Kelp are ecologically important in wave-swept habitats because their thalli provide food and habitat to many other organisms. Fronds of kelp thalli can be broken off by hydrodynamic forces that exceed frond strength, especially if the fronds are weakened by wounds inflicted by herbivores. Previous studies hypothesized that breaking benefits some kelp by reducing their size and the risk of dislodgement by large hydrodynamic forces, but we know little about the long-term effects of breaking on kelp growth and survival. Here, we used the intertidal kelp Egregia menziesii to study the relationship between the breaking of the kelp’s fronds ("pruning") and the kelp’s growth and survival. By surveying kelp pruning and herbivore wounds on fronds for 24 months at intertidal sites in northern California we found that pruning was positively correlated with herbivory. We also measured growth rates and long-term survival of kelp to determine if they were correlated with kelp pruning or size. For kelp of any size, heavy pruning led to reduced growth rates in every season except autumn. Contrary to suggestions in the literature that pruning enhances kelp survival, we found that heavily pruned kelp were less likely than lightly pruned kelp to survive winter storms, and heavy pruning led to reduced long-term survival. Thus, the reduction in growth rate caused by pruning of E. menziesii, which renders kelp unable to recover from tissue loss, appears to be more important to long-term survival of this strong perennial kelp than is the danger of being swept away by waves.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
The datasets collected and analyzed during the current study are available from the corresponding author on reasonable request.
Abbott IA, Hollenberg GJ (1976) Marine algae of California. Stanford University Press, Stanford
Armstrong SL (1987) Mechanical properties of the tissues of the brown alga Hedophyllum sessile (C. Ag.) Setchell: variability with habitat. J Exp Mar Biol Ecol 114:143–151
Arnold M, Teagle H, Brown MP, Smale DA (2016) The structure of biogenic habitat and epibiotic assemblages associated with the global invasive kelp Undaria pinnatifida in comparisons to native macroalgae. Biol Invasions 18:661–676
Barnard PL, Hoover D, Hubbard DM, Snyder A, Ludka BC, Allan J, Kaminsky GM, Ruggiero P, Gallien TW, Gabel L et al (2017) Extreme oceanographic forcing and coastal response due to the 2015–2016 El Niño. Nat Commun 8:14365
Bekkby T, Rinde E, Gundersen H, Norderhaug KM, Gitmark JK, Christie H (2014) Length, strength and water flow: relative importance of wave and current exposure on morphology in kelp Laminaria hyperborea. Mar Ecol Prog Ser 506:61–70
Biedka RF, Gosline JM, DeWreede RE (1987) Biomechanical analysis of wave-induced mortality in the marine alga Pterygophora californica. Mar Ecol Prog Ser 36:163–170
Black R (1974) Some biological interactions affecting intertidal populations of the kelp Egregia laevigata. Mar Biol 28:189–198
Black R (1976) The effects of grazing by the limpet, Acmaea insessa, on the kelp, Egregia laevigata, in the intertidal zone. Ecology 57:265–277
Blanchette CA (1997) Size and survival of intertidal plants in response to wave action: a case study with Fucus gardneri. Ecology 78:1563–1578
Boller ML, Carrington E (2007) Interspecific comparison of hydrodynamic performance and structural properties among intertidal macroalgae. J Exp Biol 210:1874–1884
Burnett NP, Koehl MAR (2018) Knots and tangles weaken kelp fronds while increasing drag forces and epifauna on the kelp. J Exp Mar Biol Ecol 508:13–20
Burnett NP, Koehl MAR (2019) Mechanical properties of the wave-swept kelp Egregia menziesii change with season, growth rate and herbivore wounds. J Exp Biol 222:jeb190595
Carrington E (1990) Drag and dislodgment of an intertidal macroalga: consequences of morphological variation in Mastocarpus papillatus Kutzing. J Exp Mar Biol Ecol 139:185–200
Chapman JW (2007) Gammaridea. In: Carlton JT (ed) The Light and Smith manual: intertidal invertebrates from central California to Oregon. University of California Press, Berkeley, pp 545–586
Conlan KE, Chess JR (1992) Phylogeny and ecology of a kelp-boring amphipod, Peramphithoe stypotrupetes, new species (Corophioidea: Amphithoidea). J Crustacean Biol 12:410–442
Dayton PK, Tegner MJ, Parnell PE, Edwards PB (1992) Temporal and spatial patterns of disturbance and recovery in a kelp forest community. Ecol Monogr 62:421–445
de Bettignies T, Thomsen MS, Wernberg T (2012) Wounded kelps: patterns and susceptibility to breakage. Aquat Biol 17:223–233
