Habitat photos

Habitat Photos

underwater photos of underwater habitats and seascapes

By Floor Anthoni (2006)
www.seafriends.org.nz/images/habitat.htm
All images A5 unless further indicated

One of the main attractions of diving in cool temperate waters, is the capriciousness of the seascape. Whereas tropical coral reefs are quite monotonous, temperate seas offer a great variety of habitat, varying from plants to animals and flat sea bottom to steep rocks with caves. On this page you will see only some of this great variety.

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Keywords: NZ, New Zealand, underwater, marine, ocean, sea, community, communities, habitat, seascape,

f020518: The deep reef of the Poor Knights, at 40m depth, enjoys clear and tranquil water. The rocks are not grazed by urchins, which allows carpet sponges to bulk up, and sensitive, long-lived creatures to thrive.

f020519: closeup of the bead coral (Primnoides sp.), which always grows perpendicular to the currents.

f020516: the deep reef community at the Poor Knights. Primnoides, carpet sponges and yellow geodesic dome sponges.

f029908: these sensitive gorgoneans are found in relatively shallow waters, under overhangs. The top left in this picture is still within reach of grazing urchins.

f029918: at the boundary of the kelp forest, around 30m depth, the rocks are but occasionally grazed, allowing a patchwork of colourful carpet sponges to grow.

sessile filterfeeders under the kelp canopy

f029924: on a shaded vertical wall, the community that normally lives underneath the kelp forest, could be photographed.

barrens grazed by the purple urchin Centrostephanus rodgersi

f030621: the purple urchin (Centrostephanus rodgersi) is a powerful grazer, but not as meticulous as the common urchin. As a result, carpet sponges can just survive.
This urchin is happy with the shaded habitat, which is not preferred by the common urchin.

f023025: a snorkeldiver shows the dimensions of this shallow habitat found on sheltered steep walls. It is occasionally grazed by the common urchin, but a storm sends these back to the deep, allowing fast growing algae like sea lettuce to flourish.

f029907: under a sheltered overhang, exposed to currents, one may find this community of fragile organisms, bryozoa, nudibranchs and gorgoneans. The experience is almost impossible to catch in a single photograph. (above Bernie's Cave)

robust wireweed Carpophyllum angustifolium

f028417: the wire weed (Carpophyllum angustifolium) is characteristic of the highly exposed rocky shore. At the Poor Knights it may be found to depths of six metres, where no other seaweed can hold. Divers find this weed as strong as Number Eight fencing wire, a New Zealand icon. [A6]

f007205: Mayor Island has perhaps the most varied community of seaweeds along the North Island. This picture shows the shallow bladderkelp habitat, where also Xiphophora, Vidalia and sea lettuce are found.

f007206: another picture of the shallow water habitat at Mayor Island. [A6]

f007210: because of wave action, urchins (see centre) cannot reach the top of this pinnacle frequently, thereby allowing sea lettuce to grow in abundance. Normally this weed is grazed fiercely by plant eating fish, but around Mayor Island, most fish have been caught.

f006837: a boulder-strewn habitat like this is a minefield for sea urchins, who find it difficult to navigate. It invites kelp to grow where a barren zone is expected. The boulders also house young crayfish as seen bottom left.

f022912: this picture shows habitat zoning in a moderately exposed area. Because of the steepness of the rocks, urchins cannot hold there, and the barren zone between the bladderkelps (C. maschalocarpum) on top and the stalked kelp below, is not present.

f022235: a young snapper peeps out between a gap in the rocks. In the past, this rock was covered in red Vidalia but it disappeared as the environment degraded slowly.

broken territory invites for biodiversity

f001921: A banded wrass finds its highway under the kelp blocked by the photographer. The topography underneath the kelp forest allows for highways, taken by fish.

For the barren urchin-grazed habitat, see the document on urchins.

f017101: the deep reef habitat extends down from 18m. The sponge flats occur where sand occasionally blankets the flat rocks, making it difficult for plants to settle. Almost everywhere in the reserve, the sponge habitat has been degrading, except where wave action, combined with sand, scours the rocks. In this photo two species of orange finger sponge (Raspailia topsenti, Axinella sp.), the dark pink meatball sponge (Aaptos aaptos), yellow nipple sponge (Polymastia ramosa?) and the boring sponge (Cliona cellata) in the background.

f000125: orange finger sponges and yellow nipple sponges on a seemingly barren reef. The deep reef is denser where the currents run.

f001811: a tranquil moment enjoyed by many species in profusion. Juvenile fish abound. Such sights have become rare. Spotty and parore in the foreground. Young snapper on right and young trevally on left. [A6]

f022801: caves are important habitats for the night shift, here represented by bigeyes on top and slender roughies, almost invisible, near the bottom. Caves are also important for red moki.

sheltered shallows with Carpophyllum plumosum

f013414: inside the Hauraki Gulf, the rocky shores are more sheltered by the protection of Little and Great Barrier Islands. Here one finds the sheltered reef, recognisable by different species and different growth forms. This kelp garden consists of the featherweed (Carpophyllum plumosum), which has various growth forms, like this broad-leaved one.

