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|data||files||public||Herbivore grazing rates in Viti Levu, Fiji from 2010-2012 (Killer Seaweeds project)||I M||background||BCO-DMO||bcodmo_dataset_674163|
|Row Type||Variable Name||Attribute Name||Data Type||Value|
|attribute||NC_GLOBAL||acquisition_description||String||The study was conducted from November 2010 through February 2011 and between
November 2011 and January 2012 on shallow (~1 m below the surface at low tide,
equal or shallower than 2 m at high tide), intertidal fringing reefs platforms
(up to 800-m wide) along the Coral Coast (18\u00ba\u00a013.05\u2019S,
177\u00ba\u00a042.97\u2019E) of Viti Levu, Fiji\u2019s main island. Many of
the owners of traditional fishing rights along the Coral Coast have
established small, customary no-take MPAs to improve and sustain their
adjacent fishing grounds. The MPAs in this region are delimited by surface
markings and enforced by local villagers, and they have been closed to all
fishing activities since their inception (about 10 years). The only exception
to this closure was a small experimental hook and line fishing research
project that was conducted in the MPAs of Votua and\u00a0Namada. In the
\u00a0non-MPAs, the main fishing targets are species of Acanthuridae
(Nasinae), Epinephelidae, Labridae, Mullidae, and Lutjanidae. Permission for
the research was granted by the Fijian Ministry of Education, National
Heritage, Culture & Arts, Youth & Sports, which is authorized to approve field
studies in Fijian waters. No animal collection or experimental procedures
involving animals were conducted during the study, and no endangered species
were recorded during our assessments.\u00a0
To assess the effects of MPAs on fish assemblages, fish feeding group
composition, herbivory rates, benthic cover, and coral recruit density, we
compared three spatially paired MPA and adjacent, fished, areas (non-MPAs)
associated with the villages of
Votua,\u00a0Vatu-o-lalai\u00a0and\u00a0Namada.\u00a0 Comparisons of fish
assemblages inside and outside of closures are widely used for determining the
effects of reserves, but it should be acknowledged that this approach does not
reveal the state of an MPA relative to an undisturbed baseline.\u00a0
The studied MPAs were established in 2002 (Vatu-o-lalai,\u00a0Namada) and 2003
(Votua), and shortly after establishment, coral cover was low (~7%),
and\u00a0macroalgal\u00a0cover was high (~35\u201345%) in both the MPAs and
\u00a0non-MPAs. All surveys and assays were conducted during the same season
(austral summer) to minimize seasonal variation in sampling. The reef extends
approx. 1 km from shore within each MPA and\u00a0non-MPA,\u00a0and all data
were collected between 30 and 700 m of the shore (i.e., shoreward of the reef
crest) parallel to the\u00a0shoreline.
Herbivory rates: Rates of grazing by parrotfishes and macroalgal browsing were
assessed across the six study sites using established techniques. The feeding
rates of parrotfishes were estimated within each of the six study sites from
December 2011\u2013January 2012 using remote stationary video cameras; this
method was selected as it has been shown to reduce observer effects on fish
behavior. Underwater cameras (GoPro) attached to a small lead weight were
randomly positioned next to areas covered by algal turfs within each study
site, and all feeding on the benthos was recorded for 2 hours. At the start of
each video, a length of chain was used to demarcate a 4-m2 area and
probablyvide a scale for estimating the length of any fishes in the video. The
chain was removed after one minute, and the cameras were left to record all
feeding activities in the absence of divers.\u00a0
To ensure similar sampling effort among sites, sampling was conducted over 18
days, always during high tide. In the first week, during which high tide
occurred in the morning, four cameras were distributed in the MPA and four in
the non-MPA of a given village, and over the following two days, the same
procedure was repeated for the remaining two villages. A few days later, when
high tide occurred during the middle of the day, the same procedure was
repeated and then repeated again for the afternoon period. This entire
sampling scheme was performed twice, so we recorded a total of eight videos
per study site per time period within each village. All videos were
subsequently viewed, and all parrotfishes observed feeding on the reef
substrata were identified to species, and their length estimated. Grazing
rates were then calculated as the product of species-specific bite rates and
bite areas, and expressed as the percentage of the 4m2 area grazed per day.
