Current Landscape Ecology Reports

, Volume 4, Issue 4, pp 91–102 | Cite as

Rough Around the Edges: Lessons Learned and Future Directions in Marine Edge Effects Studies

  • John M. CarrollEmail author
  • Danielle A. Keller
  • Bradley T. Furman
  • Amber D. Stubler
Landscape Ecology of Aquatic Systems (K Hovel, Section Editor)
Part of the following topical collections:
  1. Topical Collection on Landscape Ecology of Aquatic Systems


Purpose of Review

After several decades of research on edge effects in marine habitats, we still have little understanding of how organisms respond to marine ecotones, and methodological gaps appear to be limiting our progress. Using recent literature (2010–2018), we synthesized responses and processes of organisms across several marine habitats. Specifically, we examined the uniformity of studies across biogenic habitats, the scales selected for exploring edge effects, the experimental approaches used, and the confounding influences that muddle our interpretation of results.

Recent Findings

The majority of edge effect studies are still conducted in seagrass systems and focused on response patterns. We found that the majority of studies were equally likely to report an increase, decrease, neutral, or equivocal effect depending on the context of the organism or habitat. Additionally, only a single measure, or a few related responses, is assessed and causal mechanisms are rarely tested. We note that most studies quantitatively defined an edge habitat as a linear distance from a habitat boundary (e.g., < 1 m, < 5 m), but the distances were not usually scaled to the size, trophic level, or mobility of focal organisms.


We provide a conceptual diagram as a roadmap for researchers for navigating the myriad influences that affect floral and faunal responses to marine habitat edges. Future efforts should seek to move beyond mensurative searches, explicitly incorporate potentially confounding variables, and more consistently test putative causal factors when known or hypothesized. Additionally, we advise expanding research on habitat types other than seagrasses (e.g., mangroves, shellfish, corals) and adjusting observational scales to more appropriately match mechanisms. Ultimately, we should move beyond pattern description, repeated in a limited subset of nearshore habitats, and toward a quantitative understanding of the processes acting in these unique and potentially impactful marine ecotones.


Edge Biogenic habitat Ecosystem Habitat loss Spatial scale Ecotone 



We would like to thank Dr. Kevin Hovel and Dr. Lenore Fahrig for inviting us to participate in this review. In addition, a number of people participated in initial ideas and discussions for this paper, including Dr. Bradley Peterson of Stony Brook University, Dr. Joel Fodrie at the University of North Carolina and Dr. Lauren Yeager at the University of Texas. Finally, we would like to thank Dr. Laura Treible from Georgia Southern University for providing feedback on this manuscript.

Authors’ Contribution

All authors were involved in determining the scope of this review. J.M.C. was responsible for overall literature searches, summarizing the shellfish literature and writing the initial draft. D.A.K. was responsible for summarizing the overall literature in terms of patterns and processes. Both B.T.F. and A.D.S. were involved in reviewing relevant literature in their study areas, and summarizing issues in scaling. All authors made significant contributions to the subsequent drafts and have given their final approval for publication.

Compliance with Ethical Standards

Conflict of Interest

John Carroll, Bradley Furman, Danielle Keller and Amber Stubler declare that they have no conflicts of interest.

Human and Animal Rights and Informed Consent

This article does not contain any studies with human or animal subjects performed by any of the authors.

Supplementary material

40823_2019_43_MOESM1_ESM.docx (150 kb)
ESM 1 (DOCX 150 kb)


Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance

  1. 1.
    • Kangeri AKW, Jansen JM, Joppe DJ, Dankers N. In situ investigation of the effects of current velocity on sedimentary mussel bed stability. J Exp Mar Biol Ecol. 2016;485:65–72. combination ofin situmeasurements and manipulations to examine how flow speed and sediment characteristics affect mussel byssus production and likelihood of being dislodged across a mussel bed. They found higher byssal production and courser sediment associated with higher flow at bed edge, the combination of which increased adhesive strength of mussels in these locations. CrossRefGoogle Scholar
  2. 2.
    Peterson CH, Luettich RA, Micheli F, Skilleter GA. Attenuation of flow inside seagrass canopies of differing structure. Mar Ecol Prog Ser. 2004;268:81–92.CrossRefGoogle Scholar
  3. 3.
    Macreadie PI, Connolly RM, Jenkins GP, Hindell JS, Keough MJ. Edge patterns in aquatic invertebrates explained by predictive models. Mar Freshw Res. 2010;61:214–8.CrossRefGoogle Scholar
  4. 4.
    Fagan W, Cantrell R, Cosner C. How habitat edges change species interactions. Am Nat. 1999;153:165–82.CrossRefGoogle Scholar
  5. 5.
    Ries L, Fletcher RJ, Battin J, Sisk TD. Ecological responses to habitat edges: mechanisms, models and variability explained. Annu Rev Ecol Evol Syst. 2004;35:491–522.CrossRefGoogle Scholar
  6. 6.
    Carroll JM, Peterson BJ. Ecological trade-offs in seascape ecology: bay scallop survival and growth across a seagrass seascape. Landsc Ecol. 2013;28(7):1401–13. Scholar
  7. 7.
    Ceccherelli G, Pinna S, Cusseddu V, Bulleri F. The role of disturbance in promoting the spread of the invasive seaweed Caulerpa racemosa in seagrass meadows. Biol Invasions. 2014;16(12):2737–45. Scholar
  8. 8.
    Bostrom C, Pittman SJ, Simenstad C, Kneib RT. Seascape ecology of coastal biogenic habitats: advances, gaps, and challenges. Mar Ecol Prog Ser. 2011;427:191–217.CrossRefGoogle Scholar
  9. 9.
    Hinchey E, Nicholson M, Zajac R, Irlandi EA. Preface: marine and coastal applications in landscape ecology. Landsc Ecol. 2008;23:1–5.CrossRefGoogle Scholar
  10. 10.
    Didham RK, Lawton JH. Edge structure determines the magnitude of changes in microclimate and vegetation structure in tropical forest fragments. Biotropia. 1999;31:17–30.Google Scholar
  11. 11.
    Cadenasso ML, Traynor MM, Pickett STA. Functional location of forest edges: gradients of multiple physical factors. Can J For Res. 1997;27:774–82.CrossRefGoogle Scholar
  12. 12.
    Meyer CL, Sisk TD, Covington WW. Microclimatic changes induced by ecological restoration of ponderosa pine forests in northern Arizona. Restor Ecol. 2001;9:443–52.CrossRefGoogle Scholar
  13. 13.
    Watkins RZ, Chen J, Pickens J, Brosofske KD. Effects of forest roads on understory plants in a managed hardwood landscape. Conserv Biol. 2003;17:411–9.CrossRefGoogle Scholar
  14. 14.
    Schlaepfer MA, Gavin TA. Edge effects on lizards and frogs in tropical forest fragments. Conserv Biol. 2001;15:1079–90.CrossRefGoogle Scholar
  15. 15.
    •• Manderson JP. Seascapes are not landscapes: an analysis performed using Bernhard Reimann's rules. ICES J Mar Sci. 2016;73:1831–8 An important review paper because it describes the major differences in chemical and physical properties between air and water and why that might affect our ability to apply terrestrial landscape ecological principles to seascapes. CrossRefGoogle Scholar
  16. 16.
    Carroll JM, Furman BT, Tettelbach ST, Peterson BJ. Balancing the edge effects budget: bay scallop settlement and loss along a seagrass edge. Ecology. 2012;93(7):1637–47. Scholar
  17. 17.
    Moore EC, Hovel KA. Relative influence of habitat complexity and proximity to patch edges on seagrass epifaunal communities. Oikos. 2010;119(8):1299–311. Scholar
