Characterizing patterns of larval dispersal is essential to understanding the ecological and evolutionary dynamics of marine metapopulations. Recent research has measured local dispersal within populations, but the development of marine dispersal kernels from empirical data remains a challenge. We propose a framework to move beyond point estimates of dispersal towards the approximation of a simple dispersal kernel, based on the hypothesis that the structure of the seascape is a primary predictor of realized dispersal patterns. Using the coral reef fish Elacatinus lori as a study organism, we use genetic parentage analysis to estimate self-recruitment at a small spatial scale (<1 km). Next, we determine which simple kernel explains the observed self-recruitment, given the influx of larvae from reef habitat patches in the seascape at a large spatial scale (up to 35 km). Finally, we complete parentage analyses at six additional sites to test for export from the focal site and compare these observed dispersal data within the metapopulation to the predicted dispersal kernel. We find 4.6% self-recruitment (CI95%: ±3.0%) in the focal population, which is explained by the exponential kernel y = 0.915x (CI95%: y = 0.865x, y = 0.965x), given the seascape. Additional parentage analyses showed low levels of export to nearby sites, and the best-fit line through the observed dispersal proportions also revealed a declining function y = 0.77x. This study lends direct support to the hypothesis that the probability of larval dispersal declines rapidly with distance in Atlantic gobies in continuously distributed habitat, just as it does in the Indo-Pacific damselfishes in patchily distributed habitat.
All reef patches shape file
This .shp file shows the centroids of all reef patches within 35 km of Curlew. Suggested projection: Datum (WGS84); Projection (UTM Zone 16N).
Modified_centroids_shape.shp
All reef patches shape file .shx
This .shx file is associated with the .shp files for the centroids of all reef patches near Curlew.
Modified_centroids_shape.shx
All reef patches shape file .dbf
This .dbf file is associated with the all reef patches shape file that shows the centroids of all reef patches near Curlew.
Modified_centroids_shape.dbf
Curlew Caye Shape File
This .shp file shows the centroid of the Curlew Caye reef patch, which was our focal study site. Suggested projection: Datum (WGS4); Projection (UTM Zone 16N).
Curlew.shp
Curlew Caye Shape File .shx
This .shx file supports the Curlew shape file.
Curlew.shx
Curlew Caye Shape File .dbf
This .dbf file supports the Curlew .shp file.
Curlew.dbf
Export sites shape file
This .shp file shows the centroids of the six additionally sampled export reef patches for the export parentage analysis. Suggested projection: Datum (WGS 84); Projection (UTM zone 16N).
Export_Sites_shape.shp
Export sites shape file .shx
This .shx file supports the Export Sites .shp file that shows the centroids of the additionally sampled sites for parentage analysis.
Export_Sites_shape.shx
Export sites shape file .dbf
This .dbf file supports the export sites shape file that shows the six additionally sampled sites for the export parentage analyses.
Export_Sites_shape.dbf
Raw data for sampling sites and distribution data
This excel file contains all raw data collected from the field. In the first sheet we have listed: the collection date , GPS waypoint, and depth of every sponge in the study area, as well as sponge morphological data and data on the fish present in every sponge (fish presence/absence, number of fish, and size of each fish). On the second sheet are the specific geographic coordinates that correspond to each GPS waypoint.
Raw_distribution_data.xlsx
Microsatellite genotypes
This files contains the genotypes for all gobies at 14 polymorphic microsatellite markers. Gobies include all individuals from Curlew Caye (here, we list their standard length [SL] and whether they are categorized as a potential offspring or parent for the parentage analysis). We also include genotypes for the additional settlers collected at each of the 6 sites for the export analyses.
microsatellite_genotypes_allgobies.xlsx
Raw distance data between all reef patches in the study
The first sheet of this Excel file contains the distance between Curlew and all reef patches within 35 km of Curlew. It also has a histogram of the distances. The second sheet lists each of the six additional export sites, and for each of those sites, lists the raw distances between every other patch within 35 km and the given focal site.
Distance_Distributions.xlsx
Self-recruitment Simulation
This Excel file shows step-by-step how we completed the simulation of dispersal to determine which simple dispersal kernel explains the observed self-recruitment percentage. Based on the distance between all reef patches within 35 km of the focal site (Curlew Caye), we iteratively apply a simple exponential decay rate. Based on the cumulative relative probability of dispersal to that site, we can predict self-recruitment and compare to the observed value. Further details are given within the file by Excel comments.
Self-recruitment_Simulation.xlsx
Export Analysis Simulations
This Excel file shows how we predicted the proportion of settlers to have originated from Curlew Caye (focal site) to each of the six additional export sites. For each export site, we calculate the cumulative relative probability of dispersal to that site based on the approximated dispersal kernel and the distance to all reef patches within 35 km. We can then predict the proportion to have originated from Curlew, based on the distance between Curlew and each export site. Additional details are given in Excel comments within the file.
ExportAnalysis_Simulation.xlsx