Species-specific bite areas were obtained from the literature, and where these
were not available the bite area of a closely related species with a similar
feeding type and body size was used.
Macroalgal browsing was assessed at each site using a series of macroalgal
assays during December 2011. Five common macroalgal species in the non-MPAs
(Hormophysa triquetra, Padina boryana, Sargassum polycystum, Sargassum sp.,
and Turbinaria ornata) were collected by hand, spun in a salad spinner for 20
revolutions to remove water and weighed . One thallus of each alga was
randomly selected and attached at equal intervals along a 60-cm length of
3-ply rope by inserting the holdfast between the strands. The order of the
algal species along the rope was randomized among replicates. Three replicate
assays (or ropes) were exposed to herbivores, and three assays were placed in
exclusion cages (60 x 20 x 20 cm, 1-cm square mesh) at each site and left on
the reef for 5 h. Assays within each site were separated by 20-50 m. After 5h
the assays were collected and each thallus was carefully removed from the
rope, spun and weighed, and the reduction in algal biomass was calculated.
|attribute||NC_GLOBAL||awards_0_funder_name||String||NSF Division of Ocean Sciences|
|attribute||NC_GLOBAL||awards_0_program_manager||String||David L. Garrison|
|attribute||NC_GLOBAL||awards_1_funder_name||String||National Institutes of Health|
Version 6 January 2017
|attribute||NC_GLOBAL||Conventions||String||COARDS, CF-1.6, ACDD-1.3|
|attribute||NC_GLOBAL||creator_email||String||info at bco-dmo.org|
|attribute||NC_GLOBAL||data_source||String||extract_data_as_tsv version 2.3 19 Dec 2019|
|attribute||NC_GLOBAL||keywords||String||bco, bco-dmo, biological, chemical, data, dataset, dmo, erddap, grazed, management, oceanography, office, preliminary, site, status|
|attribute||NC_GLOBAL||people_0_affiliation||String||Georgia Institute of Technology|
|attribute||NC_GLOBAL||people_1_affiliation||String||Woods Hole Oceanographic Institution|
|attribute||NC_GLOBAL||people_1_role||String||BCO-DMO Data Manager|
|attribute||NC_GLOBAL||projects_0_description||String||Extracted from the NSF award abstract:
Coral reefs are in dramatic global decline, with reefs commonly converting from species-rich and topographically-complex communities dominated by corals to species- poor and topographically-simplified communities dominated by seaweeds. These phase-shifts result in fundamental loss of ecosystem function. Despite debate about whether coral-to-algal transitions are commonly a primary cause, or simply a consequence, of coral mortality, rigorous field investigation of seaweed-coral competition has received limited attention. There is limited information on how the outcome of seaweed-coral competition varies among species or the relative importance of different competitive mechanisms in facilitating seaweed dominance. In an effort to address this topic, the PI will conduct field experiments in the tropical South Pacific (Fiji) to determine the effects of seaweeds on corals when in direct contact, which seaweeds are most damaging to corals, the role allelopathic lipids that are transferred via contact in producing these effects, the identity and surface concentrations of these metabolites, and the dynamic nature of seaweed metabolite production and coral response following contact. The herbivorous fishes most responsible for controlling allelopathic seaweeds will be identified, the roles of seaweed metabolites in allelopathy vs herbivore deterrence will be studied, and the potential for better managing and conserving critical reef herbivores so as to slow or reverse conversion of coral reef to seaweed meadows will be examined.
