Shark depredation—the act of sharks stealing fish from
anglers or commercial fishermen—is nothing new.
Ernest
Hemingway wrote about sharks “apple coring” bluefin tuna—attacking a hooked
fish so relentlessly that an angler was left with little more than a head, a
tail, and a near-fleshless backbone in-between—in the mid-1930s, and when I
began fishing for cod from Rhode Island party boats three decades later, it was
pretty well understood that we’d lose a few on every trip to the sharks that would
inevitably be attracted to the struggling fish we reeled up from the ocean’s
floor.
Offshore sportfishing is a relatively new sport, not much
more than a century old, but it’s a pretty good bet that the fishermen who
first set a net or threw a spear into the ocean, hoping to drag some food from
the sea, learned first-hand about shark depredation, long before anyone gave it
a name or developed the alphabet needed to record its occurrence.
Still, shark depredation has been getting a lot more press during
the last few years, and there is little doubt that depredation events are
becoming more common, both in northern and southern waters.
The big question is “Why?”
The researchers came up with a correlation between shark
abundance, prey fish abundance, and angling activity that suggests why rates of
shark depredation have varied over the years, which seems to make intuitive
sense and corresponds with what I’ve observed on the water over the past 60 or
so years.
Early in the paper, its authors note that
“At its essence, shark depredation is the result of
human-wildlife overlap; in this case, spatially and temporally dynamic overlap between
recreational anglers and sharks competing for a shared resource. Navigating the challenges associated with
recent increases in shark depredation (real or perceived) requires a broader
understanding of how this overlap has evolved over time. Therefore, we present a conceptual model
incorporating historical information to broadly characterize a century of
overlap between US Atlantic recreational anglers, target fisheries species, and
sharks… [citations omitted]”
One of the more interesting aspects of the analysis is that
shark depredation, along with the factors that cause it, ebbs and flows over
time; it does not follow a consistent trajectory.
In the beginning—meaning the beginning of the 100-year span
analyzed in the paper, not the beginning of all interactions between fishermen
and sharks—depredation occurred, but there wasn’t too much overlap between
anglers, sharks, and their shared target species in the quarter-century between
1925 and 1950. Angler populations were
certainly far lower than they are today, and target fish populations, being
under far less pressure, were almost certainly much higher. But what might be the most surprising aspect
of the latter half of that period is that the shark population was probably
somewhat depressed, at least in the waters off Florida, where some of the
highest levels of shark depredation reportedly occur today.
That was due, as the paper notes, to the need to find a substitute
for cod liver oil, which was then one of the most-used vitamin supplements. Once the start of the Second World War, and
the threat of German U-boats, cut off cod liver oil shipments from Europe, shark
livers, processed at a plant in Port Salerno, Florida, provided a viable
substitute.
It’s probably important to note a description of the
then-new commercial shark fishery that was quoted in the paper:
“Thus the shark, a pest and a menace to Florida
fishermen and sport lovers, the scourge of Florida waters, is being
transformed into one of the most valuable creatures of the sea, [emphasis added]”
because when we hear fishermen complain about current levels
of shark abundance, we often hear them
say that sharks “need to be controlled,” or that
shark populations are “out of control.”
The
supposed overabundance of sharks is blamed on the National Marine Fisheries
Service’s efforts to manage shark populations, with one charter boat captain whining
that
“The sharks have been protected for decades, and I believe it’s
time that we need to control these predators as their population is spiraling
out of control.”
But the early-1940s comment about sharks being “a pest and a
menace to Florida fishermen and sport lovers” confirms that there is nothing
new about shark depredation; it was going on long before NMFS began regulating
shark landings, and long before “depredation” became the buzzword that it is
today.
In the next quarter-century—1951 through 1975—the paper suggests
that the overlap between anglers, sharks, and the various prey species
increased substantially. The number of
recreational fishermen increased as the typical worker had more leisure time, as
well as a better selection of affordable fishing boats, while the availability
of fish traditionally targeted by recreational fishermen began to decline due
to increased landings, largely by the commercial fishery; at the same time,
shark abundance was generally stable, as the commercial fishery declined while recreational
shark fishing, spurred on by the
book, and later the movie, Jaws, became more and more popular.
This was the era in which I was born, began angling, saw my
first recreationally caught sharks, and had my first experiences with shark
depredation. It was also the time when I
first experimented with recreational shark fishing, and the time that created
my personal baseline for shark depredation.
At that point, sharks were generally cursed at by anglers
when they stole a tuna, billfish, or cod, but shark depredation was not the cause
celebre that it is today. It was merely
a nuisance that fishermen learned to live with when they ventured out onto the
sea.
That being said, it could easily be argued that today’s
discontent over shark depredation was born in the third quarter-century defined
in the paper, the years 1976 through 2000.
They were years when the angling population continued to increase, while
the populations of both sharks and the various target fish species were both in
decline. There was relatively little
overlap between the three groups. In
fact, according to the paper’s authors, the years between 1976 and 2000
resulted in the least overlap of any period during the past hundred years.
As the paper observes, during this period,
“commercial shark fisheries were explored as an underutilized
resource, and public interest in recreational shark fishing continued to
grow. Expanding trade relations with
China during this period also offered massive new markets for US seafood
exports, including shark fins.
Consequently, commercial shark landings escalated by an order of
magnitude, from 135 tons in 1979 to 7172 tons in 1989, yet it wasn’t until 1993
that the first fishery management plan for US Atlantic sharks was enacted. By then, most primary targets of commercial
shark fisheries…were overfished…
[citations omitted]”
Some species of shark saw their abundance fall to historic
lows.
