Revisiting the Science of Conch Maturity Five Years Later in Belize

In the effervescent waters of coastal Belize, a culinary and cultural staple is at risk. The conch fishery continues to encounter growing pressure from overfishing and minimal harvesting size. Recent reports indicate that Belize’s exports of Queen conch meat have seen a notable rise, doubling in volume from 200 metric tons (MT) to 400 MT between 2003 and 2018. The value of these exports has more than tripled during the same period, setting the Queen conch’s position as the second most important fishery in the country, after spiny lobster. While the exact impacts of Queen conch on tourism and household food security remains unclear, they are believed to be considerable (Queen conch Case Study – Belize Fisheries Project). Strict and dedicated management efforts are critical to safeguarding this valued shellfish and ensuring that it doesn’t vanish from our plates.

In February 2024, the National Oceanic and Atmospheric Administration (NOAA) announced a final rule that listed the Queen conch as threatened under the Endangered Species Act. NOAA cites overfishing as an illegal, unreported, and unregulated fishing threat to the species. The organization says that in making the declaration, it considered the “best scientific and commercial information available, the status review report, and efforts to protect the species. Under the Endangered Species Act, a threatened species is defined as one whose existence will possibly become jeopardized within the near future “throughout all or a significant portion of its range” according to NOAA.

Over the past few decades, the overall harvesting of conch has increased ominously due mainly to international demand, increasing populations, and tourism growth in the Caribbean, including Belize. Currently, conch is commercially harvested in at least 26 countries in the region and has become a luxury food item, revealing its scarcity and high market price, according to 1996 and 1997 studies (Queen conch Abundance Survey). Annually, Conch is a key part of Belize’s economy: Belize earns US$8 million annually from exporting conch to Central America, the Caribbean, South America and the United States. In 2023, Queen conch meat production amounted to 953,900 pounds (85% market clean, meaning that the conch has been removed from the shell and the gonads and claws are cut off), which generated US$6,559,090 in foreign exchange earnings in Belize, according to data from the Belize Fisheries Department.

Though there are limited statistics on how much is consumed locally, Belizeans are known to eat, on a regular basis, during the open season, conch ceviche, fritters, soup, and other delicacies. That is why there have been some efforts to prevent decline: There is an annual closed season, based on a quota, first established in 2002 after a Queen conch population assessment. The results of the Queen conch assessment were used to declare the first conch quota and revise the conch fishery regulations. Before the implementation of a catch quota system in 2002, Queen conch meat production was under 600,000 pounds annually. The Belize Fisheries Department has continued carrying out bi-annual National Queen Conch Surveys, which is used to determine quota annually. The last quota in 2023 was set at 925,000 pounds. Since then, fishers have only been able to harvest Queen conch if the shell length is 7 inches or longer to avoid harvesting immature conch due to the shallow fishing nature of the fishery. Conch can be found in both shallow and deep water, but those in deeper water are known to have thicker lips. For example, in replenishment or no-take zones, designated protected areas where fishing and resource extraction are prohibited to protect vital habitats and ensure the reproductive capacity of fish species. Within these protected areas are wilderness zones that have minimal human impact and are designed to preserve ecosystems and biodiversity while prohibiting development and resource extraction; and general use zone that allows various activities, such as recreation and resource extraction, while balancing conservation efforts with public access.

Yet, despite fishers, regional bodies, the then Fisheries Administrator, cooperative members, non-government organizations (NGO’s), and other interested parties agreeing in 2019 that the conch fishery is one of the most important to Belize’s economy, they were split on the topic of lip thickness versus the current method of using shell length to determine maturity of the Queen conch (Lobatus gigas) and if it is enough to sustain the industry.

The recommendation to use lip thickness as a more accurate way of measuring maturity was made in a 2018 research paper, written by Dr. Alexander Tewfik (et. al), of the Wildlife Conservation Society (WCS), and supported in an earlier study in 2017, written by Drs. James Foley and Miwa Takahashi of the Toledo Institute for Development and Education, (TIDE). The president of Hopkins Fisher Association, Norman Castillo, said back then that his Association would support any legislative changes that would help to sustain the seafood industry, including the use of calipers to measure lip thickness, if necessary. That was in 2019, when many were not too concerned about the prospect of conch becoming extinct. But five years later, Castillo’s sentiments remain the same.