de Bettignies T, Wernberg T, Lavery PS, Vanderklift MA, Gunson JR, Symonds G, Collier N (2015) Phenological decoupling of mortality from wave forcing in kelp beds. Ecology 96:850–861
de Bettignies T, Wernberg T, Lavery PS, Vanderklift MA, Mohring MB (2013) Contrasting mechanisms of dislodgement and erosion contribute to production of kelp detritus. Limnol Oceanogr 58:1680–1688
Delf EM (1932) Experiments with the stipes of Fucus and Laminaria. J Exp Biol 9:300–313
Demes KW, Harley CDG, Anderson LM, Carrington E (2013) Shifts in morphological and mechanical traits compensate for performance costs of reproduction in a wave-swept seaweed. J Ecol 101:963–970
Denny M, Brown V, Carrinton E, Kraemer G, Miller A (1989) Fracture mechanics and the survival of wave-swept macroalgae. J Exp Mar Biol Ecol 127:211–228
Denny MW (1988) Biology and the mechanics of the wave-swept environment. Princeton University Press, Princeton
Denny MW, Gaylord BP, Cowen EA (1997) Flow and flexibility. II. The roles of size and shape in determining wave forces on the bull kelp Nereocystis luetkeana. J Exp Biol 200:3165–3183
Denny M, Gaylord B, Helmuth B, Daniel T (1998) The menace of momentum: dynamic forces on flexible organisms. Limnol Oceanogr 43:955–968
Dudgeon SR, Johnson AS (1992) Thick vs. thin: thallus morphology and tissue mechanics influence differential drag and dislodgement of two co-dominant seaweeds. J Exp Mar Biol Ecol 165:23–43
Duggins D, Eckman JE, Siddon CE, Klinger T (2001) Interactive roles of mesograzers and current flow in survival of kelps. Mar Ecol Prog Ser 223:143–155
Filbee-Dexter K, Scheibling RE (2012) Hurricane-mediated defoliation of kelp beds and pulsed delivery of kelp detritus to offshore sedimentary habitats. Mar Ecol Prog Ser 455:51–64
Gaylord B, Denny MW (1997) Flow and flexibility. I. Effects of size, shape and stiffness in determining wave forces on the stipitate kelps Eisenia arborea and Pterygophora californica. J Exp Biol 200:3141–3164
Gaylord B, Denny MW, Koehl MAR (2008) Flow forces on seaweeds: field evidence for roles of wave impingement and organism inertia. Biol Bull 215:295–308
Gaylord B, Rosman JH, Reed DC, Koseff JR, Fram J, MacIntyre S, Arkema K, McDonald C, Brzezinski MA, Largier JL, Monismith SG, Raimondi PT, Mardian B (2007) Spatial patterns of flow and their modification within and around a giant kelp forest. Limnol Oceanogr 52:1838–1852
Graham MH, Harrold C, Lisin S, Light K, Watanabe JM, Foster MS (1997) Population dynamics of giant kelp Macrocystis pyrifera along a wave exposure gradient. Mar Ecol Prog Ser 148:269–279
Graham MH, Vásquez JA, Buschmann AH (2007) Global ecology of the giant kelp Macrocystis: from ecotypes to ecosystems. Oceanogr Mar Biol 45:39–88
Gunnill FC (1983) Seasonal variations in the invertebrate faunas of Pelvetia fastigiate (Fucaceae): effects of plant size and distribution. Mar Biol 73:115–130
Harder DL, Stevens CL, Speck T, Hurd CL (2006) The role of blade buoyancy and reconfiguration in the mechanical adaptation of the southern bullkelp Durvillaea. In: Herrel A, Speck T, Rowe N (eds) Ecology and biomechanics: a mechanical approach to the ecology of animals and plants. Dekker Publisher, Boca Raton, pp 61–84
Helmuth B, Denny MW (2003) Predicting wave exposure in the rocky intertidal zone: do bigger waves always lead to larger forces? Limnol Oceanogr 48:1338–1345
Holbrook NM, Denny MW, Koehl MAR (1991) Intertidal “trees”: consequences of aggregation on the mechanical and photosynthetic properties of sea-palms Postelsia palmaeformis Ruprecht. J Exp Mar Biol Ecol 146:39–67
Johnson AS, Koehl MAR (1994) Maintenance of dynamic strain similarity and environmental stress factor in different flow habitats: thallus allometry and material properties of a giant kelp. J Exp Biol 195:381–410
Kawamata S (2001) Adaptive mechanical tolerance and dislodgement velocity of the kelp Laminaria japonica in wave-induced water motion. Mar Ecol Prog Ser 211:89–104
Koehl MAR (1984) How do benthic organisms withstand moving water? Am Zool 24:57–70
Koehl MAR (1986) Seaweeds in moving water: form and mechanical function. In: Givnish TJ (ed) On the economy of plant form and function. Cambridge University Press, Cambridge, pp 603–634
Koehl MAR (1999) Ecological biomechanics of benthic organisms: life history, mechanical design and temporal patterns of mechanical stress. J Exp Biol 202:3469–3476
Koehl MAR, Alberte RS (1988) Flow, flapping, and photosynthesis of Nereocystis luetkeana: a functional comparison of undulate and flat blade morphologies. Mar Biol 99:435–444
