Hood Canal dissolved oxygen at critical levels

[Biodiversity_Guy]

http://seattletimes.nwsource.com/html/l ... nal08.html

This fall we may be facing another serious fish (and invertebrate) kill in Hood Canal. The DO levels are very very low at depth and all it will take is a sustained strong south wind to push the surface waters away and pull the low DO deeper waters up into the shallows.

I was out at Sund Rock this past weekend. one Wolf eel at 20 feet, fully exposed and acting lethargic, others deeper but not too active. I found rockfish as deep as ~100' but they were resting on the bottom for the most part. Some of the deeper California sea cucumbers were starting to show signs of stress.

[nwscubamom]

I'm heading out there next Wednesday to do a few surveys - crossing my fingers that things will be OK. A lot of the problem this year is that the weather patterns didn't flush out last year's old low-O2 waters out of the canal, so we started the year off with residual low O2.

So far so good though - only mild signs of stress in what I've been observing the past month or so and from what I've been hearing from others - at least in the 'shallow' waters. (recreational diving depths).

- Janna

[Biodiversity_Guy]

Yep, not a crisis yet, but if we get a strong southern wind the situation may change rapidly.

[nwbobber]

Do you have pics of what it looks like when the cukes are stressed? We were at sund yesterday, and I saw a cucumber with its "feathers" out. Not sure if this is feeding behavior or what. We saw rockfish at 95 feet suspended or sitting on the rocks. We saw a spot prawn in 30 ft, not sure if they are normally deeper, I don't think I have ever seen one that shallow before.

[nwscubamom]

Was the spot prawn small or large? I've seen plenty of smaller ones in the shallows year round, but it's unusual to see larger ones up shallow.

BTW, it's normal for Sea cukes to have several of their feeding tentacles out, mopping up stuff off the ocean floor. What's unusual is when all 20 of them are out, and they start looking kinda shriveled up.

- Janna

[Biodiversity_Guy]

Down about 120+ there were more spot prawn present than I think I have ever seen there. Hundreds lined up along the contour, maybe 10' wide and as far as the eye could see. In with them were many slim sculpins (I usually see only 0-2 per dive) and two of the unknown sculpins.

[nwbobber]

Was the spot prawn small or large? I've seen plenty of smaller ones in the shallows year round, but it's unusual to see larger ones up shallow.

BTW, it's normal for Sea cukes to have several of their feeding tentacles out, mopping up stuff off the ocean floor. What's unusual is when all 20 of them are out, and they start looking kinda shriveled up.

- Janna

The prawn was probably 8 inches long. The sea cucumber looked just like your pic.

[nwscubamom]

That's NOT good....heading there Wednesday to check things out...

[mz53480]

Octopus hole, 9-12-10 ~3pm
depth: ~25fsw
? about this guy:

1

9-12-10.JPG (7.62 KiB) Viewed 2244 times

Not sure if they normally show 'breathing' or not, but he was doing it fairly regularly.

MZ

[nwscubamom]

Conditions are BAD BAD BAD right now...looks like the hypoxic water level is around 30 feet or so. Forecasted winds in the Hoodsport area the next bunch of days are from the South :( Prime ingredients for a fish kill....cross your fingers and hope we can squeak by without a major event.

Going to Sund Rock tomorrow to see how things look.

Look at the bottom row, far left graph. That's dissolved O2, and the corresponding depth. The dashed line is the threshold of dissolved oxygen in the water that critters need to survive, and you can see in waters deeper than about 30 feet (the measurements there are in meters), the water is hypoxic.

- Janna :(

[CaptnJack]

Is that the Hoodsport Buoy? :(

[nwscubamom]

Yup, Hoodsport, today, couple hours ago.

http://orca.ocean.washington.edu/data_hoodsport.html

- Janna

[kat]

i realise that this is a "stupid question" but, would diving help to increase oxygen levels? obviously not enough to have an impact, but... ? i have always wondered.

[nwscubamom]

Not a stupid question at all - believe me all sorts of ideas have been tossed around.
I don't think the amount that we oxygenate the water with our exhaled bubbles would be enough to make any sort of difference.

In fact, I am more concerned about the harm we might cause (inadvertently, of course!) by diving during one of these events. Just a thought I've had - nothing proven about it - but critters often feel the need to move away when we're near them. And moving uses up precious oxygen in their systems.

If the critters are all up in the 30 feet or less area, I'd sure hate to see a typical Open Water class come barreling through.

Experienced divers can tell when a fish is getting 'twitchy' or bothered by our presence. If you see that - back off and give it the space it needs.

I wish Sund Rock would post something to that effect during these times: Warning - Critters under stress - hands off, give them wide berth! or something to that effect.

OK, so that's just my crazy thoughts...

- Janna

[archaeofish]

Hi Janna,
Thank you for posting the link to the monitoring buoy. Do you know often are the new measurements uploaded? Have a good trip to the Canal and please let us know what you see.

Ross

[selkie]

Not a stupid question at all - believe me all sorts of ideas have been tossed around.
I don't think the amount that we oxygenate the water with our exhaled bubbles would be enough to make any sort of difference.