But not all fishers feel this way, and the Belize Fisheries Department has said they do not intend to change the Queen conch fishery management plan right now. Paola Colman, a member of Wabafu Fisher Association in Dangriga, says she prefers to continue fishing shell length to determine maturity of conch. Colman explains that even though she has found that there are times that the conchs with thicker lips weigh more and are indeed more mature, she does not agree with having any legislative changes that would mandate fishers using lip thickness to determine maturity of conch. 

“For me, there are not many conchs with thick lips. If legislation were to pass, fishers will not be able to catch as much as they are doing now,” she says.

Meanwhile, Shanika Martinez, who fishes conch but who is also a tour guide from Hopkins Village in the Stann Creek District, exclaims that if there are to be any changes, she "would suggest they do boat outreach for that prior to season opening and maybe even provide calipers and show fishers how to use them."

"It would be time-consuming trying to determine the maturity of the conch when you can just catch it and sell the bigger ones to the cooperatives and the smaller ones to local restaurants. It’s what fishers do!” she adds.

The study found that shell morphology, sex organ development and soft tissue masses indicate that mature adult conch at Glover’s Atoll, Belize, were those with thick shell lips more than 10 mm, eroded shells and heavier soft tissue masses. Therefore, shell-length-based regulations cannot serve as a proxy for maturity and harvest. According to the research, use of minimum size limits for shell length, i.e. 178 mm [7 inches], 85 g market clean meat mass, has allowed significant juvenile harvest and the fishery appears to have reduced the shell-length size distribution of conch with a flared shell lip (i.e. adults). This means that even though the conch may have a shell length over the minimum required of 7 inches, it may still be immature.

According to the latest report from the Fisheries Department, the national Queen conch survey analysis results showed that 21% of the population were considered legal size and 79% were sublegal. The percentage composition of the population is highly influenced by the high abundance of sub-adults, according to the report. The study noted that the reduced shell-length observed in lipped conch, studied over a 15-year period, may lead to a significant impact on the reproductive success of the population as well as diminished economic yield from the fishery, as smaller adult conchs of the same age have lower gonad and meat weight.

The 2017 study found similar results: It states that while data shows fishers comply with the shell length limit, the density of conch populations are not recovering. It suggests that the current size limit may not be protecting juvenile conch, and that research in other parts of the Caribbean shows shell lip thickness may be a better indicator of sexual maturity in conch than shell length. 

For instance, a 2012 study in the Bahamas shows that male and female Queen conch reached sexual maturity when their shell lips were 9 mm or 12 mm thick, respectively. The study determined that shell lip thickness serves as an indicator of a Queen conch’s age, but it alone does not reliably indicate sexual maturity, as some conchs may mature with thinner lips than the typically flared lip, which signifies a minimum age of 3.5 years. Recent studies suggest that maturity may occur later in various populations, complicating the assessment of reproductive readiness. Drs. Foley’s and Takahashi’s study noted that local research needs to be conducted to determine relationships between maturity and both lip thickness and shell length. Both studies argued that lip thickness is a key tool for fisheries sustainability.

There is a prohibition on the use of SCUBA gear for commercial fishing since 1977, which allows for the permanent maintenance of a healthy deep water adult spawning stock that consistently supply abundant recruits and sub-adults to the shallow fishing areas (5-75 ft in depth) that is backed up by scientific evidence, according to Belize Fisheries Department data.

In its recent study on the status of the Queen conch Population of Belize in 2024, the Fisheries Department, (FD) says the Queen conch population is stable. “The Queen conch fishery remains healthy, robust, there is consistent high annual recruitment over time series and the fishery is responding well to current fishing effort,” according to fisheries officers, Mauro Gongora and Kenneth Esquivel. But the Belize Federation of Fishers, BFF, who are part of the Belize Fisheries Project, BFP, says conch is on the brink of depletion if extra management measures such as fishers using lip thickness to measure conch maturity, are not put in place (Belize Fisheries Project).

