or spatial statistics, to that one organism’s habitat linking seascape ecology and quantify the geometry of pat- patch is to another a mosaic of behavioural ecology. The organ- terning in the environment. Two patches. For example, the way ism’s activity space helps us to families of metrics exist: (1) land-

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scape metrics or indices that are applied to two-dimensional patch-matrix and patch-mosaic models of the environment (i.e. benthic habitat maps); and (2) terrain morphometrics that are applied to characterise the struc- ture of three-dimensional digital terrain models (i.e. bathymetry). Landscape metrics are avail- able in free online software such as FRAGSTATS or Patch Analyst, that quantify a wide range of structural attributes of composi- tion (amount and variety of patch types) and configuration Key findings (spatial arrangement of patches). Since the early 1990s, land- For example, area (e.g. area of scape ecology approaches have patch type); edge (e.g. edge den- been applied in several marine sity); shape (e.g. fractal dimen- shallow subtidal and intertidal sion); isolation/proximity (e.g. ecosystems, such as in seagrass mean proximity index); diversity ecosystems and salt marshes in (e.g. patch richness); the United States and Australia. contagion/interspersion (e.g. These have primarily focused on clumpiness index) and connec- the faunal response to structural tivity indices. In contrast, terrain attributes of individual patches morphometrics more familiar to (e.g. size, edge, shape, isolation). industrial metrologists and geo- The influence of patch level morphologists measure variables structural attributes has been coral reefs, however, are becom- such as topographic complexity, highly variable with no decisive ing widespread in the Indo- curvature and slope from digital generalities identified. Several Pacific oceans and the Caribbean elevation models. Some metrics studies, however, in subtropical Sea. It is likely that a better have well-documented ecological Australia and the Caribbean understanding of the impor- effects and others are less well found that the structural attrib- tance of three-dimensional phys- known, or have yet to be evaluat- utes of the surrounding seascape ical structure on species distribu- ed, forming a major research contributed significantly to tions and diversity will allow us focus. explanations of the spatial vari- to more reliably forecast the eco- Geographical Information ability in faunal diversity and logical consequences of structur- Systems (GIS) enable seascape abundance. For example, the al change including predicting ecologists to work with and juxtaposition of adjacent sea- species loss and range changes quantify geometry in maps. grass beds and coral reefs or from reef collapse. In the open Multi-scale analysis is easily mangroves results in a synergis- ocean, quantification of oceanic processed in a GIS using a mov- tic boost in the local diversity of fronts and plankton patches has ing-window analysis or by clip- fish and the biological productiv- enabled ecologists to identify ping out seascape units of vary- ity for some species. This is hotspots of productivity and ing sizes surrounding a biologi- known as ‘seascape complemen- diversity to inform the site selec- cal survey location and applying tation or supplementation’. In tion process in placement of pattern metrics. In this way, we the Caribbean, a multi-scale marine protected areas (MPAs) treat the seascape unit much as seascape ecology approach and network design. we would a quadrat used to sam- demonstrated how benthic habi- ple the abundance of benthic tat maps can be used to identify Bridging the gap communities, albeit a larger unit optimal seascape types for fish Marine managers often area in most seascape applica- species and fish assemblage receive ecological data from ecol- tions. Furthermore, GIS com- diversity. A similar approach, but ogists that is interesting and per- bined with statistical modelling using terrain models instead of tinent with high resolution provides accurate, quantitative habitat maps, have shown topo- detail, but with limited spatial and cost-effective tools to model graphic complexity to be an distribution. A key utility of the the geography of organism– excellent predictor of habitat seascape approach to ecology is seascape relationships extending suitability for fish and coral the potential to provide ecologi- to spatial predictive mapping of species abundance and diversity. cally meaningful information at species distributions. Reports of structural collapse of spatial scales that are opera-

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tionally relevant for decision and ecological processes, includ- making in marine management. ing the impact of changing pat- Knowledge of the ecological con- terns on predator–prey dynam- sequences of seascape configura- ics, animal movement pathways, tion can be used to help deter- foraging behaviour and individ- mine the best placement and ual growth rates. This can be design of MPAs to optimise examined through manipulative restoration strategies, to under- experiments, some of which will stand the influence of structural need to be opportunistic, given and functional connectivity on that the scale of interest may be biodiversity patterns and to bet- too broad for conventional ter predict the effects of environ- manipulations. In terrestrial sys- mental change. Marine spatial tems, microlandscapes have planning efforts increasingly been constructed in the laborato- require spatial information on ry to examine individual essential fish habitat, diversity responses such as movement and hotspots and ‘blue corridors’ to habitat selection to differing incorporate ecological connectiv- patch structures. Computer sim- ity into the planning process. ulation models also can be used Seascape ecology techniques can tools to conduct sophisticated to examine the effect of pattern be used to predict these priority spatial analyses, although on process. locations cost-effectively. The progress in marine applications Adoption of a multi-scale and multi-scale approach has now is uncommon. The recent global multi-habitat landscape ecology been effectively implemented in surge in interest in marine spa- perspective may move us closer several locations worldwide to tial planning should fuel the to fulfilling the original vision for predict fish distributions, deep evolution of conceptual and Ökologie (ecology), first defined water corals, seabirds and operational approaches in by Ernst Haeckel in 1866 as “the cetaceans in support of marine seascape ecology. science of the relationship of spatial planning and MPA net- The immediate focus of organisms to their surround- work design. seascape ecology research ings”. Landscape ecology helps should be to determine which define the relevance of the sur- Future directions theoretical constructs, analytical roundings. Without such an Although much is made of techniques and structural pat- approach, important pieces of the differences between marine terns or features from landscape the ecological puzzle will be miss- and terrestrial environments, ecology are relevant to marine ing. In a world where spatial many commonalities exist in the organisms and their habitats. data is a core component of deci- way that organisms respond to Gaining a better understanding sion-making throughout society, structure in their environment, of faunal–seascape relationships, seascape ecologists have an aca- whether they are a bird or a fish including the identifications of demically rewarding challenge on land or sea. The new genera- threshold effects, is a major ahead and great potential to tion of ecologists embracing big research priority. We now also change the way we perceive and data and the spatial revolution is need to build the evidence for manage the marine environ- fast becoming equipped with the causal linkages between patterns ment. One has only to look at the rise of terrestrial landscape ecol- ogy in the past 30 years to obtain a sense of what lies ahead. 

Simon Pittman is a marine ecologist working with the Biogeography Branch of the U.S. National Ocean Service, U.S. National Oceanic and Atmospheric Administration and is a Visiting Research Fellow based at the Marine Institute, University of Plymouth, UK. A Theme Section on seascape ecology was published in Marine Ecology Progress Series (Issue 427) in 2011. [email protected] Research papers available at http://uvi.academia.edu/Simon JamesPittman

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