Danielle Simmons Prize
Antipatharians | Taxonomy | Phylogenetics
Happening Here in Heron:
Checklist of black coral species, descriptions of undescribed species, and conservation of biodiversity. Oh my!
By Jeremy Horowitz
James Cook University
B
lack corals have been on Earth for over 400 million years and they provide food and shelter for a wide range of fish and invertebrates. Like many coral groups, black coral populations are threatened, particularly in areas where they are harvested for the jewellery industry. However, little is known about the distributions of black coral species, which is required to conserve black coral populations.
Focusing mainly on the Great Barrier Reef (GBR) and Coral Sea, I collected and identified black coral species to update their ranges. I found that black coral diversity varied between reefs, but it was not clear what drives these variations. Next, I wanted to understand what enables or restricts black corals from occurring on a given reef. Answering this knowledge gap can help to build a model that predicts where different black coral species occur.
I was awarded the Australian Coral Reef Society Danielle Simmons award to describe black coral
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REEF IN REVIEW
assemblages around Heron Island, an area where very few black coral species had been recorded. Teaming up with Project Phoenix, I documented and collected black corals on diverse habitats and compared the collection locations and coral morphologies to various abiotic features to understand what limits black corals from flourishing in the region.
I spent one week diving around Heron Island, which confirmed that black corals were rare compared to other parts of the GBR. Specimens collected were identified species based on morphological characteristics, including the colonies overall shape and size, polyp (feeding mouth) and tentacle shapes and sizes, and skeletal spine characteristics, which are small (<1 mm in height) features found all along the skeleton and can differ in shape and size between closely related species. A scanning electron microscope was needed to view the spine characteristics. I also identified the abiotic characteristics at each collection site including depth, habitat type, and current
strength. I compared the data from Heron to equivalent data collected from previous trips to other sites on the GBR to determine which abiotic characteristics are common where black coral diversities are high or low.
“Black coral diversity is low in Heron Island because it is a high energy environment, and generally, wave action can predict black coral biodiversity in shallow-water environments.” Branched and unbranched species were found on the protected (leeward) side of the island, only unbranched species were found in habitats with moderate protection from the open ocean and no black
