11th ICRS Abstract book - Nova Southeastern University

14-49
Quantifying The Spatiotemporal Trends in Marine Connectivity: Merging Seascape
Genetics And Biophysical Modeling Within A Graph-Theoretic Framework
Eric TREML* 1 , Patrick HALPIN 2
1 The School of Integrative Biology, University of Queensland, Brisbane, Australia,
2 Nicholas School of the Environment and Earth Sciences, Duke University, Durham, NC
Marine population connectivity, via larval dispersal, is critical for population persistence
and is a key factor influencing how a species might cope with habitat loss and
degradation due to local anthropogenic factors and future climate change. However,
identifying the patterns in marine population connectivity poses one of the greatest
challenges in marine ecology. Although several studies have discovered a general scale
of population connectivity, little progress has been made in identifying the spatiotemporal
structure of this connectivity. The objectives of this research were to 1) identify the
probable dispersal routes and spatial population structure for several marine species
throughout the Tropical Pacific, 2) test isolation-by-distance hypotheses of genetic
differentiation for several marine species using traditional and graph-theoretic metrics,
and 3) develop a framework for integrating these connectivity estimates into the regional
marine conservation planning efforts. By exploiting techniques in population genetics,
biophysical modeling, and graph theory, this work explored the hypothesis that the spatial
genetic structure of marine populations is determined by the location and strength of
biophysical connectivity. For this work, dispersal probabilities were derived for multiple
species throughout the Tropical Pacific using a spatially-explicit biophysical modeling
approach. These probabilities incorporated high-resolution hydrodynamics, pelagic larval
duration, simplistic larval behavior, mortality, and settlement probability. The resultant
spatiotemporal structure, including persistent dispersal corridors and barriers, were
uncovered using clustering and connectivity algorithms from graph theory. The
correlation between the biophysical connectivity predictions and the observed population
genetic structure was tested within a Mantel regression framework. Finally, this research
evaluated methods for integrating the spatial structure of marine population connectivity
into regional conservation planning.
14-51
Where Have All The Larvae Gone? Connectivity Within The Hawaiian Archipelago
Rob TOONEN* 1 , Chris BIRD 1 , Anuschka FAUCCI 2 , Iliana BAUMS 3 , Derek
SKILLINGS 1 , Brian BOWEN 1
1 Hawaii Institute of Marine Biology, University of Hawaii, Kaneohe, HI, 2 Department of
Biology, University of Hawaii, Kaneohe, HI, 3 Pennsylvania State University, University
Park, PA
The Papahânaumokuâkea Marine National Monument, encompassing all of the
Northwestern Hawaiian Islands, is the largest Marine Protected Area in the world
(>350,000 km2), and studies of connectivity between reef habitats across this broad
region are currently lacking. To this end, we are surveying a broad range of fish and
invertebrate species to understand connectivity patterns throughout the Hawaiian
Archipelago. We now have data for more than a dozen species, and using Monmonier’s
algorithm as implemented in BARRIER, we have determined areas of restricted gene
flow across many species within the Hawaiian Archipelago. Comparing these concordant
population genetic breaks with results of a layered Lagrangian model of larval dispersal
developed by Kobayashi, we argue that connectivity among coral reef habitats is unlikely
to match passive diffusion models based solely on fluid dynamics. We also show that
variability among even closely-related species is the norm, and argue that such broad
taxonomic surveys are necessary to draw robust conclusions about general patterns of
connectivity that will guide management or conservation efforts. Our data show a
number of concordant breaks that were previously unknown and suggest that population
structure across the Hawaiian Archipelago does not fit predictions based on broad-scale
oceanographic currents or advection-diffusion models of larval dispersal driven by
geostrophic flow.
Oral Mini-Symposium 14: Reef Connectivity
14-53
Does Behavior Drive Population Genetic Structure in The Cardinalfish ostorhynchus
Doederleini?
