Some fish stocks are easier to manage than others, and Gulf of Mexico greater amberjack is certainly on the difficult end of the spectrum. While greater amberjack in the U.S. South Atlantic are not overfished nor undergoing overfishing, the Gulf of Mexico stock is both overfished and undergoing overfishing. [Note that “overfished” means there are too few fish in the stock, whereas “overfishing” means the rate of harvest is too high.]
This is not a new problem for Gulf of Mexico greater amberjack – in fact, this stock has been overfished and undergoing overfishing for decades and is now in its third rebuilding plan! The Gulf of Mexico Fishery Management Council has implemented many regulations for Gulf of Mexico greater amberjack over the years, such as closed seasons, reductions in catch limits, and increases in size limits. Unfortunately, despite these measures, the stock is still struggling to rebuild from past fishing pressure.
Why is the U.S. South Atlantic stock doing well, and why has the Gulf of Mexico stock failed to rebuild? How are these stocks similar, and how do they differ? In response to these unknowns, Congress appropriated funds for an extensive $11.7 million greater amberjack study referred to as the Greater Amberjack Count.
Greater Amberjack Count is challenging
Like the preceding Great Red Snapper Count, the Greater Amberjack Count’s overarching goal is to estimate the number (“absolute abundance”) of greater amberjack in the Gulf of Mexico. However, the Greater Amberjack Count will be more comprehensive and challenging than the Great Red Snapper Count for several reasons.
First, there is less prior knowledge of greater amberjack biology and ecology compared to that of red snapper, so the Greater Amberjack Count will also aim to expand knowledge of greater amberjack distribution, movement, growth and mortality.
Second, greater amberjack are much more mobile than red snapper, so greater amberjack will be inherently more difficult to study.
Third, the Greater Amberjack Count will encompass a larger study area (the U.S. South Atlantic and Gulf of Mexico) than the Great Red Snapper Count (the Gulf of Mexico only).
Report tagged fish for rewards
Like the Great Red Snapper Count, the Greater Amberjack Count involves a wide-scale tag-return initiative. Scientists have recently begun deploying two types of tags on greater amberjack throughout the project’s study area. Some greater amberjack are being fitted with acoustic tags – electronic transmitters surgically implanted inside a fish’s body cavity.
Many more greater amberjack are being fitted with conventional tags, which are simple, plastic-coated objects that are applied externally and resemble colorful streamers.
Some greater amberjack will have one conventional tag, while others will have two (“double-tagged”). This strategy will help scientists determine how often greater amberjack shed their conventional tags. Notably, all acoustically-tagged greater amberjack will also be tagged with at least one conventional tags.
The success of the conventional tagging study critically depends on participation from fishermen of all sectors. Upon catching a conventionally-tagged greater amberjack, fishermen should call the phone number printed on the tag(s) to report the recapture to the Greater Amberjack Count project team.
Each tagged greater amberjack, regardless if it has one or two tags, will carry a reward of $250. The physical tag(s) must be mailed in to claim the reward, so fishermen should clip off and save the tag(s), even if they plan to release the fish.
For more information about the Greater Amberjack Count, including tag-return instructions, visit the project webpage.
Meet the author
(J.) Marcus Drymon, Ph.D.
Marine Fisheries Extension Lead
Marcus is a marine fisheries ecologist, and his research interests are in applied fisheries ecology. The bulk of his research has focused on coastal sharks. He works on many commercially and... Read more
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