Every Week is Shark Week for Jill Hendon

Jill Hendon

For most of us, the movie Jaws prompted us to consider moving to Kansas or some other place far from salt water.  But Jill Hendon says that her continuing fascination with marine science, and sharks in particular, probably began during her childhood while watching Jaws and a documentary on humpback whales. Jill followed her marine interests and earned a B.S. in biology and English at the University of Wisconsin at Eau Claire and an M.S. in marine immunology from Southern Miss. She began teaching the Summer Field Program in 2005 and joined GCRL’s Center for Fisheries Research and Development as a research scientist in 2008.  She now leads the shark research group at GCRL, where every week is shark week. 

Most of Jill’s work deals with monitoring the populations of coastal shark species, focusing on their distribution and movement, though she has also worked on their reproduction, growth, and stress physiology.  “Coastal shark” is a fisheries management term that includes all the species of sharks found in and near Mississippi waters, from the common Atlantic Sharpnose to the Bull Shark and the Hammerheads.  Only the Shortfin Mako is not included.  At the heart of Jill’s work are two ongoing long-term field survey programs:  a longline survey and a gillnet and handline survey. 

Population Surveys

Jill Hendon and Gary Gray remove the hook from a bull shark before measuring, tagging, and releasing the shark. The white tube is supplying fresh seawater to the shark's gills.
Jill Hendon and Sarah Ashworth weigh a Blacktip Shark caught on a longline survey. The shark was weighed, measured, and tagged before being released in good condition. Click for larger image.

The longline survey consists of monthly sampling from March through October at defined locations in Mississippi Sound and the Gulf of Mexico just north and south of the barrier islands.  The basic objective is to determine what sharks are there and when they are there.  The project began in 2008 and continues with funding from SEAMAP, the Southeast Area Monitoring and Assessment Program.  A one-mile length of 1200-pound monofilament line is baited with 100 evenly spaced fishing lines and is fished on the bottom for one hour.   Notes are made on each captured shark, including their species, length, sex, and condition.  Smaller sharks are weighed, while length measurements help document the size of larger animals too large to weigh.  Sharks in good condition are tagged prior to release.  Occasionally, specimens are retained for particular research projects.  Approximately 800-1000 sharks are caught each year using longline gear. 

The gillnet and handline survey relies on different fishing gear, but is otherwise similar to the longline survey, with monthly sampling trips from March through October.   The gillnet work is conducted with a 600-foot net while the handline is a shorter 500-foot longline that targets smaller sharks.  The work is funded by the U.S. Fish and Wildlife Sportfish Restoration Program via the Mississippi Department of Marine Resources and has resulted in a valuable dataset that spans more than ten years.   The program accounts for another 800-1000 shark captures annually.

All other fish species encountered on these surveys are measured and weighed, too.  Red Drum are a common catch by both the longline survey and the gillnet and handline survey; they are tagged prior to release. 

Shark Identification Guide

For straightforward information on identifying sharks, download the free 58-page Identification Guide to Sharks of Mississippi on the GCRL websites.  Anglers should be aware that several species of sharks are strictly protected on the state and federal level.

Read more about shark research at GCRL in this recent Southern Miss Now feature, with video.

Jill’s interests and research are not limited to sharks.  She’s also involved with research on common sport fish species, as well as seasonal trawl and plankton surveys.  Working through the Science Center for Marine Fisheries, headquartered at GCRL, Jill will coordinate and manage the survey component of two projects addressing fisheries issues with Black Sea Bass, Monkfish, and Yellowtail Flounder off the U.S. Atlantic coast.

Directed Research Projects

In addition to ongoing survey work, Jill engages in directed research addressing specific scientific questions, such as reproduction of Finetooth Sharks and Blacknose Sharks.   Investigating the reproductive state of sharks captured throughout the year makes it possible to learn when the sharks mate, the length of the gestation period, and when the pups are born.  GCRL researchers are finding that the populations in the Gulf use different reproductive periodicities than populations in the Atlantic.  For example, Blacknose Sharks in the Gulf are reproduce annually while the Altantic population exhibits biennial reproduction (every two years).  The Finetooth Shark portion of the study revealed that the Gulf population exhibits a mix of annual and biennial periodicity, which had never been seen previously in a population within a discrete area. 

Jeremy Higgs is using the Finetooth portion of this project for his master’s degree.  This project was funded by the NOAA Cooperative Research Program and was a collaborative effort with James Sulikowski (University of New England), Eric Hoffmayer (NOAA NMFS) and Trey Driggers (NOAA NMFS).

Jill and Dr. Andy Evans, Assistant Professor and Aquatic Molecular Physiologist in the Division of Coastal Sciences, are currently working together to establish the GCRL Shark Research Program as  a research entity that will focus on the ecophysiology of elasmobranchs (sharks and rays) in the northern Gulf of Mexico.

Whale Shark Research

The largest fish on the planet, the Whale Shark, is a regular resident of the Gulf of Mexico, but little is known about the 40-foot giant’s life history and habits.  GCRL is working with the Louisiana Department of Wildlife and Fisheries and NOAA’s National Marine Fisheries Service Mississippi Lab to fill that void.  Jill and Senior Fisheries Biologist Jim Franks lead the GCRL team.  Both the LDWF and NOAA team leaders have a previous GCRL connection.  Jennifer McKinney from LDWF was a graduate student and technician at GCRL and Dr. Eric Hoffmeyer was a GCRL fisheries scientist before joining NOAA.

