The Comeback of Blacktip Sharks

March 03, 2014 By Jeff Weakley

A fan favorite of inshore anglers stages a comeback in the Gulf.

Blacktip shark, Carcharhinus limbatus, is a popular sport fish in Florida, recovering from years of commercial overfishing.

This wasn't just another shark. Not for Christen Duxbury—it was her first.

For Capt. Jonnie Walker, a 40-year guide in Sarasota, the fish was one of a growing number of blacktips intercepting baits in recent years. Clearly, blacktips are booming and science tells us that is in fact the case.

From where I was standing, in the bow of Walker's tidy center console, Christen's catch was the happy conclusion to a dramatic fishery management story. Twenty years ago, the future of blacktip shark looked bleak, mired in commercial overfishing.

Today, handling light trolling gear like a pro, Christen reeled a 30-pounder boatside, where Walker reached out with longnose pliers and twisted the

hook free. The strong fish whipped its tail, delivering something like a celebratory shower on guide and angler, before disappearing back into the dusty, blue-green water.

Around us, the scene looked like something out of the good ol' days: Dozens of small boats clustered up within a few miles of shore, fishing the Spanish

mackerel migration. Most of the anglers were using live pilchards on single hooks. And most were fishing for sport, selecting a few mackerel for the table, releasing most everything.

Along with countless mackerel, we caught four blacktips on Walker's boat, and let all of them go. Under different circumstances, I might've been inclined to keep one for the table. That blacktips are quite good to eat is no big secret. In fact, the appeal of their firm, white flesh—and a stupid fixation for their fins—caused a commercial fishery to spiral out of control during the 1980s.

The blacktip is a member of the Carcharhinidae family, which includes bull and dusky shark; among them, blacktips are smaller, but as fish go, they're still pretty impressive, frequently reaching 100 pounds, occasionally topping 200. They are strong and fast on the line, and frequently jump early in the fight. A May 2012 stock assessment for blacktip in the Gulf of Mexico indicated the species is “neither overfished nor undergoing overfishing.” In the choppy parlance of contemporary fish management, that's a way of saying, “Blacktips are out of trouble.” For now, anyway.

Scientists aren't certain of blacktip status on the Atlantic coast, but anglers there are seeing more and more each year. A formal assessment is expected after 2014.

Blacktip shark is managed by the Highly Migratory Species Division of the National Marine Fisheries Service. The HMS Division makes fishing regulations

for species whose nomadic lifestyles make them vulnerable to fishing pressure across many geographic boundaries—domestic as well as international.

According to scientists, blacktip aren't as nomadic as, say, swordfish or yellowfin tuna. As it turns out, blacktip seem grouped according to regional sub-populations.

Tagging studies revealed no migrations or exchange between blacktip populations in the Atlantic and Gulf of Mexico. The blacktips I frequently catch around Stuart, Florida, on the east coast, are not of same stock Walker sees off Sarasota, on the Gulf Coast.

“That's why we contemplated managing them in separate stocks,” said Dr. Enric Cortes, lead scientist on the May 2012 assessment at the Panama City Laboratory of the Southeast Fisheries Science Center. Furthermore, said Cortes, “there is little evidence of movement from the west and east in the Gulf of Mexico.”

I interviewed Cortes by telephone, trying to clarify the acronym-heavy blacktip assessment, from which I derived some of the content for this article. As luck would have it, after fishing with Capt. Walker and Duxbury, I had dinner with another leading shark researcher, Dr. Bob Hueter at Mote Marine Laboratory in Sarasota. In an email after our meeting, Hueter summarized the blacktip situation, in lay terms, thusly:

“A combination of severe cutbacks in the commercial Total Allowable Catch of large coastal sharks over the last 20 years, plus the advantage that blacktip sharks are relatively fast-growing compared to other large coastal species—they mature in 5-7 years instead of the 12-15 years involved for some other fished sharks—has made the blacktip shark a sustainable fishery resource in the Gulf.”

