Mer Island Reef

Surveyed 25-Feb-2013 as part of the NERP-TE Project 2.3

Mer Reef back
Mer Reef first flank
Mer Reef front
Mer Reef second flank

Mer Island Reef was surveyed for the first time using manta tow in 2013. Median reef-wide live coral cover was moderate (20-30%) and small numbers of crown-of-thorns starfish were recorded below outbreak levels. Signs of coral bleaching were restricted to small numbers of individual colonies scattered around the reef perimeter during surveys in 2013. Signs of white syndrome disease were observed on small numbers of individual scattered coral colonies on the first flank and front of the reef. White syndrome was common on the back reef where it affected more than ten colonies per two minute manta tow. No signs of black band disease were observed. Mer Island Reef was classified as No Outbreak.

Structural heterogeneity of the reef was higher than other reefs sampled in the Torres Strait region. There was a distinct reef crest and greater diversity of reef slope habitats around the island. Estimates of coral cover on the reef crest from Reef Health and Impact Surveys (RHIS) were variable both within and between sites. Hard coral ranged from 2-48% and soft coral from less than !% to 55%. Photo transects were sampled from the reef crest, the reef slope and the lower reef slope at Mer Island Reef. The reef crest and reef slope habitats had similar hard coral cover (41% and 44% respectively) while the lower reef slope had 25% cover. The composition of the hard coral assemblages differed between the three habitats. Acroporidae (23%) was the dominant hard coral family on the reef crest site followed by Pocilloporidae (8%), Faviidae (6%) and Poritidae (4%). On the reef slope Acroporidae and Poritidae were equally abundant at 18% while Pocilloporidae had 4%. On the lower reef slope Acroporidae was the most dominant family with 10% cover, followed by Pocilloporidae (6%), a mixture of families (6%), Poritidae (2%) and Faviidae (1%). Soft coral cover, predominantly composed of Alcyoniidae, increased with depth from 2% on the reef crest to 20% on the lower slope and was variable between sites. The algae community was high (41- 56% cover), fairly consistent between habitats and was composed of turfing algae (31%) and coralline algae (13%).

Manta Tow:

Fish and Benthos Surveys:
RHIS surveys:

Mer Reef Perimeter Hard Coral Crown-of-thorns starfish graph

 
Mer Reef Crest Benthic Group Graph
Mer Reef Crest Hard Coral Families Graph
 
Mer Reef Slope Benthic Group Graph
Mer Reef Slope Hard Coral Families Graph
 
Mer Reef Lower Slope Benthic Group Graph
Mer Reef Lower Slope Hard Coral Families Graph