AV俱乐部

Although water occupies 70% of the earth's surface, we know more about the moon and Mars than we do about the depths of our own oceans. This has become even more apparent with the recent discovery of deep-sea coral on the Scotian Margin. Despite inadvertently hauling up coral caught in fishing gear for the past two centuries, it was less than a decade ago that reductions in fishing quotas prompted a fisherman to bring a coral sample to scientists' attention.

Nine deep-sea coral specimens of the tree-like coral Primnoa resedaeformis from water depths between 300-500m in the Northeast Channel were analyzed to identify the associate foraminiferal assemblage. A total of 29 foraminiferal species have been found attached to the coral, two of which may be used to indicate coral distribution on the margin from sediment samples.

The presence of one of these indicator species, Discanomalina semipunctata in abundances of 5% or greater has been used along with Detrended Correspondance Analysis to identify past coral locations from 89 sediment samples. Thirty sites have been identified as having higher potential for present and past deep-sea coral occurrences. The discovery of these coral associated foraminifera provides a cost effective means and more accurate way of mapping both paleo-coral and coral distribution. The remnant foraminifera found in the sediment record provide a proxy for the paleo-coral distribution, thus providing a basis for sustainable conservation practices.

The high abundance of planktonic foraminifera attached to the coral specimens has many potential indications; a previously unknown life stage within a planktonic foraminifera's life cycle or evolutionary response to changing environmental parameters. This may also affect the accuracy of derived paleo-sea surface temperatures that unknowingly used these 'pseudo-planktonics' in their analyses.

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Supervisor: David Scott