Biomechanical analysis of wave-induced mortality in the marine alga Pterygophora californica

Biedka, RF; Gosline, JM; Wreede, RE De

doi:10.3354/meps036163

Cited by 40 publications

(29 citation statements)

References 7 publications

(10 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is, however, reasonable to assume that factors like those discussed in the present study have an impact on the longevity and recovery (regeneration) of the fronds. Wave action is, for example, a major agent of disturbance (Koehl 1986, Biedka et al 1987, Denny 1987, 1988, Denny et al 1989. Softening of fronds of C. crispus by endophytic infections likely facilitates fractures by wave action, and furthermore, when fronds are grazed, the removed biomass will accelerate the fracture process by producing flaws on the surface where the wave forces concentrate and amplify (Biedka et al 1987, Denny et al 1989).…”

Section: Discussionmentioning

confidence: 99%

Endophytic algae of Chondrus crispus (Rhodophyta). IV Effects on the host following infections by Acrochaete operculata and A. heteroclada (Chlorophyta)

Ja¹,

McLachlan²

1992

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

The rhodophycean seaweed Chondrus crispus was infected under laboratory conditions by the green algal endophytes Acrochaete operculata and A. heteroclada. Such infections resulted in detrimental effects on host performance, including slower growth and carrageenan yields. Regeneration capacity of the host was diminished, with the extent determined by the density of the infection. Infections also caused softening of host tissue in both laboratory-infected and wild fronds; in the former the degree of softness was directly related to density of infections. Infected C. crispus was preferred over non-infected material when offered to Idotea baltica and Gammarus oceanicus, and the consurnption of infected fronds was similar to that of the highly palatable chlorophyte Ulva sp. In general, infection by A. heteroclada affected the 2 life-history generations of the host similarly, whereas A. operculata affected mainly sporophytic fronds. This study shows that A. operculeta and A. heteroclada are pathogens of C. cnspus, and that their effects on the host, either as primary cause of dysfunctions or as agents facilitating secondary infections by other pathogens, can have major effects on both natural and cultivated populations.

show abstract

Section: Discussionmentioning

confidence: 99%

Endophytic algae of Chondrus crispus (Rhodophyta). IV Effects on the host following infections by Acrochaete operculata and A. heteroclada (Chlorophyta)

Ja¹,

McLachlan²

1992

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…For such materials, strength reduction can be predicted reliably with Eqn·3. For seaweeds, however, large deformations act to round the crack tip and reduce stress concentrations, thereby limiting the utility of linear elastic expressions in predicting strength reduction in the presence of cracks (Biedka et al, 1987;Denny et al, 1989;DeWreede et al, 1992). Cracktip rounding ameliorates the strength reduction predicted by Eqn·3.…”

Section: Cracks Reduce Strengthmentioning

confidence: 99%

“…Once a crack has formed in an alga through fatigue, herbivory or abrasion, it can locally amplify stress, thereby decreasing the alga's ultimate strength (where strength is calculated from bulk force applied to a specimen, disregarding local amplifications) and rendering the alga more susceptible to breakage by the imposition of a single large stress (e.g. Black, 1976;Johnson and Mann, 1986;Armstrong, 1987;Biedka et al, 1987;Denny et al, 1989;Lowell et al, 1991;DeWreede et al, 1992). Even if an alga containing a crack does not experience stress sufficient to break it in a single loading, repeated stresses below the alga's ultimate strength may cause a crack to grow to a length at which breakage occurs (Hale, 2001).…”

Section: The Role Of Fatiguementioning

confidence: 99%

“…Crack area A is calculated as crack length multiplied by specimen thickness. Some confusion in biological literature has arisen due to differing definitions of dA (Biedka et al, 1987;Denny et al, 1989;Hale, 2001). Sometimes new crack surface area created in crack extension is taken to include surface area of both faces of the crack, while at other times it includes surface area on only one face of the crack.…”

