What 50 Years of Shark Surveys Have Revealed
Insights from the world’s longest running fishery-independent shark population study
As a shark conservation scientist, one of the most common questions people ask me is, “How are shark populations doing?” To answer this question, it’s important to understand two types of fishery surveys: fishery-independent and fishery-dependent. Fishery-dependent population surveys gather data from fishermen’s catches. These data are valuable because there are many more fishermen on the water than marine biologists. However, they are limited because fishermen fish with the intent to catch as much as possible, which means they regularly change their methods to achieve higher yields. This makes sense economically but limits the scientific value of the data.
Related Reading: Great White Shark Tagged Off Florida Coast Amid Surge in Sightings
In contrast, fishery-independent surveys are designed to use the same methods, which are scientifically more rigorous. “They provide an unbiased characterization of many different things, particularly changes in the abundance of fish populations over time,” Dr. Robert Latour, a professor at the Virginia Institute of Marine Science (VIMS) at William and Mary. “Since the survey is performed the same way during every research cruise, any changes in what you catch are due to something going on with the population, not changes in how we’re fishing.”
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History of VIMS Shark Research Program
Dr. Latour runs the shark longline survey at VIMS. Founded in 1973, two years before “Jaws” was released, the VIMS shark survey is the longest-running fisheries-independent shark population study in the world. The program was founded by Dr. Jack Musick, a legend in the field of shark science, who passed away in 2021.
During that time, the program has graduated 50 Ph.D. students who now work all over the world and has produced numerous research papers and reports on shark biology and conservation.
Some of the study’s early work contributed to raising alarm about shark overfishing, which led to the establishment of various U.S. shark conservation measures in the 1990s. Excitingly, in certain species. “At least in the Southeastern United States, some shark populations are recovering. We’re seeing some signs of improvement,” Dr. Latour said.
So far, the program has caught over 8,000 sharks. Once the VIMS research team catches the sharks, a variety of measurements and samples are collected and shared with colleagues around the world. One studied sandbar shark was caught in 1996 and recaptured in 2023, which remains the world record for a recapture of a tagged shark. The biggest individual shark they’ve caught was a 13-foot tiger shark!
To celebrate their 50th anniversary, the VIMS shark program released a free online app that lets anyone explore their data.
https://gmralph.shinyapps.io/sharks50_app/
As a shark conservation scientist, one of the most common questions people ask me is, “How are shark populations doing?” To answer this question, it’s important to understand two types of fishery surveys: fishery-independent and fishery-dependent. Fishery-dependent population surveys gather data from fishermen’s catches. These data are valuable because there are many more fishermen on the water than marine biologists. However, they are limited because fishermen fish with the intent to catch as much as possible, which means they regularly change their methods to achieve higher yields. This makes sense economically but limits the scientific value of the data.
Related Reading: Great White Shark Tagged Off Florida Coast Amid Surge in Sightings
In contrast, fishery-independent surveys are designed to use the same methods, which are scientifically more rigorous. “They provide an unbiased characterization of many different things, particularly changes in the abundance of fish populations over time,” Dr. Robert Latour, a professor at the Virginia Institute of Marine Science (VIMS) at William and Mary. “Since the survey is performed the same way during every research cruise, any changes in what you catch are due to something going on with the population, not changes in how we’re fishing.”
A
History of VIMS Shark Research Program
Dr. Latour runs the shark longline survey at VIMS. Founded in 1973, two years before “Jaws” was released, the VIMS shark survey is the longest-running fisheries-independent shark population study in the world. The program was founded by Dr. Jack Musick, a legend in the field of shark science, who passed away in 2021.
During that time, the program has graduated 50 Ph.D. students who now work all over the world and has produced numerous research papers and reports on shark biology and conservation.
Some of the study’s early work contributed to raising alarm about shark overfishing, which led to the establishment of various U.S. shark conservation measures in the 1990s. Excitingly, in certain species. “At least in the Southeastern United States, some shark populations are recovering. We’re seeing some signs of improvement,” Dr. Latour said.
So far, the program has caught over 8,000 sharks. Once the VIMS research team catches the sharks, a variety of measurements and samples are collected and shared with colleagues around the world. One studied sandbar shark was caught in 1996 and recaptured in 2023, which remains the world record for a recapture of a tagged shark. The biggest individual shark they’ve caught was a 13-foot tiger shark!
To celebrate their 50th anniversary, the VIMS shark program released a free online app that lets anyone explore their data.
https://gmralph.shinyapps.io/sharks50_app/
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