This document discusses a case study of coral reefs in Bonaire and the role of parrotfish in maintaining the health and resilience of the reefs. It finds that Bonaire has much higher abundances of parrotfish compared to other areas in the Eastern Caribbean due to a ban on spearfishing implemented in the 1970s. This has helped control seaweed growth and facilitated high coral cover, juvenile coral abundance, and an overall resilient reef ecosystem compared to other locations, making Bonaire a success story for local fisheries management.

1. Parrotfish and the “recovery resilience” of
coral reefs: A case study from Bonaire
Bob Steneck
University of Maine
School of Marine Sciences

2. Jackson et al 2014

3. Seaweed Abundance
CoralAbundance
1970s
1980s - Now
Jackson et al 2014
NOW: Seaweed or
Macroalgae reefs

4. Antigua December 2013
Although many have become
seaweed reefs …

5. BonaireOthers have not …

6. 70006000500040003000200010000
0
100
200
300
Herbivore Biomass (g/100 m2)
(Scarids, Acanthurids & Microspathodon)
algalbiomass(AIperarea)
R2 = 0.5
Jamaica
Andros
Bonaire
Venezuela
Saba & Statia
Herbivores (like parrotfish)
Drive seaweed abundance
AGRRA 2003

7. 70006000500040003000200010000
0
100
200
300
Herbivore Biomass (g/100 m2)
(Scarids, Acanthurids & Microspathodon)
algalbiomass(AIperarea)
R2 = 0.5
Jamaica
Andros
Bonaire
Venezuela
Saba & Statia
Herbivores (like parrotfish)
Drive seaweed abundance down
AGRRA 2003
SeaweedAbundance
eg. Parrotfish

8. 85% Undersides
Parrotfish improve Coral
nursery habitats
N= >1300 plates
5 regions throughout
Caribbean

9. Parrotfish Deterrent Device
Steneck et al 2014
Baby coral
“recruit” to
settlement
plates

10. Ineffective Small Parrotfish
Frustrated Big Parrotfish Grazing Control PED
Fish Deterrent Device
Limits access of large
parrotfish only!

11. Parrotfish Deterrent Device Control
Steneck et al 2014

12. Carrie Bow Caye,
Belize
Steneck et al 2014

13. Steneck et al 2014

14. Glovers Reef, Belize
*
*
Seaweed
abundance
Baby corals
Steneck et al 2014

15. Agaricia spp babies
Porites astreoides babies
0
0.5
1
1.5
2
2.5
3
3.5
AverageNo.SpatPerPlate
0 1000 2000 3000 4000 5000 6000 7000
Algal Abundance increasing (biomass proxy)
Baby Corals vs Seaweed Abundance
All babies of this reef-
building coral die!
Steneck et al 2014
Coral
Recruits
(baby
corals)
More seaweed
Translation: Parrotfish HERBIVORY may be necessary for controlling seaweed
and maintaining the recovery resilience of coral reefs

16. Seaweed is trouble for coral reefs
They poisons corals
Reduce coral reproductive output
Kills baby corals
Herbivores (especially parrotfish) can reduce
algal abundance and improve coral
recruitment!
Reduce coral recruitment
BUT
In short, seaweed on reefs are

17. Bonaire
Bonaire Case Study An example of successful management
CAUSE FOR OPTIMISM

18. Bonaire’s reefs…

19. But why so little seaweed? –
How did it get this way?
A brief history

20. Courtesy: Wesley Chirino
Fishermen’s stories and photos of the fish they
speared in the 1960s

21. Courtesy: Wesley Chirino

22. Courtesy: Wesley Chirino
Within a decade big fish were
disappearing
In 1971 Bonaire fishermen
agreed to STOP spearfishing!

23. Parrotfish: big easy targets (poor swimmers)
They also go into fish traps (not used in Bonaire)

24. Did parrotfish management work?
Are parrotfish more a abundant in
Bonaire?
Eastern Caribbean sites for
comparison
Including
Fished & No Take Reserves
2018

25. No-Take Reserve
FISHED
Parrotfish Abundance
Bonaire’s 2003 - 2019Parrotfishabundance
Biomass(g/100m2)
Steneck et al 2019
Eastern Caribbean
parrotfish
Bonaire has twice the
parrotfish biomass
compared to no-take
reserves of the Eastern
Caribbean

26. Live coral cover
The first AGRRA survey
My monitoring began
Very high coral cover!
Steneck et al 2019

27. Fall 2010: Extremely warm summer/fall - Massive Coral Bleaching

28. Live coral cover
Bleaching
Steneck et al 2019

29. B
Caribbean average
= 800 - 1000
Seaweed abundance on the reef
Steneck et al 2019

30. B
NTR
FISHED
Juvenile Coral Abundance
Steneck et al 2019

31. Bonaire 2019
This study
Caribbean Average
1970 -1983
Caribbean Average
1984 -1998
1999 -2011
Let’s return briefly to the BIG Caribbean study 1970 - 2011
Steneck et al 2019

32. 2019

33. Conclusions from Bonaire’s coral reefs
Bonaire may be the FIRST clear example of
resilient coral reef ecosystem in the Caribbean
resulting from prohibiting the harvest of parrotfish.
It suffered from a hurricane and coral bleaching
but recovered fully and remains healthy
It shows LOCAL fisheries management protecting
especially parrotfish & working with local
communities can improve the recovery resilience of
Caribbean coral reefs

34. Thank you

35. Thanks to so
many working
together over
the years have
helped in all
phases