Fish Spawning Aggregations: A Reef Resilience Toolkit Module

Species at Risk

Many of the most endangered species of fish spawn in aggregations. Besides the vulnerability associated with fish species that use this reproductive strategy, many of these species have particular life history characteristics that can increase the risk of overexploitation.

Caribbean

Snapper and grouper populations have drastically declined in the Caribbean, including many that form spawning aggregations1. The goliath grouper, Epinephelus itajara, the Nassau grouper, E. striatus, mutton snapper, Lutjanus analis, and cubera snapper, L. cyanopterus are now listed as vulnerable or endangered on the IUCN (International Union for the Conservation of Nature) Red List.

Other grouper species appear to be showing similar declines, and a number of aggregation-forming species are near threatened, or have insufficient data to characterize their status. Of these, some may be in decline, particularly some of the larger deepwater species whose life histories and spawning habits are unknown. The IUCN Groupers and Wrasses Specialist Group has recently updated the status of several groupers, and showed that 50% of threatened grouper species form spawning aggregations. These declining trends are common throughout the Caribbean, where many known grouper spawning aggregations have been fished out, or nearly so; yet very few of these FSA sites have been included within MPAs.

Fish holding pens for the live reef fish trade. Photo © Soames Summerhays

Indo-Pacific

Overfishing by the live reef food fish trade (LRFFT) has depleted many of the known spawning aggregations of groupers, as well as many humphead wrasse, Cheilinus undulatus, FSAs. Many other FSAs unknown to scientists or managers have likely been lost to the trade. Recent assessments by IUCN now show that squaretail coralgrouper, Plectropomus areolatus, are vulnerable to extinction, with both the camouflage grouper, Epinephelus polyphekadion, and brown-marbled grouper, E. fuscoguttatus, near threatened. All are valued in the LRFFT, and typically co-aggregate throughout the Indo-Pacific. In addition to the LRFFT, local artisanal fishers are also responsible for some declines and extirpations of FSAs, particularly those associated with nighttime spearfishing, although line fishing has also had an impact2.

Examples

Examples by region of aggregation-forming species at risk of extinction are below.

Tropical Western Atlantic

Epinephelus striatus—Nassau grouper.
Photo © John E. Randall

Serranidae
Epinephelus striatus Nassau grouper
E. guttatus Red hind
E. itajara Goliath grouper
E. adscensionis Rock hind
E. niveatus Snowy grouper
E. flavolimbatus Yellowedge grouper
Dermatolepis inermis Marbled grouper
Mycteroperca venenosa Yellowfin grouper
M tigris Tiger grouper
M. bonaci Black grouper
M. microlepis Gag grouper
M. interstitialis Yellowmouth grouper

Lutjanidae
Lutjanus cyanopterus Cubera snapper
L. jocu Dog snapper
L. analis Mutton snapper

Indo-Pacific

Serranidae
Plectropomus areolatus Squaretail coralgrouper
P. laevis Blacksaddled coralgrouper
P. leopardus Leopard coralgrouper
P. maculatus Spotted coralgrouper
P. oligocanthus Highfin coralgrouper
P. pessuliferus Roving coralgrouper
Epinephelus fuscoguttatus Brown-marbled grouper
E. lanceolatus Giant grouper
E. polyphekadion Camouflage grouper

Labridae
Cheilinus undulatus Humpback wrasse

Scaridae
Bolbometopon muricatum Green humphead parrotfish

Eastern Atlantic

Serranidae
Epinephelus marginatus Dusky grouper
Mycteroperca fusca Island grouper

Eastern Pacific

Serranidae
M. jordani Gulf grouper

The IUCN Redlist is an excellent source of information on endangered and threatened species.

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