Carpophyllum maschalocarpum tolerates murky water

f005118: In the shallows, spotties abound and in the wave zone, the bladder kelp (Carpophyllum maschalocarpum) prevails. The environment is stressed by sediments and dense plankton blooms.

Carpophyllum flexuosum is most tolerant to murky water

f005104: the long-leaved flexible weed (Carpophyllum flexuosum) grows tall in rather murky conditions, where other kelps can't survive. The flexible weed can remove the muck on its leaves by secreting slime. Here it is seen towering above the stalked kelp, which it will eventually shade out. It provides protection for huundreds of young spotties.

f004909: where some wave action remains, the flexible weed is trimmed to stay short, letting light in for this photograph. Carpet sponges like Crella can only just survive here.

f005103: sediment-covered flexible weed is a nursery for a profusion of young spotties. Notolabrus celidotus

f017317: because the murky water rapidly absorbs all light, the deep reef starts at 6-10m. Here is enough wave action to keep the sponges clean. Deeper down, only muddy rock is found. In the centre an orange crust sponge (Crella), and in the distance orange finger sponges (Raspailia topsenti) The yellow nipple sponges are various Polymastia species.

f017316: this photo shows the stress suffered by sponges in these degrading habitats, but fortunately an army of sea cucumbers (Stichopus mollis) cleans them with their ten sticky mops. The large yellow-orange boring sponge (Cliona cellata) clearly shows where it has been cleaned. In the foreground a nipple sponge (Polymastia hirsuta) and a pink golfball sponge (Tethya ingalli). Unfortunately, sea cucumbers are now harvested for human food.

golden golfball sponges cleaned by sea cucumbers

f017315: sediment-covered orange golfball sponges (Tethya aurantium) showing where a sea cucumber has cleaned them.

f004933: A sea cucumber has climbed an orange finger sponge to feed from the plankton-rich sediment, which chokes the fine sponge animals, preventing them from feeding on phyto plankton. The yellow nipple sponge has been cleaned already.

a cluster of Atrina fan shells Atrina pectinata zelandica

f004929: the fan shell (Atrina pectinata zelandica) provides for 'artificial' rocky habitat in clusters like these, which can be found on a sandy bottom. Fan shells recruiting in the shelter of a larger one, are more likely to survive extraction by large storms, and thus a cluster forms over many years, consisting of many year classes. Notice the scallops growing in the shelter (behind) of this cluster.

Atrina fan shells invite other organisms Atrina pectinata zelandica

f005108: deadmans finger (Alcyonium sp), solitary seasquirts and nesting mussels (Modiolarca impacta) have attached themselves to this fan shell. They are not able to live in or on the surrounding sand. Invisible to the eye, and burrowed under the sand, various sea soil organisms enjoy the stability offered by this deep-burrowing shell.

f005121: a large stand of old fan shells has completely changed the muddy habitat of this harbour entrance (Mahurangi), encouraging a community of fragile organisms like soft corals and sea slugs to survive. In the meantime, a large scallop dredge has almost entirely destroyed this habitat. [A6]

f005136: a beautifully shaped seaslug (Tritonia incerta) lives from the soft coral that lives on the substrate provided by the fan shell bed. The red fingers in the foreground belong to a species of soft coral (Alcyonarium sp), which has contracted itself into a thick leathery skin. The thinner orange softcoral in the background is a different species.

f027104: A South Island shallow water kelp community showing tall Macrocystis pyrifera amongst a variety of other species.

f026720: a budding bull kelp starts with a strong holdfast, and a thick stipe. Later, it will be crowned with enormous fronds.

f026704: a shallow water kelp, growing on a level below the bull kelp.

f210336: the strategy of floating one's leaves on the water, guarantees a sufficient supply of sunlight, but it also subjects all leaves to extreme forces. Near Christchurch.

f027118: both space on the hard rock and the sunlight coming from above, are precious. Here a kelp is seen shading out others below it.

f026728: floating bull kelp leaves provide a spectacular show of graceful movement.

f026726:

f027119: an exposed shallow water community of seaweeds, near Bluff.

f027102: a sheltered shallow water community of seaweeds, near Dunedin.

f026719: A budding bull kelp is starting to tower above other exposed water kelps.

f026723: a budding bull kelp plant.

f026435: a snorkeldiver is dwarfed by the enormous fronds of some bull kelp species. Near Christchurch.

f210714: mature bull kelp fringing a seal rookery, near Bluff. In the distance, the sheltered bay has been occupied by females with young, protected by a 'beach master' bull seal. The juvenile seals, however, have to make do with less desirable spots like the one in the foreground.

f027127: seal and shallow water kelp community. [A6]

f027120: framed by various kelps, a seal gracefully arches its back in the background.

f026718: sea tulips are seasquirts on stalks. It gives them the advantage to reach out over other organisms for the nutricious phytoplankton, distributed by the water's movement.

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