Comment on Status of White Marlin: Capt. Monty Hawkins 2/19/07
On a fine day in August 1968 a charter boat, the Sunshine, put 2 white marlin on the dock. One of the fish was still alive. The fish had been caught at Great Gull Shoal scarcely 5 nautical miles south-east of Ocean City Maryland's inlet. Among the few boats trolling there that day, 7 fish were caught.
Numerous accounts of white marlin caught within sight of land can be found. Before there was an inlet, 1933, when boats were launched from the beach, marlin were a nuisance ~ to be avoided because of their ability to wreck gear.
That marlin were once common on inshore grounds must be factored into rebuilding efforts. Yes, the fishers of the earlier eras were not big on catch and release. Still, the manager must ask what else is missing besides the fish. While overfishing remains the most common thread amidst depleted fisheries management and rightly so, here there is a case to be made for the effects of diminished habitat.
Below I have listed coordinates of some of the places where marlin were targeted before the era of 'canyon' fishing. Those coordinates are being overlaid on a GIS charting project of various nearshore seafloor habitats with Jay Odell, Gwynn Crichton and Chris Bruce of TNC's Virginia Program. Though not complete, the work already offers some insight. Using my own coordinates, there are 219.6 square miles that contain hard-bottom patch reefs, or substrates suitable for reef growth, inside the 25 fathom line between Cape May and Winter Quarter. What's striking for the purposes of this comment is the proximity of these reefs to historical marlin fishing grounds.
Why. Other than an overall increase in marine productivity, and certainly a crucial importance to demersal species, why would meadows of sea whip and other reef types influence the migratory patterns of billfish?
I think part of the answer is squid. Numerous times I have found large concentrations of squid (loligo) on hardbottom reef. I believe that their behavior indicates spawning. Spawning concentrations of any species attract predators. According to several papers, cephalopods represent a large percentage of the stomach contents of billfishes.
Squid too are depleted in the mid-Atlantic. However, if these reef's life cycles were interrupted by various fishing gears -and perhaps the occasional category 4 hurricane- then it stands to reason that spawning habitat loss could play a role in the region's diminishment of squid. No bait concentrations~ no predator concentrations.
That's one reason. Another missing piece of the food web may come from the tops of the shoals. According to the Canadian DFO's web page on sand lance (sand eel - A. americanus) these prey fish prefer shallow marine waters, especially the tops of shoals. Unfortunately, so do surf clams ~ The peak of the unregulated 'gold rush' clam fishery coincides with the loss of billfish and other species at numerous locations. Admittedly, modern stomach content analysis papers do not show sand lance as a major prey item of billfish. They are, however, consumed by many or all of the fish that marlins might eat. It's a step away.
Going back a few years brings the issue into sharper focus. Einarsson (1951) found sand eels an important prey item of white marlin. Direct observations by fishers on the inshore marlin grounds through the late 60s offer numerous accounts of sand eels being spit up by white marlin. Observations of today's offshore fishery have turned up none.
Perhaps as the shoals were hydraulically harvested for surf clam -and this beneath the 'high energy zone'- the composition of the sand was altered unfavorably for sand eel settlement/survival.
This clam fishery was not the fishery of today. No harvest caps, no permits and no end for consumers want of clam strip dinners kept a growing fleet of boats working. The fishery peaked around 1973. Clam fishers of the era have related to me how they would often see 'dozens of clam boats working within sight of one another'. It is certainly possible that the hydraulic liquification of so much bottom had an adverse effect on the benthos. Indeed, most fishers with historical experience in the bluefish, marlin, or sea bass fisheries point to clamming as the primary reason for the decline of the inshore fisheries.
The damaging sequence of overfishing and habitat loss leading to prey reduction may have led to the extirpation of nearshore marlins. Habitat/feeding/spawning site fidelity may have further exacerbated this situation. Showing up in many species; the instinctual or learned behavior of fish returning to the same areas each year is common. While unable to find works on the subject concerning billfish, it seems likely in marlins as evidenced by anecdotal accounts; especially a blue marlin that was seen numerous years on the bass grounds until it was harpooned and lost. There have been no reports of blue marlin there since.
Surely, were there a collapse of prey the marlin that remained of the inshore stock would have moved on to better feeding areas. Offshore perhaps ~ their numbers concentrating in regions with abundant prey. Once these places of improved forage were learned by -or imprinted on- the stock, they would have returned annually. When these areas were discovered by fishers it furthered the cascade.
Habitat and prey availability's function in the fisheries is poorly understood and, in this region, unmanaged.
Perhaps a closer examination of their effects could shed light on other problematic fishery declines as well.
Finally, there is water quality. Every single fisher I've interviewed about historical fisheries has decried the loss of blue water on the inshore grounds. Numerous effects of pollution and eutrophication are causing a degradation of marine waters.
We know of the oyster's ability to filter water and sequester enrichments. Water quality will remain the focus of those who are trying to restore our rivers and estuaries. Still, we do not know what similar effect a thriving tube worm colony 7 miles long by 1-1/2 miles wide might have. We do not know how much sea whip meadows might filter either. Perhaps these complex habitat forming animals offer no effect on water quality. But, if any - it could be multiplied many times over if left to flourish.
Catch location data below.
Regards,
Capt. Monty Hawkins
Historical White Marlin Catches: DelMarVa Region (Almost all can be anecdotally confirmed by fishers still alive)
NW DE Light. 38d41.5 ~ 74d55.4 Catches to late 60s.
DE Light 38d27.1 ~ 74d55.5 Catches as late as mid 80s. Rarely to present.
SE DE Light 38d22.3 ~ 74d35.3 Catches to mid 80s - possibly to present.
Great Gull. 38d16.6 ~ 75d00.0 to 38d13.5 75d03.2 Catches from 1920s (From son of surf boat fisher and another capt. that started in 1934 when the inlet was opened - both deceased) to late 60s.
Fenwick Island Shoal - Located 5 miles offshore MD/DE line. Catches to early 60s.
Bass Grounds. 38d18.6 ~ 74d52.8 to 38d16.8 ~ 74d55.2 Catches from the mid 30s/early 40s to late 60s. Last blue marlin harpooned there circa 1988. (habitat fidelity almost a certainty - fish was seen numerous years)
Second Lump. 38d16.7 ~ 74d49.6 to 38d14.7 ~ 74d52.7 Catches to late 60s.
Third Lump 38d16.7 ~ 74d46.8 to 38d15.4 ~ 74d52.7 Catches at least to late 70s - maybe some later.
SE Ridge. 38d04.6 ~ 74d54.4 to 38d08.2 ~ 74d52.2 Catches to early 70s.
Sugar Lump. 38d04.8 ~ 75d00.5 to 38d03.2 ~ 75d02.5 Catches to early/mid 70s.
Inshore Winter Quarter 38d59.9 ~ 75d00.9 to 37d58.9 ~ 75d02.5 Catches to at least mid 50s - could probably find later reports to late 60s early 70s.
Offshore Winter Quarter 37d55.7 ~ 74d55.6 Catches to early 80s.
Jackspot Shoal 38d06.0 ~ 74d45.8 SE to 38d05.1 ~ 74d44.9 SW to 38d03.2 ~ 74d48.5 NW to 38d04.7 ~ 74d49.6. Catches (rarely) to present. Was literally world famous amongst billfishers into the late 70s.
Great Eastern Reef: Constructed in mid 1990s - first marlin in 05...