Section: Crack Propagation Energy Considerations (Linear Elastic Fracmentioning

confidence: 99%

See 1 more Smart Citation

Techniques for predicting the lifetimes of wave-swept macroalgae: a primer on fracture mechanics and crack growth

Mach

Nelson

Denny

2007

Journal of Experimental Biology

View full text Add to dashboard Cite

SUMMARY Biomechanical analyses of intertidal and shallow subtidal seaweeds have elucidated ways in which these organisms avoid breakage in the presence of exceptional hydrodynamic forces imposed by pounding surf. However, comparison of algal material properties to maximum hydrodynamic forces predicts lower rates of breakage and dislodgment than are actually observed. Why the disparity between prediction and reality? Most previous research has measured algal material properties during a single application of force, equivalent to a single wave rushing past an alga. In contrast, intertidal macroalgae may experience more than 8000 waves a day. This repeated loading can cause cracks– introduced, for example, by herbivory or abrasion – to grow and eventually cause breakage, yet fatigue crack growth has not previously been taken into account. Here, we present methods from the engineering field of fracture mechanics that can be used to assess consequences of repeated force imposition for seaweeds. These techniques allow quantification of crack growth in wave-swept macroalgae, a first step towards considering macroalgal breakage in the realistic context of repeated force imposition. These analyses can also be applied to many other soft materials.

show abstract

“…Stress (force/cross-sectional area) and strain (extended stipe length normalized to initial length, [l -l i ]/l i ) at failure were measured and the elastic modulus (stress/strain) at failure was calculated (see Koehl & Wainwright 1986, Biedka et al 1987, and Denny et al 1989 for further discussion of mechanical tests). Work per volume required to break the stipe was estimated by approximating the area under the stressstrain curves, and the total work required to break the stipe was calculated from that value.…”

Section: Methodsmentioning

confidence: 99%

Desiccation facilitates wave-induced mortality of the intertidal alga Fucus gardneri

Haring¹,

Dethier

Williams³

2002

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

Physical factors such as desiccation and water motion can influence the abundance and performance of intertidal seaweeds. We addressed the hypothesis that the intertidal seaweed Fucus gardneri can be dislodged or damaged by relatively small waves if weakened by the effects of desiccation. Stress-strain curves generated for desiccated and hydrated thalli revealed that desiccated stipes were more brittle than hydrated stipes and required less total work (energy) to break. Results from a dynamic loading experiment suggest that the oscillating motion of the waves may be an important factor in breaking brittle stipes. Therefore, seemingly benign water motion may provide sufficient force to damage or dislodge desiccated thalli. In the late spring and summer in this area, waves are generally small but desiccating conditions are common as low tides fall during midday. Mortality of field populations is high during these seasons; thalli experimentally protected from desiccation suffered many fewer losses. However, desiccated F. gardneri can rehydrate rapidly (less than 1 min), minimizing the window of time that wave forces can break stipes. This study provides an example of how 2 sub-lethal physical factors, desiccation and benign waves, can interact to cause mortality in an upper intertidal seaweed.

show abstract

Biomechanical analysis of wave-induced mortality in the marine alga Pterygophora californica

Abstract: Biomechanical analysis of wave-induced mortality in the marine alga Pterygophora californica MARINE ECOLOGY-PROGRESS SERIES Mar. Ecol. h o g. Ser.

Cited by 40 publications

References 7 publications

Endophytic algae of Chondrus crispus (Rhodophyta). IV Effects on the host following infections by Acrochaete operculata and A. heteroclada (Chlorophyta)

Endophytic algae of Chondrus crispus (Rhodophyta). IV Effects on the host following infections by Acrochaete operculata and A. heteroclada (Chlorophyta)

Techniques for predicting the lifetimes of wave-swept macroalgae: a primer on fracture mechanics and crack growth

Desiccation facilitates wave-induced mortality of the intertidal alga Fucus gardneri

Contact Info

Product

Resources

About