The Belize Federation of Fishers (BFF), which represents over 500 fishers across the country, also supports the recommendation to use lip thickness as a measurement for conch maturity, saying that if management regimes to protect Queen conch are not put in place urgently, there is a possibility that Belize’s conch fisheries could be no more. 

According to technical advisor for BFF, George Myvett, a former senior fisheries officer, who worked at the Belize Fisheries Department in the '80s and '90s, recent research, spearheaded by the BFP with funding from the Summit Foundation, which is also supporting Internews' Earth Journalism Network's work on building capacity for Belizean journalists, found that most of the conch that fishers catch in Belize are not sexually mature. “And if they are not sexually mature, it means that they are unable to reproduce." he explains.

"I am convinced that if we don’t do something significant about conch within the next two years, the conch fishery in Belize will collapse," says Myvett.

This declaration seems not to mean much for Belize, as the Fisheries Department says Belize’s conch fishery is stable. The Department explains that the notion of using lip thickness as a management measure would only be applicable to fishing for conch in spawning aggregation (SPAG) sites where many fish gather in one place to fertilize eggs. 

According to fisheries officer Mauro Gongora, the 2024 Conch Assessment, which is used to calculate the quota structure for conch in Belize, shows that “the conch fishery has the capacity to replenish itself in just three to five months.” Gongora explains that in Belize, fishers have access to conch in shallow waters only. ‘Sub-adults’ does not mean illegal. It means that the species are no longer hatchlings but a little bigger than juvenile.

Meanwhile, a new study based on surveys conducted in the Bahamas may support previous research and Gongora’s explanation. The study found that breeding populations of Queen conch within a protected marine reserve, where fishing is prohibited, sustain populations beyond the borders of the reserve. According to the Fisheries Department, it is the same in Belize for not only Nassau groupers in spawning aggregation sites, but also conch in marine protected areas. 

Belize has nine marine protected areas (MPAs), with an additional 13 protected fish Spawning Aggregation sites. This represents almost 25% of the country’s territorial waters even though there is only a small proportion of this area that is fully protected in no-take areas. The study also identifies where additional protections could help to ensure the survival of future Queen conch generations, a notion that both the CRFM Executive Director, Haughton, and the National Fishermen Cooperatives head, Rodriguez, alluded to in 2019, and one which Rodriguez has maintained.

“The nature of Belize’s fishery is that we have shallow-water conch,” says Kenneth Esquivel, data officer at the Belize Fisheries Department. This means that fishers will dive a maximum of between 30-60 feet for the species. “We have historical data, which shows that the population is stable.” When the Fisheries Department does its conch surveys, “we involve many other organizations” such as TIDE, TASA, BAS, SEA (Southern Environmental Association, and Hol Chan Marine Reserve. “It is important for us to do these surveys systematically on a sustainable basis,” Gongora adds. 

He says that if Belize were to legislate lip thickness as a means of determining conch maturity or as a management measure to conch fisheries in Belize, it would affect the economic, social, and physical fabric and structure of the country. “It would be social chaos and economic disaster,” says Gongora. “There would be drastic, significant decline in production. If we are catching 950,000 pounds now, then we won’t be catching more than 20% adult conch.” "The biggest losers" would be the 3,500 fishers and their families. "Livelihoods will be lost.”

Both Gongora and Esquivel say Belize does not need to manage conch using lip thickness because the current management system aims to reap the most without affecting the industry long-term. Gongora says it is estimated annually using information from “rigorous and systematic scientific stock assessments via underwater transects done, since 2003, at predetermined samplings stations.”

Veronica Tun, Dangriga fisherwoman and member of the recently formed Women in Fisheries Association of Belize, disagrees. She says, “As a fisherwoman, I see using lip thickness to measure conch as a more reliable way to ensure we’re harvesting mature individuals, since shell length alone can be misleading. Lip thickness shows when a conch has stopped growing and is ready to reproduce, which helps protect the breeding stock for future generations."

"It might take time for fishers to adjust, but this method will benefit our livelihoods by ensuring the sustainability of conch populations in the long run," she says.

This story was produced with support from Internews' Earth Journalism Network. It was first published in The San Pedro Sun on October 20, 2024 and has been lightly edited for length and clarity.

Banner image: Queen conch photographed at Glover’s atoll in Belize / Credit: Henry Brown for WCS.