Bahamian Conch Fisheries in Danger of Collapsing

by Larry Smith

 

MARSH HARBOUR, Abaco --Since 2004 Abaco’s home-grown conservation group - Friends of the Environment - has staged a two-day conference every two years that brings together scientists, students and the public to discuss important research.

According to Olivia Patterson, who coordinated the most recent meeting, "as we were helping more and more researchers with their logistics on Abaco, we decided to provide an opportunity to share this research with the community. We also wanted to make sure that the information is available for education and to help inform decision-making for sustainable development."

This year’s event featured more than a dozen presentations on topics like coral reef decline, mangrove restoration, endangered birds, plant biodiversity, seawater quality, and landscape change on Abaco 900 years ago. Sponsors included RBC Royal Bank, J S Johnson and New Vision Ministries.

One of the most important presentations was by Martha Davis, of the non-profit research group Community Conch. Davis has a graduate degree in marine conservation from Scripps Institute of Oceanography. In 2009 she teamed up with top conch biologist Dr Allan Stoner and Exuma-based environmental scientist Catherine Booker to study conch fisheries in the Bahamas.

 

"Our mission is to effect the sustainable harvest of queen conch through research, education and collaboration with local communities, the government and other organisations,” Davis said. "Conch has been a primary food staple for Bahamians, but has recently become threatened by over-exploitation."

 

The regional history of conch fisheries is instructive. In the Florida Keys the fishery collapsed in 1975 when commercial harvesting was banned. A few years later, commercial and recreational conch fishing was banned in all Florida waters. 

 

Bermuda’s conch fishery also collapsed in the late 1970’s. And despite strict regulation, neither fishery has recovered. Other countries such as Jamaica and Cuba have been forced to use fishing moratoriums repeatedly over the last decades to prevent over-fished stocks from collapsing.

"The Bahamas is fortunate to have comparably vast areas of suitable conch habitat and a relatively small human population size, which has allowed the harvest of conch to continually increase when it seemed all other nation’s stocks were in trouble. But today, the signs of stock decline in The Bahamas are undeniable,” Davis said.

“We started our research five years ago and have published four papers so far,” she added. “We started in the Berry Islands, moved to Andros, then to the Exumas, and then to Abaco. Last year we researched the Jumentos Cays and Ragged Island, and this summer we will be working on the Little Bahama Bank, giving us nationwide coverage.”

The target areas for research are identified by the Department of Marine Resources and refined after consultation with fishermen. Volunteers then count adult and juvenile conchs, mating pairs and egg casings in these areas - either towed behind boats in shallow water or scuba diving in deep water. They also measure shell lip thickness, which determines age and sexual maturity.

The drop-dead number from all this research is 50. That is the minimum density of adult conch per hectare required for successful mating. And Community Conch has confirmed that in every commercial fishing ground surveyed over the past five years there are less than 10 conchs per hectare - a density which cannot sustain reproduction.

Community Conch’s academic guru is Dr Allan Stoner, who began his career at Florida State University and joined the US National Marine Fisheries Service in 1996. Over the last 25 years, Stoner and his research partners have published more than 50 peer-reviewed papers on queen conch, and the function of marine protected areas.

It was Stoner who, in 1996, showed that densities of adult conch on the shallow bank around Warderick Wells in the Exuma Cays Land and Sea Park were 31 times higher than densities in comparable habitats with moderate fishing pressure near Lee Stocking Island.

Since that study, fishing pressure has grown with higher demand for seafood and increased use of compressed air by conch divers, Davis said. As a result, juveniles are being harvested illegally, and previously inaccessible deepwater stocks are being exploited, leaving no refuge for conch reproduction.

 

Originally from Texas, Davis is an experienced sailor who has been visiting the Bahamas since the 1980s. In 2008 - as part of her Scripps degree - she began researching the contribution of recreational boaters to overfishing, which led her to understand the pressures being put on conch resources in Bahamian waters.

 

"I had an idea for starting an education project at Black Point, Exuma to inform the children of fishermen about the biology and economics of queen conch. So I started cold calling conch scientists and got a positive response from Stoner. Initially, we considered replicating Stoner's early studies in the Exumas.

