Patterns in larval reef fish distributions and assemblages, with implications for local retention in mesoscale eddies

Abstract

Benthic marine populations are often replenished by a combination of larvae from local and distant sources. To promote retention of locally spawned larvae in strong, unidirectional boundary current systems, benthic marine organisms must utilize biophysical mechanisms to minimize advective loss. We examined patterns in larval fish abundance, age distribution, and assemblage in relation to environmental variables in the Straits of Florida to better understand the factors underlying larval transport and retention in a boundary current system. Depth was the primary structuring element; larval assemblages were more distinct across vertical distances of tens of metres than they were over horizontal distances of tens to hundreds of kilometres. However, depth distributions were species-specific, and larval assemblages inside and outside of mesoscale eddies were distinct. Age distributions were consistent with the hypothesis that mesoscale eddies provide opportunities for retention. Our data indicate that the effect of eddies on larval retention is likely taxon-specific and temporally variable, as synchronization of reproductive output, larval distribution, and timing of eddy passage are prerequisite to entrainment and subsequent retention of locally spawned larvae.

Submesoscale and Mesoscale Eddies in the Florida Straits: Observations from Satellite Ocean Color Measurements

“…The lack of observations also leads to a poor understanding on how these submesoscale features may affect local nutrient transport, biology, and ecology. This problem is particularly significant for the Florida Straits (FS), a subtropical region hosting the largest reef system in the continental United States and rich in submesoscale eddies as revealed by field surveys (Chew, ; ; de Morais & Reinert, ; Fiechter et al, ; Lee, ; Haus et al, , ; Lee & Atkinson, ; Lee et al, ; Scott et al, Shulzitski et al, ). Here submesoscale eddies refer to those with diameters less than a baroclinic Rossby radius of deformation (about 30 km; He & Weisberg, ; de Morais & Reinert, ; Kourafalou & Kang, ; Shay et al, ).…”

DNA barcoding of fish eggs collected off northwestern Cuba and across the Florida Straits demonstrates egg transport by mesoscale eddies

“…Based on long‐term satellite ocean color measurements, Zhang, Hu, Liu, Weisberg, and Kourafalou (2019) revealed strong seasonality of mesoscale cyclonic eddy occurrence in the Florida Straits with the highest occurrence in the summer and lowest occurrence in the winter. These cyclonic eddies are highly productive ecosystems that are rich in nutrients, phytoplankton, and copepods (Hitchcock et al., 2005; Lee, Clarke, Williams, Szmant, & Berger, 1994) and can influence cross‐shelf transport of fish larvae (Lane, Smith, Graber, & Hitchcock, 2003; Lee et al., 1992; Limouzy‐Paris, Graber, Jones, Röpke, & Richards, 1997; Shulzitski, Sponaugle, Hauff, Walter, & Cowen, 2016; Shulzitski et al., 2017; Sponaugle, Lee, Kourafalou, & Pinkard, 2005). Sponaugle et al.…”

How Life History Characteristics and Environmental Forcing Shape Settlement Success of Coral Reef Fishes

“…Our modeling tool synthesizes current knowledge on reef fish ecology to test hypotheses that can direct future field and lab research to explain population dynamics and how larval fish use biophysical mechanisms in ways that minimize advective loss of larvae (e.g., Shulzitski et al, 2017). Moreover, we can use the model in future analyses to identify important knowledge gaps (e.g., environmentally dependent development rates, spatially and temporally varying mortality) needed to explore reef fish adaptive strategies and associated coral reef ecosystem dynamics.…”

“…Regardless of eddy size, it is possible that some larvae are able to actively respond to the eddy gradient allowing them to control the length of residence in the eddy and leave the eddy when it is time to settle (McManus and Woodson, 2012). In addition to retention mechanisms that help to maintain larvae close to original or nearby islands, eddies may also allow for faster growth by providing increased food resources or temperatures and thus likely higher survival of the larvae (Shulzitski et al, 2016(Shulzitski et al, , 2017.…”