  18. 18.
    •• Hanke MH, Posey MH, Alphin TD. The influence of habitat characteristics on intertidal oyster Crassostrea virginica populations. Mar Ecol Prog Ser. 2017;571:121–38. of just a few studies that investigated oyster reefs, this paper investigated within patch location and patch size effects on oyster demographic rates at both natural and constructed oyster reefs; they found mixed patterns. Oyster density increased with distance from the patch edge, although recruitment decreased over the same scale. Oyster condition was not affected.CrossRefGoogle Scholar
  19. 19.
    • Macreadie PI, Geraldi NR, Peterson CH. Preference for feeding at habitat edges declines among juvenile blue crabs as oyster reef patchiness increases and predation risk grows. Mar Ecol Prog Ser. 2012;466:145–53. paper investigated the role of predator behavior and feeding at habitat edges in artificially created oyster habitats in mesocosms. Even at a small spatial scale of operation, the authors demonstrated that small predators altered their edge habitat use, and thus their predation on prey resources, when their predators were present. CrossRefGoogle Scholar
  20. 20.
    Sheaves M, Johnston R, Baker R. Use of mangroves by fish: new insights from in-forest videos. Mar Ecol Prog Ser. 2016;549:167–82. authors investigated fish use of mangroves on incoming tides to determine whether and where they dispersed over time. CrossRefGoogle Scholar
  21. 21.
    Robbins B, Bell S. Seagrass landscapes: a terrestrial approach to the marine subtidal environment. Trends Ecol Evol. 1994;9:301–4.CrossRefGoogle Scholar
  22. 22.
    Levin SA. The problem of pattern and scale in ecology: the Robert H. MacArther Award Lecture. Ecology. 1992;73:1943–67.CrossRefGoogle Scholar
  23. 23.
    Jiang XT, Peng X, Deng GH, Sheng HF, Wang Y, Zhou HW, et al. Illumina sequencing of 16S rRNA tag revealed spatial variations of bacterial communities in a mangrove wetland. Microb Ecol. 2013;66(1):96–104. Scholar
  24. 24.
    • Stubler AD, Jackson LJ, Furman BT, Peterson BJ. Seed Production Patterns in Zostera marina: Effects of Patch Size and Landscape Configuration. Estuar Coasts. 2017;40(2):564–72. paper investigated seed production inZostera marinabeds across multiple spatial scales, and found that within patch location did not have an effect on seed production, but rather, production was impacted by the total seagrass cover in the surrounding seascape. CrossRefGoogle Scholar
  25. 25.
    • Langston AK, Kaplan DA, Angelini C. Predation restricts black mangrove (Avicennia germinans) colonization at its northern range limit along Florida's Gulf Coast. Hydrobiologia. 2017;803(1):317–31. field survey and manipulative approach to asses location and predation effects on mangrove propagule survival. More soil disturbance and burrowing activity at creek edges, but almost 100% mortality of uncaged propagules regardless of location. CrossRefGoogle Scholar
  26. 26.
    •• Mahoney RD, Kenworthy MD, Geyer JK, Hovel KA, Fodrie FJ. Distribution and relative predation risk of nekton reveal complex edge effects within temperate seagrass habitat. J Exp Mar Biol Ecol. 2018;503:52–9. combination of mensurative and manipulative approaches were used to assess predation pressure on common mesopredators in seagrass landscapes. They found higher survival in seagrass edges, but no differences in their capture rates (i.e., spatial distribution) or the foraging patterns of an important higher order predator. Interactive effects of seagrass shoot density were also considered. CrossRefGoogle Scholar
  27. 27.