Blacktip sharks inhabit a spectrum of waters, from estuarine bays to offshore wrecks. “Juvenile blacktip utilize nursery areas, inshore coastal areas,”explained Cortes, “where there are lots of interactions with fishermen. As they become larger, they start migrating to deeper water, expanding their home range.”

Blacktips are generalist feeders; based on my fishing observations, I'd long thought they were somehow tied to mackerel schools, but Cortes said that's not always the case.

“Many sharks have a diet dominated by crustaceans when they're smaller, but blacktips are notoriously piscivorous—fish-eaters. And they're not solely dependent on one food source. They have a diverse diet, able to switch to different prey sources.”

That certainly dovetails with what I observed aboard Walker's boat. We had blacktips eating 2-inch pilchards, and going after 20-inch mackerel. In my own recent encounters, on the east coast, I've watched blacktips mow through fields of tiny anchovies, then rise to whallop 10-inch silver mullet. Blacktips are versatile, but not invulnerable.

High-volume commercial gear—drift gillnets and longlines in particular—put a hurting on these fish through the 1980s and well into the 1990s. Early conservation measures following the 1976 Magnuson Stevens Act, which restricted foreign fishing in U.S. waters and implemented reporting requirements, were inadequate to deal with the skyrocketing domestic pressure on sharks.

During the 1980s, regional Fishery Management Councils were responsible for U.S. shark management. Blacktips were lumped into a Large Coastal Sharks

unit, and those LCS species were in serious decline. A growing Chinese market for sharkfin soup contributed to the demand. The year 1989 saw a peak in

Large Coastal Shark landings, with attendant signs of overfishing. The councils requested the Secretary of Commerce implement a shark Fishery Management

Plan (FMP). In 1990, amendments to the Magnuson Act gave the Secretary authority to manage sharks and other Highly Migratory Species (HMS) in the Exclusive Economic Zone, and transferred authority therein from the councils to the Dept. of Commerce. In 1993, a management plan for sharks in the Atlantic Ocean implemented a 2,436 metric ton quota (dressed weight) for Large Coastal Sharks, among them, blacktip. That figure, in retrospect, was about five times too high. Through the mid-1990s, NMFS made some efforts to limit the growth of landings, while it became increasingly evident shark landings needed to drop—by a lot.

That's when the National Coalition for Marine Conservation, based in Virginia, and National Audubon Society stepped onto the scene. The two began drumming up support for major reductions in LCS landings. Ken Hinman, President of NCMC, went so far as to suggest a complete closure in 1997, or at

the very least, a 50-percent reduction.

In 1999 came a package of management measures supported by NMFS, the conservation community and recreational anglers. Among the measures were a sharp reduction in the Large Coastal Shark quota, tighter recreational limits, an expanded list of prohibited species (including dusky), and limited

access to commercial permits. The commercial industry attempted to torpedo the measures in a District Court in Tampa, Florida, but a judge ruled in favor of shark conservation.

By 2006, shark recovery was under full sail. Two LCS stock assessments, in 2002 and 2005, demonstrated urgent need for tighter regulations. The terms of a consolidated Fishery Management Plan under the HMS Division established regional quotas, limited access to the commercial shark fishery, required sharks be landed with fins attached, and implemented shark identification and other standards for the remaining commercial fleet. For blacktips, the plan separated the species into Gulf and Atlantic stocks.

The 2012 Gulf blacktip assessment suggests management is on the right course, though it leans toward commercial allocation [as revealed in this month's

“On the Conservation Front”].

“Fifteen years later, it's great to hear that blacktip shark is making a comeback,” Ken Hinman of NCMC said, when I called to mention old newsletters of his I'd found in my files. “That seems like a long time, but for many sharks, rebuilding programs are measured in decades. These fish take a long time to grow, to reproduce, and that's why they're particularly vulnerable to overfishing. Hopefully we'll see conservation successes for dusky and other threatened sharks.”

In the ledger of fisheries, it appears the blacktip shark, for now, is out of the red and in the black. - FS