On July 10, 2014, the Whale Shark group set a new record by placing satellite tracking tags on fourteen whale sharks in a single day.  The divers made spot patterns photos and collected DNA samples from the fourteen tagged sharks and from eight additional sharks.  Spot patterns are unique to individual Whale Sharks and can be used for identification.  The photos became part of the international database of nearly 30,000 observations of more than 5600 individual Whale Sharks.  One of the sharks encountered on July 10, designated H-021,  was first documented in 2000 near Belize.  The links show the observation history for H-021 and a summary of the animals observed on July 10, 2014, with spot pattern photographs.

Acoustic  and Satellite Tracking of Sharks and Other Fishes

Jill and Jim Franks also collaborate on monitoring the movement of several species of fish using passive acoustic receivers.  Jill and Jim surgically implant acoustic transmitting tags in Spotted Sea Trout, Gag Grouper, Grey Snapper, Lane Snapper, Atlantic Sharpnose Shark, Blacktip Shark, and Bonnethead Shark.  Whenever a tagged fish is within the radius of one of the receivers, the receiver records its presence.  GCRL’s Dr. Mark Peterson also has a receiver array deployed for Gulf Sturgeon and by sharing data, the two groups are able to discern smaller scale movements by their tagged fish over a larger area.

The acoustic tracking work is supported by Tidelands funds through the Mississippi Department of Marine Resources.  For 2015, an additional Tidelands grant will allow Jill and Jim to build on this project and begin monitoring Red Drum (redfish) and small bull sharks in Bay St. Louis and near Cat Island.  The work on Red Drum will attempt to shed light on the mystery of where three- to four-year-old Red Drum go.  While the movements of younger and older Red Drum are well understood, the three- to four-year-old fish are seldom encountered by either researchers or anglers.

The GCRL shark team uses satellite tracking tags to investigate the movement patterns and habitat preferences of Silky Sharks, Dusky Sharks, and Bull Sharks.  Another joint effort by GCRL, NOAA, and LDWF is using satellite tags to monitor the movements of Tiger Sharks and Hammerheads.  The tracking results for several of the collaborative’ s tagged sharks can be tracked on the web.

Interesting Tag and Recapture Results

Report Your Tagged Shark Catch

Recapture reports of tagged fish from anglers are very important to the shark tagging project.  If you catch a shark with a tag, please contact the GCRL Shark Research Program at 228. 872.4257 or jill.hendon@usm.edu with the following information: tag number, shark species, sex, total length, date, and location (GPS position preferred). 

Teaching and Professional Service

Jill Hendon and Gary Gray remove the hook from a bull shark before measuring, tagging, and releasing the shark. The white tube is supplying fresh seawater to the shark's gills.
2014 Summer Field Program Shark Biology class. Click for larger image.

Jill shares her knowledge and enthusiasm for sharks and shark research with others through several teaching efforts.  After attending the first session of the Shark Biology course in GCRL’s Summer Field Program as a student in 2003, Jill began teaching the course in 2005. The popular class fills to its maximum capacity every year.  She also serves on the committees for two M.S. students: Jeremy Higgs and Danielle Bailey.  Jeremy is investigating Finetooth Shark reproduction and Danielle will be investigating the effects of capture and handling stress on Atlantic Sharpnose Sharks.

Jill assisted in setting up the shark survey component of the GCRL Marine Education Center’s Shark Fest program and trained staff members in survey techniques.  Participants catch sharks in Mississippi Sound with hand-lines and rod-and-reel tackle and then document, tag, and release them.  Jill credits Shark Fest and other MEC programs as an important source of valuable field data that supports her research.   “The students and the MEC staff use standard resource survey protocols so that the results provide sound scientific data that complements our ongoing surveys.  In fact, the recapture rate of tagged sharks has increased noticeably as a result of their contributions.” 

Jill also conducts presentations as part of the MEC’s continuing education programs for teachers and the public.  On September 18, 2014, she’ll present the science side of a session on Red Drum in the MEC’s popular Catch More Fish With Science seminar series.

Jill’s education orientation extends into her everyday work and she’s noted for being an excellent team leader and for conducting safe, organized, and productive field sampling programs.  Jennifer McKinney, a former graduate student and technician summed it up.  “Jill is not just an excellent scientist.  She’s also very good at leading and educating the people who work with her, and she makes learning fun, especially the hands-on parts.  She’s team oriented and shares the credit.  She creates an atmosphere in which everyone understands what’s going on and why, and that guarantees smooth operations and a good result.  I’m doing my best to pattern my own work after her example.”   

Jill is recognized by the American Fisheries Society as a Certified Fisheries Professional.  She also serves as a member of the National Marine Fisheries Service’s Advisory Panel for the Atlantic Highly Migratory Species, Southeast Data Assessment and Review.

Jill is married to Michael Hendon, a fishery biologist at the NOAA National Marine Fisheries Service lab in Pascagoula.  It’s no surprise that the couple’s children, three-year old Noah and two-year old Elyse, already love the water and enjoy the family’s frequent boat trips on the waters near their Ocean Springs home.

Jill Hendon and Gary Gray remove the hook from a bull shark before measuring, tagging, and releasing the shark. The white tube is supplying fresh seawater to the shark's gills.
Jill Hendon and Gary Gray remove the hook from a Bull Shark. The white tube is supplying fresh seawater to the shark's gills. Click for larger image.