HOPKINS, Belize — The Nassau grouper is drawn by the winter moon, between December and March, to particular locations the place tons of of the cryptic fish have interaction in a reproductive dance that generally lasts days. Northeast Level at Glover’s Reef Atoll, off the coast of southern Belize, is a type of locations.
The Nassau grouper (Epinephelus striatus) is a large-bodied, top-level predatory reef fish. Its pale tan to reddish-brown physique with 5 darkish vertical bars makes it simply recognizable. Whereas these fish cover properly, spending their days lounging in reef crevices and solely rising to feed at night time, their extremely predictable spawning aggregations make for a simple catch for opportunistic fishers. The species was as soon as essentially the most plentiful and commercially necessary fish within the Caribbean. In Belize, fisheries information point out that Nassau grouper was the most-caught fish throughout the Sixties, with estimated catches of greater than 30,000 fish per yr from a single aggregation website, Caye Glory.
Northeast Level is considered one of Belize’s 13 formally acknowledged fish spawning aggregation (FSA) websites for Nassau grouper. The aggregation there was additionally as soon as a powerful sight, drawing an estimated 15,000 fish in 1975. In the present day, that moonlit annual gathering has all however vanished. The variety of fish attending has declined by 85% over the previous 20 years and is now “on a trajectory in direction of native extirpation,” in line with a latest research. It attributes the decline to the federal government’s restricted capability to implement rules aimed toward defending the groupers from fishing at this distant website.
“Since in regards to the ’80s, the Belize Fisheries Division and scientists have been discussing methods through which they should do one thing in regards to the Nassau grouper scenario,” Myles Phillips, a Ph.D. candidate at James Prepare dinner College in Australia who led the research, instructed Mongabay in an interview. “This didn’t begin in a single day.”
The research examines the standing of the Nassau grouper inhabitants at Glover’s Reef Atoll, which is wholly encompassed by Glover’s Reef Marine Reserve (GRMR). The authors mixed spawning counts, catch information and visible censuses taken between 2000 and 2023 to guage the inhabitants adjustments.
“Spawning aggregations of Nassau grouper again within the ’60s and ’70s on common used to have like 30,000 fish, and Caye Glory specifically used to have 100,000,” mentioned Phillips, who was previously a analysis coordinator at Glover’s Reef Atoll for the U.S.-based conservation group Wildlife Conservation Society. Nonetheless, a long time of intense fishing throughout the predictable aggregations have resulted in steep declines, the research famous, and the species is now critically endangered.
On the flip of the century, Northeast Level had round 3,000 groupers spawning, in line with the research, making it considered one of two websites in Belize the place greater than 1,000 fish nonetheless gathered. A 2001 research estimated that the inhabitants at this website would “disappear” by 2013, however the aggregation survived.
In accordance with Phillips, that is the results of measures enacted by the Belize Fisheries Division to guard the groupers. These measures, nonetheless, haven’t been adequate to cease the decline altogether. In 2018 and 2020, solely round 900 fish attended the annual reproductive gathering. By 2023, the newest yr included within the newest research, simply 463 people had been recorded — a 97% drop since 1975.
Northeast Level’s seclusion contributed to the decline, decreasing exterior recruitment of latest fish. It sits removed from different reefs in Belize, and the atoll is surrounded by waters some 300-1,000 meters (about 1,000-3,300 ft) deep, which Nassau groupers can’t simply cross since they like to stay to the reef. Tagging research have helped present the fish that spawn on the Northeast Level FSA additionally use the territory as their dwelling floor and don’t sometimes migrate off website, in line with Phillips.
Against this, he mentioned, the Caye Glory aggregation was so massive as a result of the location is linked to the Mesoamerican Barrier Reef, which extends 1,000 kilometers (620 miles) between Mexico to the north and Honduras to the south, giving fish from far-off a transparent path to succeed in the spawning website.
In an e-mail interview with Mongabay, Alicia Eck-Nunez, a fisheries officer on the Belize Fisheries Division, mentioned that because of the tough waters and problem accessing the Northeast Level FSA, the division has deployed hydrophones to assist monitor spawning based mostly on the sounds the fish make.
“As soon as processed, these knowledge will present worthwhile insights into fish behaviour and may establish timing, depth, and length of spawning occasions on the website,” she mentioned. Nonetheless, she added that there’s presently “no in-house capability” to do that evaluation.
