Off the western tip of Little Cayman, one of nature’s great mysteries plays out every year. With the coming of the full moon in January and February, Nassau Groupers congregate in their thousands to spawn. It is a sight that few have ever seen and one that so easily could have been lost forever had it not been for swift action to protect the Nassau Grouper and its spawning aggregations in Cayman waters. In fact, the Little Cayman aggregation is the last big Nassau Grouper spawning aggregation in the region, after all the other known aggregations had been fished to a point where they are no longer viable.
With the protection afforded to these aggregations set to expire in December 2011, noted marine scientist and artist Guy Harvey and award-winning filmmaker George Schellenger have produced a documentary to focus attention on this unique event and the need for continued protection and even extended protection measures.
Discovery and exploitation
The particular ‘grouper hole’ in Little Cayman came to the attention of the Cayman public in February 2001 after fishermen from Cayman Brac arrived on Grand Cayman followed by a barge load of frozen groupers that they had caught during the spawning aggregation. The fishermen said that over the course of four days they had hauled in more than 4,000 pounds of grouper.
“We filled up the Brac and Little Cayman, so thought we’d come over here and fill up Grand Cayman as well,” said one of them at the time.
The following year, fishermen caught almost 2,000 groupers over a 10 day period.
The event sparked outrage and acted as a catalyst for the protection of the spawning aggregations to be pushed through, with an eight year period of protection coming into effect in 2003.
The quick institution of a ban following the discovery of the spag goes a long way to explaining why the grouper hole still exists and is still viable, for at the rate extraction was taking place after its discovery the aggregation would quite possibly have been fished out within another two years.
“It was a very responsible move by the government here to actually protect the site and to say enough is enough, we’re going to protect the site and the time of this aggregation because in all fisheries management it is ludicrous to take any species while it is spawning, whether it is congregating or not,” says Harvey.
Even though the protection was able to save the aggregation on Little Cayman, it was too late for the other known aggregations in the Cayman Islands, which had been fished for much longer.
“The research work done by Department of Environment and by REEF has shown that some of the spags like Southwest Point here on Grand Cayman only have a couple of hundred fish left when there used to be tens of thousands. This is why the site at the western end of Little Cayman has become so important as it is the only large remaining spag in the entire Caribbean. For a species that was common as dirt this is tragic,” says Harvey.
“If you’ve only got 300 or 400 fish spawning in a spag, chances of a few eggs getting through to larvae and juveniles and settling out on the reef are very, very slim.”
However, with the current protection running out at the end of the year, there are already people lobbying to have the protection watered down, which according to Harvey, is the exact opposite of what should be happening.
“The counts have been very consistent over the time so you’re treading water, keeping an equilibrium, but you’re not making progress. The researchers reckon it’s 2,500 to 3,000 fish participating in the spag, and the impression I got from Bryce Semmens (the leader of the research project) is that he was disappointed that there wasn’t a big increase this year or last year in the numbers participating.”
Harvey believes that the reason for the expected increase not materialising is simple.
“Whatever gains were made by protecting the spag have actually been lost in allowing continual fishing and fishing with a minimum size that is totally unrealistic,” says Harvey.
Under current rules, Nassau Groupers under 12 inches have to be returned to the water, but Harvey points out that this limit does not allow fish to reach reproductive age, with the fish taking some seven years to reach maturity.
“A 12 inch Nassau Grouper is probably a three or four year old fish, so fish above that size, if you are following up with enforcement, still haven’t reproduced, so you are still defeating the whole purpose,” he says.
Traditions and beliefs
According to Harvey, there has been a long tradition of fishing the Nassau Grouper spawning aggregations. However, the limited means available to preserve the fish meant that fishermen were limited as to how much fish they could catch.
I’ve learnt that the East Enders and the Brackers and Little Cayman fishermen would fish in the old days and just dry the fish to have just enough to keep for a long period as they had no refrigeration obviously. Refrigeration changed everything and once the boats from Jamaica came in the 1950s and 1960s they paid the guys here to catch them and that’s where the heavy exploitation started that saw the demise of the spags,” he says.
