Aquatic Environment and Biodiversity Annual Review 2012

AEBAR 2012: Marine Biodiversity
acidity), which may physically dissolve CaCO3 shells and/or skeletons and affect the
shell/skeleton generation, as well as influencing many other physiological processes. Flow on
effects to the viability of populations and the economic benefit that can be derived from
commercially important species are likely. There is very little information on how key NZ
calcifying species will respond to this change.
This project is using laboratory experiments to quantify responses of key New Zealand mollusc
species (paua, Haliotus iris, cockles, Austrovenus stutchburyi, and oysters Tiostrea chiliensis) to
levels of ocean CO2 saturation predicted to occur in NZ waters over the following decades.
Results will be combined with information on the role of these key species in influencing
ecosystem structure and function, to assess local and ecosystem-scale implications of acidification
of NZ coastal waters expected in the following decades.
ZBD2010-41. Potential effects of ocean acidification on habitat forming deep-sea corals in the New
Zealand region.
Specific Objectives of this research were to 1. Determine the carbonate mineralogy of selected
deep-sea corals found in the New Zealand region, 2. Assess the distribution of deep-sea coral
species in the region relative to improved knowledge of current and predicted aragonite (ASH)
and calcite saturation horizons (CSH), and 3. Assess potential locations vulnerable to deepwater
upwelling and areas of key deep-water fishery habitat. Through a literature search and analysis,
the project aimed to determine the most appropriate tools to age corals and measure the effects of
ocean acidification on deep-sea habitat-forming corals, and recommend the best approach for
future assessments of the direct effects of declining ocean pH on these key fauna.
Under Objective 1, new results of investigations into the carbonate mineralogy of selected deepsea
corals found in the New Zealand region were presented, and previous work on coral
mineralogy summarised. The mineralogy and trace element concentration (Sr and Mg) of the five
branching stony coral species (Order: Scleractinia) Goniocorella dumosa, Solenosmilia
variabilis, Enallopsammia rostrata, Madrepora oculata, and the endemic Oculina virgosa, and
for the key habitat forming gorgonian coral species (Order: Alcyonacea) Keratoisis spp.,
Lepidisis spp., Paragorgia spp. and Primnoa sp., was ascertained. Stony branching corals are all
aragonitic with high Sr and low Mg while most of the gorgonian corals are made of high Mg and
low Sr, with high Mg calcite (>8 mol% Mg). The gorgonian sea fan, Primnoa sp., is aragonitic.
Under Specific Objective 2, up to date position and depth data were used to produce distribution
maps for the study species. Data compare well with previous publications from biodiversity
research, research trawl, and observer sampling effort on wide regional distribution, but
individual species display variations within the region. The peak depth distributions are unimodal
at about 800-1000 m for most of the above species, but G. dumoas, E. rostrata, and Lepidisis
spp. show bi-modal distributions and O. virgosa occurs primarily in shallow depths. In the
second year of the project these distribution data will be compared with existing and predicted
aragonite and calcite saturation horizons, particularly in areas of key deepwater fishery habitat.
Also under Specific Objective 2, on-going opportunistic water sampling analyses are being
carried out to determine alkalinity and dissolved inorganic carbon (DIC), and modelling to
determine aragonite (ASH) and calcite saturation horizon (CSH) data is in progress. The aim is to
compare water carbonate chemistry with regional biogeochemistry models and future scenarios
to identify areas potentially at risk from ocean acidification.
Under Specific Objective 3, at-sea sampling of live corals for aquarium studies has been carried
out to investigate the feasibility of keeping the corals alive for growth and ocean acidification
experiments. The corals collected in April, 2012 are still alive in the laboratory and include one
small colony of S. variabilis. A literature search and analysis to determine the most appropriate
tools to age and measure the effects of ocean acidification on deep-sea habitat-forming corals is
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