Reef Research: Volume 8 No. 3-4 September-December 1998
What's out there?
Kim Davis
In this issue of What's Out There? we take a look at some of the monitoring projects that the Research and Monitoring Coordination Unit is currently involved with.

Hardy Reef - Monitoring of the impact of
the relocation of the Fantasea Cruises pontoon

Status: Project completed
Consultants: Sea Research
T
he Great Barrier Reef Marine Park Authority is responsible for ensuring that pontoon operations in the Great Barrier Reef Marine Park do not cause significant environmental impacts on the Marine Park and its users. All pontoon operations within the Marine Park require a permit and the permittee must fund and maintain an environmental monitoring program for the pontoon. This program is undertaken by a consultant who is nominated by the permittee but who enters into a contract with the Authority.

In December 1995, the Authority granted Fantasea Cruises permission to relocate their pontoon, Reefworld I, about a kilometre south of its original position at Hardy Reef. Hardy Reef is situated in the Whitsunday Group. A monitoring program was initiated to establish the effect of the relocation and the ongoing operations of the pontoon on the reef community; specifically on the percentage cover of encrusting organisms and the extent of damage caused to coral colonies.

Results of this project indicate that in the reef-flat habitat, tourist snorkelling activities apparently had no measurable effect on the coral community. Even though coral cover decreased slightly during this study at both the impact and control sites, the consultants attribute this decrease to some unknown perturbation which occurred during 1995 and to cyclone Justin which occurred during March 1997.

The effect of inexperienced resorts divers on the coral community was also investigated. An increase in coral damage levels was recorded along the dive trail immediately after the pontoon was relocated. However, after 15 months of the pontoon operating, coral cover and damage levels were recorded at similar levels along the dive trail and in the control sites. This suggests that use of the dive trail was having a minimal impact on the reef communities.

Biological monitoring at the Quicksilver Connections
visitor pontoon, Agincourt Reef No. 3, 1994-96

Status: Project completed
Consultants: Marine Environmental Monitoring
I
n July 1994 the Authority contracted Marine Environmental Monitoring to monitor fish and coral assemblages at the Quicksilver Connections visitor pontoon at Agincourt Reef No. 3. Agincourt Reef No. 3 is a 2-kilometre long outer-shelf reef located approximately 40 kilometres east of Cape Tribulation. Marine Environmental Monitoring was asked to meet a number of monitoring requirements for this project including:
photo: Tourist Pontoon
An environmental monitoring program is required for pontoon operations in the Great Barrier Reef Marine Park
  • documenting the loss of coral cover on the four main bommies beneath the pontoon;
  • determining if resort divers were damaging prominent corals, through physical contact, and quantifying the amount of damage;
  • documenting changes in the aggregation of large mobile predatory fishes; and
  • quantifying changes in small benthic fish resulting from the pontoon operation.
Results show that there were reductions in coral cover on the bommies that were surveyed both under and beside the pontoon which may be attributed to shading effects. However, it should be noted that bommies made up less than 10 per cent of the area directly below the pontoon and the coral mortality in these areas was anticipated during the environmental impact assessment which was carried out by marine park management staff. Marine Environmental Monitoring also found small increases in the average number of new breaks, and a decrease in mean height, for individual staghorn colonies in two of the high diver-use areas and in one of the medium diver-use areas. Increases in the number and variety of fish under the pontoon were observed during the initial site surveys and mooring installation but this levelled out during the first year of tourist operation.

A visual survey of demersal biota in
the Cairns Section of the Great Barrier Reef Marine Park

Status: Project due to be completed in 1998
Consultants: B. Mapstone, H. Choat & A. Ayling
I
n 1991, the Authority implemented a new zoning plan for the Cairns Section of the Great Barrier Reef Marine Park. A research project was developed to examine the effects of the previous zoning strategies for this section as well as to prepare a baseline for future examination of the effects of the new zoning plan. The aim of the project was to survey selected organisms on reefs in the Cairns Section prior to commencement of the new zoning plan.

Fifty reefs were surveyed, including reefs that had a history of closure to fishing, reefs that had always been open to most uses, and reefs that were to have their zoning status changed under the new zoning plan. Counts of the following organisms were taken: coral trout, chaetodontids, acanthurids, lethrinid and lutjanid species, crown-of-thorns starfish, blue starfish, clams, pomacentrids and total live soft and hard corals.

