11th ICRS Abstract book - Nova Southeastern University

22.837
Trajectories Of Ecosystem Change in An Extremely Degraded Reef in The
Philippines
Rollan GERONIMO* 1 , Porfirio ALIÑO 1 , Fernando CASTRENCE, JR. 1 , Andre Jon
UYCHIAOCO 2
1 Marine Science Institute, University of the Philippines, Quezon City, Philippines,
2 Partnerships in Environmental Management for the Seas of East Asia, Quezon City,
Philippines
The Bolinao-Anda reef complex in the Philippines has been in various states of
degradation and overfishing since the first systematic surveys were conducted in the
1980s. It has been subjected to a wide range of stresses for three decades. The massive
bleaching in 1998 reduced live coral cover from 45% to 17% in three sites surveyed a
year before and after the event. While the reef has yet to recover completely from this
disturbance, it was again recently hit by bleaching.
Given the overexploited state of the reef fish communities in the Bolinao-Anda reef
complex and other degrading influences, are the reef fishes of the system recovering or
changing? Fisher population growth, continued overfishing and other stressors continue
to affect the reef. On the other hand the establishment of Marine Protected Areas and
other management interventions have also been initiated.
Coral reef benthic and fish data obtained from 1995 to 2006 were analyzed to determine
the changes in reef community structure throughout this time. Results show no change in
fish biomass from 1995 to 2002 but increased from 2003 to 2006 while fish densities
fluctuated throughout this time. Changes in fish community composition were also
evident with lower trophic levels such as herbivores and zoobenthivores increasing in
total biomass in the last four years. These trends possibly indicate that reef fishes are
growing to larger sizes than before and may be a partial indication of the positive impacts
of protection.Other larger-scale natural processes can also have masked the direct effects
of management given that unprotected sites are also showing the same increasing trend in
fish biomass.
22.838
Do Mangroves and Seagrass Beds Enhance Growth of Juvenile Coral Reef Fish?
Monique GROL* 1 , Martijn DORENBOSCH 1 , Eva KOKKELMANS 1 , Ivan
NAGELKERKEN 1
1 Animal Ecology and Ecofysiology, Radboud University Nijmegen, Nijmegen,
Netherlands
Mangroves and seagrass beds have long been considered important nursery grounds for
various species of juvenile reef fishes due to their higher abundances in these habitats
compared to coral reefs. It is assumed that these putative nurseries provide juveniles with
more shelter, higher food availability, and higher growth and survival rates than on the
reef. However, this nursery function is still ambiguous, and experimental field studies
testing this hypothesis in these tropical habitats are missing. In this study, growth rate of
juvenile Haemulon flavolineatum and the availability of its preferred food were
determined in seagrass, mangrove and coral reef habitats. It was hypothesized that
somatic growth rates as well as the amount of preferred food are higher within these
putative nurseries than on the reef (according to the nursery hypothesis). Growth of small
juveniles (3.5 – 4.2 cm FL) was studied at two Caribbean islands using in situ
experimental growth cages. Gut content analysis of the caged fishes showed that
Copepoda were by far the most consumed food items by juveniles in all three habitats.
Copepoda in the plankton samples were more abundant on the reef than in the
mangrove/seagrass habitats. Growth rates of fishes showed the same pattern: higher
growth rates in length and weight, and a higher weight-length ratio on the reef compared
to the mangrove/seagrass habitats. Based on these observations it appears that the coral
reef would be a more suitable habitat for small juveniles, when not taking other factors
such as predation risk into account. Nevertheless, highest juvenile fish abundances are
found in mangrove/seagrass nurseries where predation risk, but also growth rate, is lower.
Therefore, it appears that a trade-off exists between food abundance/growth rate and
predation pressure/mortality risk, where fish select habitats that minimise the ratio of
mortality risk to growth rate.
Poster Mini-Symposium 22: Coral Reef Associated Fisheries
22.839
Management Options To Be Adopted By Artisanal Fishers in Colombian Caribbean
William ZUBIRIA-RENGIFO* 1 , Roberto RIVERA 2 , Isabel Cristina CHACON-GOMEZ 1
1 Universidad Nacional de Costa Rica, Puntarenas, Costa Rica, 2 Ed. Bahia Centro, Corporacion
Colombia Internacional, Santa Marta, Colombia
Along Colombian Caribbean, one of the fishing gear that is mostly used is called “chinchorro”.
It is a conical shaped net. The holes in that net are very small. Therefore, it generates a big
damage on the ecosystems. When they separate what was captured, most of the animals are
dead. About 35 % of what is captured with this net is composed by juveniles of fish and other
organisms that are not commercially attractive. The low selectivity of this net, added to the
great effort becomes a big suffering for the different species and it is not regulated by
authorities. The reason why most fishermen use it is because it is cheap, it captures a lot of fish
and it does not need a big boat to be maneuvered. Besides, when it breaks for any reason
(mainly coral damage), it is easy and cheap to repair. Based on observations during the artisanal
fishery monitoring at the Colombian Caribbean during a project developed by International
Colombian Corporation and the Colombian Institute for rural development, it was possible to
establish some interesting conclusions about the problems occurring there. It is definitely
needed to generate some alternatives that give fishermen the possibility to work without
affecting the ecosystems so much. The easiest solution to propose is to increase the size of the
hole, as a strategy that diminishes the capture of small fish and not target species. This would
have to be regulated and monitored for a long time until fishermen change all their gears. One
of the possibilities is to motivate them to change the gear by giving them some help by
organizing their commercial activity or giving them some financial support as a reward.
22.840
Assessing The Socio-Economic Impact Of Export Trade In Coral Reef Resources On
Fijian Society
Louise TEH* 1 , Lydia TEH 1 , Benjamin STARKHOUSE 1 , Ussif Rashid SUMAILA 1
1 Fisheries Centre, University of British Columbia, Vancouver, BC, Canada
Rising demand for coral reef resources worldwide has spurned an active international trade in
reef fish, invertebrates, and corals that are sourced primarily from tropical developing nations.
Although these trades tend to be lucrative, it is unclear what economic benefit flows to the
exporting country. Our purpose is to use Fiji as a case study to investigate this question. We test
the hypothesis that trade in coral reef resources provides net economic benefits to Fijian society.
We assess Fijian coastal communities’ economic dependence on coral reef trade and analyse the
coral reef resource supply chain to determine the allocation of benefits among agents in each
step of the trade. Coastal communities’ reliance on coral reef trade is examined under the
context of a livelihood approach. The economic analysis will be based on data collected from
trade statistics and from key informant interviews which will be conducted in early 2008. Our
research will provide a basis for reef resource managers to assess the socio-economic costs and
trade-offs associated with reef management policies (e.g., Marine Protected Areas) and changes
to market demand for coral reef resources.
474