Oregon coast kelp forests threatened with near extinction

[quattroluvr]

Hi all - Key fish habitat on the Oregon coast, i.e. kelp forests, are in the process of being wiped out by an ecosystem imbalance that started in 2014. NorCal has already lost 90% of their kelp forest area to this catastrophe. Divers, mostly members of this group, (I was lead author) wrote a proposal to the Oregon state Ocean Policy Advisory Council with 4 specific recommendations to help preserve our kelp forests. You can download the proposal here (use the download button in upper right).

Please consider reviewing the proposal and writing to ODFW to motivate them to respond in a timely way. It's mostly up to ODFW to update their rules which were OK in 2012 - but actually facilitate this ongoing disaster today. (When the rules are changed, or a special permit granted this year, we hope, the other thing fisherfolk can do that have boats is ferry divers to select reefs - to cull-in-place the main culprit, which is the population-explosion of purple urchins that wipe out kelp and turn reefs into permanent urchin-barrens.)

Cheers,
Leigh Anderson

 

[GaryP1958]

Lack of otters is the problem!

 

[quattroluvr]

Lack of otters is the problem!

well, you're correct that otters can be part of the solution eventually, (but only in southern Oregon coast due to adequate sheltering terrain and large quanitiy of surviving kelp (so far, if we can preserve it vs N. Oregon).) See https://www.elakhaalliance.org/ for details of sea otter reintro, which may take a decade or two to have a significant effect.

In the meantime, the only near-term solution is the 4 points in the proposal, especially volunteer diver culling-in-place of purple urchins on select reefs to preserve some oases of kelp forest. The large Orford reef for example has large urchin barrens and ODFW estimated 380 million purple urchins.

 

[wils]

divers killing one sea urchin at a time is going to require a LOT of divers.
with over 300,000,000 purple sea urchins running rampant over the reefs with little to no natural predation, is anyone working with the commercial urchin fishery and ODFW to try to get the daily limit of TEN raised to a viable number?

 

[quattroluvr]

divers killing one sea urchin at a time is going to require a LOT of divers.
with over 300,000,000 purple sea urchins running rampant over the reefs with little to no natural predation, is anyone working with the commercial urchin fishery and ODFW to try to get the daily limit of TEN raised to a viable number?

reasonable questions. and yes removing ODFW limits on purples _entirely_ is in the Proposal to the state.
With that rule change (or a permit for select reefs), we know from other regions that a 1-tank scuba dive can cull in place about 3,000 urchins. 2 tanks per outing x 10 divers gets 60,000 urchins per day. That's enough that within a feasible # of days we can have a big impact on smaller reefs we can feasibly save.
Yes commercial harvesting and on-shore fattening the uni in purples with farmed kelp is being tested in Port Orford, but very difficult and spendy to set up, only feasible in areas with gigantic amounts of urchins and infrastructure. It wouldn't be economic at all for smaller reefs in N. Oregon. The problem with purples is they have the ability after consuming all kelp to go zombie/hibernate with shrunken gonads and subsist on detritus till it's time to mow down the emerging kelp again - shrunken gonads have zero commercial value.

 

[Fummus]

Wow, very interesting read, and thank you for the heads up on this issue. Seems that urchins, like everything else, require management and wise stewardship. Yes nature can and will right itself eventually even without our intervention, but from what I've seen with other species it's usually a fairly drastic pendulum swing involving predation, starvation, pestilence/parasites, or some combination thereof. I know ODFW used to hold public meetings at their various offices to ask for the public's input on the current fishing regs, and suggestions for future regulations. The more people promoting an idea at these meetings, the better the chances of the idea being implemented. If these meetings are still being held, would be an easy way for any of us who are interested to pitch in and possibly effect some positive changes to the current management strategies for purples. That being said, I also know that it's not simply a matter of ODFW recognizing a problem and then initiating a solution. There are usually a whole host of special interest groups that must be appeased as well. The most recent rotenone treatments of Diamond lake are a good example of this.

 

[Upnorth]

Well I would like to put in my two cents. One of the main issues is that researchers, have stopped commercial harvest of purple sea urchins, by creating these marine reserves. Now nature has taken over with the spread of the Purple sea urchin. Unfortunately ecosystems, are very delicate, and now there is an imbalance which needs to be solved in order to sustain the other part of the ecosystem. Unfortunately we are creating our own mess by trial and error. We’ve seen this in other areas.

 

[rogerdodger]

interesting turn to this thread, here's a new take on it, one that seems to be supported in the legitimate reporting I found on this, the ecosystem out of balance is perhaps the one called Earth? ¯\_(ツ)_/¯

warmer ocean water- bad for the kelp

man- "Over the past half century, overfishing and pollution killed off sheepshead fish, abalone, and other marine animals along the Los Angeles Coast that either preyed on purple urchins or competed with them for habitat."

key predator dying OFF- "The purple sea urchin is native to the region, but a perfect storm of warming waters and a disease that killed off starfish, its predator, led to an explosion in its population."

I have not found a reference for marine reserves adding to the problem, still looking for that.

https://www.nationalgeographic.com/...ts shape,stretch of California's north coast.
https://www.nbcnews.com/news/us-new...forests-decimated-purple-sea-urchins-n1067906

 

[Admin]

The planet isn't going anywhere. We are...
The planet will shake us off like a bad case of fleas...
(c) George Carlin

 

[rogerdodger]

this just dropped from UC Santa Cruz, good summary of the multiple factors causing the kelp decline. towards the end they mention efforts from divers in selected areas to test whether that approach can, at least in limited areas, help the kelp recover.

https://phys.org/news/2021-03-collapse-northern-california-kelp-forests.html