Saturday, 29 May 2010

Harbour biodiversity (2 of 3)


Whilst the ferry, Proclaim, hove to, Dr Poore discussed with us some of the underwater life around the very popular (in season, of course) swimming beach, Neilsen Park, which is on the southern shore of the harbour. Much of the harbour foreshore is national park.

Neilsen Park is one of a number of harbour beaches that has a shark net.


This net has encouraged a growth in the population of a tiny variety of seahorse which uses the netting as a breeding ground. So many seahorse cling to it, that it gets too heavy to do its job properly and each off-season, is 'cleaned' by National Park rangers and UNSW researchers. Sydney Harbour is home to two species, the potbelly seahorse and the more common White's seahorse.

Just in front of the sandstone rocks, is an underwater 'field' of seaweed which has been infested by the Long-Spined Sea-urchin which breeds in warmer waters. Because the Eastern Australian Current is 2 degrees warmer over the last decade, this urchin has now spread as far south as Tasmania with disastrous effects on the more jungle like seaweed in those waters.

11 comments:

Lois said...

I am fascinated by the seahorse and every once in awhile I have seen them here on some of the Gulf of Mexico beaches. Of course we are hoping the giant oil spill does not some ashore and ruin it for all the sea creatures we love.

Tulsa Gentleman said...

Shark nets and Seahorses are two things you will never see in Oklahoma. I really like your third photo today. The textures of stone and wood shining in the wet splash of water are really nice.

brattcat said...

Two degrees in a decade seems like a lot!

Marka said...

I like the colors in the rocks.

Bruce Caspersonn said...

That net will never keep any Subs out...

Peter said...

Also love the rock photo, there should be a colour called Sydney Harbour Green.

Joan Elizabeth said...

Interesting facts previously unknown to me. I especially like the colours and textures of the rock shot. Hard to imagine a glut of seahorses they seem such mysterious creatures .

diane said...

I used to go swimming at Neilson Park as a teenager. It is a beautiful spot. Interesting facts about the changes in the environment.

J Bar said...

I don't think I've seen the beach at Neilsen Park from that perspective before. I really love the shot of the rocks.

Davine said...

I love your photos and I love seahorses.

Mary Ann said...

The textures in the second picture are lovely. Let's hope the next decade doesn't bring another 2 degrees with it.