 

"But when we went to the government, the Department of Marine Resources instead asked us to survey the new Berry Islands Marine Reserve and adjacent conching areas, so we set about forming Community Conch, using my sailboat (Deer Dancer) as the primary mother boat for our work. We have now completed five years of conch surveys."

 

At the Abaco conference, Davis discussed her latest research. In 2012 Community Conch investigated key fishing grounds in the Bight of Abaco, off Sandy Point and Moore’s Island. In the Sandy Point area densities averaged just over six conch per hectare, and were about 10 conch per hectare west of More’s Island. Average lip thickness ranged from 6 to 9 mm, indicating very young populations.

Most male conch do not reach sexual maturity until their shell lip thickness reaches 10 mm, and most females are not sexually mature until the lip thickness is 15 mm. The conclusion is that conch with a lip thickness of less than 15 mm should not be harvested. Only three mating pairs among more than a thousand flared lip conch were encountered during two weeks of survey work in these areas.

“It is clear that conch fishers in the Bight of Abaco have become dependent upon compressed air and deepwater populations of adult conch are now relatively rare on the traditional shallow-bank grounds,” the research report said. We predict that the Sandy Point and Moore’s Island conch fishing grounds are approaching collapse.”

Last year Community Conch researched the Jumentos Cays and Ragged Islands between Water Cay in the north and Little Ragged Island in the south. The average density of adult conch in this region was 122 per hectare, with density decreasing from north to south. 

“The number of mating pairs observed revealed that most mating occurred at densities over 85 adults per hectare,” the report said. "This corresponds closely with other lightly fished areas in the Bahamas and supports the recommendation that management for the species should be designed to achieve minimum densities of 100 adults per hectare.”

The report concluded that “based on the collection of data over five years in 10 conch fishing grounds, there is a clear trend for local conch populations to be overfished to densities incapable of reproduction, and for densities to increase with distance from human settlements. 

 

"The best example of a fully functioning population other than in the Exuma Cays Land and Sea Park (where fishing is prohibited) is the significant adult breeding population in the most remote part of the Jumentos Cays."

Based on their research, Community Conch offered the following recommendations: 

1. Establish marine protected areas, fishery co-operatives and a sustainable fishery certification programme.

2. Update regulations related to minimum lip thickness, quotas, closed seasons and use of hookahs.

3. Develop area-specific management plans for each major conch resource.

4. Research population connectivity and the impact of discarding knocked conch in active fishing grounds.

5. Evaluate the impact of ending conch exports.

Most of the conch available for international trade is purchased by US importers. And conch has been legally exported from the Bahamas since 1992. About 600,000 pounds leaves the country every year, which only increases fishing pressure on our dwindling conch stocks.

It makes little sense to allow the export hundreds of thousands of pounds of conch meat every year, while watching the decline of this key Bahamian fishery. Over the years conch fisheries have been closed throughout the Caribbean. Do we really want to see the end of this important cultural catch in the Bahamas? 

Comments

[Dr Robert Fritz]

1. Please stop all exports of conch meat immediately.

2. Close conch fishing like we do for grouper, until the conch population returns to 50/hectare concentration.

3. Place strict limits on the number of conch that can be taken during an open season.

Thank you.

[al rogers]

This data and argument should be abbreviated to a one-page big letter SIMPLE presentation which could be presented to every boater entering the Bahamas. We cruisers simply must be contributing the the problem. Controlling the local fishermen may not even be possible but that, too, would be worth a try.

[Buck Gebhart]

I agree. Close the fishery until the population is replenished.

[Gael Carlson]

Clearly need restrictions on harvest and export. As a boater/snorkeler/diver I have observed a noticeable decline in conch grouper and lobster. Government needs to act sooner rather than later.

[George V. Wise, III]

I am not from the Bahamas but love every aspect the area has to offer. To hear that the Conch population has declined in the Bahamas is a scary thought. Knowing that Conch is such an important part of life to the residents of the Bahamas I ask the Question: Has the idea of Conch farming been researched to aid in taking the pressure off "wild Conch". If so how could it be introduced as an opportunity for its residents.