ECO-EXPEDITIONS

The Mackay / Capricorn Section

The Mackay/Capricorn section of the Great Barrier Reef (GBR) extends from the Whitsunday Island group in the North (~20ºS), to the Capricorn-Bunker group of reefs at the very southern limit of the GBR (~24ºS). Like the Central section, it contains a vast number of platform and island fringing reefs, and remains relatively unexplored by recreational scuba divers. From an Eco-expeditions perspective, the Mackay / Capricorn section has similarities to the Far-northern section, in that it contains many high-quality reefs which are relatively difficult to access due to their distance from the nearest suitable port. This is not to suggest the Mackay / Capricorn section lacks facilities; in fact, Gladstone Harbour is one of the biggest and busiest ports in Queensland.

The problem is that in the southern part of the GBR, the continental shelf is extremely wide (for more information see the Overview of the Great Barrier Reef page). The innermost platform reefs commence 125km from shore, and the seaward edge of the Swains reefs is more than 300km out! Reef development on this massive shelf has been extensive, and in many places huge platform reefs have grown so large that they are now seperated from one another by tiny channels a few hundred metres wide. Along the shelf edge offshore from Mackay, these fused platform reefs form an almost continuous barrier which is known colloquially as "The Hard Line". The location of the reef matrix such a long way offshore ensures high water quality year-round. Furthermore the Mackay / Capricorn section has not been affected by recent Crown of Thorns starfish outbreaks, so coral cover is good and the reefs support a highly diverse and abundant marine fauna. For more information on Crown-of-thorns starfish and the current status of reefs in the outbreak zone, visit:

• The CRC Reef Research Center

• The Great Barrier Reef Marine Park Authority (GBRMPA)

• The Australian Institute of Marine Science

In common with many other parts of the GBR, it is safe to say that commercial scuba diving activities take place on very few of the reefs of the Mackay / Capricorn section, and hundreds (if not thousands) of great dive sites remain to be discovered. The major ports in this section that support reef access are found at The Whitsundays, Mackay, & Gladstone. This is compounded by the complex structure of the reef matrix - until the advent of GPS, it was too risky to take a vessel into many of the areas in the Mackay / Capricorn section.

The climate of the Mackay / Capricorn section is similar to that found in the central section. Alternating periods of moderate SE trade winds and calm spells during April-October, and lighter northerly winds during November-march. However, the Mackay / Capricorn section is so far south on the coast that it is affected only infrequently by the monsoon, so summer (Dec-feb) represents an ideal time to visit this area, as water and air temperatures are warm and sea conditions slight.

In terms of geomorphology, the Central section marks the point where the edge of the continental shelf begins to diverge away from the coast (for more information see the Overview of the Great Barrier Reef page). Here, the shallow part of the shelf suitable for reef development becomes relatively wide. For example, near Townsville, the first reefs are 75km from the coast, and the outermost reefs are 125km offshore. In general, large platform reefs (up to 20km long) are found closer to the coast, while smaller reefs (1-5km long) are found near the shelf edge in 60-100m of water. Water moves freely over the shelf in the Central section, and due to their distance from shore, most dive locations in this section have very good underwater visibility and abundant marine life.

In our opinion, the Central section offers some of the best opportunities for Eco-expeditions on the GBR. This is due to a combination of factors.

1. The platform reefs in the Central section are situated an ideal distance from the coast - far enough to be in very clear water, but close enough to be accessible by boat within a few hours.

2. There are countless numbers of high quality dive locations to choose from in this section, due to the large number of reefs. Many of these locations would have never been dived before. Also, the presence of many inshore island fringing reefs means it is possible to examine changes in reef community structure along the gradient of water quality that exists across the shelf.

3. A variety of charter vessel and accommodation options are available in Townsville and Airlie Beach. Both centers have large airports which receive daily flights from other domestic ports within Australia, and connecting flights from the international airport in Cairns.

4. At present, the reefs in the Central section have very high coral cover, and they have not yet been affected by the current Crown-of-Thorns starfish outbreak. This is in contrast to the Cairns section, where the majority of the reefs have suffered substantial declines in coral cover. For more information on Crown-of-thorns starfish and the current status of reefs in the outbreak zone, visit:

• The CRC Reef Research Center

• The Great Barrier Reef Marine Park Authority (GBRMPA)

• The Australian Institute of Marine Science

The weather in the Central section is more favourable for Eco-expeditions than that experienced in the sections further north. During the "dry" season from April to October, moderate SE trade winds (15-20 knots) alternate with periods of clear, calm weather. During the "wet" season from November to March, the Central section experiences lighter northerly winds, hot humid weather, and thunderstorms. Periods of torrential rain do occur during the wet season (usually in February), however this depends on the monsoon trough moving south from its usual position over Cape York Peninsula (and the Far-Northern and Cairns sections). In most years, the months at the beginning and end of the dry season (April/May, & October/November) usually have excellent weather, with light winds, clear skies, and daytime temperatures around 30ºC.

In summary

In our opinion, the Central section currently offers the best opportunities for Eco-expeditions on the GBR, because it facilitates relatively quick access to numerous high quality coral reefs. In comparison, the Far-Northern and Mackay Capricorn sections have slightly better reefs, but more difficult access due to the distance between the reef and and a suitable port. The Cairns section has very quick access, but overall the reef quality is lower due to the current Crown-of -Thorns starfish outbreak.

Click here to see information on the Ecological themes we examine on Tevene'i Marine Eco-expeditions.

Click here to read about our Eco-expeditions Philosophy.