Herbivorous Sea Urchins (Echinometra Mathaei) Support Resilience on Overfished and Sedimented Tropical Reefs

Overview

Journal Sci Rep

Specialty Science

Date 2024 Feb 15

PMID 38360981

Authors

Caitlin R Fong

Nefertiti Smith

Elijah Catalan

Blanca Alvarez Caraveo

Paul H Barber

Peggy Fong

Affiliations

Soon will be listed here.

Abstract

Human impacts are dramatically changing ecological communities, motivating research on resilience. Tropical reefs are increasingly undergoing transitions to short algal turf, a successional community that mediates either recovery to coral by allowing recruitment or transitions to longer turf/macroalgae. Intense herbivory limits turf height; subsequently, overfishing erodes resilience of the desirable coral-dominated reef state. Increased sedimentation also erodes resilience through smothering and herbivory suppression. In spite of this critical role, most herbivory studies on tropical reefs focus on fishes, and the contribution of urchins remains under-studied. To test how different herbivory and sedimentation scenarios impact turf resilience, we experimentally simulated, in situ, four future overfishing scenarios derived from patterns of fish and urchin loss in other reef systems and two future sedimentation regimes. We found urchins were critical to short turf resilience, maintaining this state even with reduced fish herbivory and increased sediment. Further, urchins cleared sediment, facilitating fish herbivory. This study articulates the likelihood of increased reliance on urchins on impacted reefs in the Anthropocene.

References

Halpern B, Frazier M, Afflerbach J, Lowndes J, Micheli F, OHara C . Recent pace of change in human impact on the world's ocean. Sci Rep. 2019; 9(1):11609. PMC: 6691109. DOI: 10.1038/s41598-019-47201-9. View

Cavanaugh K, Kellner J, Forde A, Gruner D, Parker J, Rodriguez W . Poleward expansion of mangroves is a threshold response to decreased frequency of extreme cold events. Proc Natl Acad Sci U S A. 2014; 111(2):723-7. PMC: 3896164. DOI: 10.1073/pnas.1315800111. View

Bellwood D, Hughes T, Folke C, Nystrom M . Confronting the coral reef crisis. Nature. 2004; 429(6994):827-33. DOI: 10.1038/nature02691. View

Hughes T, Barnes M, Bellwood D, Cinner J, Cumming G, Jackson J . Coral reefs in the Anthropocene. Nature. 2017; 546(7656):82-90. DOI: 10.1038/nature22901. View

Hughes T . Catastrophes, phase shifts, and large-scale degradation of a Caribbean coral reef. Science. 1994; 265(5178):1547-51. DOI: 10.1126/science.265.5178.1547. View

Scheffer M, Carpenter S, Foley J, Folke C, Walker B . Catastrophic shifts in ecosystems. Nature. 2001; 413(6856):591-6. DOI: 10.1038/35098000. View

Hughes T, Rodrigues M, Bellwood D, Ceccarelli D, Hoegh-Guldberg O, McCook L . Phase shifts, herbivory, and the resilience of coral reefs to climate change. Curr Biol. 2007; 17(4):360-5. DOI: 10.1016/j.cub.2006.12.049. View

Adam T, Schmitt R, Holbrook S, Brooks A, Edmunds P, Carpenter R . Herbivory, connectivity, and ecosystem resilience: response of a coral reef to a large-scale perturbation. PLoS One. 2011; 6(8):e23717. PMC: 3162008. DOI: 10.1371/journal.pone.0023717. View

Tebbett S, Bellwood D . Sediments ratchet-down coral reef algal turf productivity. Sci Total Environ. 2020; 713:136709. DOI: 10.1016/j.scitotenv.2020.136709. View

10.

Lewis S . Herbivory on coral reefs: algal susceptibility to herbivorous fishes. Oecologia. 2017; 65(3):370-375. DOI: 10.1007/BF00378911. View

11.

Hughes T, Bellwood D, Folke C, McCook L, Pandolfi J . No-take areas, herbivory and coral reef resilience. Trends Ecol Evol. 2006; 22(1):1-3. DOI: 10.1016/j.tree.2006.10.009. View

12.

Burkepile D, Hay M . Herbivore species richness and feeding complementarity affect community structure and function on a coral reef. Proc Natl Acad Sci U S A. 2008; 105(42):16201-6. PMC: 2565647. DOI: 10.1073/pnas.0801946105. View

13.

Holbrook S, Schmitt R, Adam T, Brooks A . Coral Reef Resilience, Tipping Points and the Strength of Herbivory. Sci Rep. 2016; 6:35817. PMC: 5090207. DOI: 10.1038/srep35817. View

14.

McCulloch M, Fallon S, Wyndham T, Hendy E, Lough J, Barnes D . Coral record of increased sediment flux to the inner Great Barrier Reef since European settlement. Nature. 2003; 421(6924):727-30. DOI: 10.1038/nature01361. View

15.

Maina J, de Moel H, Zinke J, Madin J, McClanahan T, Vermaat J . Human deforestation outweighs future climate change impacts of sedimentation on coral reefs. Nat Commun. 2013; 4:1986. PMC: 3709493. DOI: 10.1038/ncomms2986. View

16.

Hayes H, Kalhori P, Weiss M, Grier S, Fong P, Fong C . Storms may disrupt top-down control of algal turf on fringing reefs. Coral Reefs. 2021; 40(2):269-273. PMC: 7784215. DOI: 10.1007/s00338-020-02045-y. View

17.

Tebbett S, Schlaefer J, Bowden C, Collins W, Hemingson C, Ling S . Bio-physical determinants of sediment accumulation on an offshore coral reef: A snapshot study. Sci Total Environ. 2023; 895:165188. DOI: 10.1016/j.scitotenv.2023.165188. View

18.

Goatley C, Bellwood D . Ecological consequences of sediment on high-energy coral reefs. PLoS One. 2013; 8(10):e77737. PMC: 3790735. DOI: 10.1371/journal.pone.0077737. View

19.

Tebbett S, Goatley C, Bellwood D . The Effects of Algal Turf Sediments and Organic Loads on Feeding by Coral Reef Surgeonfishes. PLoS One. 2017; 12(1):e0169479. PMC: 5207718. DOI: 10.1371/journal.pone.0169479. View

20.

Pandolfi J, Bradbury R, Sala E, Hughes T, Bjorndal K, Cooke R . Global trajectories of the long-term decline of coral reef ecosystems. Science. 2003; 301(5635):955-8. DOI: 10.1126/science.1085706. View