11th ICRS Abstract book - Nova Southeastern University

14-2
Oceanographic Coupling Across Multiple Trophic Levels Shapes Source-Sink
Dynamics in Coral Reef Metacommunities
Will WHITE 1 , Jameal SAMHOURI 2 , Robert WARNER* 3
1 Dept. of Wildlife, Fisheries, and Conservation Biology, University of California - Davis,
Davis, CA, 2 Northwest Fisheries Science Center, NOAA Fisheries, Seattle, WA, 3 Dept.
of Ecology, Evolution, and Marine Biology, University of California - Santa Barbara,
Santa Barbara, CA
A central goal of most studies of marine population connectivity is to determine which
subpopulations have the greatest value to the larger metapopulation. That is, where are
the ‘sources’ that are most essential to population persistence? In a single-species
context, this is a straightforward question, and theoretical models typically identify sites
with high recruitment, especially high self-recruitment, as having the highest value.
However, the oceanographic forces that shape the larval delivery of a given species are
also likely to influence the recruitment of that species’ predators, prey, and competitors.
We present empirical evidence from the Virgin Islands and Bahamas that oceanographic
forces produce spatial coupling between the recruitment of planktivorous fishes, the
recruitment of their predators, and the productivity of their zooplankton prey. Both
empirical and theoretical evidence suggests that this coupling causes planktivores at the
highest recruitment sites to experience higher, more strongly density-dependent mortality
(a consequence of higher predator densities). At the same time, planktivores at high
recruitment sites demonstrate faster growth and higher fecundity (a consequence of
higher zooplankton densities) than planktivores at low recruitment sites. Furthermore,
the results of both analytical and simulation metapopulation models reveal that the
relative strength of oceanographic coupling between the three trophic levels strongly
determines whether a given reef acts as a source or sink. Consequently, we argue that the
potential for such coupling should be incorporated into future models of coral reef
metapopulation dynamics and considered in the design of marine protected areas.
14-3
Coral Reef Conservation Planning With Connectivity
Maria BEGER* 1 , Hugh POSSINGHAM 1
1 The Ecology Centre, The University of Queensland, St Lucia, Brisbane, Australia
There are biophysical linkages and interactions between coral reefs and adjacent realms,
as well as connections among reefs themselves. Contemporary conservation planning
and reserve design theory and practice is largely incapable to deal systematically (i.e.
spatially explicit, repeatable, and mathematically sound) with connectivity. This talk
explores two new frameworks of how connectivity can be incorporated into the
systematic design of conservation area networks.
Firstly we present a classification scheme of cross-realm connections that provides a
basis for conservation planning. This includes four broad types of interactions: a) narrow
interfaces such as inter-tidal zones; b) broad interfaces such as estuaries; c) constrained
connections such as corridors of native vegetation used by amphibian to move between
natal ponds and adult habitat; and d) diffuse connections such as the movements of birds
or sea turtles between breeding and feeding habitats. We then use this classification to
describe a framework of technical approaches to conservation planning that promote the
persistence of these types of processes, with formulations and case studies of
implementation in decision support software.
Secondly, we present new methods of incorporating marine population connectivity into
systematic conservation planning. We develop a framework of incorporating the spatial,
temporal and species-specific variability of connectivity and present the newly developed
capability of the decision support system MARXAN to incorporate connectivity, and
demonstrate the improvement of potential reserve networks with connectivity above
reserve systems without for a Great Barrier Reef case study.
Oral Mini-Symposium 14: Reef Connectivity
14-4
Tropical-Temperate Connectivity Of Expatriated Fishes: Backtracking Dispersal Along
The East Coast Of Australia
Will FIGUEIRA* 1
1 Department of Environmental Sciences, Univeristy of Technology, Sydney, Broadway,
Australia
Juvenile coral reef fishes from the families Pomacentridae (Damselfish) and Chaetodontidae
(Butterflyfish) are commonly found along the east coast of Australia as far south as the New
South Wales - Victorian border (37°S) during the austral summer months, though they typically
fail to survive the ensuing winter. Previous work has highlighted the role of the East Australian
Current in the transport of the larvae of these species and indicated the possibility that while
some of the Pomacentrid species may be sourced from year-round populations located well
south of the Great Barrier Reef (GBR), the Chaetodontids more likely originate from the
southern end of the GBR. In order to evaluate these hypotheses, potential larval pathways of
collected individuals were back-calculated using an individually-based larval dispersal model.
Dispersion was behaviourally influenced by larval swimming and orienting (contingent upon
larval age) and forced in an advective-diffusive manner using modeled flow data from the
Bluelink Ocean Forcasting System. Using estimated planktonic larval durations and date of
settlement (from otolith analysis) of fish collected at sites all along the south coast from 2003 to
the present, a mean dispersal pathway (MDP) and point of origin probability distribution (OPD)
was estimated from 100 repeated simulations. MDPs and OPDs were compared between
species and among species across sites and years to look for consistent patterns. The
importance of larval behaviour parameters was also assessed. Variability in the structure of the
EAC led to a large degree of complexity in the estimated dispersal patterns. There is general
support for the supply of some of the Pomacentrid species from temperate sites but patterns for
the Chaetodontids were less clear.
14-5
A numerical study on larval dispersal in the Southeast Asia and West Pacific (SEA-WP)
regions using a new Indo-Pacific Ocean Circulation Model
Aditya R. KARTADIKARIA* 1 , Kazuo NADAOKA 1 , Yasumasa MIYAZAWA 2 , Nina
YASUDA 1
1 Mechanical and Environmental Informatics, Tokyo Institute of Technology, Tokyo, Japan,
2 Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and
Technology, Yokohama, Japan
The South East Asia and West Pacific (SEA-WP) region is a significant reservoir of the world’s
richest marine biodiversity. However, coral reef communities of this region are now severely
threatened by numerous environmental factors. It is therefore of vital importance to reveal the
reef-connectivity to effectively conserve and manage this region. Recent molecular ecological
studies on genetic variations have shown that the gene flow patterns in this area are associated
with a number of factors but are found mostly in discordance with the present overall
schematics of the surface ocean current, although the knowledge on the ocean currents in this
region is still limited. To provide more detailed and reliable information on the ocean currents
in SEA-WP region and thereby to examine associated larval dispersal processes in the
complicated topographic area having numerous islands, we have been developing a numerical
simulation model based on a new Indo-Pacific Ocean Circulation model. In addition to the
complicated topographic effect, the SEA-WP region may be influenced by atmospheric
disturbances including monsoon and typhoon and the various through-flows across straits and
passages with the Pacific and Indian Oceans. For properly simulating ocean currents in the
SEA-WP region under these effects, the Indo-Pacific Ocean Circulation model is coupled with a
regional atmospheric model. The model simulation results elucidate detailed characteristics of
Indonesian Through Flow (ITF) and other through-flows at Luzon strait and North Australia-
Pacific passage and their effects on larval dispersal processes.
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