Koehl MAR, Silk WK, Liang H, Mahadevan L (2008) How kelp produce blade shapes suited to different flow regimes: a new wrinkle. Integr Comp Biol 48:834–851
Koehl MAR, Wainwright SA (1977) Mechanical adaptations of a giant kelp. Limnol Oceanogr 22:1067–1071
Leighton DL (1971) Grazing activities of benthic invertebrates in southern California kelp beds. In: North WJ (ed) The biology of giant kelp beds (Macrocystis) in California. Verlag Von J Cramer, Lehre, pp 421–453
Lowell RB, Markham JH, Mann KH (1991) Herbivore-like damage induces increased strength and toughness in a seaweed. Proc R Soc B 243:31–38
Martone PT, Kost L, Boller M (2012) Drag reduction in wave-swept macroalgae: alternative strategies and new predictions. Am J Bot 99:806–815
O’Brien JM, Scheibling RE (2016) Nipped in the bud: mesograzer feeding preference contributes to kelp decline. Ecology 97:1873–1886
O’Donnell MJ, Denny MW (2008) Hydrodynamic forces and surface topography: centimeter-scale spatial variation in wave forces. Limnol Oceanogr 53:579–588
Ogle DH, Wheeler P, Dinno A (2018) FSA: fisheries stock analysis. R package version 0.8.22
Ojeda FP, Santelices B (1984) Invertebrate communities in holdfasts of the kelp Macrocystis pyrifera from southern Chile. Mar Ecol Prog Ser 16:65–73
Peng CJ, Lee KL, Ingersoll GM (2002) An introduction to logistic regression analysis and reporting. J Educ Res 96:3–14
Pfister CA, Betcher SP (2018) Climate drivers and animal host use determine kelp performance over decadal scales in the kelp Pleurophycus gardneri (Laminariales, Phaeophyceae). J Phycol 54:1–11
Poore AGB, Gutow L, Pantoja JF, Tala F, Madariaga DJ, Thiel M (2014) Major consequences of minor damage: impacts of small grazers on fast-growing kelps. Oecologia 174:789–801
R Core Team (2019) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria
Santelices B, Castilla JC, Cancino J, Schmiede P (1980) Comparative ecology of Lessonia nigrescens and Durvillaea Antarctica (Phaeophyta) in Central Chile. Mar Biol 59:119–132
Schiel DR, Foster MS (2015) The structure, function, and abiotic requirements of giant kelp. In: Schiel DR, Foster MS (eds) The biology and ecology of giant kelp forests. University of California Press, Berkeley, pp 23–40
Seymour RJ, Tegner MJ, Dayton PK, Parnell PE (1989) Storm wave induced mortality of giant kelp, Macrocystis pyrifera, in Southern California. Estuar Coast Shelf S 28:277–292
Smith SDA, Simpson RD, Cairns SC (1996) The macrofaunal community of Ecklonia radiata holdfasts: description of the faunal assemblage and variation associated with differences in holdfast volume. Aust J Ecol 21:81–95
Stewart HL (2006) Hydrodynamic consequences of flexural stiffness and buoyancy for seaweeds: a study using physical models. J Exp Biol 209:2170–2181
Teagle H, Hawkins SJ, Moore PJ, Smale DA (2017) The role of kelp species as biogenic habitat formers in coastal marine ecosystems. J Exp Mar Biol Ecol 492:81–98
Tegner MJ, Dayton PK, Edwards PB, Riser KL (1995) Sea urchin cavitation of giant kelp (Macrocystis pyrifera C. Agardh) holdfasts and its effects on kelp mortality across a large California forest. J Exp Mar Biol Ecol 191:83–99
Watanabe JM, Phillips RE, Allen NH, Anderson WA (1992) Physiological response of the stipitate understory kelp, Pterygophora californica Ruprecht, to shading by the giant kelp, Macrocystis pyrifera. J Exp Mar Biol Ecol 159:237–252
Winkler NS, Pérez-Matus A, Villena AA, Thiel M (2017) Seasonal variation in epifaunal communities associated with giant kelp (Macrocystis pyrifera) at an upwelling-dominated site. Austral Ecol 42:132–144
Wolcott BD (2007) Mechanical size limitation and life-history strategy of an intertidal seaweed. Mar Ecol Prog Ser 338:1–10
We thank E. Armstrong, A. Belk, T. Burnett, D. Chan, S. Chang, J. Judge, E. King, L. Louis, W. Kumler, R. Romero, C. Runzel, E. Sathe, D. Springthorpe, R. Tanner and D. Weiler for help with field surveys.
This work was funded by a Point Reyes National Seashore Marine Science Fund grant and the National Science Foundation [DGE-1106400 to N.P.B.; DGE-0903711 to R. Full, M.A.R.K., R. Dudley and R. Fearing].
Conflict of interest
The authors declare they have no conflicts of interest.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Reviewed by undisclosed experts.
Responsible Editor: K. Bischof.
Electronic supplementary material
Below is the link to the electronic supplementary material.
About this article
Cite this article
Burnett, N.P., Koehl, M.A.R. Thallus pruning does not enhance survival or growth of a wave-swept kelp. Mar Biol 167, 52 (2020). https://doi.org/10.1007/s00227-020-3663-5