Permit Spawning Aggregation Dynamics and Predator Ecology

From Apr 28 – May 6, 2026, The International SeaKeepers Society assisted researchers from Florida International University and Carleton University in conducting research on permit (Trachinotus falcatus) spawning aggregations and associated predators in the Lower and Middle Florida Keys. Permit aggregate on natural and artificial reefs in the Keys surrounding the full moons in the spring. Catch-and-release angling for permit during their spawning season has become a popular sport fishery for many anglers. Although catch-and-release angling is not inherently detrimental to the fishery since permit harvest is prohibited between April 1 and July 31 throughout the Special Permit Zone (myfwc.com/fishing/saltwater/recreational/permit/), depredation (i.e., the removal of hooked fish by a predator) has produced a high level of concern regarding the sustainability of this practice. As a result, Florida Fish and Wildlife Conservation Commission implemented a seasonal fishing closure from April 1-July 31 each year at Western Dry Rocks (WDR), where depredation mortality has been historically high, to protect permit and other species that aggregate here.

The objectives of this expedition were to quantify the 1) relative abundance and 2) size structure of permit at spawning aggregations in the Florida Keys. Remote underwater video and 360° camera surveys were conducted to gather data on permit and potential predators (i.e., shark species composition, abundance, behavior), which were complemented by permit fork length measurements. These data will be used to assess changes in permit aggregation dynamics and demographics in response to the fishing closure, given our continued research on these aggregations since before the closure went into effect.

Some highlights from data collected on this trip:
• Initial results from the video surveys suggest that permit abundance is high (>1,500 individuals) at the Lower Keys aggregation site, which is comparable to previous seasons. Other schools of aggregating species were also observed, including horse-eye and crevalle jacks.
• The range (55-88 cm fork length) and average size of permit (71 cm fork length) were larger than previous survey years, indicating an increase in the abundance of large, fecund individuals as well as new recruits within the spawning aggregation.
• We observed a previously acoustically tagged Caribbean reef shark (Carcharhinus perezi) and several untagged individuals at the Lower Keys aggregation site. Several other species, including blacktip (Carcharhinus limbatus), great hammerhead (Sphyrna mokarran) and bull (Carcharhinus leucas) sharks, were observed near aggregations at Lower and Middle Keys sites.
• We conducted exploratory video and environmental DNA surveys at several artificial reefs in the Gulf, which will assess habitat-use and colonization rates across recreationally important species (i.e., snappers, jacks, groupers, sharks).