The consultants have found that there were no definite patterns in the abundances of organisms related to either zoning or notional tourist use. For many of the taxa surveyed, there was no effect of either past zoning or tourist use. For other taxa, the zoning-related patterns frequently depended on either where across the continental shelf the consultants were, on the habitat considered, or on the notional history of consistent tourist use. Patterns in abundances which related to the frequency of tourist use also varied with habitat, zoning status or shelf position.

Generally, the consultants concluded that the potential to infer effects of management strategies from simple one-off 'before and after' estimates of abundance or community structure is poor. They stated that greater attention needs to be paid to the assessment and monitoring of management strategies.

Magnetic Quays monitoring
program benthic transects: a re-survey

Status: Completed
Consultants: Sea Research
A
benthic monitoring program was initiated in December 1988 to determine the effects of dredging and other construction activities from the Magnetic Quays Development on the fringing reefs of Nelly Bay, Magnetic Island (off Townsville, Queensland). A number of permanent transects were set up and surveyed as part of this reef monitoring program. However, these were not surveyed again, excluding some sites that were surveyed in 1993, and the Authority became concerned that the transects would not be able to be relocated in the future if they were not maintained.

In 1997 Sea Research was contracted to re-survey and re-mark all of the transects that were located on the reef slope using both line intersect techniques and video techniques.

A comparison of the line intersect technique and the video technique showed that generally, the video technique overestimated the cover of Sargassum algae and turf algae. Similarly, the video technique underestimated the cover of sponges, hard corals, faviid and fungiid corals. The underestimates were generally thought to be due to the corals being covered by Sargassum fronds.

The researchers also found that coral cover had increased markedly in all sites in the 4.5 years since the last survey of the area. This was primarily due to increases in the cover of the fast growing Acropora and Montipora species, along with Turbinaria species in Nelly Bay.

The Cod Hole: long-term monitoring of human usage,
fish populations and injuries to fish and the environment

Status: Report due to be completed in 1998
Consultants: L. Vail & A. Hoggett
T
he Cod Hole is an internationally renowned dive site in the Cairns Section of the Great Barrier Reef Marine Park. The main attraction of this area is the numerous large potato cod which allow divers to approach them. Through an industry volunteer monitoring program conducted by the staff of Volare, data on
photo: Cod Hole
Large potato cod draw many visitors to the Cod Hole each year
visitor/diver numbers and the number of potato cod at the Cod Hole have been collected since April 1992. The aim of this monitoring program is to monitor the number of potato cod and also to record diver visitation rates, injuries to cod and other large animals. In May 1997, the Authority contracted Lizard Island Research Station to collate, analyse and write up the data for the period April 1992 - April 1997.

In October 1995, the Cod Hole was granted further protection when, in addition to its National Park zone status, it was designated a Special Management Area. Following this designation anchoring was prohibited in the area and boats visiting the area had to use one of the four moorings installed there.

Human usage of the Cod Hole peaked in 1993-94 and since that time usage has dropped only slightly. Despite increased protection of the area the contractors report that the number of potato cod at the Cod Hole has declined significantly. The average number of potato cod seen per dive has almost halved since 1992. On average, 11.9 cod were seen per dive in 1992-93. In the last three years of the survey 6.5 and 7.3 cod were counted, on average, per dive. The cause of this decline is unknown. Virtually nothing is known about the demography of the population at the Cod Hole, the home range of individuals and very little is known about the life history of the potato cod. The consultants do, however, report that recruitment of small potato cod into the Cod Hole population appears to have occurred during the last three years of their survey.

The consultants also report that injuries were noted to potato cod and other large fish at the Cod Hole and a conflict between fish during feeds by divers was most probably responsible.

The decline in numbers of potato cod at the Cod Hole is somewhat of a concern for local industry groups and reef managers. However, the level of experience being offered to divers is probably still highly satisfactory to many and staff from the Lizard Island Research Station report that monitoring of numbers of potato cod will continue.


If you would like further information regarding any of the above projects please contact Ray Berkelmans or Kim Lally at the Authority on +61 7 4750 0700.


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Great Barrier Reef Marine Park Authority
PO Box 1379 TOWNSVILLE QLD 4810. Phone: (07) 4750 0700, Fax: (07) 4772 6093
E-mail: registry@gbrmpa.gov.au