Walter Munk: father of the surf forecast

(This item was spotted on the New Scientist website by reporter Rob…)

Walter Munk was never much of a surfer, but that hasn’t kept him from becoming a legend in the sport. An oceanographer by training, Munk has spent 67 years studying how waves form, how they travel and how they break when they hit the beach. In the second world war, he saved countless lives by helping the Allied military determine when troops could make amphibious landings without being swamped by big surf hundreds of metres from a hostile shore. After the war, Munk’s methods helped surfers find the biggest waves. Today, anyone who checks out a surf forecast on the internet is drawing on his pioneering research.

via Surf’s up: Learning to forecast the waves – environment – 28 June 2009 – New Scientist.

fewer sharks = more jellyfish?

Sharks are under siege from humans and the consequences are far reaching. It turns out that you can’t pull a top predator out of an ecosystem and expect everything else to remain the same.

A recent article in the Age (Taste for delicacy puts sharks at risk) canvasses the issues. A quote or two…

A THIRD of the world’s open-water sharks — including the great white and hammerhead — face extinction, according to a conservation survey that singles out overfishing as the main culprit.

…

The report identified the great hammerhead and scalloped hammerhead shark and the giant devil rays as endangered. The smooth hammerhead, great white, basking and oceanic white-tip sharks are listed as vulnerable as are two species of makos.

…

Dr Huveneers said sharks were important in the ecosystem, especially those at the top of the food chain such as the white, great white and great hammerhead. Reducing their numbers could prompt an increase in the number of cownose rays, which consumed scallops.

That last quote reminded me of a story I’d recently come across about an explosion in the number of giant Nomura jellyfish in Japan. (These critters are up to 2 metres across and can weigh up to 220kg.)  So I did a bit of research and turned up a picture and a backgrounder here.

But there was an even more interesting feature on the New York Times site entitled Stinging Tentacles Offer Hint of Oceans’ Decline

From Spain to New York, to Australia, Japan and Hawaii, jellyfish are becoming more numerous and more widespread, and they are showing up in places where they have rarely been seen before, scientists say. The faceless marauders are stinging children blithely bathing on summer vacations, forcing beaches to close and clogging fishing nets.

But while jellyfish invasions are a nuisance to tourists and a hardship to fishermen, for scientists they are a source of more profound alarm, a signal of the declining health of the world’s oceans.

“These jellyfish near shore are a message the sea is sending us saying, ‘Look how badly you are treating me,’ ” said Dr. Josep-María Gili, a leading jellyfish expert, who has studied them at the Institute of Marine Sciences of the Spanish National Research Council in Barcelona for more than 20 years.

The explosion of jellyfish populations, scientists say, reflects a combination of severe overfishing of natural predators, like tuna, sharks and swordfish; rising sea temperatures caused in part by global warming; and pollution that has depleted oxygen levels in coastal shallows.

They’re talking sharks over on the RealSurf forums too…

A few little ones about on the low at 7am

1-2 feet at best this morning on the low tide at 7.30 but little lines could be seen and there were a few punters braving the average conditions but it was clean, offshore and uncrowded.  Should be sign of a new little swell coming in by tomorrow and wednesday (3-4 feet) with a bigger south swell due by the weekend.  Winds look favourable all week- enjoy!

Avalon to Narrabeen Rpt

Um,….pretty tiny out there

Oh dear

Long, long wait in the cold for this little line.

Late yesterday there was a little spike in the period into the ten second range and if you were in the right place there were waves into the chest high range. But we’re back to 7 seconds average for the metre or so of SSE windswell. What that means for Dee Why is a very occasional knee high set, followed by another long, long wait.

Speaking of waits, it looks as though that’s what we’ll be doing over the next day or so. The models are showing little of interest until around Weds, when there are indications that we could get a brief but fun sized SE pulse with wave faces into the shoulder high plus range.

Today and tomorrow on the other hand is not looking terribly hopeful for a decent size wave. Dunno about you, but I’m going head down bum up to knock over chores over the next couple days…

Go well with your day’s plans!

Here’s the Bureau’s call.

Sydney Coastal Waters, Broken Bay to Port Hacking and 60nm seawards:
Monday until midnight: Wind: W’ly 10/15 knots, reaching 15/20 knots at times during the morning and then again tonight.Sea: 1 to 2 metres.Swell: S/SE about 1 metre.
Tuesday: Wind: NW 15/20 knots, increasing to 20/25 knots during the day and 20/30 knots later.Sea: 1 to 2 metres, rising to 2 to 3 metres. Swell: SE 1 to 2 metres.
Wednesday: Wind: W/NW 15/25 knots, easing to 10/20 knots late.

C C Small

Fine, dry and cold on the Central Coast this Monday morning.  The swell is smooth, small and inconsistent at 1 – 2 feet from the east.  There is cool & light west northwest breeze.  Low tide 0740 and high tide around 1400.  Local barometer 1004 hpa, 7 degrees C. 92% humidity.   Have a great week. 

Byron Bay Today June 28th 2009