Location, location, location: small shifts in collection site result in large intraspecific differences in macroalgal palatability

Keeley, Kathryn N.; Stroh, Jolie D.; Tran, Diem Samantha C.; Fong, Caitlin R.; Fong, Peggy

doi:10.1007/s00338-015-1274-2

Cited by 9 publications

(5 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Acanthophora spicifera was the most consumed, almost four times more than L. variegata and H. opuntia; between these latter two there were no differences. These results indicate that macroalgal species vary in palatability between the herbivores on coral reefs (Hay, 1991;Keeley et al, 2015). In our experiments, urchins consumed a greater quantity of A. spicifera, a palatable early-successional turf macroalga, avoiding the less palatable late-successional fleshy species such as L. variegata and H. opuntia.…”

Section: Discussionmentioning

confidence: 51%

Assessing the herbivore role of the sea-urchin Echinometra viridis: Keys to determine the structure of communities in disturbed coral reefs

Sangil

Guzmán

2016

Marine Environmental Research

View full text Add to dashboard Cite

Echinometra viridis previously was considered a cryptic species unable to control the development and growth of macroalgae on coral reefs. Its role as a herbivore was seen as minor compared to other grazers present on the reef. However, the present disturbed state of some reefs has highlighted the role played by this sea-urchin. Combining field data with experiments on the Caribbean coast of Panama, we demonstrate that the current community organization on disturbed coral reefs in the Mesoamerican Caribbean is largely due to the action of E. viridis. It is the most abundant sea-urchin species, together with two others (Diadema antillarum and Echinometra lucunter). Field data also indicate that the relationship between its density and the abundance of macroalgae is stronger and it is more negative in impact than those of the other two. However, the niche this urchin exploits most efficiently is confined to leeward reefs with low levels of sedimentation. Outside these habitats, their populations are not decisive in controlling macroalgal growth. Grazing experiments showed that E. viridis consumes more fresh macroalgae per day and per weight of sea-urchin, and is a more effective grazer than D. antillarum or E. lucunter. E. viridis showed food preferences for early-successional turf macroalgae (Acanthophora spicifera), avoiding the less palatable late-successional and fleshy macroalgae (Lobophora variegata, Halimeda opuntia). However, it becomes a generalist herbivore feeding on all varieties of macroalgae when resources are scarce. H. opuntia is the macroalga that most resists E. viridis activity, which may explain its wide distribution.

show abstract

Section: Discussionmentioning

confidence: 51%

Assessing the herbivore role of the sea-urchin Echinometra viridis: Keys to determine the structure of communities in disturbed coral reefs

Sangil

Guzmán

2016

Marine Environmental Research

View full text Add to dashboard Cite

show abstract

“…One recent study found that within‐species palatability can vary on much smaller spatial scales (<15 m) than previously considered (Keeley et al . ). Finally, selectivity may be facilitated by higher algal abundance, potentially from reduced herbivory pressure, which results in a greater availability of a more diverse algal resource.…”

Section: Discussionmentioning

confidence: 97%

“…All algae were collected from the same area (<15 m apart; Keeley et al . ), sorted to species, cleaned of debris and other organisms, spun in a salad spinner to remove excess water and weighed into 5.0 g samples. Samples of all four species were cable‐tied to 10 × 10 cm mesh plates and placed into plastic bags filled with seawater to minimize handling losses during transportation.…”

Section: Methodsmentioning

confidence: 99%

Size matters: experimental partitioning of the strength of fish herbivory on a fringing coral reef in Moorea, French Polynesia

et al. 2016

Self Cite

View full text Add to dashboard Cite

While the importance of top-down control by grazers in maintaining tropical reef community structure is well known, the effect of 'fishing down the food web', which simultaneously changes the abundance and size of herbivorous fishes, has received less attention. As many fishing practices target the biggest fish and regulations often set minimum size limits, understanding size-dependency of this controlling force is important. We evaluated the hypothesis that reduction in the abundance and size of fish, regardless of species identity, reduces the role of herbivory in controlling algal abundance on reefs and assessed variation in efficacy of this top-down control on different types of common macroalgae. We quantified herbivory rates within cages of differing opening sizes on assemblages of four common algal species (Padina boryana, Dictyota bartayresiana, Halimeda opuntia and Galaxaura fasciculata) on two fringing reefs in Moorea, French Polynesia. Small acanthurids (<15 cm length) were the dominant herbivorous fish while other herbivorous fish were rare. For the two most palatable algae, the majority of herbivory occurred in open plots, with herbivory reduced by >50% in the largest opening cages (6 9 6 cm) where the maximum size fish entering was 12 cm in length (mean = 7.6, SE = 0.4). Fish entering medium (4.5 9 4.5 cm openings, maximum fish length = 8 cm, mean = 6.3, SE = 0.4) and small (3 9 3 cm openings, no fish observed entering) cages had herbivory rates approximately equal to the control treatment (1 9 1 cm openings). Consumption varied among algal species, with minimal consumption of physically and chemically defended algae and no pattern across treatments. Our results demonstrate a need for management plans to not only maintain the overall abundance of herbivorous fish but to protect the largest sizes for effective top-down control of algal communities.

show abstract

“…For example, Keeley et al (2015) documented that fish consumed S. polycystum transplanted from the intertidal 6 times more rapidly than conspecifics grown <15 m away in the subtidal. This could result from higher grazing in the deeper site causing induction of defence in algae growing there, while less grazing in the intertidal (no fish were observed in that region during the study) left the algae there un-induced.…”

Section: Discussionmentioning

confidence: 99%

Induced defence to grazing by vertebrate herbivores: uncommon or under-investigated?

Dell

Hay

2016

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

There are many examples of macroalgae inducing defence in response to small invertebrate herbivores like amphipods, isopods, and gastropods but few cases of induction in response to vertebrate macrograzers like herbivorous fishes. This may be because larger grazers rapidly consume large quantities of seaweed before induction can occur, thus selecting for constitutive rather than induced defences. Alternatively, the pattern could occur because induction due to feeding by macrograzers is less commonly investigated. In Fiji, field assays with the brown macroalga Sargassum polycystum demonstrated that thalli growing in marine protected areas (MPAs) with abundant herbivorous fishes were significantly less palatable than those growing in adjacent fished areas (non-MPAs) with few herbivorous fishes. This significant preference occurred in 11 of 13 trials over 5 time periods and across 3 pairs of MPAs and spatially associated non-MPAs. This preference was not positively associated with algal nitrogen content or with the toughness of algal fronds. When S. polycystum ramets were taken from the non-MPA and half were partially grazed by fishes while the other half were protected from grazing, new growth from the controls was strongly preferred to new growth from the previously grazed ramets although these fronds originated from the same holdfast. This suggests that S. polycystum upregulates defences (probably chemical) in response to grazing by herbivorous fishes. This is one of the few published examples of induction of macroalgal defence in response to feeding by large, mobile grazers. It is unclear whether induced defences against fishes are rare or just under-investigated.

show abstract

Location, location, location: small shifts in collection site result in large intraspecific differences in macroalgal palatability

Cited by 9 publications

References 19 publications

Assessing the herbivore role of the sea-urchin Echinometra viridis: Keys to determine the structure of communities in disturbed coral reefs

Assessing the herbivore role of the sea-urchin Echinometra viridis: Keys to determine the structure of communities in disturbed coral reefs

Size matters: experimental partitioning of the strength of fish herbivory on a fringing coral reef in Moorea, French Polynesia

Induced defence to grazing by vertebrate herbivores: uncommon or under-investigated?

Contact Info

Product

Resources

About