A species of sea pen hitherto unknown to science was discovered early in 2013 by scientists working in remote Fiordland.
Using a remote operated vehicle (ROV) equipped with cameras and a grappling arm in Fiordland’s undiveable deep waterways, scientists from NIWA and the Department of Conservation were able to find and sample several seafloor species.
“We found two specimens [of sea pens] of two different species,” says NIWA Marine Biologist and ROV operator Dr Sean Handley in a press release, “one of which is completely new to us.”
The discovery of the ‘soft-coral’ animals, which look like antique feather quill pens, was made at a depth of about 80 m in Acheron Passage, near Dusky Sound.
Extraordinary diversity in Fiordland Marine Area
“This was our second exploration of Fiordland’s deep waters in the last few years, and on both occasions, we’ve discovered previously unknown fauna. We can only guess at the treasure trove of life still waiting to be discovered down there,” says Dr Handley.
Of the Fiordland Marine Area, only Doubtful and Dusky Sounds have been explored so far using the ROV.
“We’ve found marked differences in fauna and habitats between the two, so it stands to reason that Fiordland’s marine environment as a whole could harbour an extraordinary diversity of life. It is an important area to study because it is geologically unique and largely undisturbed by human activity.”
Sea pens are classified as soft corals and, like coral, they colonise the seabed and ledges by burying themselves in soft sediment. However, they lack a hard outer skeleton.
“They’re essentially row upon row of feeding polyps growing out of a soft stalk,” explains Dr Handley.
That soft stalk is itself a single polyp (the rachis), which has lost its tentacles and formed a bulbous root at its base that it anchors in sandy or muddy seabeds in order to act as host for the rest of its team-mates. They usually don’t move once rooted, but they can and have been documented doing so, uprooting themselves and relocating if need be.
At 65 cm long, the specimens discovered in 2013 are among the largest sea pens found in New Zealand. Some species, such as the tall sea pen (Funiculina quadrangularis), can grow as large as 2 m in length.
The creatures are rarely found above 10 m water depth and usually prefer deeper unpolluted and undisturbed environments. Some species have been found as deep as 2000 m.
Sea pens can bioluminesce (give off a glow) in the dark, which helps to attract the phytoplankton they feed on. The new specimens will be logged in a biodiversity database and then international sea pen experts will be consulted to help formally identify and name them.
Introduce your students to biodiversity using this activity. They make models of a marine ecosystem and explore human impact on ecosystems and biodiversity.
Find out more about Fiordland’s marine reserves on the Department of Conservation website.