Data from: Impacts of predator depletion by fishing on the biomass and diversity of non-target reef fish communities (Kadavu Islands, Fiji)

Data Records

The data in this sampling event resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 70 records.

2 extension data tables also exist. An extension record supplies extra information about a core record. The number of records in each extension data table is illustrated below.

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.

Versions

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How to cite

Researchers should cite this work as follows:

Jennings S, Polunin N (2024). Data from: Impacts of predator depletion by fishing on the biomass and diversity of non-target reef fish communities (Kadavu Islands, Fiji). Version 1.2. Southwestern Pacific Ocean Biogeographic Information System (OBIS) Node. Samplingevent dataset. https://nzobisipt.niwa.co.nz/resource?r=fiji_reef_fish_jennings_polunin_1997&v=1.2

Rights

Researchers should respect the following rights statement:

The publisher and rights holder of this work is Southwestern Pacific Ocean Biogeographic Information System (OBIS) Node. This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License.

GBIF Registration

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Keywords

Samplingevent; Observation

Contacts

Geographic Coverage

Kadavu Islands, Fiji

Sampling Methods

Quantitative estimates of the abundance and size of target-fishes in the ten qoliqoli were made using an underwater visual census (uvc) point count technique based on that developed by Samoilys and Carlos (1992). We selected a point count technique because net movements of target fishes along the reef front (frequently a response to the prevailing current) would not bias abundance estimates as they would if transect techniques were used (Watson et al. 1995). Validation of the uvc point count methodology, and the benefits and disadvantages of the technique, were discussed by Samoilys (1992), Samoilys and Carlos (1992) and Jennings and Polunin (1995c).

Method step description:

1. All members of the families Chaetodontidae (butterflyfishes), Labridae (wrasses), Lutjanidae (snappers), Mullidae (goatfishes), Scaridae (parrotfishes) and the sub-family Epinephelinae (groupers and coral trout) which could be reliably identified were selected for study. Lethrinidae (emperors) are of key importance in the fishery (Jennings and Polunin 1995a) but were not included because the census methodology is inappropriate for these species (Jennings and Polunin 1995c). Abundance estimates of the target species were made at seven replicate sites in each qoliqoli. The sites were selected by dividing all areas of reef front (well-developed reef front sloping directly to a depth of at least 10 m, openly exposed to the open ocean, with low siltation rates and estimated mean coral cover in excess of 25%: as confirmed by direct underwater observation) in each qoliqoli into 100 m sections (on aerial photographs from the Australian Aerial Mapping 1994 survey conducted on behalf of the Land and Survey Department, Government of Fiji) and randomly selecting seven of these sites. At each site, the abundance and size of target fishes > 8 cm fork length was estimated within 12 adjacent census areas of 7 m radius by counting each fish and making an estimate of its length to the nearest 1 cm. The 12 areas were censused in a random sequence and each census area was centered on the 6 m depth contour (on the reef slope). Boundaries of each census area were estimated from as far above or to one side of the census area as the prevailing visibility permitted and counts of the wariest fishes began immediately. Species in each census area were recorded sequentially, the most active species being recorded first. When a count for one species was complete, all further movements of that species in or out of the census area were disregarded. The time required to complete a count was not standardized since this was dependent on the number and diversity of fish in the census area and the complexity of habitat to be searched. In practice, counts took 6-13 minutes. Following the count, the diameter of the census area was measured twice (once parallel with, and once perpendicular to, the reef slope) to determine the accuracy with which the dimensions of the census area had been estimated. In addition, the depth at the center of the census area was recorded to confirm that the area was centered on the 6 m depth contour. All counts were conducted by the same observer (SJ), during daylight hours, from September 1995 to January 1996.
2. Accuracy of fish length estimation was maintained by practicing with objects of known length at intervals throughout the study period (57 lengths of plastic 2.0 cm diameter white plastic tube cut to lengths from 8 to 65 cm in 1 cm increments and threaded onto a 1.0 cm diameter rope in a haphazard sequence) and assessed using methods based on Polunin and Roberts (1993).

Bibliographic Citations

1. Jennings, S. and Polunin, N.V.C., 1997. Impacts of predator depletion by fishing on the biomass and diversity of non-target reef fish communities. Coral reefs, 16, pp.71-82.

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