    Ollivier QR, Bramwell NA, Hammill E, Foster-Thorpe C, Booth DJ. Are the effects of adjacent habitat type on seagrass gastropod communities being masked by previous focus on habitat dyads? Aust J Zool. 2015;63(5):357–63. Scholar
  28. 28.
    Tuya F, Vanderklift MA, Hyndes GA, Wernberg T, Thomsen MS, Hanson C. Proximity to rocky reefs alters the balance between positive and negative effects on seagrass fauna. Mar Ecol Prog Ser. 2010;405:175–86. Scholar
  29. 29.
    Amortegui-Torres V, Taborda-Marin A, Blanco JF. Effect of Neritina virginea (Neritimorpha, Neritinidae) population in a black mangrove stand (Magnoliopsida, Avicenniaceae: Avicennia germinans) in southern Caribbean. Pan-Am J Aquat Sci. 2013;8:68–78.Google Scholar
  30. 30.
    •• Jurgens LJ, Gaylord B. Edge effects reverse facilitation by a widespread foundation species. Sci Rep. 2016;6. authors were able to demonstrate an edge effect on mussels across a small (~12cm) spatial scale but also were able to link this effect directly to a temperature stress gradient.
  31. 31.
    Nicastro KR, Zardi GI, McQuaid CD, Pearson GA, Serrao EA. Love Thy Neighbour: Group Properties of Gaping Behaviour in Mussel Aggregations. PLoS One. 2012;7(10). Scholar
  32. 32.
    • Hanke MH, Posey MH, Alphin TD. The effects of intertidal oyster reef habitat characteristics on faunal utilization. Mar Ecol Prog Ser. 2017;581:57–70. paper investigated within patch location and patch size effects on oyster reef associated fauna on both natural and constructed reefs and found that spatial patterns varied across fauna, reef size and reef type. CrossRefGoogle Scholar
  33. 33.
    Macreadie PI, Hindell JS, Keough MJ, Jenkins GP, Connolly RM. Resource distribution influences positive edge effects in a seagrass fish. Ecology. 2010;91(7):2013–21. Scholar
  34. 34.
    Hitt S, Pittman SJ, Nemeth RS. Diel movements of fishes linked to benthic seascape structure in a Caribbean coral reef ecosystem. Mar Ecol Prog Ser. 2011;427:275–91. Scholar
  35. 35.
    Hammerschlag N, Serafy JE. Nocturnal fish utilization of a subtropical mangrove-seagrass ecotone. Mar Ecol. 2010;31(2):364–74. Scholar
  36. 36.
    • Reis JA, Giarrizzo T, Barros F. Tidal migration and cross-habitat movements of fish assemblage within a mangrove ecotone. Mar Biol. 2016, 163(5). analysis of fish use of mangroves. They found that the mangrove ecotone was used by the entire fish assemblage, but depending on tidal stage, fish migrated to a number of microhabitats.
  37. 37.
    Nobbs M, Blamires SJ. Spatiotemporal distribution and abundance of mangrove ecosystem engineers: burrowing crabs around canopy gaps. Ecosphere. 2015;6(5). Scholar
  38. 38.
    • Rietl AJ, Sorrentino MG, Roberts BJ. Spatial distribution and morphological responses to predation in the salt marsh periwinkle. Ecosphere. 2018;9(6). mensurative study of snail density and biomass along 50m transects from marsh edge to interior across multiple sites in Louisiana. They found that snail density tended to be highest around 10m from the edge, whereas biomass was highest 20-30m from the edge. CrossRefGoogle Scholar
  39. 39.
    Coppa S, Guala I, DeLucia GA, Massaro G, Bressan M. Density and distribution patterns of the endangered species Pinna nobilis within a Posidonia oceanica meadow in the Gulf of Oristano (Italy). J Mar Biol Assoc UK. 2010;90:885–94.CrossRefGoogle Scholar
  40. 40.
    Hammerschlag N, Ovando D, Serafy JE. Seasonal diet and feeding habits of juvenile fishes foraging along a subtropical marine ecotone. Aquat Biol. 2010;9(3):279–90. Scholar
  41. 41.
    Statton J, Gustin-Craig S, Dixon KW, Kendrick GA. Edge Effects along a Seagrass Margin Result in an Increased Grazing Risk on Posidonia australis Transplants. PLoS One. 2015;10(10). Scholar
  42. 42.
