The Cairns 1,000 lb plus black marlin phenomenon
Dr Julian Pepperell and Ray Joyce
If, like me you have ever pored over ancient sea charts and maps, perhaps from the seventeenth century or earlier, you might have noticed a warning inscribed on some of them, usually in a mysterious, uncharted region at the edge of the known world. This warning simply read’Here be monsters’, usually with an etching of some fearsome beast rising from the sea. The edge of the Great Barrier Reef would certainly have qualified in those days, and was indeed at the edge of the known world until relatively recently. And for commercial and recreational fishers alike, monsters were and are indeed found along the outer edge of this natural wonder of the world. Here be monsters to be sure monsters of the 1,000lb+ black marlin kind, that is.
We all know that the magic weight of a thousand pounds is an artificial number. Nevertheless, there is still something about such round numbers which sounds and looks special. Convert to metric and I’m sure you will agree that 453.59237kg doesn’t quite have the same ring. While several versions of the pound have existed in the past, the one we use today was invented by merchants in England in 1303. This pound is defined as a unit of mass equal to 16 ounces, with one ounce equalling exactly 7000 grains â€“ whatever a grain is. Regardless of the arbitrary nature of the figure though, 1,000 pounds is a mark which anglers the world over take serious notice of. Of the nearly 30,000 known species of fish on the planet, very few grow to a weight of 1,000 pounds and beyond, and in the case of the ultimate gamefishes the billfishes, only three species attain this weight. They are, of course the broadbill swordfish, the blue marlin and the black marlin. The number of thousand pound swordfish ever weighed or intentionally released could probably be counted on one’s fingers while the number of thousand pound blue marlin in the Pacific and the Atlantic combined would almost certainly be less than 100. But did you know that there have been more than 600 thousand pound plus black marlin weighed, 94% of which have come from north Queensland waters? And that doesn’t count a further 260 estimated thousand pounders tagged and released!
To be sure, reasonable numbers of thousand pound marlin, both blue and black, had been caught elsewhere before that landmark 1,064 pound fish was landed in 1966 by George Bransford and Richard Obach. However, in the case of black marlin, thousand pounders had only been caught off Cabo Blanco Peru, all during the 1950s. There, between 1952 and 1959, 38 thousand pound black marlin were weighed, two of which were, and still are, the standing men’s and women’s world records (read more about the Cabo Blanco fishery in the article ‘Black Beauty’ in this issue).
The news of the Bransford/Obach capture created an overnight charter industry in Cairns, but captures of thousand pound fish still had to be earned.Â No doubt many were lost in those early years, but the numbers slowly started to build. By 1970, only 10 thousand pounders had been weighed in total, but in 1972 and 1973, 31 and 50 granders were caught off the Cairns grounds, setting the scene for the most incredible big fish fishery the world has ever seen.
The List: All the Cairns Thousand Pounders
The main aim of this article is to attempt to compile a list of all the thousand pound fish caught off the Cairns-Lizard Island region which have been weighed. This turned out to be no mean task.
The primary sources of data for the list are the records of the Cairns Game Fishing Club, which published a newsletter from 1973 to 1977. Daphne Nielsen was the meticulous keeper of records and her compilations have been extremely important in producing this list. Other sources have been photographs which included at least the weight of the fish, but preferably the date, angler and boat, personal logs and diaries of charter captains and crew and other first hand reports by anglers and crew.
We must stress that the list is very much a work in progress. As you will see, there are quite a few blanks and gaps which need to be filled, and it is also highly likely that the list is not complete. For example, captures recorded for the years 1983 and 1989 are much lower than might be expected. We are therefore appealing to anyone who thinks they can help in correcting any wrong entries or adding more to the list, to let us know. In the long run, we want this to be an accurate, complete record of this unique fishery, so any suggestions, no matter how minor, will be taken on board with thanks.
The full list is printed here in all its glory and imperfections. But having now compiled such a fascinating list, what are some of the stand-out statistics since that first famous fish was weighed in Cairns way back in September 1966?
