Fish Spawning Aggregations in the Southeast Florida Coral Reef Ecosystem Conservation Area: A Case Study Synthesis of User Reports, Literature, and Field Validation Efforts

Abstract

The formation of fish spawning aggregations (FSAs) is an essential part of the life history of many economically important fish species; however, their status are often poorly described in the literature either due to their occurrence in remote locations, during seasons with unsafe ocean conditions, or because they move on space and time scales that are difficult to predict and validate. Even in areas that are relatively accessible and heavily fished, such as southeast Florida, regionally relevant information describing FSA dynamics is generally absent from the literature and unaccounted for in existing management plans. We propose that this can be attributed to the fact that information is often held by stakeholders or found in unpublished manuscripts and reports. These sources are not widely disseminated and are therefore difficult to locate and integrate into fisheries management decisions. In this paper, we present a case study demonstrating the value of regional data syntheses as a tool to improve management activities in southeast Florida. Specifically, we engaged with local stakeholders to collect reports of FSA occurrence, and used Web of Science queries to collate information describing the reproductive dynamics of locally occurring snapper and grouper species. Reports were combined with regional FSA literature and provided to managers as a support tool to anticipate FSA occurrence, and to guide policy development and future FSA research. Resource users identified 13 potential aggregations from five species, but Web of Science queries revealed a paucity of information. Echosounder, camera, and fisheries dependent surveys were then used to corroborate reportedly active cubera snapper (Lutjanus cyanopterus), hogfish (Lachnolaimus maximus), and gag grouper (Mycteroperca microlepis) aggregations. Variability in the spatiotemporal aspects of FSA occurrence make them difficult to study, but this may also explain how certain species have avoided detrimental impacts from aggregation fishing. These data represent a first step toward describing FSAs that have historically occurred in the Southeast Florida Coral Reef Ecosystem Conservation Area and can be used by managers to prioritize future research efforts focused on species or hotspots of multispecies activity along the northern extent of the Florida Reef Tract.

Reproduction of grey snapper (Teleostei: Lutjanidae) in the southern Gulf of Mexico

“…Larger movements by grey snapper are related to spawning migration and it is probable that this species aggregates at offshore spawning sites (SEDAR 2018). However, L. griseus spawning aggregations have not yet been fully validated Colin 1997, Lindeman et al 2000;Binder et al 2021). The Campeche Bank L. griseus population exhibits an asynchronous ovarian organization and is a batch spawner (Macal-López et al in press).…”

An evaluation of survey designs and model-based inferences of fish aggregations using active acoustics

“…Volume-backscattering strength (S v ; dB re 1m -1 ) data were thresholded at -60 dB re 1 m -1 to eliminate sources of backscatter that did not originate from swim-bladdered fish. Backscatter representing large-bodied goliath grouper was isolated by applying a -40 dB re 1 m 2 threshold to the target strength (TS; dB re 1 m 2 ) data (Binder, 2022). The areas in the TS echogram attributed to goliath grouper were then masked over the S v echogram of swim-bladdered fish, which was used to calculate the nautical area scattering coefficient (s A ; m 2 nmi -2 ) from echo integrals in 5 m along-track x 5 m depth intervals from the best bottom candidate exclusion line (MacLennan et al, 2002).…”

Using eDNA sampling for species-specific fish detection in tropical oceanic samples: limitations and recommendations for future use

“…Tens of thousands of fish in constant movement can be influenced by currents and the presence of divers, which can also influence how fish interact and behave during spawning ( Kobara & Heyman, 2008 ). Other methods to first locate FSAs include hydroacoustic surveys such as echosounders ( Binder et al, 2021 ) and underwater microphones (hydrophones) ( Appeldoorn et al, 2013 ; Chérubin et al, 2020 ). Some of these methods can also be used to monitor FSAs ( Schärer et al, 2012 ), among other methods such as digital imaging using baited or non-baited video cameras ( Cappo, Harvey & Shortis, 2006 ), acoustic tagging ( Tuohy et al, 2015 ), and remote sensing ( Kobara & Heyman, 2007 ).…”