    Kallen J, Muller H, Franken ML, Crisp A, Stroh C, Pillay D, et al. Seagrass-epifauna relationships in a temperate south African estuary: interplay between patch-size, within-patch location and algal fouling. Estuar Coast Shelf Sci. 2012;113:213–20. Scholar
  43. 43.
    Murphy HM, Jenkins GP, Hindell JS, Connolly RM. Response of fauna in seagrass to habitat edges, patch attributes and hydrodynamics. Austral Ecol. 2010;35(5):535–43. Scholar
  44. 44.
    Tuya F, Vanderklift MA, Wernberg T, Thomsen MS. Gradients in the Number of Species at Reef-Seagrass Ecotones Explained by Gradients in Abundance. PLoS One. 2011;6(5). Scholar
  45. 45.
    Vonk JA, Christianen MJA, Stapel J. Abundance, edge effect, and seasonality of fauna in mixed-species seagrass meadows in Southwest Sulawesi, Indonesia. Mar Biol Res. 2010;6(3):282–91. Scholar
  46. 46.
    Hammerschlag N, Morgan AB, Serafy JE. Relative predation risk for fishes along a subtropical mangrove-seagrass ecotone. Mar Ecol Prog Ser. 2010;401:259–67. Scholar
  47. 47.
    Dolmer P, Christensen HT, Hansen BW, Vismann B. Area-intensive bottom culture of blue mussels Mytilus edulis in a micro-tidal estuary. Aquac Environ Interact. 2012;3(1):81–91. Scholar
  48. 48.
    • Gross C, Donoghue C, Pruitt C, Trimble AC, Ruesink JL. Taxonomic and functional assessment of mesopredator diversity across an estuarine habitat mosaic. Ecosphere. 2017;8(4). seining survey that found edge habitats to be intermediate to sand and core habitats in terms of mesopredator community structure, with site effects generally exceeding edge effects.CrossRefGoogle Scholar
  49. 49.
    Wong MC, Dowd M. Patterns in taxonomic and functional diversity of macrobenthic invertebrates across seagrass habitats: a case study in Atlantic Canada. Estuar Coasts. 2015;38(6):2323–36. Scholar
  50. 50.
    • Gross C, Donoghue C, Pruitt C, Ruesink JL. Habitat use patterns and edge effects across a seagrass-unvegetated ecotone depend on species-specific behaviors and sampling methods. Mar Ecol Prog Ser. 2018;598:21–33. and video data were used to assess mesopredator abundance and diversity in eelgrass-dominated landscape. Edge effects, relative to core and unvegetated sites, varied by species and sampling method based on available species pools and species-specific behavioral characteristics. CrossRefGoogle Scholar
  51. 51.
    Matias MG, Coleman RA, Hochuli DF, Underwood AJ. Macrofaunal Responses to Edges Are Independent of Habitat-Heterogeneity in Experimental Landscapes. PLoS One. 2013;8(4). Scholar
  52. 52.
    Knights AM. Spatial variation in body size and reproductive condition of subtidal mussels: considerations for sustainable management. Fish Res. 2012;113:45–54.CrossRefGoogle Scholar
  53. 53.
    Barnes RSK. Are seaward pneumatophore fringes transitional between mangrove and lower-shore system compartments. Mar Environ Res. 2017;125:99–109. paper found various macrobenthic assemblages across habitat ecotones, which shows consideration should be given to examining transitions between complex focal and matrix habitats. CrossRefPubMedGoogle Scholar
  54. 54.
    Toscano BJ, Griffen BD. Predator size interacts with habitat structure to determine the allometric scaling of the functional response. Oikos. 2013;122(3):454–62. Scholar
  55. 55.
    Hammerschlag N, Heithaus MR, Serafy JE. Influence of predation risk and food supply on nocturnal fish foraging distributions along a mangrove-seagrass ecotone. Mar Ecol Prog Ser. 2010;414:223–35. Scholar
  56. 56.
    Smith TM, Hindell JS, Jenkins GP, Connolly RM, Keough MJ. Edge effects in patchy seagrass landscapes: the role of predation in determining fish distribution. J Exp Mar Biol Ecol. 2011;399(1):8–16. Scholar
  57. 57.