Even though there is a long tradition of fishing for groupers, Harvey does not believe that the fishing of aggregations, or any grouper for that matter, is truly necessary.
“This is a long standing tradition, but it is no longer necessary, nobody depends on it. Typically with traditional fishing or artisanal fishing, people would depend to a greater or lesser extent on that resource for a subsistence level of living, not for gain, and that’s where the difference is.”
Many of the beliefs surrounding groupers and their habits also present a challenge to those seeking to protect the species from exploitation. However, the research on the aggregation in Little Cayman has come up with scientific information to challenge many of those long-held beliefs.
“Fishermen believe that the groupers come from the deep, they come from Pickle Bank, they come from Cuba, they come from all over to spawn at that site, but it’s not true,” says Harvey.
“There are no secrets out there any more and they’ve put to rest all these old wives about where the fish come from, how many there are, what they do.”
Through a laborious process of tagging and monitoring Nassau Groupers participating in the aggregation, the scientists were able to gather some very interesting information.
“They proved that the participating groupers in the spag all came from one island by catching them and tagging them with sonic transducers and then tracking them through a series of listening stations that are in place around all three islands right now. The groupers only come from that island, and from all around the island they all go at the same time to the west end. It’s amazing.”
Due to the length of time the eggs of grouper can survive in the plankton, it is also very unlikely that it will repopulate from other areas.
“Different species have different lengths of time in the plankton - the Nassau Grouper can survive up to 45 days. So if you’re looking at Little Cayman, you may get some spill into Cayman Brac, but probably not into Grand Cayman. But what is not happening is larvae making it all the way over here from Cuba or from Jamaica, because they can’t survive that amount of time,” says Harvey.
Measurements taken during the spawning period also showed that due to the currents and eddies around Little Cayman, the grouper eggs seem to remain in the vicinity of Little Cayman.
“By and large their offspring come back to that site, so they are self regenerating and self populating and that’s why it’s important again to protect brood stock,” he says.
Documenting the aggregation
In order to build awareness of the importance of the protection currently afforded the grouper, as well as the need for it to be renewed and even expanded, Harvey produced a documentary The Mystery of the Grouper Moon
, which will premiere at the Harquail Theatre on 13 September. The documentary was produced in cooperation with award-winning filmmaker George Schellenger with funding from the Guy Harvey Ocean Foundation.
When it comes to conservation especially of creatures that many may never see in their natural habitat, Harvey believes the documentary could prove a vital tool in carrying the conservation message to a wider audience.
“It’s ‘out of sight, out of mind’ for most of the population, which is why it is so important to carry these images to everybody through the documentary medium,” he says.
Due to the imminent threat posed to the aggregation by the expiry of the protection at the end of the year, Harvey saw the completion of the documentary as a matter of urgency.
“I’m responding to that directly by hastening the production of the documentary and as soon as school starts, once we’ve had the premiere we will be going around to schools or get it shown so that the kids can have a look,” he says.
He hopes that this can create a groundswell of support for the continuation of protection for the groupers by encouraging those who see the documentary either to sign a petition or to send an e-mail or a letter in support of the continuation of the ban.
“This is not a flash in the pan, uneducated commentary - you are dealing with some of the top scientists in the world, you are dealing with a renowned and respected organisation in the Department of Environment, you are dealing with people who have a great track record in this field, and we are all concerned, so pay attention,” says Harvey.
According to Harvey, the ideal outcome would be to see a complete ban on the taking of Nassau Grouper.
“Banning taking of the Nassau Grouper would be the ultimate thing and it wouldn’t change anybody’s life in terms of their well being and their livelihood on Little Cayman and it would follow along with the protection that they’ve given to the birds, the iguanas, everything else that makes Little Cayman so unique. This would really complement it.”
He strongly believes that the benefit will not be limited to Little Cayman either.
“It would be very beneficial to the other islands eventually because there would be some replenishment of other islands whether by man or by natural means, that could also be achieved, and you could actually grow back this population to a meaningful level in the next five or 10
years if there was a will to do it. We’re not dependent on anybody else’s assistance or influence - this is entirely Cayman. We can do it.”