This was the time when I became an active recreational shark
fisherman, catching, killing, and eating my first sharks in the late 1970s,
then buying my first (more-or-less) offshore-capable boat in 1982, catching my
first sharks from that boat a year later, when I also ended up moving from my original
home in Connecticut, where fishing was restricted to a shark-starved Long Island
Sound, to the South Shore of New York’s Long Island, a move motivated by my
desire for ready access to the ocean and the sharks and tuna that roamed within.
During those years, I became an active tournament fisherman,
and saw anglers fishing from my boats place a number of prize-winning sharks on
the scales. But I also saw some species of
shark fall into notable decline, dusky and sandbar (“brown”) sharks foremost
among them. The big tiger sharks that
were once relatively common off New York during the summer became far less abundant,
and even the shortfin mako, the most popular species in our local shark
fishery, appeared to grow somewhat scarcer and trend smaller in size as the 20th
Century reached its end.
Anglers became accustomed to an ocean where sharks were
fewer and farther between than was the case in previous decades.
Thus, they were mentally unprepared for what happened over
the last 25 years.
The paper refers to the years 2001 through 2025 as a time of
“Greatest overlap and lifting baselines,”
when
“there are more anglers than ever before, shark populations
are rebuilding following three decades of management, and many target fishery
species are recovering from overfishing.”
“Instances where populations have been overfished and then
rebuilt can create a perception of overabundance. When the species that’s recovering is a
predator, that can lead to human-wildlife conflict.”
That’s arguably what we’re seeing with shark depredation
today.
Still, the shark depredation issue can’t be ignored, because
sharks do steal fish from anglers, and anglers do get upset when that happens.
The paper, relying on input from various sources, identified
22 species of shark that engage in depredation, and 51 target fish species that
suffered from the events. The
depredation events involved 207 different combinations of shark and target fish
species, with bull sharks and sandbar sharks named as the most frequent
depredators. Those figures probably
underestimate the number of possible shark/target fish combinations that
actually occur, as I recall that my early recollections of depredation on the
Rhode Island cod boats involved blue, shortfin mako, and dusky sharks, although
duskies were not listed as one of the reported cod depredators in the study.
Perhaps most significantly, the paper stated that
“There are no ‘silver bullet’ shark depredation solutions
that will work across all of the fishery scenarios identified in our analysis. Ideally, any approach should simultaneously
maximize access to target fishery species while minimizing shark
interactions. Yet, in reality, potentially
available mitigation options may only marginally reduce conflict, not eliminate
it. Depredation mitigation options
currently include three primary mechanisms: (1) using technical/physical
deterrents, (2) modifying fishing behaviors, or (3) reducing shark
populations.”
It notes that
“researchers are testing the efficacy of technical/physical
deterrents with promising results,”
while also observing that
“Shark population reduction, either through targeted removal
or optimizing sustainable harvest of sharks, is often proposed by anglers as
the preferred mitigation option,”
although such population reduction might prove impractical
because
“Killing prohibited species…is illegal, while targeted removal
of authorized species…without widely marketable products is wasteful and inconsistent
with US fisheries law.”
As an angler who has fished on every coast of the United
States, and is more than familiar with the Atlantic coast shark fishery and
other Atlantic coast fisheries, I would argue that the second option, modifying
fishing behaviors, probably holds the greatest promise. While the paper merely states that
“modifications to fishing behaviors such as changing
locations and using electric reels are likely to reduce depredation,”
I would argue that the best way to minimize shark
depredation is to get a hooked fish up to the boat as quickly as possible, and
either land it or release it in the shortest practicable time.
“We try to fight them fast but never rough. The secret is for the angler never to
rest. Any time he rests, the fish is
resting. That gives the fish a chance to
get strong again…You don’t have to kill a horse to break him. You have to convince him…”
“The longer an angler fought a tarpon on the line, the
greater the chances for depredation…
“There is a quick solution…Fight tarpon harder, and get ‘em
landed and released in under 10 minutes.
Of course, a shark could still go after it once released, but at least
the fish has a fighting chance of survival.”
It’s only common sense.
The less time a fish is struggling in the water, the less time there is
for its struggles to attract a shark, and even if they do, the less time the
shark will have to locate and depredate the fish.
But a lot of current angling trends work counter to those
truths.
There has been a trend over the years to use spinning tackle
to catch larger fish, including tuna, sailfish, and larger reef fish such as
amberjack and big groupers. While anglers
might find such gear more enjoyable to use, from an ergonomic standpoint, it is
far less efficient than the traditional, conventional rod and reel, either
paired with a belt and stand-up
harness or, when the fish are particularly large, a bucket harness,
footrest, and fighting chair, either of which allow the angler to bring the
full force of their shoulders, back, and legs into the fight. A spinning rod, on the other hand, doesn’t
take full advantage of all of an angler’s muscle, and so adds extra time—with
tuna, sometimes an hour or more—to the battle, time which makes depredation all
the more likely.
In recent years, we have also seen trends like slow-pitch
jigging, which employ rods that lack any meaningful backbone, and are largely useless
for pumping a big fish up from the bottom; instead, the angler just slowly
cranks the reel until the fish finally gives up the ghost, again extending
fighting times. Another relatively
recent trend, deep-dropping,
sees anglers lower baits to the bottom in 800, 900, or even in more than 1,000
feet of water, giving cruising sharks more than enough time to intercept
hooked fish somewhere between the bottom and the boat.
Yet anglers blame the sharks for depredation, rather than
blaming themselves for setting up what amounts to an all-you-can-eat shark
buffet.
Thus, while the new paper provides valuable insights into
why and how shark depredation occurs, preventing depredation remains a
challenge. Science can only go so far in
addressing that challenge; anglers must be willing to do their part as well.