    Amrhein V, Greenland S, McShane B. Scientists rise up against statistical significance. Nature. 2019;567(305-307) This comment highlights some of the issues with improper interpretation of results based on P values. CrossRefGoogle Scholar
  58. 58.
    Sullivan GM, Feinn R. Using effect size - or why the P value is not enough. J Grad Med Educ. 2012;4:279–82.CrossRefGoogle Scholar
  59. 59.
    • Beninger PG, Boldina I, Katsanevakis S. Stengthening statistical usage in marine ecology. J Exp Mar Biol Ecol. 2012;426–427:97–108 This review provides numerous examples of problems with using traditional statistics and assigning too much weight to P values. In particular, the authors point out the differences between statistical significance and biological relevance, and make suggestions for other methods of data analysis and interpretation. CrossRefGoogle Scholar
  60. 60.
    Furman BT, Jackson LJ, Bricker E, Peterson BJ. Sexual recruitment in Zostera marina: a patch to landscape-scale investigation. Limnol Oceanogr. 2015;60:584–99.CrossRefGoogle Scholar
  61. 61.
    Furman BT, Peterson BJ. Sexual recruitment in Zostera marina: Progress toward a predictive model. PLoS One. 2015;10:e0138206.CrossRefGoogle Scholar
  62. 62.
    Espino F, Gonzalez JA, Haroun R, Tuya F. Abundance and biomass of the parrotfish Sparisoma cretense in seagrass meadows: temporal and spatial differences between seagrass interiors and seagrass adjacent to reefs. Environ Biol Fish. 2015;98(1):121–33. Scholar
  63. 63.
    • Carroll JM, Furman BT, Jackson LJ, Hunter EA, Peterson BJ. Propagule risk in a marine foundation species: seascape effects on Zostera marina seed predation. J Ecol. 2019. authors investigated seagrass seed predation across multiple spatial scales, and using structural equation modelling, demonstrated that within patch locations explained a small proportion of the variation in seed predation, with predation being increased at patch centers. CrossRefGoogle Scholar
  64. 64.
    Baillie CJ, Fear JM, Fodrie FJ. Ecotone effects on seagrass and saltmarsh habitat use by juvenile nekton in a temperate estuary. Estuar Coasts. 2015;38(5):1414–30. Scholar
  65. 65.
    Arroyave-Rincon A, Amortegui-Torres V, Blanco-Booksellers JF, Taborda-Marin A. Border effect on ble crab population Cardisoma guanhumi (Decapoda:Gecarcinidae) in the mangrove swamp of El Uno Bay, Uraba gulf (Colombia): an approach to its artisanal capture. Biol News. 2014;36:47–57.Google Scholar
  66. 66.
    Macreadie PI, Hindell JS, Jenkins CN, Connolly RM, Keough MJ. Fish responses to experimental fragmentation of seagrass habitat. Conserv Biol. 2009;23:644–52.CrossRefGoogle Scholar
  67. 67.
    Travaille KL, Salinas-de-Leon P, Bell JJ. Indication of visitor trampling impacts on intertidal seagrass beds in a New Zealand marine reserve. Ocean Coast Manag. 2015;114:145–50. Scholar
  68. 68.
    Silliman BR, van de Koppel J, McCoy MW, Diller J, Kasozi GN, Earl K, et al. Degradation and resilience in Louisiana salt marshes after the BP-Deepwater horizon oil spill. Proc Natl Acad Sci. 2012;109:11234–9.CrossRefGoogle Scholar
  69. 69.
    Caitano B, Dodonov P, Delabie JHC. Edge, area and anthropization effects on mangrove-dwelling ant communities. Acta Oecol. 2018;91:1–6. field survey approach for arboreal ant communities in fragmenting mangrove forests. They found no effect of distance to edge on ant abundance or community measures.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Department of BiologyGeorgia Southern UniversityStatesboroUSA
  2. 2.Institute of Marine SciencesUniversity of North Carolina Chapel HillMorehead CityUSA
  3. 3.Florida Fish and Wildlife Conservation CommissionFish and Wildlife Research InstituteSt. PetersburgUSA
  4. 4.Department of BiologyOccidental CollegeLos AngelesUSA

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