Fish and benthic community surveys in the Coringa-Herald National Nature Reserve (Coral Sea)

Brief description

Fish, benthic and bêche-de-mer surveys were conducted in the Coringa-Herald National Nature Reserve (CHNNR) from the 28 March to 2 April 2003. Five of the six islets and cays in the Reserve were surveyed. These were NE and SW Herald, Coringa (also known as South West Islet), Chilcott and SE Magdelaine. Restrictions were placed on diving, due to the remote location of the Reserve and surveys were limited to depths of around 9 metres. Four sites were sampled on each reef and sites were distributed so as to include the major habitats, reef fronts, back reefs and reef flanks. Species level data and crude abundance estimates of the benthic communities were obtained using a rapid visual assessment protocol (RAP). Video transect surveys were used to obtain more rigorous abundance estimates of biota at a finer taxonomic resolution.Species composition data and crude abundance estimates of the fish communities were obtained using a timed swim, rapid visual census method. Visual census transects provided more rigorous density estimates of a select group of species and a solid baseline for future monitoring surveys.Thirteen species of Holothuria (bêche-de-mer), crown of thorns starfish (COTS) and giant clams (Tridacna gigas) were surveyed on the reef flat and back reef of each reef. Reef flats were surveyed on snorkel, along transects. The back reef was surveyed using manta tow.SCUBA searches, along transects, were used to provide information on numbers of COTS in defined size classes, COT scars, Drupella (a coral eating snail) and other sources of coral mortality including coral bleaching and coral disease. Two temperature loggers were also deployed in the NE Herald Cay lagoon. This research was undertaken as part of a monitoring program, which will be used to determine the effectiveness of management practices within the National Nature Reserve. Where possible, comparisons were to be made with the two previous fish and coral surveys conducted in the Reserve. The Coringa-Herald National Nature Reserve (CHNNR) is one of two protected areas in the Coral Sea region. The Reserve is located some 400 kilometres east of Cairns, Far North Queensland. It was proclaimed on the 16th August 1982 under the National Parks and Wildlife Conservation Act 1975. The Coringa-Herald National Nature Reserve and Lihou Reef National Nature Reserve Management Plan states that both reserves are to be managed as strict nature reserves - World Conservation Union (IUCN) category Ia. Such reserves are primarily for scientific research to ensure habitats, ecosystems, and native species are preserved in as undisturbed state as possible. The reserves also form part of the National Representative System of Marine Protected Areas (NRSMPA).

Lineage

Maintenance and Update Frequency: notPlanned

Statement: Statement: The following is a list of references for the survey protocols used in this project:1. Benthic Rapid Assessment Protocol (RAP):DeVantier LM, De'ath G, Done TJ, Turak E (1998) Ecological assessment of a complex natural system: A case study from the Great Barrier Reef. Ecological Applications 8: 480-496.2. Video Transect Surveys:Page C, Coleman G, Ninio R, Osborne K (2001) Surveys of benthic reef communities using underwater video. Long-term Monitoring of the Great Barrier Reef, Standard Operational Procedure No. 2, Australian Institute of Marine Science, Townsville.Osborne K, Oxley WG (1997) Sampling benthic communities using video transects. pp 363-376. In: English S, Wilkinson C, Baker V (eds) Survey manual for tropical marine resources. 2nd Ed. Australian Institute of Marine Science.3. Fish Rapid Visual Census Method:The rapid visual census method used was a timed swim count modified from that described in "Williams DMcB (1982) Patterns in the distribution of fish communities across the central Great Barrier Reef. Coral Reefs 1: 33-43."4. Fish Visual Census Transects:Halford A, Thompson AA (1994) Visual Census Surveys of Reef Fish. Standard Operational Procedure 3. AIMS Townsville.English S, Wilkinson C, Baker V (eds) (1997) Survey Manual for Tropical Marine Resources. 2nd edition. Australian Institute of Marine Science, Townsville. 402pp.5. Manta TowsBass DK, Miller IR (1996) Crown-of-thorns starfish and coral surveys using the manta tow and scuba search techniques. Long-term Monitoring of the Great Barrier Reef, Standard Operational Procedure No. 1, Australian Institute of Marine Science, Townsville. 38pp.Other Survey Methods:Snorkel swims were used to survey shallow water reef flats. These reef flats were only accessible by small boats when the tide height was at least 1.5m above Lowest Astronomical Tide (LAT). Therefore, around the morning high tide, each observer censused a 500m by 5m belt transect, covering 2500 m2 of substrate. The four observers swam side-by-side, from just behind the surf zone, towards the back of the reef (with the prevailing waves) approximately 10m apart. Observers recorded numbers of clams, COTS, and bêche-de-mer. The transect length was determined by marking a waypoint on entry and then having the tender proceed 500m from this waypoint (judged by the GPS distance from the original waypoint), drop a buoy and standby. The snorkellers were able to observe the tender and swim towards it. Water depths ranged from 1-5m. The latitude and longitude of the start and end point of each transect were recorded (using a GPS) to assist in future surveys of the same area.SCUBA searches provided a more detailed picture of the causes and relative scale of coral mortality than was possible with either the manta tow or video techniques. A 2m belt (1m either side of the central tape measure) was visually searched along each 50m transect and data recorded for the following categories:Crown of thorns starfish - Total count in 3 size classesCrown of thorns starfish scars - Total countDrupella spp - Total countDrupella scars - Total countWhite syndrome disease scars - Total countBlackband disease scars - Total countUnknown scars -Total countCoral bleaching- Estimate of bleaching as a percentage of live coral cover on the transect.

Notes

Credit
Sweatman, Hugh PA, Dr (Custodian)