Strict administration measures exist to guard Nassau groupers on the Northeast Level FSA from overfishing, however insufficient enforcement is what’s primarily driving the decline, in line with the research.
Phillips mentioned unlawful transboundary fishing contributes to overfishing. “The placement is so near Honduras, it’s straightforward for them to get there undetected, and it’s handy; they’ll see the enforcement brokers coming. We’ve got gone out to the location and seen boats dropping gear, dropping fish, every kind of issues, and heading out,” he mentioned, describing how fishers jettison proof of their criminal activity as they attempt to keep away from arrest. “And yearly we might go diving on the website, we might see new fishing traces, new hooks, new anchors discarded on the backside.”
He famous that the tumultuous waters close to the FSA make enforcement tough and expensive.
Whereas there’s a nationwide closed season from Dec. 1 to March 31 for Nassau grouper, fishing is all the time closed at Glover’s Reef — in idea not less than. That’s as a result of in 2009, the Belize Fisheries Division made a “gentleman’s settlement” with the fishers of the GRMR, in line with Eck-Nunez. The fishers agreed to not catch Nassau groupers yr spherical, and in alternate, the division allow them to dive for conch and lobster throughout the atoll.
The settlement nonetheless stands, however not all fisherfolk comply, in line with an area fisher Mongabay interviewed for this story, who requested to stay nameless for worry of reprisal from colleagues and the fisheries division.
The fisher mentioned each native and transboundary unlawful fishing are main issues on the Northeast Level FSA, and enforcement has by no means been adequate to cease it.
Native fishers can’t have spearguns throughout the atoll; in the event that they’re caught with one, authorities assume they’re concentrating on Nassau groupers. Different rules place a measurement restrict of 20-30 inches (0.5-0.75 meters), a requirement for Nassau grouper to be landed entire, and a requirement for all fish fillets to be landed with a pores and skin patch to permit identification.
“The fisheries division has been doing loads. There may be all the time extra you are able to do, however being affordable and life like, they’ve accomplished quite a bit to attempt to handle the species,” Phillips mentioned.
But doing extra seems to be the one approach to give the groupers an opportunity. “Closure of administration gaps, together with persistent enforcement useful resource deficits, might not assure restoration, however has been a needed precursor to restoration of different fish spawning aggregations within the Caribbean,” the research factors out.
The Belize Fisheries Division declined to reply questions on its enforcement capability and limitations at this and the nation’s different Nassau grouper FSAs.
The paper famous that Nassau grouper FSAs have already been extirpated at different websites in Belize, together with Rocky Level and Gladden Spit. However on the different 12 different extant FSAs the place the species is protected within the nation, populations have remained steady during the last 20 years, Phillips mentioned, emphasizing that the fates of Belize’s FSAs have been various. For instance, the Sandbore Caye aggregation has been steady since 2000, he mentioned. And the famously large Caye Glory aggregation, regarded as extirpated within the early 2000s, has reappeared — although with solely round 2,000 fish, it’s only a wisp of its former measurement.
The Belize Federation of Fishers, nonetheless, emphasised the long-term decline of Nassau grouper and failure of administration to successfully defend the Northeast Level FSA, in a launch responding to the brand new paper. “This isn’t only a organic disaster — it’s an institutional governance failure,” the discharge mentioned. “Regardless of 20 years of protecting rules, enforcement stays under-resourced, and unlawful fishing continues unchecked.”
It known as the survival of the spawning aggregation at Glover’s Reef “a matter of nationwide and regional urgency.”
Citations:
Phillips, M., Tewfik, A., & Burns-Perez, V. (2025). Impending extirpation of an remoted Nassau grouper (Epinephelus striatus) inhabitants at Glover’s Atoll, Belize, based mostly on 20 years of monitoring. Coral Reefs, 44(5), 1513-1533. doi:10.1007/s00338-025-02697-8
Sala, E., Ballesteros, E., & Starr, R. M. (2001). Speedy decline of Nassau grouper spawning aggregations in Belize: Fishery administration and conservation wants. Fisheries, 26(10), 23-30. doi:10.1577/1548-8446(2001)0262.0.co;2
This article by Marco Lopez was first printed by Mongabay on 20 November 2025. Lead Picture: A Nassau grouper. Picture by Connor Holland/Ocean Picture Financial institution.
