Cold Water!

[jim77]

Went out for a look around this morning. I had been watching the offshore water temps in the hope that things might finally have improved. After temps over 22 degrees earlier in the week and plenty of fish in that warmer water i was hopeful... Then towards the end of yesterday the temp at the Sydney Waverider dropped from 22.3 to 18.6 - not good signs.

Anyway i thought i would go and have a look outside anyway just to make sure. After gathering livies up the LCR with the water nudging 23 degrees i was sceptical but as i hit the entrance to the heads there was a line. On one side it was 20 degrees plus... on the other it started to drop and quickly. The coldest i got was 16.3 but i had a mate who went to the colours area who had temps as low as 15 degrees!!!!! It was so cold that it was causing mist to form and and you could actually feel the coolness in the air.

Anyway to cut a long story short - there was absolutely NOTHING offshore, not even any bait. As soon as you get back in to the warm stuff in the harbour there are fish everywhere. As others have mentioned catching bonito atm is like shooting fish in a barrel. I had trolled all of about 50m before my first hook up. They were good size bonito however and good fun on light gear. I also scored a rat king on a rapala. I soon got bored of that and went off searching for some bigger Kings.

tried a few likely spots in the harbour and finally managed to get a 70cm King - although it was one of the skinniest Kings i have ever seen!

When is the summer going to start properly and produce some consistent fishing??!!!!!!

Good luck if you're heading out.

[fishmaniac]

Pitty about the cold water after such promising signs earlier this week.

It looks like we will be getting light winds this weekend and some southerly winds next week. Might push in some warmer water!!!

Bring on a real Summer!!!

[GerardC]

Apparently, when the Noreasters blow consistently as they have over the last few weeks it causes an upwelling from the cold deep waters and you get 16 deg on the beach in summer. The EAC is still active so the currents on the shelf are as you would expect - 21 to 26 degs. Cheers

[gobbledock]

Bad luck Jim, Hope things change soon. This unseasonal weather is driving everyone nuts i think, fishing and work wise for me. Hopefully things will change by Monday

[spongy]

Thanks for the report Jim.

Im heading out tomorrow most likely, so will poke my head out past the heads, but will probably just end up in middle harbour somewhere.

Anyone know if the water is warmer out at the Twelve?

Jeff

[jim77]

Jeff - its 17 degrees at the Waverider this am, so it might be slightly warmer at the 12 but not much! Sea surface temp maps don't look too promising.

[Trapper Tom]

Hey guys

It is damn cold isn't.

Its called a "Eckman effect". Its a upwelling of colder water due to the winds particular direction against the coastline

Once the wind changes direction all will be good and the EAC can take over.

Keep your eyes on the weather sites !!!

Cheers

Trapper Tom

[Aqua Naut]

Won't last to long. Warmer currents pushing through. Give it a week or 2 and you'll see the difference.

[prawn*]

we need some more southerly winds to pull the warmer water down i know how u feel port hacking is suffering same affect i never bother fishing in north easters it totally shuts down fishing for me,

[Marfoir]

Does anybody know about the El Nina effect and if this has anything to do with the cold water temperatures?

[rozza_b]

Does anybody know about the El Nina effect and if this has anything to do with the cold water temperatures?

El Nina has something to do with unusually warm sea surface temperature's I thought but yeah doesn't really make sense with our current water temps

[DirtyDaz]

Got this off the net, have heard about it before though....

"Most Sydney-siders associate southerly winds with cool air temperatures, and northerly winds with warmth. But after a spell of nor'easters along the East Coast, the water temperature will often drop a couple of degrees. Why is this so?

The process that causes this is called 'Ekman Transport', and it refers to an upwelling effect that occurs under certain synoptic situations.

When the wind blows along the ocean's surface, the effects of the Coriolis force diverts the top layer of water to the left in the southern hemisphere (while in the northern hemisphere, the top layer of water is diverted the to the right). Therefore, a NE'ly wind blowing along the coast pushes the top layer of water out into the Tasman Sea.

As this water needs to be replaced, an 'upwelling' effect draws in cooler (and usually nutrient-rich) water from below. It usually takes a couple of days of nor'easters to see any noticeable change, and you'll also find that certain parts of the coastline tend to react more than others - usually due to the presence of underwater ridges and canyons that amplify the upwelling effect.

There are various spin offs from an upwelling event, depending on where you live - many parts of the southern coastline will see an increased risk of sea fog, if a warm and moist airmass settles on top of the cooler sea surface temperatures. Afternoon sea breezes may also be enhanced due to an increase in the temperature gradient between the land and the ocean. It can sometimes take weeks for these upwelling effects to ease - Newcastle had a spell of cool water in January of 2004 that took around three weeks to settle down.

This process works similarly in reverse. A southerly airstream in the Tasman Sea pushes the surface layer of water to the left (ie towards land), which will usually return near-shore sea surface temperatres to a more stable average.

Fisherman can really benefit from an upwelling event - the nutrient rich water dragged up from greater ocean depths is photosynthesised as it nears the surface layers, and this sharp increase in food source can rapidly build fish stocks"

Hope that answers some questions..