Preliminary results indicate that seaweeds may commonly damage corals via lipid- soluble allelochemicals. Such chemically-mediated interactions could kill or damage adult corals and produce the suppression of coral fecundity and recruitment noted by previous investigators and could precipitate positive feedback mechanisms making reef recovery increasingly unlikely as seaweed abundance increases. Chemically-mediated seaweed-coral competition may play a critical role in the degradation of present-day coral reefs. Increasing information on which seaweeds are most aggressive to corals and which herbivores best limit these seaweeds may prove useful in better managing reefs to facilitate resilience and possible recovery despite threats of global-scale stresses. Fiji is well positioned to rapidly use findings from this project for better management of reef resources because it has already erected >260 MPAs, Fijian villagers have already bought-in to the value of MPAs, and the Fiji Locally-Managed Marine Area (FLMMA) Network is well organized to get information to villagers in a culturally sensitive and useful manner.
The broader impacts of this project are far reaching. The project provides training opportunities for 2-2.5 Ph.D students and 1 undergraduate student each year in the interdisciplinary areas of marine ecology, marine conservation, and marine chemical ecology. Findings from this project will be immediately integrated into classes at Ga Tech and made available throughout Fiji via a foundation and web site that have already set-up to support marine conservation efforts in Fiji and marine education efforts both within Fiji and internationally. Business and community leaders from Atlanta (via Rotary International Service efforts) have been recruited to help organize and fund community service and outreach projects in Fiji -- several of which are likely to involve marine conservation and education based in part on these efforts there. Media outlets (National Geographic, NPR, Animal Planet, Audubon Magazine, etc.) and local Rotary clubs will be used to better disseminate these discoveries to the public.
PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
Rasher DB, Stout EP, Engel S, Kubanek J, and ME Hay. "Macroalgal terpenes function as allelopathic agents against reef corals", Proceedings of the National Academy of Sciences, v. 108, 2011, p. 17726.
Beattie AJ, ME Hay, B Magnusson, R de Nys, J Smeathers, JFV Vincent. "Ecology and bioprospecting," Austral Ecology, v.36, 2011, p. 341.
Rasher DB and ME Hay. "Seaweed allelopathy degrades the resilience and function of coral reefs," Communicative and Integrative Biology, v.3, 2010.
Hay ME, Rasher DB. "Corals in crisis," The Scientist, v.24, 2010, p. 42.
Hay ME and DB Rasher. "Coral reefs in crisis: reversing the biotic death spiral," Faculty 1000 Biology Reports 2010, v.2, 2010.
Rasher DB and ME Hay. "Chemically rich seaweeds poison corals when not controlled by herbivores", Proceedings of the National Academy of Sciences, v.107, 2010, p. 9683.
|attribute||NC_GLOBAL||projects_0_geolocation||String||Viti Levu, Fiji (18º13.049’S, 177º42.968’E)|
|attribute||NC_GLOBAL||projects_0_name||String||Killer Seaweeds: Allelopathy against Fijian Corals|
|attribute||NC_GLOBAL||publisher_name||String||Biological and Chemical Oceanographic Data Management Office (BCO-DMO)|
|attribute||NC_GLOBAL||standard_name_vocabulary||String||CF Standard Name Table v55|
|attribute||NC_GLOBAL||summary||String||Herbivore grazing rates in Viti Levu, Fiji from 2010-2012 (Killer Seaweeds project)|
|attribute||NC_GLOBAL||title||String||Herbivore grazing rates in Viti Levu, Fiji from 2010-2012 (Killer Seaweeds project)|
|attribute||status||description||String||Status of area where sampling was done; Marine Protected Area (MPA) or non-MPA (NON)|
|attribute||grazed||description||String||Grazing rates were then calculated as the product of species-specific bite rates and bite areas and expressed as the percentage of the 4m2 area grazed per day.|
The information in the table above is also available in other file formats (.csv, .htmlTable, .itx, .json, .jsonlCSV1, .jsonlCSV, .jsonlKVP, .mat, .nc, .nccsv, .tsv, .xhtml) via a RESTful web service.