For starters, a mind boggling total of 577 black marlin weighing 1,000 pounds or more have been weighed, (and bear in mind this does not include a further 39 possible thousand pounders listed at the end of the table for which little information other than the fish weight and name of angler or skipper exists). Referring at Graph 1, we can summarise the amazing statistics as follows:
|Of the 577, the number weighing 1000 â€“ 1099lb||311|
|Number weighing 1,100 â€“ 1,199lb||162|
|Number weighing 1,200 â€“ 1,299lb||77|
|Number weighing 1,300 â€“ 1,399lb||25|
|Number weighing 1,400lb +||2|
Tag and Release and Free Releases
As well as these incredible numbers, a further 260 black marlin have been tagged which were estimated to weigh 1,000 pounds or more (these are also shown in Graph 1). I’m sure many readers will have opinions on calls of fish over the magic ‘ton’. Some captains might be tempted to overestimate the size of a fish to give a client the thrill of boasting a grander, but I am inclined to think that it goes the other way much more often that is, a conservative estimate is made, with most captains not wanting to give away granders too easily.
As well as the official numbers, many fish are also caught and released in this fishery without being tagged. While it is impossible to know that number, there is good reason to believe it is quite high. For example, after the 1999 season, I interviewed the captains of 15 charter boats and asked how many fish over 800 lb they had caught that season (‘caught’ meaning released, with or without tags). The tally from that subsample of all boats which fished was 139 fish over 800 pounds. However, the tagging data from NSWDPI and information on captures showed that only 27 fish over 800lb had been officially recorded (26 tagged and one weighed), so there is obviously a major discrepancy which is probably explained by the tendency to free release very large fish.
As indicated above, it is of course important to note that, as well as the thousand pound plus fish, there have been many, many fish weighed and tagged which fell within the weight ranges of 800 to 899lb and 900 and 999lb. Due to space restrictions, these fish are not shown here, however, the master list compiled for all captured fish, plus the NSWDPI tagging database, show that, since 1966, 230 fish have been weighed in the 800 to 899lb range, and 773 tagged, while the numbers for fish in the 900 to 999lb range are 244 weighed and 601 tagged. Adding all these figures together, we come up with grand totals for fish greater than 800lb of 1,051 weighed and 1,634 tagged in the 40 year history of the fishery. Simply amazing, I am sure you will agree.
A Sustainable Fishery?
The existence and predictability of this unique concentration of huge black marlin at the same place every spring raises many questions. Why do the fish come, where do they come from and where do they go after they leave in early summer? What proportion of the total population of black marlin does this aggregation represent, do they stay for the whole season, and are the big female fish at the end of their breeding life? Finally, is this fishery sustainable?
While the answers to many of these questions are unknown, we do have a fair idea about some of them. We know that the black marlin come to the area to spawn. All of the large females are mature females bearing eggs and most of the smaller fish are running ripe males. The big females may come from all over the Pacific, or perhaps just from the Coral Sea. We know from tagging that at least some small fish make epic journeys across the Pacific once they leave the reef, but we don’t know much about the movements of the big females. We do know from electronic tagging that fish do not seem to stay close to the reef for long, perhaps indicating that the population during the spring aggregation is not static. We don’t know what proportion of the total black marlin population come to the reef, and we are fairly confident that, rather than being at the end of their breeding life, the big females are the main contributors to the next generation of black marlin. And what of sustainability? With 40 years of capture, tagging and catch rate information to draw on, it can be stated with considerable confidence that the black marlin recreational fishery off the Great Barrier Reef is a fine example of long term sustainability. The lessons as to why this is so are there to be learned, hopefully for the benefit of not just this fishery but for other billfish fisheries the world over.
Julian Pepperell compiled records of weighed black marlin from his own field notes, from the annual newsletters of the Cairns Game Fishing Club and from other material kindly supplied by Daphne Nielsen and Bob Lowe. The records of estimated weights of tagged fish were extracted with permission from the Gamefish Tagging Database of NSWDPI (Fisheries). Contact Julian at firstname.lastname@example.org.
Ray Joyce, of the Pacific Marinelife Institute, compiled his comprehensive list of weighed black marlin from many sources including published records, numerous photographs of weighed fish and through contacting many captains and crew who have been part of the fishery from its origins to the present day. Contact Ray at email@example.com.
To all of the above, we are extremely grateful, and remind any readers to contact us if they feel they can fill any gaps, fix errors or add to this remarkable list.