Gabriele GERLACH* 1,2 , Jelle ATEMA 3 , Michael KINGSFORD 4
1 University of Oldenburg, Oldenburg, Germany, 2 Marine Biological Laboratory, Woods Hole,
3 Boston University, Boston, MA, 4 James Cook University, Townsville, Australia
Many marine fish and invertebrates show a dual life history where settled adults produce
dispersing larvae. While ocean currents are a major force in larval dispersal, recent studies and
our own research show far greater retention than predicted by advection models. Based on
microsatellite markers, we compared the genetic structure of adult cardinalfish, Ostorhynchus
doederleini, at different reefs at the Capricorn Bunker Reef (Great Barrier Reef, Australia) at a
geographical scale from 2 to 140 km over 5 different years. While the genetic structure in 2003
and 2005 showed statistically significant genetic differences between all reefs the populations
seemed to have mixed up in 2006 probably driven by storm events. Surprisingly, significant
differences were found again in 2007 and these populations were genetically similar to those
from 2003 and 2005. Such a rapid reconstitution of the former genetic structure might be
explained by behavioral mechanisms leading to different mortality of settling larvae. In order to
test this, we collected adult O. doederleini at 4 different reefs and settling larvae from 2 reefs. In
a random order we introduced a single larva into a tank containing 2 adults from either reef and
observed the aggressive behavior towards this larva. The aggressive interaction of adults were
significantly stronger when they originated from reefs different from those where larvae were
collected; 7 out of 43 tested larvae were killed by foreign adults while no larvae were killed by
adults from their own reef population. Our results indicate that differential aggressive behavior
of adults might select against foreign, genetically dissimilar larvae and result in differential
mortality of settling larvae from different origin.
14-54
Connectivity And Gene Flow in The Dominant Caribbean Reef-Building Coral,
montastraea Annularis
Nicola FOSTER* 1 , Claire PARIS 2 , Iliana BAUMS 3 , Mark VERMEIJ 4 , Shannon GORE 5 ,
Phillippe BUSH 6 , Croy MCCOY 6 , Sascha STEINER 7 , Judith MENDES 8 , Ernesto WEIL 9 ,
Carolina BASTIDAS 10 , Juan SANCHEZ 11 , Claudia AGUDELO 11 , Renata FERRARI 12 , Patricia
GONZALEZ 13 , Michael MCCARTNEY 14 , Reia GUPPY 15 , Owen DAY 16 , Jamie STEVENS 1 ,
Peter MUMBY 1
1 School of Biosciences, University of Exeter, Exeter, United Kingdom, 2 University of Miami,
Miami, FL, 3 The Pennsylvania State University, University Park, PA, 4 University of Hawaii,
Lahaina, HI, 5 BVI Conservation and Fisheries Department, Tortola, Virgin Islands (British),
6 Cayman Islands Government, George Town, Cayman Islands, 7 Institute for Tropical Marine
Ecology, Roseau, Dominica, 8 University of West Indies, Mona, Jamaica, 9 University of Puerto
Rico, Lajas, Puerto Rico, 10 Universidad Simon Bolivar, Caracas, Venezuela, 11 Universidad de
los Andes, Bogota, Colombia, 12 Fundacion de Ecologia de Punta Cana, Punta Cana, Dominican
Republic, 13 Universidad de La Habana, Havana, Cuba, 14 University of North Carolina,
Wilmington, Wilmington, NC, 15 University of newcastle, Newcastle, United Kingdom,
16 Buccoo Reef Trust, Carnbe, Trinidad and Tobago
Understanding patterns of connectivity among populations of aquatic organisms is essential for
the development of realistic, spatially explicit models of population dynamics and for
determining the placement of effective marine reserve networks. Traditionally, two approaches
have been used to infer levels of larval connectivity among aquatic (generally marine)
populations. The first uses oceanographic models of currents to predict potential levels of
dispersal among sites and the second uses population genetics to infer aspects of connectivity
from observed gene flow. Rarely have both methods been applied simultaneously. Here, we
analysed variation at six polymorphic microsatellite loci to assess gene flow among 30
populations of the reef-building coral, Montastraea annularis, across the Caribbean. This data
was then compared to the results from a model of larval dispersal. Using geographical
coordinates and genetic distance matrices, an area of reduced gene flow was identified between
populations in the eastern and western Caribbean. A further area of lowered gene flow was
detected between populations in Belize and those in Honduras and Nicaragua. The observed
breaks in gene flow were consistent with the results of the larval dispersal model. Such
information regarding the connectivity of populations should be incorporated into future
management plans.
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