In fact, I am more concerned about the harm we might cause (inadvertently, of course!) by diving during one of these events. Just a thought I've had - nothing proven about it - but critters often feel the need to move away when we're near them. And moving uses up precious oxygen in their systems.

If the critters are all up in the 30 feet or less area, I'd sure hate to see a typical Open Water class come barreling through.

Experienced divers can tell when a fish is getting 'twitchy' or bothered by our presence. If you see that - back off and give it the space it needs.

I wish Sund Rock would post something to that effect during these times: Warning - Critters under stress - hands off, give them wide berth! or something to that effect.

OK, so that's just my crazy thoughts...

- Janna

I don't know if you have asked or not but I wonder if Hoods n Dive would post a sign like that? It might even work better if someone made the sign and offered to put it so they didn't have to expend effort and would be more likely to say yes.

[scottsax]

I wish Sund Rock would post something to that effect during these times: Warning - Critters under stress - hands off, give them wide berth! or something to that effect.

OK, so that's just my crazy thoughts...

- Janna

I don't know if you have asked or not but I wonder if Hoods n Dive would post a sign like that? It might even work better if someone made the sign and offered to put it so they didn't have to expend effort and would be more likely to say yes.

I think it's a great idea, but isn't that site on private property? I think it'd be great if the owner was amenable...

[nwscubamom]

Hi Janna,
Thank you for posting the link to the monitoring buoy. Do you know often are the new measurements uploaded? Have a good trip to the Canal and please let us know what you see.
Ross

Looks like it's every 2-4 hours from what I've seen today.

- Janna

[whatevah]

Neat to see these plots real-time. Especially cool to compare against the Point Wells data. What I would really be interested in seeing is a view of this information over time - perhaps the average oxygen concentration in the top 30m, plotted over the past 3 years, with say, 1hr granularity. It would be interesting to see the tidal and seasonal effects, and variations from one year to the next. I suppose the other questions I wonder about are: how far back do we have information like this for Hood Canal, and how does it compare to other similar waterways (some of the inlets on BC's Sunshine Coast for example) ?

[CaptnJack]

I suppose the other questions I wonder about are: how far back do we have information like this for Hood Canal, and how does it compare to other similar waterways (some of the inlets on BC's Sunshine Coast for example) ?

The buoys were installed about 3 years ago.

Before that there's CTD data (profiles) generated by Ecology's monthly ambient monitoring flights and a bunch more spot measurements. I don't think those profiles are accessible on webpages directly, but they are in some of the older Ecology reports.

[nwscubamom]

Quick update from yesterday's dive: A whole lotta heavy breathing going on! I stopped to carefully watch Blackeye gobies and Northern Ronquil - even the smallest of fish are sitting on the bottom, working their gills in and out to breathe. Ling cod and Wolf eel were having an especially hard time of it, with VERY apparent efforts at breathing. We saw 3 wolfies, but all were still tucked in their dens.

Wolfie, labored breathing video:
http://nwgeogirl.smugmug.com/gallery/13 ... 1037_Kpgpc

Ling cod heavy breathing video here:
http://nwgeogirl.smugmug.com/The-Beauti ... 8887_qEW6x

Georgia said there were a massive amount of spot prawns down around 125 feet - I only went to 116 ft and saw a few scattered here and there on up to about 60 feet. There were smaller ones shallower than that, but the big guys were deeper.



California Sea Cucumbers did show signs of stress - all feeding tentacles out, and looking shriveled. Sunflower stars were starting to look bad too.



I had to bug outta there after the 1st dive though - so maybe Georgia can tell you more about what she saw on her dives there.

- Janna

[dwashbur]

We were thinking about doing a day trip to Sund Rock next week, but I think maybe we'll try somewhere else so we don't take a chance of contributing to the critters' stress...

[nwscubamom]

http://www.king5.com/news/environment/A ... 03574.html

http://www.kitsapsun.com/news/2010/sep/ ... p-dead-in/

[nwscubamom]

From Jan Newton, Oceanographer with UW and the HCDOP:
Surface oxygen conditions at Hoodsport are much improved today (>5 mg/L), likely as the exported surface layer returned
and re-established. A thick hypoxic layer still exists, but it is relatively deep (>10 m), for now.

Wayne Palsson (WDFW) reports this morning that the mortality on the beaches looks old, with the exception
of more spot prawns. Many are swimming into freshwater streams for the oxygen, but encountering low salinity and
perishing.

Wayne and I will be working with others to write up observations and posting to the HCDOP web site, along with
pictures and information. For your convenience, I've updated the data plots below:

The Hoodsport and Twanoh ORCA buoy are recording every 3 h. These plots are from NANOOS NVS (http://www.nanoos.org/nvs/nvs.php?path=NVS-Assets)
and the HCDOP websites
(http://www.hoodcanal.washington.edu/obs ... a_buoy.jsp).

Data from the UW ORCA buoys, funded through the Hood Canal Dissolved Oxygen Program and part of the NANOOS system, funded by NOAA IOOS.

Jan A. Newton, Ph.D.
Principal Oceanographer
Applied Physics Laboratory
University of Washington
1013 NE 40th St
Seattle WA 98105-6698

[Norris]

I saw a story about this on the news last night.