11th ICRS Abstract book - Nova Southeastern University

18-41
Observer Variability And Deployment Effect With Reef Check Data In Australia:
Implications For Management
Jos HILL* 1 , Andrew HARVEY 1 , Laura FANTOZZI 2 , Craig SYMS 3
1 Reef Check Australia, Townsville, Australia, 2 James Cook University, Townsville,
Australia, 3 Marine Biology and Aquaculture, James Cook University, Townsville,
Australia
In Australia there is a role for community-based coral reef monitoring programs to
supplement government datasets. Reef Check Australia (RCA) volunteers have surveyed
48 sites in the GBR Marine Park since 2001. A well-documented limitation of
community-collected data is lack of precision due to the use of multiple observers who
have limited levels of training and experience in coral reef monitoring. A key question
for reef managers is how well do the data reflect real patterns, and is data resolution
sufficient to reveal important changes in reef status? The objective of this study was to
determine the level of precision of data collected by RCA participants in order to better
inform managers on how the data should be interpreted and where RCA can best valueadd
to other datasets on coral reef status and trends. We compared data from randomly
deployed transects that were surveyed by a sample of trained RCA volunteers. Precision
was high for hard corals, with only 6.7% of the random variation due to observer effects.
Precision was lower for less abundant substratum types including rubble and recently
killed coral. Differences in precision were due to a combination of the percent cover of
different substratum types, and the level of substratum categorisation. These results
suggest that RCA data can identify temporal trends in cover of important substrata such
as hard coral, and that between-observer variability can be minimised in volunteer divers.
This enables RCA to make informed recommendations to managers and other
stakeholders, with a clear confidence interval on the RCA results. We will discuss the
relevance of this study for a successful marriage between the general community and
coral reef managers in Australia.
18-42
Assessment Of Resilience in montastrea Faveolata Inside And Outside Of A Marine
Park
Erich MUELLER* 1
1 Perry Institute for Marine Science, Jupiter, FL
Wound healing was used as a proxy for assessing organismal resilience in the coral,
Montastrea faveolata. In addition, potential effects of wounding on quantum yield
determined by PAM fluorometry were examined. Cores (2.5 cm diameter) were extracted
from parent colonies cultured at least two years in an open seawater system at Lee
Stocking Island (Exumas, Bahamas). In a mesocosm experiment, surface lesions (~0.5
cm2 x 2 mm deep) were imaged daily over 15 days to develop healing curves. Quantum
yields were obtained daily using a PAM fluorometer (2 mm fiberoptic) at four locations 5
mm away from the lesion and 10 mm away. Results demonstrated that 50% healing
occurred in 5-6 days. To examine whether wound healing (i.e. resilience) differed in the
Exuma Cays Land and Sea Park from a control location near Lee Stocking, additional
cores were removed from parent colonies (N=6) and deployed to one of three field arrays
at each site. Lesions, images and PAM measurements were made on day 0 and again 5-7
days later. These procedures were repeated in the winter, spring and summer of 2007.
There were no seasonal differences in healing rates or between genotypes. No consistent
effects of site, time of year or wounding were seen on quantum yields of surrounding
tissue, however, newly formed tissues had significantly lower yields than measured in
undamaged tissues. Healing was significantly greater at the Park site in the winter of
2007 but there were no site differences in spring or summer. This Marine Management
Area Science (Conservation International) study has developed a simple and inexpensive
method to assess coral resilience. It will be further developed examining known stressors
and with colonies in situ to provide researchers and resource managers with a tool to
identify colonies and reef areas particularly susceptible to decline.
Oral Mini-Symposium 18: Reef Status and Trends
18-43
Occupancy Models For Estimating The Size Of Reef Fish Communities
M. Aaron MACNEIL* 1 , Timothy R. MCCLANAHAN 2
1 National Research Council, NOAA Panama City Laboratory, Panama City Beach, FL,
2 Wildlife Conservation Society, Bronx, NY
Reef fish surveys conducted using underwater visual census (UVC) have the potential to
introduce substantial downward bias in species richness estimates when cryptic, mobile, or rare
species are prevalent. In particular, heterogeneity in the detection of reef fish species can inflate
or distort trends in community composition through time, compromising the quality of data
collected and degrading our ability to link observations with processes. Using a suite of models
for repeated observations through time, we develop a framework for estimating the number and
composition of species in a reef fish community that can be readily applied to conventional
survey data. Estimation of community-level quantities are made from model-based estimates of
occurrence that incorporate imperfect detection of individual species. We suggest that
occupancy models should be routinely used in monitoring programs, particularly in threatened
or recovering areas.
18-44
Evaluating The Health Of The Mesoamerican Reef
Melanie MCFIELD* 1 , Nadia BOOD 2 , Ana FONSECA 3 , Alejandro ARRIVILLAGA 4 , Albert
FRANQUESA RINOS 5 , Rosa María LORETO VIRUEL 6
1 Smithsonian Institution, Belize City, Belize, 2 Worls Wildlife Fund, Belize City, Belize,
3 Universidad de Costa Rica, San Jose, Costa Rica, 4 The Nature Conservancy, Guatemala City,
Guatemala, 5 Amigos de Sian Kaan, Puerto Morelos, Mexico, 6 CONAP, Cancun, Mexico
Like most of the world’s reefs, the health of the Mesoamerican Reef (MAR) has declined in the
last decades. The1998 coral bleaching event and Hurricane Mitch caused widespread bleaching
and significant coral mortality, particularly in Belize. Large-scale bleaching affected most reefs
within the MAR in late 2005, although resulting coral mortality was lower than in previous
bleaching years. The active 2005 storm season damaged reefs, mainly in Mexico, but may have
also contributed to greater mixing of oceanic waters and prevented ‘doldrum conditions’
associated with more severe bleaching events. The bleaching and hurricanes in 2005 may have
further delayed potential recovery from the bleaching-related losses of 1995 and 1998, as coral
cover throughout the region remains moderately low (just over 10%), with little to no overall
recovery from the 1998 losses. The 2006 Rapid Reef Assessment sponsored by TNC and WWF
was the largest reef study ever conducted in the MAR and aimed to evaluate reef recovery from
these disturbances and provide a comprehensive, representative assessment of reef health
throughout the region. The results are also being used by a variety of partners for different
management and research purposes. These data are also being combined into an Integrated Reef
Health Index, as one component of a new ecosystem report card for the Mesoamerican Reef
being developed by the Healthy Mesoamerican Reef Ecosystem Initiative. The findings from
Belize are similar to the other countries: Only 3.7% of over 5000 colonies assessed showed any
signs of coral bleaching by summer 2006. Average disease infestation was also low (